| blob | 1fd957288d4aa4084cfcb0f6a12401e9f3f9c428 |
1 /* Fold a constant sub-tree into a single node for C-compiler
2 Copyright (C) 1987-2024 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
9 version.
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 for more details.
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
20 /*@@ This file should be rewritten to use an arbitrary precision
21 @@ representation for "struct tree_int_cst" and "struct tree_real_cst".
22 @@ Perhaps the routines could also be used for bc/dc, and made a lib.
23 @@ The routines that translate from the ap rep should
24 @@ warn if precision et. al. is lost.
25 @@ This would also make life easier when this technology is used
26 @@ for cross-compilers. */
28 /* The entry points in this file are fold, size_int_wide and size_binop.
30 fold takes a tree as argument and returns a simplified tree.
32 size_binop takes a tree code for an arithmetic operation
33 and two operands that are trees, and produces a tree for the
34 result, assuming the type comes from `sizetype'.
36 size_int takes an integer value, and creates a tree constant
37 with type from `sizetype'.
39 Note: Since the folders get called on non-gimple code as well as
40 gimple code, we need to handle GIMPLE tuples as well as their
41 corresponding tree equivalents. */
43 #define INCLUDE_ALGORITHM
90 /* Nonzero if we are folding constants inside an initializer or a C++
91 manifestly-constant-evaluated context; zero otherwise.
92 Should be used when folding in initializer enables additional
93 optimizations. */
96 /* Nonzero if we are folding C++ manifestly-constant-evaluated context; zero
97 otherwise.
98 Should be used when certain constructs shouldn't be optimized
99 during folding in that context. */
102 /* The following constants represent a bit based encoding of GCC's
103 comparison operators. This encoding simplifies transformations
104 on relational comparison operators, such as AND and OR. */
122 };
154 /* This is a helper function to detect min/max for some operands of COND_EXPR.
155 The form is "(EXP0 CMP EXP1) ? EXP2 : EXP3". */
156 tree_code
158 {
168 {
170 {
171 /* X <= Y - 1 equals to X < Y. */
174 /* X > Y - 1 equals to X >= Y. */
177 /* a != MIN_RANGE<a> ? a : MIN_RANGE<a>+1 -> MAX_EXPR<MIN_RANGE<a>+1, a> */
179 {
180 value_range r;
189 }
190 }
192 {
193 /* X < Y + 1 equals to X <= Y. */
196 /* X >= Y + 1 equals to X > Y. */
199 /* a != MAX_RANGE<a> ? a : MAX_RANGE<a>-1 -> MIN_EXPR<MIN_RANGE<a>-1, a> */
201 {
202 value_range r;
211 }
212 }
213 }
216 {
221 }
223 }
225 /* Return EXPR_LOCATION of T if it is not UNKNOWN_LOCATION.
226 Otherwise, return LOC. */
228 static location_t
230 {
233 }
235 /* Similar to protected_set_expr_location, but never modify x in place,
236 if location can and needs to be set, unshare it. */
238 tree
240 {
246 {
249 }
251 }
252 \f
253 /* If ARG2 divides ARG1 with zero remainder, carries out the exact
254 division and returns the quotient. Otherwise returns
255 NULL_TREE. */
257 tree
259 {
260 widest_int quo;
267 }
268 \f
269 /* This is nonzero if we should defer warnings about undefined
270 overflow. This facility exists because these warnings are a
271 special case. The code to estimate loop iterations does not want
272 to issue any warnings, since it works with expressions which do not
273 occur in user code. Various bits of cleanup code call fold(), but
274 only use the result if it has certain characteristics (e.g., is a
275 constant); that code only wants to issue a warning if the result is
276 used. */
280 /* If a warning about undefined overflow is deferred, this is the
281 warning. Note that this may cause us to turn two warnings into
282 one, but that is fine since it is sufficient to only give one
283 warning per expression. */
287 /* If a warning about undefined overflow is deferred, this is the
288 level at which the warning should be emitted. */
292 /* Start deferring overflow warnings. We could use a stack here to
293 permit nested calls, but at present it is not necessary. */
295 void
297 {
299 }
301 /* Stop deferring overflow warnings. If there is a pending warning,
302 and ISSUE is true, then issue the warning if appropriate. STMT is
303 the statement with which the warning should be associated (used for
304 location information); STMT may be NULL. CODE is the level of the
305 warning--a warn_strict_overflow_code value. This function will use
306 the smaller of CODE and the deferred code when deciding whether to
307 issue the warning. CODE may be zero to mean to always use the
308 deferred code. */
310 void
312 {
314 location_t locus;
319 {
325 }
336 /* Use the smallest code level when deciding to issue the
337 warning. */
346 else
349 }
351 /* Stop deferring overflow warnings, ignoring any deferred
352 warnings. */
354 void
356 {
358 }
360 /* Whether we are deferring overflow warnings. */
362 bool
364 {
366 }
368 /* This is called when we fold something based on the fact that signed
369 overflow is undefined. */
371 void
373 {
375 {
378 {
381 }
382 }
385 }
386 \f
387 /* Return true if the built-in mathematical function specified by CODE
388 is odd, i.e. -f(x) == f(-x). */
390 bool
392 {
394 {
395 CASE_CFN_ASIN:
396 CASE_CFN_ASIN_FN:
397 CASE_CFN_ASINH:
398 CASE_CFN_ASINH_FN:
399 CASE_CFN_ATAN:
400 CASE_CFN_ATAN_FN:
401 CASE_CFN_ATANH:
402 CASE_CFN_ATANH_FN:
403 CASE_CFN_CASIN:
404 CASE_CFN_CASIN_FN:
405 CASE_CFN_CASINH:
406 CASE_CFN_CASINH_FN:
407 CASE_CFN_CATAN:
408 CASE_CFN_CATAN_FN:
409 CASE_CFN_CATANH:
410 CASE_CFN_CATANH_FN:
411 CASE_CFN_CBRT:
412 CASE_CFN_CBRT_FN:
413 CASE_CFN_CPROJ:
414 CASE_CFN_CPROJ_FN:
415 CASE_CFN_CSIN:
416 CASE_CFN_CSIN_FN:
417 CASE_CFN_CSINH:
418 CASE_CFN_CSINH_FN:
419 CASE_CFN_CTAN:
420 CASE_CFN_CTAN_FN:
421 CASE_CFN_CTANH:
422 CASE_CFN_CTANH_FN:
423 CASE_CFN_ERF:
424 CASE_CFN_ERF_FN:
425 CASE_CFN_LLROUND:
426 CASE_CFN_LLROUND_FN:
427 CASE_CFN_LROUND:
428 CASE_CFN_LROUND_FN:
429 CASE_CFN_ROUND:
430 CASE_CFN_ROUNDEVEN:
431 CASE_CFN_ROUNDEVEN_FN:
432 CASE_CFN_SIN:
433 CASE_CFN_SIN_FN:
434 CASE_CFN_SINH:
435 CASE_CFN_SINH_FN:
436 CASE_CFN_TAN:
437 CASE_CFN_TAN_FN:
438 CASE_CFN_TANH:
439 CASE_CFN_TANH_FN:
440 CASE_CFN_TRUNC:
441 CASE_CFN_TRUNC_FN:
444 CASE_CFN_LLRINT:
445 CASE_CFN_LLRINT_FN:
446 CASE_CFN_LRINT:
447 CASE_CFN_LRINT_FN:
448 CASE_CFN_NEARBYINT:
449 CASE_CFN_NEARBYINT_FN:
450 CASE_CFN_RINT:
451 CASE_CFN_RINT_FN:
456 }
458 }
460 /* Check whether we may negate an integer constant T without causing
461 overflow. */
463 bool
465 {
466 tree type;
475 }
477 /* Determine whether an expression T can be cheaply negated using
478 the function negate_expr without introducing undefined overflow. */
480 static bool
482 {
483 tree type;
492 {
497 /* Check that -CST will not overflow type. */
510 /* We want to canonicalize to positive real constants. Pretend
511 that only negative ones can be easily negated. */
519 {
523 /* Steps don't prevent negation. */
530 }
545 /* -(A + B) -> (-B) - A. */
548 /* -(A + B) -> (-A) - B. */
552 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
561 /* INT_MIN/n * n doesn't overflow while negating one operand it does
562 if n is a (negative) power of two. */
573 /* Fall through. */
586 /* In general we can't negate A in A / B, because if A is INT_MIN and
587 B is not 1 we change the sign of the result. */
591 /* In general we can't negate B in A / B, because if A is INT_MIN and
592 B is 1, we may turn this into INT_MIN / -1 which is undefined
593 and actually traps on some architectures. */
602 /* Negate -((double)float) as (double)(-float). */
604 {
608 }
612 /* Negate -f(x) as f(-x). */
618 /* Optimize -((int)x >> 31) into (unsigned)x >> 31 for int. */
620 {
624 }
629 }
631 }
633 /* Given T, an expression, return a folded tree for -T or NULL_TREE, if no
634 simplification is possible.
635 If negate_expr_p would return true for T, NULL_TREE will never be
636 returned. */
638 static tree
640 {
642 tree tem;
645 {
646 /* Convert - (~A) to A + 1. */
670 {
675 }
679 {
680 tree_vector_builder elts;
684 {
689 }
692 }
715 {
716 /* -(A + B) -> (-B) - A. */
718 {
722 }
724 /* -(A + B) -> (-A) - B. */
726 {
730 }
731 }
735 /* - (A - B) -> B - A */
746 /* Fall through. */
750 {
759 }
767 /* In general we can't negate A in A / B, because if A is INT_MIN and
768 B is not 1 we change the sign of the result. */
774 /* In general we can't negate B in A / B, because if A is INT_MIN and
775 B is 1, we may turn this into INT_MIN / -1 which is undefined
776 and actually traps on some architectures. */
788 /* Convert -((double)float) into (double)(-float). */
790 {
794 }
798 /* Negate -f(x) as f(-x). */
801 {
807 }
811 /* Optimize -((int)x >> 31) into (unsigned)x >> 31 for int. */
813 {
816 {
823 }
824 }
829 }
832 }
834 /* A wrapper for fold_negate_expr_1. */
836 static tree
838 {
845 }
847 /* Like fold_negate_expr, but return a NEGATE_EXPR tree, if T cannot be
848 negated in a simpler way. Also allow for T to be NULL_TREE, in which case
849 return NULL_TREE. */
851 static tree
853 {
855 location_t loc;
868 }
869 \f
870 /* Split a tree IN into a constant, literal and variable parts that could be
871 combined with CODE to make IN. "constant" means an expression with
872 TREE_CONSTANT but that isn't an actual constant. CODE must be a
873 commutative arithmetic operation. Store the constant part into *CONP,
874 the literal in *LITP and return the variable part. If a part isn't
875 present, set it to null. If the tree does not decompose in this way,
876 return the entire tree as the variable part and the other parts as null.
878 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
879 case, we negate an operand that was subtracted. Except if it is a
880 literal for which we use *MINUS_LITP instead.
882 If NEGATE_P is true, we are negating all of IN, again except a literal
883 for which we use *MINUS_LITP instead. If a variable part is of pointer
884 type, it is negated after converting to TYPE. This prevents us from
885 generating illegal MINUS pointer expression. LOC is the location of
886 the converted variable part.
888 If IN is itself a literal or constant, return it as appropriate.
890 Note that we do not guarantee that any of the three values will be the
891 same type as IN, but they will have the same signedness and mode. */
893 static tree
897 {
905 /* Strip any conversions that don't change the machine mode or signedness. */
914 /* We can associate addition and subtraction together (even
915 though the C standard doesn't say so) for integers because
916 the value is not affected. For reals, the value might be
917 affected, so we can't. */
923 {
929 /* First see if either of the operands is a literal, then a constant. */
942 /* If we haven't dealt with either operand, this is not a case we can
943 decompose. Otherwise, VAR is either of the ones remaining, if any. */
948 else
951 /* Now do any needed negations. */
958 }
963 {
964 /* -1 - X is folded to ~X, undo that here. Do _not_ do this
965 when IN is constant. */
968 }
969 else
973 {
986 }
996 }
998 /* Re-associate trees split by the above function. T1 and T2 are
999 either expressions to associate or null. Return the new
1000 expression, if any. LOC is the location of the new expression. If
1001 we build an operation, do it in TYPE and with CODE. */
1003 static tree
1005 {
1007 {
1010 }
1014 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1015 try to fold this since we will have infinite recursion. But do
1016 deal with any NEGATE_EXPRs. */
1020 {
1022 {
1035 }
1037 {
1040 }
1044 }
1048 }
1049 \f
1050 /* Check whether TYPE1 and TYPE2 are equivalent integer types, suitable
1051 for use in int_const_binop, size_binop and size_diffop. */
1053 static bool
1055 {
1062 {
1071 }
1076 }
1078 /* Combine two wide ints ARG1 and ARG2 under operation CODE to produce
1079 a new constant in RES. Return FALSE if we don't know how to
1080 evaluate CODE at compile-time. */
1082 bool
1086 {
1087 wide_int tmp;
1090 {
1112 /* It's unclear from the C standard whether shifts can overflow.
1113 The following code ignores overflow; perhaps a C standard
1114 interpretation ruling is needed. */
1121 {
1125 else
1127 }
1128 else
1133 else
1212 }
1214 }
1216 /* Returns true if we know who is smaller or equal, ARG1 or ARG2, and set the
1217 min value to RES. */
1218 bool
1220 {
1222 {
1225 }
1227 {
1230 }
1233 }
1235 /* Combine two poly int's ARG1 and ARG2 under operation CODE to
1236 produce a new constant in RES. Return FALSE if we don't know how
1237 to evaluate CODE at compile-time. */
1239 static bool
1243 {
1247 {
1265 else
1272 else
1290 }
1292 }
1294 /* Combine two integer constants ARG1 and ARG2 under operation CODE to
1295 produce a new constant. Return NULL_TREE if we don't know how to
1296 evaluate CODE at compile-time. */
1298 tree
1301 {
1302 poly_wide_int poly_res;
1308 {
1314 }
1323 }
1325 /* Return true if binary operation OP distributes over addition in operand
1326 OPNO, with the other operand being held constant. OPNO counts from 1. */
1328 static bool
1330 {
1332 {
1343 }
1344 }
1346 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1347 constant. We assume ARG1 and ARG2 have the same data type, or at least
1348 are the same kind of constant and the same machine mode. Return zero if
1349 combining the constants is not allowed in the current operating mode. */
1351 static tree
1353 {
1354 /* Sanity check for the recursive cases. */
1362 {
1368 }
1371 {
1372 machine_mode mode;
1373 REAL_VALUE_TYPE d1;
1374 REAL_VALUE_TYPE d2;
1375 REAL_VALUE_TYPE value;
1376 REAL_VALUE_TYPE result;
1380 /* The following codes are handled by real_arithmetic. */
1382 {
1393 }
1401 /* Don't perform operation if we honor signaling NaNs and
1402 either operand is a signaling NaN. */
1408 /* Don't perform operation if it would raise a division
1409 by zero exception. */
1415 /* If either operand is a NaN, just return it. Otherwise, set up
1416 for floating-point trap; we return an overflow. */
1418 {
1419 /* Make resulting NaN value to be qNaN when flag_signaling_nans
1420 is off. */
1424 }
1426 {
1427 /* Make resulting NaN value to be qNaN when flag_signaling_nans
1428 is off. */
1432 }
1437 /* Don't constant fold this floating point operation if
1438 both operands are not NaN but the result is NaN, and
1439 flag_trapping_math. Such operations should raise an
1440 invalid operation exception. */
1448 /* Don't constant fold this floating point operation if
1449 the result has overflowed and flag_trapping_math. */
1457 /* Don't constant fold this floating point operation if the
1458 result may dependent upon the run-time rounding mode and
1459 flag_rounding_math is set, or if GCC's software emulation
1460 is unable to accurately represent the result. */
1470 }
1473 {
1474 FIXED_VALUE_TYPE f1;
1475 FIXED_VALUE_TYPE f2;
1476 FIXED_VALUE_TYPE result;
1481 /* The following codes are handled by fixed_arithmetic. */
1483 {
1495 {
1502 }
1507 }
1514 /* Propagate overflow flags. */
1518 }
1521 {
1530 {
1541 mpc_mul);
1555 mpc_div);
1556 /* Fallthru. */
1562 {
1563 /* Keep this algorithm in sync with
1564 tree-complex.cc:expand_complex_div_straight().
1566 Expand complex division to scalars, straightforward algorithm.
1567 a / b = ((ar*br + ai*bi)/t) + i((ai*br - ar*bi)/t)
1568 t = br*br + bi*bi
1569 */
1570 tree magsquared
1574 tree t1
1578 tree t2
1585 }
1586 else
1587 {
1588 /* Keep this algorithm in sync with
1589 tree-complex.cc:expand_complex_div_wide().
1591 Expand complex division to scalars, modified algorithm to minimize
1592 overflow with wide input ranges. */
1598 {
1599 /* In the TRUE branch, we compute
1600 ratio = br/bi;
1601 div = (br * ratio) + bi;
1602 tr = (ar * ratio) + ai;
1603 ti = (ai * ratio) - ar;
1604 tr = tr / div;
1605 ti = ti / div; */
1616 }
1617 else
1618 {
1619 /* In the FALSE branch, we compute
1620 ratio = d/c;
1621 divisor = (d * ratio) + c;
1622 tr = (b * ratio) + a;
1623 ti = b - (a * ratio);
1624 tr = tr / div;
1625 ti = ti / div; */
1637 }
1638 }
1643 }
1647 }
1653 {
1658 /* We can operate directly on the encoding if:
1660 a3 - a2 == a2 - a1 && b3 - b2 == b2 - b1
1661 implies
1662 (a3 op b3) - (a2 op b2) == (a2 op b2) - (a1 op b1)
1664 Addition and subtraction are the supported operators
1665 for which this is true. */
1668 /* We can operate directly on stepped encodings if:
1670 a3 - a2 == a2 - a1
1671 implies:
1672 (a3 op c) - (a2 op c) == (a2 op c) - (a1 op c)
1674 which is true if (x -> x op c) distributes over addition. */
1676 else
1677 /* Similarly in reverse. */
1679 tree_vector_builder elts;
1684 {
1690 /* It is possible that const_binop cannot handle the given
1691 code and return NULL_TREE */
1695 }
1698 }
1700 /* Shifts allow a scalar offset for a vector. */
1703 {
1706 tree_vector_builder elts;
1711 {
1716 /* It is possible that const_binop cannot handle the given
1717 code and return NULL_TREE. */
1721 }
1724 }
1726 }
1728 /* Overload that adds a TYPE parameter to be able to dispatch
1729 to fold_relational_const. */
1731 tree
1733 {
1737 /* ??? Until we make the const_binop worker take the type of the
1738 result as argument put those cases that need it here. */
1740 {
1757 {
1762 }
1768 {
1784 {
1789 ? NOP_EXPR
1796 }
1799 }
1805 {
1828 {
1841 }
1844 }
1847 }
1852 /* Make sure type and arg0 have the same saturating flag. */
1857 }
1859 /* Compute CODE ARG1 with resulting type TYPE with ARG1 being constant.
1860 Return zero if computing the constants is not possible. */
1862 tree
1864 {
1865 /* Don't perform the operation, other than NEGATE and ABS, if
1866 flag_signaling_nans is on and the operand is a signaling NaN. */
1876 {
1877 CASE_CONVERT:
1884 /* If the source address is 0, and the source address space
1885 cannot have a valid object at 0, fold to dest type null. */
1896 {
1897 /* Can't call fold_negate_const directly here as that doesn't
1898 handle all cases and we might not be able to negate some
1899 constants. */
1904 }
1914 {
1918 }
1926 /* Perform BIT_NOT_EXPR on each element individually. */
1928 {
1929 tree elem;
1931 /* This can cope with stepped encodings because ~x == -1 - x. */
1932 tree_vector_builder elements;
1936 {
1942 }
1945 }
1969 {
1992 else
1997 {
2003 }
2006 }
2015 }
2018 }
2020 /* Create a sizetype INT_CST node with NUMBER sign extended. KIND
2021 indicates which particular sizetype to create. */
2023 tree
2025 {
2027 }
2028 \f
2029 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
2030 is a tree code. The type of the result is taken from the operands.
2031 Both must be equivalent integer types, ala int_binop_types_match_p.
2032 If the operands are constant, so is the result. */
2034 tree
2036 {
2045 /* Handle the special case of two poly_int constants faster. */
2047 {
2048 /* And some specific cases even faster than that. */
2050 {
2057 }
2059 {
2063 }
2065 {
2069 }
2071 /* Handle general case of two integer constants. For sizetype
2072 constant calculations we always want to know about overflow,
2073 even in the unsigned case. */
2077 }
2080 }
2082 /* Given two values, either both of sizetype or both of bitsizetype,
2083 compute the difference between the two values. Return the value
2084 in signed type corresponding to the type of the operands. */
2086 tree
2088 {
2090 tree ctype;
2095 /* If the type is already signed, just do the simple thing. */
2103 else
2106 /* If either operand is not a constant, do the conversions to the signed
2107 type and subtract. The hardware will do the right thing with any
2108 overflow in the subtraction. */
2114 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
2115 Otherwise, subtract the other way, convert to CTYPE (we know that can't
2116 overflow) and negate (which can't either). Special-case a result
2117 of zero while we're here. */
2123 else
2127 MINUS_EXPR,
2129 }
2130 \f
2131 /* A subroutine of fold_convert_const handling conversions of an
2132 INTEGER_CST to another integer type. */
2134 static tree
2136 {
2137 /* Given an integer constant, make new constant with new type,
2138 appropriately sign-extended or truncated. Use widest_int
2139 so that any extension is done according ARG1's type. */
2146 }
2148 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2149 to an integer type. */
2151 static tree
2153 {
2155 tree t;
2157 /* The following code implements the floating point to integer
2158 conversion rules required by the Java Language Specification,
2159 that IEEE NaNs are mapped to zero and values that overflow
2160 the target precision saturate, i.e. values greater than
2161 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
2162 are mapped to INT_MIN. These semantics are allowed by the
2163 C and C++ standards that simply state that the behavior of
2164 FP-to-integer conversion is unspecified upon overflow. */
2166 wide_int val;
2167 REAL_VALUE_TYPE r;
2171 {
2178 }
2180 /* If R is NaN, return zero and show we have an overflow. */
2182 {
2185 }
2187 /* See if R is less than the lower bound or greater than the
2188 upper bound. */
2191 {
2195 {
2198 }
2199 }
2202 {
2205 {
2208 {
2211 }
2212 }
2213 }
2220 }
2222 /* A subroutine of fold_convert_const handling conversions of a
2223 FIXED_CST to an integer type. */
2225 static tree
2227 {
2228 tree t;
2230 scalar_mode mode;
2232 /* Right shift FIXED_CST to temp by fbit. */
2236 {
2238 HOST_BITS_PER_DOUBLE_INT,
2241 /* Left shift temp to temp_trunc by fbit. */
2243 HOST_BITS_PER_DOUBLE_INT,
2245 }
2246 else
2247 {
2250 }
2252 /* If FIXED_CST is negative, we need to round the value toward 0.
2253 By checking if the fractional bits are not zero to add 1 to temp. */
2259 /* Given a fixed-point constant, make new constant with new type,
2260 appropriately sign-extended or truncated. */
2268 }
2270 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2271 to another floating point type. */
2273 static tree
2275 {
2276 REAL_VALUE_TYPE value;
2277 tree t;
2279 /* If the underlying modes are the same, simply treat it as
2280 copy and rebuild with TREE_REAL_CST information and the
2281 given type. */
2283 {
2286 }
2288 /* Don't perform the operation if flag_signaling_nans is on
2289 and the operand is a signaling NaN. */
2294 /* With flag_rounding_math we should respect the current rounding mode
2295 unless the conversion is exact. */
2303 /* If converting an infinity or NAN to a representation that doesn't
2304 have one, set the overflow bit so that we can produce some kind of
2305 error message at the appropriate point if necessary. It's not the
2306 most user-friendly message, but it's better than nothing. */
2313 /* Regular overflow, conversion produced an infinity in a mode that
2314 can't represent them. */
2319 else
2322 }
2324 /* A subroutine of fold_convert_const handling conversions a FIXED_CST
2325 to a floating point type. */
2327 static tree
2329 {
2330 REAL_VALUE_TYPE value;
2331 tree t;
2339 }
2341 /* A subroutine of fold_convert_const handling conversions a FIXED_CST
2342 to another fixed-point type. */
2344 static tree
2346 {
2347 FIXED_VALUE_TYPE value;
2348 tree t;
2355 /* Propagate overflow flags. */
2359 }
2361 /* A subroutine of fold_convert_const handling conversions an INTEGER_CST
2362 to a fixed-point type. */
2364 static tree
2366 {
2367 FIXED_VALUE_TYPE value;
2368 tree t;
2370 double_int di;
2377 else
2385 /* Propagate overflow flags. */
2389 }
2391 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2392 to a fixed-point type. */
2394 static tree
2396 {
2397 FIXED_VALUE_TYPE value;
2398 tree t;
2406 /* Propagate overflow flags. */
2410 }
2412 /* Attempt to fold type conversion operation CODE of expression ARG1 to
2413 type TYPE. If no simplification can be done return NULL_TREE. */
2415 static tree
2417 {
2422 /* We can't widen types, since the runtime value could overflow the
2423 original type before being extended to the new type. */
2434 {
2441 }
2443 {
2445 {
2447 /* Avoid the folding if flag_rounding_math is on and the
2448 conversion is not exact. */
2450 {
2456 }
2458 }
2463 }
2465 {
2472 }
2474 {
2477 {
2480 /* We can't handle steps directly when extending, since the
2481 values need to wrap at the original precision first. */
2482 bool step_ok_p
2486 tree_vector_builder v;
2491 {
2497 }
2499 }
2500 }
2502 }
2504 /* Construct a vector of zero elements of vector type TYPE. */
2506 static tree
2508 {
2509 tree t;
2513 }
2515 /* Returns true, if ARG is convertible to TYPE using a NOP_EXPR. */
2517 bool
2519 {
2534 {
2556 }
2557 }
2559 /* Convert expression ARG to type TYPE. Used by the middle-end for
2560 simple conversions in preference to calling the front-end's convert. */
2562 tree
2564 {
2566 tree tem;
2577 {
2580 /* Handle conversions between pointers to different address spaces. */
2585 /* fall through */
2590 {
2594 }
2608 {
2612 }
2614 {
2618 }
2620 {
2624 }
2627 {
2645 }
2650 {
2654 }
2657 {
2672 }
2676 {
2685 integer_zero_node));
2687 {
2691 {
2697 }
2705 }
2709 }
2727 }
2728 fold_convert_exit:
2731 }
2732 \f
2733 /* Return false if expr can be assumed not to be an lvalue, true
2734 otherwise. */
2736 static bool
2738 {
2739 /* We only need to wrap lvalue tree codes. */
2741 {
2774 /* Assume the worst for front-end tree codes. */
2778 }
2781 }
2783 /* Return an expr equal to X but certainly not valid as an lvalue. */
2785 tree
2787 {
2788 /* While we are in GIMPLE, NON_LVALUE_EXPR doesn't mean anything to
2789 us. */
2796 }
2797 \f
2798 /* Given a tree comparison code, return the code that is the logical inverse.
2799 It is generally not safe to do this for floating-point comparisons, except
2800 for EQ_EXPR, NE_EXPR, ORDERED_EXPR and UNORDERED_EXPR, so we return
2801 ERROR_MARK in this case. */
2803 enum tree_code
2805 {
2811 {
2842 }
2843 }
2845 /* Similar, but return the comparison that results if the operands are
2846 swapped. This is safe for floating-point. */
2848 enum tree_code
2850 {
2852 {
2878 }
2879 }
2882 /* Convert a comparison tree code from an enum tree_code representation
2883 into a compcode bit-based encoding. This function is the inverse of
2884 compcode_to_comparison. */
2886 static enum comparison_code
2888 {
2890 {
2921 }
2922 }
2924 /* Convert a compcode bit-based encoding of a comparison operator back
2925 to GCC's enum tree_code representation. This function is the
2926 inverse of comparison_to_compcode. */
2928 static enum tree_code
2930 {
2932 {
2963 }
2964 }
2966 /* Return true if COND1 tests the opposite condition of COND2. */
2968 bool
2970 {
2973 && (invert_tree_comparison
2980 }
2982 /* Return a tree for the comparison which is the combination of
2983 doing the AND or OR (depending on CODE) of the two operations LCODE
2984 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2985 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2986 if this makes the transformation invalid. */
2988 tree
2993 {
3000 {
3011 }
3014 {
3015 /* Eliminate unordered comparisons, as well as LTGT and ORD
3016 which are not used unless the mode has NaNs. */
3022 }
3024 {
3025 /* Check that the original operation and the optimized ones will trap
3026 under the same condition. */
3037 /* In a short-circuited boolean expression the LHS might be
3038 such that the RHS, if evaluated, will never trap. For
3039 example, in ORD (x, y) && (x < y), we evaluate the RHS only
3040 if neither x nor y is NaN. (This is a mixed blessing: for
3041 example, the expression above will never trap, hence
3042 optimizing it to x < y would be invalid). */
3047 /* If the comparison was short-circuited, and only the RHS
3048 trapped, we may now generate a spurious trap. */
3053 /* If we changed the conditions that cause a trap, we lose. */
3056 }
3062 else
3063 {
3068 }
3069 }
3070 \f
3071 /* Return nonzero if two operands (typically of the same tree node)
3072 are necessarily equal. FLAGS modifies behavior as follows:
3074 If OEP_ONLY_CONST is set, only return nonzero for constants.
3075 This function tests whether the operands are indistinguishable;
3076 it does not test whether they are equal using C's == operation.
3077 The distinction is important for IEEE floating point, because
3078 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
3079 (2) two NaNs may be indistinguishable, but NaN!=NaN.
3081 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
3082 even though it may hold multiple values during a function.
3083 This is because a GCC tree node guarantees that nothing else is
3084 executed between the evaluation of its "operands" (which may often
3085 be evaluated in arbitrary order). Hence if the operands themselves
3086 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
3087 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
3088 unset means assuming isochronic (or instantaneous) tree equivalence.
3089 Unless comparing arbitrary expression trees, such as from different
3090 statements, this flag can usually be left unset.
3092 If OEP_PURE_SAME is set, then pure functions with identical arguments
3093 are considered the same. It is used when the caller has other ways
3094 to ensure that global memory is unchanged in between.
3096 If OEP_ADDRESS_OF is set, we are actually comparing addresses of objects,
3097 not values of expressions.
3099 If OEP_LEXICOGRAPHIC is set, then also handle expressions with side-effects
3100 such as MODIFY_EXPR, RETURN_EXPR, as well as STATEMENT_LISTs.
3102 If OEP_BITWISE is set, then require the values to be bitwise identical
3103 rather than simply numerically equal. Do not take advantage of things
3104 like math-related flags or undefined behavior; only return true for
3105 values that are provably bitwise identical in all circumstances.
3107 Unless OEP_MATCH_SIDE_EFFECTS is set, the function returns false on
3108 any operand with side effect. This is unnecesarily conservative in the
3109 case we know that arg0 and arg1 are in disjoint code paths (such as in
3110 ?: operator). In addition OEP_MATCH_SIDE_EFFECTS is used when comparing
3111 addresses with TREE_CONSTANT flag set so we know that &var == &var
3112 even if var is volatile. */
3114 bool
3117 {
3125 /* If either is ERROR_MARK, they aren't equal. */
3131 /* Similar, if either does not have a type (like a template id),
3132 they aren't equal. */
3136 /* Bitwise identity makes no sense if the values have different layouts. */
3141 /* We cannot consider pointers to different address space equal. */
3148 /* Check equality of integer constants before bailing out due to
3149 precision differences. */
3151 {
3152 /* Address of INTEGER_CST is not defined; check that we did not forget
3153 to drop the OEP_ADDRESS_OF flags. */
3156 }
3159 {
3160 /* If both types don't have the same signedness, then we can't consider
3161 them equal. We must check this before the STRIP_NOPS calls
3162 because they may change the signedness of the arguments. As pointers
3163 strictly don't have a signedness, require either two pointers or
3164 two non-pointers as well. */
3170 /* If both types don't have the same precision, then it is not safe
3171 to strip NOPs. */
3178 }
3179 #if 0
3180 /* FIXME: Fortran FE currently produce ADDR_EXPR of NOP_EXPR. Enable the
3181 sanity check once the issue is solved. */
3182 else
3183 /* Addresses of conversions and SSA_NAMEs (and many other things)
3184 are not defined. Check that we did not forget to drop the
3185 OEP_ADDRESS_OF/OEP_CONSTANT_ADDRESS_OF flags. */
3188 #endif
3190 /* In case both args are comparisons but with different comparison
3191 code, try to swap the comparison operands of one arg to produce
3192 a match and compare that variant. */
3196 {
3204 }
3207 {
3208 /* NOP_EXPR and CONVERT_EXPR are considered equal. */
3210 ;
3212 {
3213 /* If we are interested in comparing addresses ignore
3214 MEM_REF wrappings of the base that can appear just for
3215 TBAA reasons. */
3229 }
3230 else
3232 }
3234 /* When not checking adddresses, this is needed for conversions and for
3235 COMPONENT_REF. Might as well play it safe and always test this. */
3242 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
3243 We don't care about side effects in that case because the SAVE_EXPR
3244 takes care of that for us. In all other cases, two expressions are
3245 equal if they have no side effects. If we have two identical
3246 expressions with side effects that should be treated the same due
3247 to the only side effects being identical SAVE_EXPR's, that will
3248 be detected in the recursive calls below.
3249 If we are taking an invariant address of two identical objects
3250 they are necessarily equal as well. */
3257 /* Next handle constant cases, those for which we can return 1 even
3258 if ONLY_CONST is set. */
3261 {
3274 {
3275 /* If we do not distinguish between signed and unsigned zero,
3276 consider them equal. */
3279 }
3283 {
3298 }
3302 flags)
3304 flags));
3315 flags | OEP_ADDRESS_OF
3318 {
3319 /* In GIMPLE empty constructors are allowed in initializers of
3320 aggregates. */
3324 /* See sem_variable::equals in ipa-icf for a similar approach. */
3331 {
3332 /* For arrays, check that the sizes all match. */
3338 }
3347 /* Address of CONSTRUCTOR is defined in GENERIC to mean the value
3348 of the CONSTRUCTOR referenced indirectly. */
3352 {
3356 /* Check that the values are the same... */
3361 /* ... and that they apply to the same field! */
3367 flags)
3370 flags)))
3372 }
3375 }
3379 }
3381 /* Don't handle more cases for OEP_BITWISE, since we can't guarantee that
3382 two instances of undefined behavior will give identical results. */
3386 /* Define macros to test an operand from arg0 and arg1 for equality and a
3387 variant that allows null and views null as being different from any
3388 non-null value. In the latter case, if either is null, the both
3389 must be; otherwise, do the normal comparison. */
3390 #define OP_SAME(N) operand_equal_p (TREE_OPERAND (arg0, N), \
3391 TREE_OPERAND (arg1, N), flags)
3393 #define OP_SAME_WITH_NULL(N) \
3394 ((!TREE_OPERAND (arg0, N) || !TREE_OPERAND (arg1, N)) \
3395 ? TREE_OPERAND (arg0, N) == TREE_OPERAND (arg1, N) : OP_SAME (N))
3398 {
3400 /* Two conversions are equal only if signedness and modes match. */
3402 {
3403 CASE_CONVERT:
3411 }
3421 /* For commutative ops, allow the other order. */
3429 /* If either of the pointer (or reference) expressions we are
3430 dereferencing contain a side effect, these cannot be equal,
3431 but their addresses can be. */
3438 {
3441 {
3445 /* Verify that the access types are compatible. */
3449 }
3454 /* Require the same offset. */
3460 /* Fallthru. */
3468 {
3469 /* Require equal access sizes */
3475 flags)))
3477 /* Verify that access happens in similar types. */
3480 /* Verify that accesses are TBAA compatible. */
3489 /* Verify that alignment is compatible. */
3493 }
3496 /* TARGET_MEM_REF require equal extra operands. */
3507 /* Compare the array index by value if it is constant first as we
3508 may have different types but same value here. */
3514 /* Compare low bound and element size as with OEP_ADDRESS_OF
3515 we have to account for the offset of the ref. */
3520 array_ref_low_bound
3524 array_ref_element_size
3526 flags))));
3529 /* Handle operand 2 the same as for ARRAY_REF. Operand 0
3530 may be NULL when we're called to compare MEM_EXPRs. */
3533 {
3536 /* Most of time we only need to compare FIELD_DECLs for equality.
3537 However when determining address look into actual offsets.
3538 These may match for unions and unshared record types. */
3541 {
3544 {
3548 /* Non-FIELD_DECL operands can appear in C++ templates. */
3555 flags))
3557 }
3558 else
3560 }
3561 }
3572 }
3576 {
3578 /* Be sure we pass right ADDRESS_OF flag. */
3595 /* The multiplcation operands are commutative. */
3596 /* FALLTHRU */
3604 /* Otherwise take into account this is a commutative operation. */
3617 /* BIT_INSERT_EXPR has an implict operand as the type precision
3618 of op1. Need to check to make sure they are the same. */
3624 /* FALLTHRU */
3649 /* Virtual table reference. */
3661 {
3666 }
3671 }
3675 {
3679 /* If not both CALL_EXPRs are either internal or normal function
3680 functions, then they are not equal. */
3683 {
3684 /* If the CALL_EXPRs call different internal functions, then they
3685 are not equal. */
3688 }
3689 else
3690 {
3691 /* If the CALL_EXPRs call different functions, then they are not
3692 equal. */
3694 flags))
3696 }
3698 /* FIXME: We could skip this test for OEP_MATCH_SIDE_EFFECTS. */
3699 {
3703 else
3707 }
3709 /* Now see if all the arguments are the same. */
3710 {
3721 /* If we get here and both argument lists are exhausted
3722 then the CALL_EXPRs are equal. */
3724 }
3727 }
3730 /* Consider __builtin_sqrt equal to sqrt. */
3740 {
3741 /* Consider decls with the same name equal. The caller needs
3742 to make sure they refer to the same entity (such as a function
3743 formal parameter). */
3749 }
3754 {
3758 /* In GIMPLE constructors are used only to build vectors from
3759 elements. Individual elements in the constructor must be
3760 indexed in increasing order and form an initial sequence.
3762 We make no effort to compare nonconstant ones in GENERIC. */
3767 /* Be sure that vectors constructed have the same representation.
3768 We only tested element precision and modes to match.
3769 Vectors may be BLKmode and thus also check that the number of
3770 parts match. */
3783 {
3788 /* In GIMPLE the indexes can be either NULL or matching i.
3789 Double check this so we won't get false
3790 positives for GENERIC. */
3798 }
3800 }
3803 {
3804 /* Compare the STATEMENT_LISTs. */
3810 {
3811 /* The lists don't have the same number of statements. */
3817 flags & (OEP_LEXICOGRAPHIC
3820 }
3821 }
3826 {
3837 }
3841 }
3843 #undef OP_SAME
3844 #undef OP_SAME_WITH_NULL
3845 }
3847 /* Generate a hash value for an expression. This can be used iteratively
3848 by passing a previous result as the HSTATE argument. */
3850 void
3853 {
3859 {
3862 }
3872 {
3873 /* Alas, constants aren't shared, so we can't rely on pointer
3874 identity. */
3884 {
3888 else
3892 }
3894 {
3898 }
3908 {
3915 }
3917 /* We can just compare by pointer. */
3921 /* The node itself doesn't matter. */
3925 /* Ignore. */
3928 /* A list of expressions, for a CALL_EXPR or as the elements of a
3929 VECTOR_CST. */
3934 {
3940 {
3941 /* In GIMPLE the indexes can be either NULL or matching i. */
3945 {
3948 }
3949 else
3952 }
3954 }
3956 {
3957 tree_stmt_iterator i;
3962 }
3971 /* When referring to a built-in FUNCTION_DECL, use the __builtin__ form.
3972 Otherwise nodes that compare equal according to operand_equal_p might
3973 get different hash codes. However, don't do this for machine specific
3974 or front end builtins, since the function code is overloaded in those
3975 cases. */
3978 {
3981 }
3982 /* FALL THROUGH */
3985 {
3989 }
3993 {
3994 /* DECL's have a unique ID */
3996 }
3998 {
3999 /* For comparisons that can be swapped, use the lower
4000 tree code. */
4007 }
4009 {
4010 /* NOP_EXPR and CONVERT_EXPR are considered equal by
4011 operand_equal_p. */
4015 /* Don't hash the type, that can lead to having nodes which
4016 compare equal according to operand_equal_p, but which
4017 have different hash codes. Make sure to include signedness
4018 in the hash computation. */
4021 }
4022 /* For OEP_ADDRESS_OF, hash MEM_EXPR[&decl, 0] the same as decl. */
4030 /* Don't ICE on FE specific trees, or their arguments etc.
4031 during operand_equal_p hash verification. */
4034 else
4035 {
4041 {
4057 {
4064 }
4078 {
4079 /* The multiplication operands are commutative. */
4086 }
4094 /* For TARGET_EXPR, just hash on the TARGET_EXPR_SLOT.
4095 Usually different TARGET_EXPRs just should use
4096 different temporaries in their slots. */
4101 /* Virtual table reference. */
4109 {
4111 /* We compute mangled names only when free_lang_data is run.
4112 In that case we can hash precisely. */
4115 hstate.add_object
4116 (IDENTIFIER_HASH_VALUE
4118 }
4122 }
4124 /* Don't hash the type, that can lead to having nodes which
4125 compare equal according to operand_equal_p, but which
4126 have different hash codes. */
4128 {
4129 /* Make sure to include signness in the hash computation. */
4132 }
4135 {
4136 /* It's a commutative expression. We want to hash it the same
4137 however it appears. We do this by first hashing both operands
4138 and then rehashing based on the order of their independent
4139 hashes. */
4144 }
4145 else
4149 }
4151 }
4152 }
4154 bool
4157 {
4158 /* When checking and unless comparing DECL names, verify that if
4159 the outermost operand_equal_p call returns non-zero then ARG0
4160 and ARG1 have the same hash value. */
4162 {
4164 {
4166 {
4173 }
4175 }
4176 else
4180 }
4183 }
4188 /* Conveinece wrapper around operand_compare class because usually we do
4189 not need to play with the valueizer. */
4191 bool
4193 {
4195 }
4197 namespace inchash
4198 {
4200 /* Generate a hash value for an expression. This can be used iteratively
4201 by passing a previous result as the HSTATE argument.
4203 This function is intended to produce the same hash for expressions which
4204 would compare equal using operand_equal_p. */
4205 void
4207 {
4209 }
4211 }
4212 \f
4213 /* Similar to operand_equal_p, but see if ARG0 might be a variant of ARG1
4214 with a different signedness or a narrower precision. */
4216 static bool
4218 {
4226 /* Discard any conversions that don't change the modes of ARG0 and ARG1
4227 and see if the inner values are the same. This removes any
4228 signedness comparison, which doesn't matter here. */
4236 /* Discard a single widening conversion from ARG1 and see if the inner
4237 value is the same as ARG0. */
4246 }
4247 \f
4248 /* See if ARG is an expression that is either a comparison or is performing
4249 arithmetic on comparisons. The comparisons must only be comparing
4250 two different values, which will be stored in *CVAL1 and *CVAL2; if
4251 they are nonzero it means that some operands have already been found.
4252 No variables may be used anywhere else in the expression except in the
4253 comparisons.
4255 If this is true, return 1. Otherwise, return zero. */
4257 static bool
4259 {
4263 /* We can handle some of the tcc_expression cases here. */
4272 {
4291 /* First see if we can handle the first operand, then the second. For
4292 the second operand, we know *CVAL1 can't be zero. It must be that
4293 one side of the comparison is each of the values; test for the
4294 case where this isn't true by failing if the two operands
4295 are the same. */
4304 ;
4308 ;
4309 else
4313 ;
4317 ;
4318 else
4325 }
4326 }
4327 \f
4328 /* ARG is a tree that is known to contain just arithmetic operations and
4329 comparisons. Evaluate the operations in the tree substituting NEW0 for
4330 any occurrence of OLD0 as an operand of a comparison and likewise for
4331 NEW1 and OLD1. */
4333 static tree
4336 {
4341 /* We can handle some of the tcc_expression cases here. */
4349 {
4364 {
4383 }
4384 /* Fall through - ??? */
4387 {
4391 /* We need to check both for exact equality and tree equality. The
4392 former will be true if the operand has a side-effect. In that
4393 case, we know the operand occurred exactly once. */
4406 }
4410 }
4411 }
4412 \f
4413 /* Return a tree for the case when the result of an expression is RESULT
4414 converted to TYPE and OMITTED was previously an operand of the expression
4415 but is now not needed (e.g., we folded OMITTED * 0).
4417 If OMITTED has side effects, we must evaluate it. Otherwise, just do
4418 the conversion of RESULT to TYPE. */
4420 tree
4422 {
4425 /* If the resulting operand is an empty statement, just return the omitted
4426 statement casted to void. */
4436 }
4438 /* Return a tree for the case when the result of an expression is RESULT
4439 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
4440 of the expression but are now not needed.
4442 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
4443 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
4444 evaluated before OMITTED2. Otherwise, if neither has side effects,
4445 just do the conversion of RESULT to TYPE. */
4447 tree
4450 {
4459 }
4461 \f
4462 /* Return a simplified tree node for the truth-negation of ARG. This
4463 never alters ARG itself. We assume that ARG is an operation that
4464 returns a truth value (0 or 1).
4466 FIXME: one would think we would fold the result, but it causes
4467 problems with the dominator optimizer. */
4469 static tree
4471 {
4476 /* If this is a comparison, we can simply invert it, except for
4477 floating-point non-equality comparisons, in which case we just
4478 enclose a TRUTH_NOT_EXPR around what we have. */
4481 {
4484 && flag_trapping_math
4497 }
4500 {
4519 /* Here we can invert either operand. We invert the first operand
4520 unless the second operand is a TRUTH_NOT_EXPR in which case our
4521 result is the XOR of the first operand with the inside of the
4522 negation of the second operand. */
4527 else
4550 {
4557 /* A COND_EXPR may have a throw as one operand, which
4558 then has void type. Just leave void operands
4559 as they are. */
4565 }
4577 CASE_CONVERT:
4581 /* fall through */
4603 }
4604 }
4606 /* Fold the truth-negation of ARG. This never alters ARG itself. We
4607 assume that ARG is an operation that returns a truth value (0 or 1
4608 for scalars, 0 or -1 for vectors). Return the folded expression if
4609 folding is successful. Otherwise, return NULL_TREE. */
4611 static tree
4613 {
4616 ? BIT_NOT_EXPR
4619 }
4621 /* Return a simplified tree node for the truth-negation of ARG. This
4622 never alters ARG itself. We assume that ARG is an operation that
4623 returns a truth value (0 or 1 for scalars, 0 or -1 for vectors). */
4625 tree
4627 {
4633 ? BIT_NOT_EXPR
4636 }
4637 \f
4638 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
4639 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero
4640 and uses reverse storage order if REVERSEP is nonzero. ORIG_INNER
4641 is the original memory reference used to preserve the alias set of
4642 the access. */
4644 static tree
4648 {
4651 /* Attempt not to lose the access path if possible. */
4653 {
4655 machine_mode nmode;
4657 tree noffset;
4665 && !reversep
4666 && !nreversep
4668 {
4671 }
4672 }
4681 {
4688 }
4703 }
4705 /* Optimize a bit-field compare.
4707 There are two cases: First is a compare against a constant and the
4708 second is a comparison of two items where the fields are at the same
4709 bit position relative to the start of a chunk (byte, halfword, word)
4710 large enough to contain it. In these cases we can avoid the shift
4711 implicit in bitfield extractions.
4713 For constants, we emit a compare of the shifted constant with the
4714 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
4715 compared. For two fields at the same position, we do the ANDs with the
4716 similar mask and compare the result of the ANDs.
4718 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
4719 COMPARE_TYPE is the type of the comparison, and LHS and RHS
4720 are the left and right operands of the comparison, respectively.
4722 If the optimization described above can be done, we return the resulting
4723 tree. Otherwise we return zero. */
4725 static tree
4728 {
4732 tree unsigned_type;
4735 scalar_int_mode nmode;
4740 tree mask;
4741 tree offset;
4743 /* Get all the information about the extractions being done. If the bit size
4744 is the same as the size of the underlying object, we aren't doing an
4745 extraction at all and so can do nothing. We also don't want to
4746 do anything if the inner expression is a PLACEHOLDER_EXPR since we
4747 then will no longer be able to replace it. */
4762 else
4763 {
4764 /* If this is not a constant, we can only do something if bit positions,
4765 sizes, signedness and storage order are the same. */
4766 rinner
4779 }
4781 /* Honor the C++ memory model and mimic what RTL expansion does. */
4785 {
4789 }
4791 /* See if we can find a mode to refer to this field. We should be able to,
4792 but fail if we can't. */
4800 /* Set signed and unsigned types of the precision of this mode for the
4801 shifts below. */
4804 /* Compute the bit position and size for the new reference and our offset
4805 within it. If the new reference is the same size as the original, we
4806 won't optimize anything, so return zero. */
4816 /* Make the mask to be used against the extracted field. */
4823 {
4827 /* If not comparing with constant, just rework the comparison
4828 and return. */
4836 }
4838 /* Otherwise, we are handling the constant case. See if the constant is too
4839 big for the field. Warn and return a tree for 0 (false) if so. We do
4840 this not only for its own sake, but to avoid having to test for this
4841 error case below. If we didn't, we might generate wrong code.
4843 For unsigned fields, the constant shifted right by the field length should
4844 be all zero. For signed fields, the high-order bits should agree with
4845 the sign bit. */
4848 {
4850 {
4854 }
4855 }
4856 else
4857 {
4860 {
4864 }
4865 }
4870 /* Single-bit compares should always be against zero. */
4872 {
4875 }
4877 /* Make a new bitfield reference, shift the constant over the
4878 appropriate number of bits and mask it with the computed mask
4879 (in case this was a signed field). If we changed it, make a new one. */
4887 mask);
4892 }
4893 \f
4894 /* Subroutine for fold_truth_andor_1: decode a field reference.
4896 If EXP is a comparison reference, we return the innermost reference.
4898 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
4899 set to the starting bit number.
4901 If the innermost field can be completely contained in a mode-sized
4902 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
4904 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
4905 otherwise it is not changed.
4907 *PUNSIGNEDP is set to the signedness of the field.
4909 *PREVERSEP is set to the storage order of the field.
4911 *PMASK is set to the mask used. This is either contained in a
4912 BIT_AND_EXPR or derived from the width of the field.
4914 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
4916 Return 0 if this is not a component reference or is one that we can't
4917 do anything with. */
4919 static tree
4924 {
4929 tree unsigned_type;
4932 /* All the optimizations using this function assume integer fields.
4933 There are problems with FP fields since the type_for_size call
4934 below can fail for, e.g., XFmode. */
4938 /* We are interested in the bare arrangement of bits, so strip everything
4939 that doesn't affect the machine mode. However, record the type of the
4940 outermost expression if it may matter below. */
4947 {
4953 }
4964 /* Reject out-of-bound accesses (PR79731). */
4976 /* If the number of bits in the reference is the same as the bitsize of
4977 the outer type, then the outer type gives the signedness. Otherwise
4978 (in case of a small bitfield) the signedness is unchanged. */
4982 /* Compute the mask to access the bitfield. */
4990 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
4998 }
5000 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
5001 bit positions and MASK is SIGNED. */
5003 static bool
5005 {
5009 /* If this function returns true when the type of the mask is
5010 UNSIGNED, then there will be errors. In particular see
5011 gcc.c-torture/execute/990326-1.c. There does not appear to be
5012 any documentation paper trail as to why this is so. But the pre
5013 wide-int worked with that restriction and it has been preserved
5014 here. */
5019 }
5021 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
5022 represents the sign bit of EXP's type. If EXP represents a sign
5023 or zero extension, also test VAL against the unextended type.
5024 The return value is the (sub)expression whose sign bit is VAL,
5025 or NULL_TREE otherwise. */
5027 tree
5029 {
5031 tree t;
5033 /* Tree EXP must have an integral type. */
5038 /* Tree VAL must be an integer constant. */
5047 /* Handle extension from a narrower type. */
5053 }
5055 /* Subroutine for fold_truth_andor_1 and simple_condition_p: determine if an
5056 operand is simple enough to be evaluated unconditionally. */
5058 static bool
5060 {
5061 /* Strip any conversions that don't change the machine mode. */
5070 /* Don't regard global variables as simple. They may be
5071 allocated in ways unknown to the compiler (shared memory,
5072 #pragma weak, etc). */
5075 /* Weakrefs are not safe to be read, since they can be NULL.
5076 They are !TREE_PUBLIC && !DECL_EXTERNAL but still
5077 have DECL_WEAK flag set. */
5079 /* Loading a static variable is unduly expensive, but global
5080 registers aren't expensive. */
5082 }
5084 /* Determine if an operand is simple enough to be evaluated unconditionally.
5085 In addition to simple_operand_p, we assume that comparisons, conversions,
5086 and logic-not operations are simple, if their operands are simple, too. */
5088 bool
5090 {
5109 }
5111 \f
5112 /* The following functions are subroutines to fold_range_test and allow it to
5113 try to change a logical combination of comparisons into a range test.
5115 For example, both
5116 X == 2 || X == 3 || X == 4 || X == 5
5117 and
5118 X >= 2 && X <= 5
5119 are converted to
5120 (unsigned) (X - 2) <= 3
5122 We describe each set of comparisons as being either inside or outside
5123 a range, using a variable named like IN_P, and then describe the
5124 range with a lower and upper bound. If one of the bounds is omitted,
5125 it represents either the highest or lowest value of the type.
5127 In the comments below, we represent a range by two numbers in brackets
5128 preceded by a "+" to designate being inside that range, or a "-" to
5129 designate being outside that range, so the condition can be inverted by
5130 flipping the prefix. An omitted bound is represented by a "-". For
5131 example, "- [-, 10]" means being outside the range starting at the lowest
5132 possible value and ending at 10, in other words, being greater than 10.
5133 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
5134 always false.
5136 We set up things so that the missing bounds are handled in a consistent
5137 manner so neither a missing bound nor "true" and "false" need to be
5138 handled using a special case. */
5140 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
5141 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
5142 and UPPER1_P are nonzero if the respective argument is an upper bound
5143 and zero for a lower. TYPE, if nonzero, is the type of the result; it
5144 must be specified for a comparison. ARG1 will be converted to ARG0's
5145 type if both are specified. */
5147 static tree
5150 {
5151 tree tem;
5155 /* If neither arg represents infinity, do the normal operation.
5156 Else, if not a comparison, return infinity. Else handle the special
5157 comparison rules. Note that most of the cases below won't occur, but
5158 are handled for consistency. */
5161 {
5166 }
5171 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
5172 for neither. In real maths, we cannot assume open ended ranges are
5173 the same. But, this is computer arithmetic, where numbers are finite.
5174 We can therefore make the transformation of any unbounded range with
5175 the value Z, Z being greater than any representable number. This permits
5176 us to treat unbounded ranges as equal. */
5180 {
5201 }
5204 }
5205 \f
5206 /* Helper routine for make_range. Perform one step for it, return
5207 new expression if the loop should continue or NULL_TREE if it should
5208 stop. */
5210 tree
5214 {
5220 {
5222 /* We can only do something if the range is testing for zero. */
5231 /* We can only do something if the range is testing for zero
5232 and if the second operand is an integer constant. Note that
5233 saying something is "in" the range we make is done by
5234 complementing IN_P since it will set in the initial case of
5235 being not equal to zero; "out" is leaving it alone. */
5242 {
5263 }
5265 /* If this is an unsigned comparison, we also know that EXP is
5266 greater than or equal to zero. We base the range tests we make
5267 on that fact, so we record it here so we can parse existing
5268 range tests. We test arg0_type since often the return type
5269 of, e.g. EQ_EXPR, is boolean. */
5271 {
5275 NULL_TREE))
5280 /* If the high bound is missing, but we have a nonzero low
5281 bound, reverse the range so it goes from zero to the low bound
5282 minus 1. */
5284 {
5289 }
5290 }
5298 /* If flag_wrapv and ARG0_TYPE is signed, make sure
5299 low and high are non-NULL, then normalize will DTRT. */
5302 {
5307 }
5309 /* (-x) IN [a,b] -> x in [-b, -a] */
5321 /* ~ X -> -X - 1 */
5330 /* If flag_wrapv and ARG0_TYPE is signed, then we cannot
5331 move a constant to the other side. */
5336 /* If EXP is signed, any overflow in the computation is undefined,
5337 so we don't worry about it so long as our computations on
5338 the bounds don't overflow. For unsigned, overflow is defined
5339 and this is exactly the right thing. */
5351 normalize:
5352 /* Check for an unsigned range which has wrapped around the maximum
5353 value thus making n_high < n_low, and normalize it. */
5355 {
5361 /* If the range is of the form +/- [ x+1, x ], we won't
5362 be able to normalize it. But then, it represents the
5363 whole range or the empty set, so make it
5364 +/- [ -, - ]. */
5368 else
5370 }
5371 else
5379 CASE_CONVERT:
5397 /* If we're converting arg0 from an unsigned type, to exp,
5398 a signed type, we will be doing the comparison as unsigned.
5399 The tests above have already verified that LOW and HIGH
5400 are both positive.
5402 So we have to ensure that we will handle large unsigned
5403 values the same way that the current signed bounds treat
5404 negative values. */
5407 {
5408 tree high_positive;
5409 tree equiv_type;
5410 /* For fixed-point modes, we need to pass the saturating flag
5411 as the 2nd parameter. */
5413 equiv_type
5418 else
5419 equiv_type
5422 /* A range without an upper bound is, naturally, unbounded.
5423 Since convert would have cropped a very large value, use
5424 the max value for the destination type. */
5425 high_positive
5432 high_positive),
5435 /* If the low bound is specified, "and" the range with the
5436 range for which the original unsigned value will be
5437 positive. */
5439 {
5442 integer_zero_node),
5443 high_positive))
5447 }
5448 else
5449 {
5450 /* Otherwise, "or" the range with the range of the input
5451 that will be interpreted as negative. */
5454 integer_zero_node),
5455 high_positive))
5459 }
5460 }
5462 /* Otherwise, if we are converting arg0 from signed type, to exp,
5463 an unsigned type, we will do the comparison as signed. If
5464 high is non-NULL, we punt above if it doesn't fit in the signed
5465 type, so if we get through here, +[-, high] or +[low, high] are
5466 equivalent to +[-, n_high] or +[n_low, n_high]. Similarly,
5467 +[-, -] or -[-, -] are equivalent too. But if low is specified and
5468 high is not, the +[low, -] range is equivalent to union of
5469 +[n_low, -] and +[-, -1] ranges, so +[low, -] is equivalent to
5470 -[0, n_low-1] and similarly -[low, -] to +[0, n_low-1], except for
5471 low being 0, which should be treated as [-, -]. */
5474 && low
5476 {
5479 else
5480 {
5485 }
5486 }
5495 }
5496 }
5498 /* Given EXP, a logical expression, set the range it is testing into
5499 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
5500 actually being tested. *PLOW and *PHIGH will be made of the same
5501 type as the returned expression. If EXP is not a comparison, we
5502 will most likely not be returning a useful value and range. Set
5503 *STRICT_OVERFLOW_P to true if the return value is only valid
5504 because signed overflow is undefined; otherwise, do not change
5505 *STRICT_OVERFLOW_P. */
5507 tree
5510 {
5518 /* Start with simply saying "EXP != 0" and then look at the code of EXP
5519 and see if we can refine the range. Some of the cases below may not
5520 happen, but it doesn't seem worth worrying about this. We "continue"
5521 the outer loop when we've changed something; otherwise we "break"
5522 the switch, which will "break" the while. */
5528 {
5534 {
5542 }
5551 }
5553 /* If EXP is a constant, we can evaluate whether this is true or false. */
5555 {
5562 }
5566 }
5568 /* Returns TRUE if [LOW, HIGH] range check can be optimized to
5569 a bitwise check i.e. when
5570 LOW == 0xXX...X00...0
5571 HIGH == 0xXX...X11...1
5572 Return corresponding mask in MASK and stem in VALUE. */
5574 static bool
5577 {
5600 }
5601 \f
5602 /* Helper routine for build_range_check and match.pd. Return the type to
5603 perform the check or NULL if it shouldn't be optimized. */
5605 tree
5607 {
5608 /* First make sure that arithmetics in this type is valid, then make sure
5609 that it wraps around. */
5614 {
5617 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
5618 for the type in question, as we rely on this here. */
5628 else
5630 }
5633 /* Right now all BITINT_TYPEs satisfy
5634 (unsigned) max + 1 == (unsigned) min, so no need to verify
5635 that like for INTEGER_TYPEs. */
5639 }
5641 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
5642 type, TYPE, return an expression to test if EXP is in (or out of, depending
5643 on IN_P) the range. Return 0 if the test couldn't be created. */
5645 tree
5648 {
5651 /* Disable this optimization for function pointer expressions
5652 on targets that require function pointer canonicalization. */
5659 {
5665 }
5687 value);
5690 {
5692 {
5696 }
5698 }
5700 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
5702 {
5706 {
5708 {
5711 etype
5713 else
5716 }
5719 }
5720 }
5722 /* Optimize (c>=low) && (c<=high) into (c-low>=0) && (c-low<=high-low).
5723 This requires wrap-around arithmetics for the type of the expression. */
5740 }
5741 \f
5742 /* Return the predecessor of VAL in its type, handling the infinite case. */
5744 static tree
5746 {
5752 else
5755 }
5757 /* Return the successor of VAL in its type, handling the infinite case. */
5759 static tree
5761 {
5767 else
5770 }
5772 /* Given two ranges, see if we can merge them into one. Return 1 if we
5773 can, 0 if we can't. Set the output range into the specified parameters. */
5775 bool
5778 {
5782 tree tem;
5792 /* Make range 0 be the range that starts first, or ends last if they
5793 start at the same value. Swap them if it isn't. */
5796 || (lowequal
5799 {
5803 }
5805 /* If the second range is != high1 where high1 is the type maximum of
5806 the type, try first merging with < high1 range. */
5808 && high1
5815 {
5820 /* Similarly for the second range != low1 where low1 is the type minimum
5821 of the type, try first merging with > low1 range. */
5826 }
5828 /* Now flag two cases, whether the ranges are disjoint or whether the
5829 second range is totally subsumed in the first. Note that the tests
5830 below are simplified by the ones above. */
5836 /* We now have four cases, depending on whether we are including or
5837 excluding the two ranges. */
5839 {
5840 /* If they don't overlap, the result is false. If the second range
5841 is a subset it is the result. Otherwise, the range is from the start
5842 of the second to the end of the first. */
5847 else
5849 }
5852 {
5853 /* If they don't overlap, the result is the first range. If they are
5854 equal, the result is false. If the second range is a subset of the
5855 first, and the ranges begin at the same place, we go from just after
5856 the end of the second range to the end of the first. If the second
5857 range is not a subset of the first, or if it is a subset and both
5858 ranges end at the same place, the range starts at the start of the
5859 first range and ends just before the second range.
5860 Otherwise, we can't describe this as a single range. */
5866 {
5871 {
5872 /* We are in the weird situation where high0 > high1 but
5873 high1 has no successor. Punt. */
5875 }
5876 }
5878 {
5883 {
5884 /* low0 < low1 but low1 has no predecessor. Punt. */
5886 }
5887 }
5888 else
5890 }
5893 {
5894 /* If they don't overlap, the result is the second range. If the second
5895 is a subset of the first, the result is false. Otherwise,
5896 the range starts just after the first range and ends at the
5897 end of the second. */
5902 else
5903 {
5908 {
5909 /* high1 > high0 but high0 has no successor. Punt. */
5911 }
5912 }
5913 }
5915 else
5916 {
5917 /* The case where we are excluding both ranges. Here the complex case
5918 is if they don't overlap. In that case, the only time we have a
5919 range is if they are adjacent. If the second is a subset of the
5920 first, the result is the first. Otherwise, the range to exclude
5921 starts at the beginning of the first range and ends at the end of the
5922 second. */
5924 {
5929 else
5930 {
5931 /* Canonicalize - [min, x] into - [-, x]. */
5934 {
5937 GET_MODE_BITSIZE
5940 /* FALLTHROUGH */
5953 }
5955 /* Canonicalize - [x, max] into - [x, -]. */
5958 {
5961 GET_MODE_BITSIZE
5964 /* FALLTHROUGH */
5980 }
5982 /* The ranges might be also adjacent between the maximum and
5983 minimum values of the given type. For
5984 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
5985 return + [x + 1, y - 1]. */
5987 {
5994 }
5995 else
5997 }
5998 }
6001 else
6003 }
6007 }
6008 \f
6010 /* Subroutine of fold, looking inside expressions of the form
6011 A op B ? A : C, where (ARG00, COMP_CODE, ARG01), ARG1 and ARG2
6012 are the three operands of the COND_EXPR. This function is
6013 being used also to optimize A op B ? C : A, by reversing the
6014 comparison first.
6016 Return a folded expression whose code is not a COND_EXPR
6017 anymore, or NULL_TREE if no folding opportunity is found. */
6019 static tree
6023 {
6025 tree tem;
6030 /* If we have A op 0 ? A : -A, consider applying the following
6031 transformations:
6033 A == 0? A : -A same as -A
6034 A != 0? A : -A same as A
6035 A >= 0? A : -A same as abs (A)
6036 A > 0? A : -A same as abs (A)
6037 A <= 0? A : -A same as -abs (A)
6038 A < 0? A : -A same as -abs (A)
6040 None of these transformations work for modes with signed
6041 zeros. If A is +/-0, the first two transformations will
6042 change the sign of the result (from +0 to -0, or vice
6043 versa). The last four will fix the sign of the result,
6044 even though the original expressions could be positive or
6045 negative, depending on the sign of A.
6047 Note that all these transformations are correct if A is
6048 NaN, since the two alternatives (A and -A) are also NaNs. */
6055 /* In the case that A is of the form X-Y, '-A' (arg2) may
6056 have already been folded to Y-X, check for that. */
6064 {
6076 /* Fall through. */
6087 /* FALLTHRU */
6094 {
6095 /* A <= 0 ? A : -A for A INT_MIN is valid, but -abs(INT_MIN)
6096 is not, invokes UB both in abs and in the negation of it.
6097 So, use ABSU_EXPR instead. */
6102 }
6103 else
6104 {
6107 }
6111 }
6113 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
6114 A == 0 ? A : 0 is always 0 unless A is -0. Note that
6115 both transformations are correct when A is NaN: A != 0
6116 is then true, and A == 0 is false. */
6120 {
6125 }
6127 /* Try some transformations of A op B ? A : B.
6129 A == B? A : B same as B
6130 A != B? A : B same as A
6131 A >= B? A : B same as max (A, B)
6132 A > B? A : B same as max (B, A)
6133 A <= B? A : B same as min (A, B)
6134 A < B? A : B same as min (B, A)
6136 As above, these transformations don't work in the presence
6137 of signed zeros. For example, if A and B are zeros of
6138 opposite sign, the first two transformations will change
6139 the sign of the result. In the last four, the original
6140 expressions give different results for (A=+0, B=-0) and
6141 (A=-0, B=+0), but the transformed expressions do not.
6143 The first two transformations are correct if either A or B
6144 is a NaN. In the first transformation, the condition will
6145 be false, and B will indeed be chosen. In the case of the
6146 second transformation, the condition A != B will be true,
6147 and A will be chosen.
6149 The conversions to max() and min() are not correct if B is
6150 a number and A is not. The conditions in the original
6151 expressions will be false, so all four give B. The min()
6152 and max() versions would give a NaN instead. */
6155 /* Avoid these transformations if the COND_EXPR may be used
6156 as an lvalue in the C++ front-end. PR c++/19199. */
6157 && (in_gimple_form
6163 {
6169 {
6178 /* In C++ a ?: expression can be an lvalue, so put the
6179 operand which will be used if they are equal first
6180 so that we can convert this back to the
6181 corresponding COND_EXPR. */
6183 {
6191 }
6198 {
6206 }
6219 }
6220 }
6223 }
6226 \f
6227 #ifndef LOGICAL_OP_NON_SHORT_CIRCUIT
6228 #define LOGICAL_OP_NON_SHORT_CIRCUIT \
6229 (BRANCH_COST (optimize_function_for_speed_p (cfun), \
6230 false) >= 2)
6231 #endif
6233 /* EXP is some logical combination of boolean tests. See if we can
6234 merge it into some range test. Return the new tree if so. */
6236 static tree
6239 {
6253 /* If op0 is known true or false and this is a short-circuiting
6254 operation we must not merge with op1 since that makes side-effects
6255 unconditional. So special-case this. */
6262 /* If this is an OR operation, invert both sides; we will invert
6263 again at the end. */
6267 /* If both expressions are the same, if we can merge the ranges, and we
6268 can build the range test, return it or it inverted. If one of the
6269 ranges is always true or always false, consider it to be the same
6270 expression as the other. */
6278 {
6282 }
6284 /* On machines where the branch cost is expensive, if this is a
6285 short-circuited branch and the underlying object on both sides
6286 is the same, make a non-short-circuit operation. */
6289 logical_op_non_short_circuit
6296 {
6297 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
6298 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
6299 which cases we can't do this. */
6307 {
6316 {
6319 WARN_STRICT_OVERFLOW_COMPARISON);
6323 }
6324 }
6325 }
6328 }
6329 \f
6330 /* Subroutine for fold_truth_andor_1: C is an INTEGER_CST interpreted as a P
6331 bit value. Arrange things so the extra bits will be set to zero if and
6332 only if C is signed-extended to its full width. If MASK is nonzero,
6333 it is an INTEGER_CST that should be AND'ed with the extra bits. */
6335 static tree
6337 {
6340 tree temp;
6345 /* We work by getting just the sign bit into the low-order bit, then
6346 into the high-order bit, then sign-extend. We then XOR that value
6347 with C. */
6351 /* We must use a signed type in order to get an arithmetic right shift.
6352 However, we must also avoid introducing accidental overflows, so that
6353 a subsequent call to integer_zerop will work. Hence we must
6354 do the type conversion here. At this point, the constant is either
6355 zero or one, and the conversion to a signed type can never overflow.
6356 We could get an overflow if this conversion is done anywhere else. */
6365 /* If necessary, convert the type back to match the type of C. */
6370 }
6371 \f
6372 /* For an expression that has the form
6373 (A && B) || ~B
6374 or
6375 (A || B) && ~B,
6376 we can drop one of the inner expressions and simplify to
6377 A || ~B
6378 or
6379 A && ~B
6380 LOC is the location of the resulting expression. OP is the inner
6381 logical operation; the left-hand side in the examples above, while CMPOP
6382 is the right-hand side. RHS_ONLY is used to prevent us from accidentally
6383 removing a condition that guards another, as in
6384 (A != NULL && A->...) || A == NULL
6385 which we must not transform. If RHS_ONLY is true, only eliminate the
6386 right-most operand of the inner logical operation. */
6388 static tree
6391 {
6409 {
6412 {
6415 }
6416 }
6418 {
6421 {
6424 }
6425 }
6440 }
6442 /* Find ways of folding logical expressions of LHS and RHS:
6443 Try to merge two comparisons to the same innermost item.
6444 Look for range tests like "ch >= '0' && ch <= '9'".
6445 Look for combinations of simple terms on machines with expensive branches
6446 and evaluate the RHS unconditionally.
6448 For example, if we have p->a == 2 && p->b == 4 and we can make an
6449 object large enough to span both A and B, we can do this with a comparison
6450 against the object ANDed with the a mask.
6452 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
6453 operations to do this with one comparison.
6455 We check for both normal comparisons and the BIT_AND_EXPRs made this by
6456 function and the one above.
6458 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
6459 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
6461 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
6462 two operands.
6464 We return the simplified tree or 0 if no optimization is possible. */
6466 static tree
6469 {
6470 /* If this is the "or" of two comparisons, we can do something if
6471 the comparisons are NE_EXPR. If this is the "and", we can do something
6472 if the comparisons are EQ_EXPR. I.e.,
6473 (a->b == 2 && a->c == 4) can become (a->new == NEW).
6475 WANTED_CODE is this operation code. For single bit fields, we can
6476 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
6477 comparison for one-bit fields. */
6498 /* Start by getting the comparison codes. Fail if anything is volatile.
6499 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
6500 it were surrounded with a NE_EXPR. */
6509 {
6513 }
6516 {
6520 }
6531 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
6534 {
6537 {
6542 }
6545 {
6551 }
6552 }
6557 /* If the RHS can be evaluated unconditionally and its operands are
6558 simple, it wins to evaluate the RHS unconditionally on machines
6559 with expensive branches. In this case, this isn't a comparison
6560 that can be merged. */
6567 {
6568 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
6579 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
6589 }
6591 /* See if the comparisons can be merged. Then get all the parameters for
6592 each side. */
6617 /* It must be true that the inner operation on the lhs of each
6618 comparison must be the same if we are to be able to do anything.
6619 Then see if we have constants. If not, the same must be true for
6620 the rhs's. */
6629 {
6632 }
6637 else
6640 /* If either comparison code is not correct for our logical operation,
6641 fail. However, we can convert a one-bit comparison against zero into
6642 the opposite comparison against that bit being set in the field. */
6646 {
6648 {
6649 /* Make the left operand unsigned, since we are only interested
6650 in the value of one bit. Otherwise we are doing the wrong
6651 thing below. */
6654 }
6655 else
6657 }
6659 /* This is analogous to the code for l_const above. */
6661 {
6663 {
6666 }
6667 else
6669 }
6671 /* See if we can find a mode that contains both fields being compared on
6672 the left. If we can't, fail. Otherwise, update all constants and masks
6673 to be relative to a field of that size. */
6687 {
6690 }
6700 {
6709 {
6713 }
6714 }
6716 {
6725 {
6729 }
6730 }
6732 /* If the right sides are not constant, do the same for it. Also,
6733 disallow this optimization if a size, signedness or storage order
6734 mismatch occurs between the left and right sides. */
6736 {
6740 /* Make sure the two fields on the right
6741 correspond to the left without being swapped. */
6758 {
6761 }
6772 /* Make a mask that corresponds to both fields being compared.
6773 Do this for both items being compared. If the operands are the
6774 same size and the bits being compared are in the same position
6775 then we can do this by masking both and comparing the masked
6776 results. */
6783 {
6797 }
6799 /* There is still another way we can do something: If both pairs of
6800 fields being compared are adjacent, we may be able to make a wider
6801 field containing them both.
6803 Note that we still must mask the lhs/rhs expressions. Furthermore,
6804 the mask must be shifted to account for the shift done by
6805 make_bit_field_ref. */
6814 {
6815 tree type;
6833 /* Convert to the smaller type before masking out unwanted bits. */
6836 {
6838 {
6842 }
6844 {
6848 }
6849 }
6858 }
6861 }
6863 /* Handle the case of comparisons with constants. If there is something in
6864 common between the masks, those bits of the constants must be the same.
6865 If not, the condition is always false. Test for this to avoid generating
6866 incorrect code below. */
6871 {
6873 {
6876 }
6877 else
6878 {
6881 }
6882 }
6887 /* Construct the expression we will return. First get the component
6888 reference we will make. Unless the mask is all ones the width of
6889 that field, perform the mask operation. Then compare with the
6890 merged constant. */
6901 }
6902 \f
6903 /* T is an integer expression that is being multiplied, divided, or taken a
6904 modulus (CODE says which and what kind of divide or modulus) by a
6905 constant C. See if we can eliminate that operation by folding it with
6906 other operations already in T. WIDE_TYPE, if non-null, is a type that
6907 should be used for the computation if wider than our type.
6909 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
6910 (X * 2) + (Y * 4). We must, however, be assured that either the original
6911 expression would not overflow or that overflow is undefined for the type
6912 in the language in question.
6914 If we return a non-null expression, it is an equivalent form of the
6915 original computation, but need not be in the original type.
6917 We set *STRICT_OVERFLOW_P to true if the return values depends on
6918 signed overflow being undefined. Otherwise we do not change
6919 *STRICT_OVERFLOW_P. */
6921 static tree
6924 {
6925 /* To avoid exponential search depth, refuse to allow recursion past
6926 three levels. Beyond that (1) it's highly unlikely that we'll find
6927 something interesting and (2) we've probably processed it before
6928 when we built the inner expression. */
6931 tree ret;
6936 depth++;
6938 depth--;
6941 }
6943 static tree
6946 {
6951 {
6954 {
6957 }
6961 }
6967 /* Don't deal with constants of zero here; they confuse the code below. */
6977 /* Note that we need not handle conditional operations here since fold
6978 already handles those cases. So just do arithmetic here. */
6980 {
6982 /* For a constant, we can always simplify if we are a multiply
6983 or (for divide and modulus) if it is a multiple of our constant. */
6987 {
6990 /* If the multiplication overflowed, we lost information on it.
6991 See PR68142 and PR69845. */
6995 }
7001 /* If op0 is an expression ... */
7007 /* ... and has wrapping overflow, and its type is smaller
7008 than ctype, then we cannot pass through as widening. */
7012 /* ... or this is a truncation (t is narrower than op0),
7013 then we cannot pass through this narrowing. */
7016 /* ... or signedness changes for division or modulus,
7017 then we cannot pass through this conversion. */
7021 /* ... or has undefined overflow while the converted to
7022 type has not, we cannot do the operation in the inner type
7023 as that would introduce undefined overflow. */
7028 /* Pass the constant down and see if we can make a simplification. If
7029 we can, replace this expression with the inner simplification for
7030 possible later conversion to our or some other type. */
7041 /* If widening the type changes it from signed to unsigned, then we
7042 must avoid building ABS_EXPR itself as unsigned. */
7044 {
7048 {
7051 }
7053 }
7054 /* If the constant is negative, we cannot simplify this. */
7057 /* FALLTHROUGH */
7059 /* For division and modulus, type can't be unsigned, as e.g.
7060 (-(x / 2U)) / 2U isn't equal to -((x / 2U) / 2U) for x >= 2.
7061 For signed types, even with wrapping overflow, this is fine. */
7070 /* If widening the type changes the signedness, then we can't perform
7071 this optimization as that changes the result. */
7075 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
7081 {
7088 }
7092 /* If the second operand is constant, this is a multiplication
7093 or floor division, by a power of two, so we can treat it that
7094 way unless the multiplier or divisor overflows. Signed
7095 left-shift overflow is implementation-defined rather than
7096 undefined in C90, so do not convert signed left shift into
7097 multiplication. */
7100 /* const_binop may not detect overflow correctly,
7101 so check for it explicitly here. */
7110 ctype,
7112 t1),
7117 /* See if we can eliminate the operation on both sides. If we can, we
7118 can return a new PLUS or MINUS. If we can't, the only remaining
7119 cases where we can do anything are if the second operand is a
7120 constant. */
7127 /* If not multiplication, we can only do this if both operands
7128 are divisible by c. */
7131 {
7136 }
7138 /* If this was a subtraction, negate OP1 and set it to be an addition.
7139 This simplifies the logic below. */
7141 {
7143 /* If OP1 was not easily negatable, the constant may be OP0. */
7145 {
7148 }
7149 }
7154 /* If either OP1 or C are negative, this optimization is not safe for
7155 some of the division and remainder types while for others we need
7156 to change the code. */
7158 {
7166 }
7168 /* If it's a multiply or a division/modulus operation of a multiple
7169 of our constant, do the operation and verify it doesn't overflow. */
7173 {
7176 /* We allow the constant to overflow with wrapping semantics. */
7180 }
7181 else
7184 /* If we have an unsigned type, we cannot widen the operation since it
7185 will change the result if the original computation overflowed. */
7189 /* The last case is if we are a multiply. In that case, we can
7190 apply the distributive law to commute the multiply and addition
7191 if the multiplication of the constants doesn't overflow
7192 and overflow is defined. With undefined overflow
7193 op0 * c might overflow, while (op0 + orig_op1) * c doesn't.
7194 But fold_plusminus_mult_expr would factor back any power-of-two
7195 value so do not distribute in the first place in this case. */
7203 op1);
7208 /* We have a special case here if we are doing something like
7209 (C * 8) % 4 since we know that's zero. */
7212 /* If the multiplication can overflow we cannot optimize this. */
7217 {
7220 }
7222 /* ... fall through ... */
7226 /* If we can extract our operation from the LHS, do so and return a
7227 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
7228 do something only if the second operand is a constant. */
7244 /* If these are the same operation types, we can associate them
7245 assuming no overflow. */
7247 {
7262 }
7264 /* If these operations "cancel" each other, we have the main
7265 optimizations of this pass, which occur when either constant is a
7266 multiple of the other, in which case we replace this with either an
7267 operation or CODE or TCODE.
7269 If we have an unsigned type, we cannot do this since it will change
7270 the result if the original computation overflowed. */
7278 {
7281 {
7287 }
7290 {
7296 }
7297 }
7302 }
7305 }
7306 \f
7307 /* Return a node which has the indicated constant VALUE (either 0 or
7308 1 for scalars or {-1,-1,..} or {0,0,...} for vectors),
7309 and is of the indicated TYPE. */
7311 tree
7313 {
7322 else
7324 }
7327 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
7328 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
7329 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
7330 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
7331 COND is the first argument to CODE; otherwise (as in the example
7332 given here), it is the second argument. TYPE is the type of the
7333 original expression. Return NULL_TREE if no simplification is
7334 possible. */
7336 static tree
7341 {
7349 /* Do not move possibly trapping operations into the conditional as this
7350 pessimizes code and causes gimplification issues when applied late. */
7358 {
7362 /* If this operand throws an expression, then it does not make
7363 sense to try to perform a logical or arithmetic operation
7364 involving it. */
7369 }
7372 {
7377 }
7378 else
7379 /* Detect the case of mixing vector and scalar types - bail out. */
7385 /* This transformation is only worthwhile if we don't have to wrap ARG
7386 in a SAVE_EXPR and the operation can be simplified without recursing
7387 on at least one of the branches once its pushed inside the COND_EXPR. */
7396 {
7400 else
7402 }
7404 {
7408 else
7410 }
7412 /* Check that we have simplified at least one of the branches. */
7417 }
7419 \f
7420 /* Subroutine of fold() that checks for the addition of ARG +/- 0.0.
7422 If !NEGATE, return true if ZERO_ARG is +/-0.0 and, for all ARG of
7423 type TYPE, ARG + ZERO_ARG is the same as ARG. If NEGATE, return true
7424 if ARG - ZERO_ARG is the same as X.
7426 If ARG is NULL, check for any value of type TYPE.
7428 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
7429 and finite. The problematic cases are when X is zero, and its mode
7430 has signed zeros. In the case of rounding towards -infinity,
7431 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
7432 modes, X + 0 is not the same as X because -0 + 0 is 0. */
7434 bool
7437 {
7441 /* Don't allow the fold with -fsignaling-nans. */
7445 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
7449 /* There is no case that is safe for all rounding modes. */
7453 /* In a vector or complex, we would need to check the sign of all zeros. */
7459 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
7463 /* The mode has signed zeros, and we have to honor their sign.
7464 In this situation, there are only two cases we can return true for.
7465 (i) X - 0 is the same as X with default rounding.
7466 (ii) X + 0 is X when X can't possibly be -0.0. */
7468 }
7470 /* Subroutine of match.pd that optimizes comparisons of a division by
7471 a nonzero integer constant against an integer constant, i.e.
7472 X/C1 op C2.
7474 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
7475 GE_EXPR or LE_EXPR. ARG01 and ARG1 must be a INTEGER_CST. */
7477 enum tree_code
7480 {
7485 /* We have to do this the hard way to detect unsigned overflow.
7486 prod = int_const_binop (MULT_EXPR, c1, c2); */
7492 {
7496 /* Likewise *hi = int_const_binop (PLUS_EXPR, prod, tmp). */
7499 }
7501 {
7504 {
7523 }
7524 }
7525 else
7526 {
7527 /* A negative divisor reverses the relational operators. */
7532 {
7551 }
7552 }
7565 }
7567 /* Test whether it is preferable to swap two operands, ARG0 and
7568 ARG1, for example because ARG0 is an integer constant and ARG1
7569 isn't. */
7571 bool
7573 {
7587 /* It is preferable to swap two SSA_NAME to ensure a canonical form
7588 for commutative and comparison operators. Ensuring a canonical
7589 form allows the optimizers to find additional redundancies without
7590 having to explicitly check for both orderings. */
7596 /* Put SSA_NAMEs last. */
7602 /* Put variables last. */
7609 }
7612 /* Fold A < X && A + 1 > Y to A < X && A >= Y. Normally A + 1 > Y
7613 means A >= Y && A != MAX, but in this case we know that
7614 A < X <= MAX. INEQ is A + 1 > Y, BOUND is A < X. */
7616 static tree
7618 {
7625 else
7634 {
7637 }
7639 {
7642 }
7643 else
7650 {
7651 /* Convert the pointer types into integer before taking the difference. */
7655 }
7656 else
7663 }
7665 /* Fold a sum or difference of at least one multiplication.
7666 Returns the folded tree or NULL if no simplification could be made. */
7668 static tree
7671 {
7675 /* (A * C) +- (B * C) -> (A+-B) * C.
7676 (A * C) +- A -> A * (C+-1).
7677 We are most concerned about the case where C is a constant,
7678 but other combinations show up during loop reduction. Since
7679 it is not difficult, try all four possibilities. */
7682 {
7685 }
7687 {
7690 }
7691 else
7692 {
7693 /* We cannot generate constant 1 for fract. */
7698 }
7700 {
7703 }
7705 {
7707 /* As we canonicalize A - 2 to A + -2 get rid of that sign for
7708 the purpose of this canonicalization. */
7712 {
7715 }
7716 else
7718 }
7719 else
7720 {
7721 /* We cannot generate constant 1 for fract. */
7726 }
7729 /* Prefer factoring a common non-constant. */
7739 /* No identical multiplicands; see if we can find a common
7740 power-of-two factor in non-power-of-two multiplies. This
7741 can help in multi-dimensional array access. */
7743 {
7746 HOST_WIDE_INT tmp;
7748 tree maybe_same;
7750 /* Move min of absolute values to int11. */
7752 {
7757 }
7758 else
7765 /* The remainder should not be a constant, otherwise we
7766 end up folding i * 4 + 2 to (i * 2 + 1) * 2 which has
7767 increased the number of multiplications necessary. */
7769 {
7777 }
7778 }
7785 /* We are neither factoring zero nor minus one. */
7793 /* Same may be zero and thus the operation 'code' may overflow. Likewise
7794 same may be minus one and thus the multiplication may overflow. Perform
7795 the sum operation in an unsigned type. */
7800 /* If the sum evaluated to a constant that is not -INF the multiplication
7801 cannot overflow. */
7808 /* Do not resort to unsigned multiplication because
7809 we lose the no-overflow property of the expression. */
7811 }
7813 /* Subroutine of native_encode_expr. Encode the INTEGER_CST
7814 specified by EXPR into the buffer PTR of length LEN bytes.
7815 Return the number of bytes placed in the buffer, or zero
7816 upon failure. */
7818 static int
7820 {
7824 {
7830 {
7832 /* More work is needed when adding _BitInt support to PDP endian
7833 if limb is smaller than word, or if _BitInt limb ordering doesn't
7834 match target endianity here. */
7839 }
7840 else
7842 }
7843 else
7854 /* Dry run. */
7860 {
7862 /* Extend EXPR according to TYPE_SIGN if the precision isn't a whole
7863 number of bytes. */
7867 {
7874 else
7876 }
7877 else
7881 }
7883 }
7886 /* Subroutine of native_encode_expr. Encode the FIXED_CST
7887 specified by EXPR into the buffer PTR of length LEN bytes.
7888 Return the number of bytes placed in the buffer, or zero
7889 upon failure. */
7891 static int
7893 {
7897 FIXED_VALUE_TYPE value;
7912 }
7915 /* Subroutine of native_encode_expr. Encode the REAL_CST
7916 specified by EXPR into the buffer PTR of length LEN bytes.
7917 Return the number of bytes placed in the buffer, or zero
7918 upon failure. */
7920 static int
7922 {
7928 /* There are always 32 bits in each long, no matter the size of
7929 the hosts long. We handle floating point representations with
7930 up to 192 bits. */
7939 /* Dry run. */
7948 {
7953 {
7960 else
7962 }
7963 else
7964 {
7967 {
7968 /* Reverse bytes within each long, or within the entire float
7969 if it's smaller than a long (for HFmode). */
7972 }
7973 }
7978 }
7980 }
7982 /* Subroutine of native_encode_expr. Encode the COMPLEX_CST
7983 specified by EXPR into the buffer PTR of length LEN bytes.
7984 Return the number of bytes placed in the buffer, or zero
7985 upon failure. */
7987 static int
7989 {
7991 tree part;
8005 }
8007 /* Like native_encode_vector, but only encode the first COUNT elements.
8008 The other arguments are as for native_encode_vector. */
8010 static int
8013 {
8017 {
8018 /* This is the only case in which elements can be smaller than a byte.
8019 Element 0 is always in the lsb of the containing byte. */
8028 /* Zero the buffer and then set bits later where necessary. */
8037 {
8043 {
8046 }
8047 }
8049 }
8054 {
8056 {
8059 }
8070 }
8072 }
8074 /* Subroutine of native_encode_expr. Encode the VECTOR_CST
8075 specified by EXPR into the buffer PTR of length LEN bytes.
8076 Return the number of bytes placed in the buffer, or zero
8077 upon failure. */
8079 static int
8081 {
8086 }
8089 /* Subroutine of native_encode_expr. Encode the STRING_CST
8090 specified by EXPR into the buffer PTR of length LEN bytes.
8091 Return the number of bytes placed in the buffer, or zero
8092 upon failure. */
8094 static int
8096 {
8099 /* Wide-char strings are encoded in target byte-order so native
8100 encoding them is trivial. */
8115 else
8116 {
8119 {
8122 }
8124 }
8126 }
8129 /* Subroutine of fold_view_convert_expr. Encode the INTEGER_CST, REAL_CST,
8130 FIXED_CST, COMPLEX_CST, STRING_CST, or VECTOR_CST specified by EXPR into
8131 the buffer PTR of size LEN bytes. If PTR is NULL, don't actually store
8132 anything, just do a dry run. Fail either if OFF is -1 and LEN isn't
8133 sufficient to encode the entire EXPR, or if OFF is out of bounds.
8134 Otherwise, start at byte offset OFF and encode at most LEN bytes.
8135 Return the number of bytes placed in the buffer, or zero upon failure. */
8137 int
8139 {
8140 /* We don't support starting at negative offset and -1 is special. */
8145 {
8166 }
8167 }
8169 /* Try to find a type whose byte size is smaller or equal to LEN bytes larger
8170 or equal to FIELDSIZE bytes, with underlying mode precision/size multiple
8171 of BITS_PER_UNIT. As native_{interpret,encode}_int works in term of
8172 machine modes, we can't just use build_nonstandard_integer_type. */
8174 tree
8176 {
8177 machine_mode mode;
8179 {
8186 {
8190 }
8191 }
8197 {
8205 }
8208 }
8210 /* Similar to native_encode_expr, but also handle CONSTRUCTORs, VCEs,
8211 NON_LVALUE_EXPRs and nops. If MASK is non-NULL (then PTR has
8212 to be non-NULL and OFF zero), then in addition to filling the
8213 bytes pointed by PTR with the value also clear any bits pointed
8214 by MASK that are known to be initialized, keep them as is for
8215 e.g. uninitialized padding bits or uninitialized fields. */
8217 int
8220 {
8223 /* We don't support starting at negative offset and -1 is special. */
8231 {
8235 mask);
8250 {
8251 tree min_index;
8269 {
8274 {
8277 }
8282 else
8286 {
8290 offset_int wpos
8298 offset_int wcount
8305 }
8307 {
8310 offset_int wpos
8318 }
8321 {
8323 {
8334 }
8336 {
8340 }
8341 }
8345 do
8346 {
8351 {
8353 {
8356 fieldsize);
8359 }
8361 ptr
8364 fieldsize,
8367 mask
8371 else
8372 {
8375 }
8376 }
8379 {
8380 /* Partial overlap. */
8386 {
8390 fieldsize);
8391 }
8392 else
8393 {
8397 }
8400 }
8402 }
8404 }
8406 }
8409 {
8419 {
8425 {
8428 }
8431 {
8440 }
8444 else
8448 {
8449 tree fld;
8451 {
8464 }
8466 {
8470 }
8473 {
8474 cnt--;
8480 }
8481 }
8486 {
8499 {
8504 }
8505 }
8506 else
8507 {
8512 }
8516 /* Prepare to deal with integral bit-fields and filter out other
8517 bit-fields that do not start and end on a byte boundary. */
8519 {
8524 {
8530 }
8536 }
8546 {
8547 /* FIXME: Handle PDP endian. */
8558 {
8561 }
8562 else
8563 {
8571 else
8572 {
8575 }
8576 }
8586 else
8599 /* If the bitfield does not start at byte boundary, handle
8600 the partial byte at the start. */
8603 {
8605 {
8610 {
8613 else
8615 }
8616 }
8617 else
8618 {
8623 {
8626 else
8630 }
8631 }
8632 }
8633 /* If the bitfield does not end at byte boundary, handle
8634 the partial byte at the end. */
8638 {
8640 {
8647 }
8648 else
8649 {
8656 }
8657 }
8661 {
8666 }
8667 else
8668 {
8669 /* Partial overlap. */
8673 {
8676 }
8680 }
8682 }
8687 {
8690 {
8693 {
8697 }
8700 }
8703 fldsize,
8713 }
8714 else
8715 {
8716 /* Partial overlap. */
8722 {
8726 fieldsize);
8727 }
8728 else
8729 {
8733 }
8736 }
8737 }
8739 }
8741 }
8742 }
8745 /* Subroutine of native_interpret_expr. Interpret the contents of
8746 the buffer PTR of length LEN as an INTEGER_CST of type TYPE.
8747 If the buffer cannot be interpreted, return NULL_TREE. */
8749 static tree
8751 {
8754 {
8760 {
8762 /* More work is needed when adding _BitInt support to PDP endian
8763 if limb is smaller than word, or if _BitInt limb ordering doesn't
8764 match target endianity here. */
8769 }
8770 else
8772 }
8773 else
8782 }
8785 /* Subroutine of native_interpret_expr. Interpret the contents of
8786 the buffer PTR of length LEN as a FIXED_CST of type TYPE.
8787 If the buffer cannot be interpreted, return NULL_TREE. */
8789 static tree
8791 {
8794 double_int result;
8795 FIXED_VALUE_TYPE fixed_value;
8805 }
8808 /* Subroutine of native_interpret_expr. Interpret the contents of
8809 the buffer PTR of length LEN as a REAL_CST of type TYPE.
8810 If the buffer cannot be interpreted, return NULL_TREE. */
8812 tree
8814 {
8818 /* There are always 32 bits in each long, no matter the size of
8819 the hosts long. We handle floating point representations with
8820 up to 192 bits. */
8821 REAL_VALUE_TYPE r;
8831 {
8832 /* Both OFFSET and BYTE index within a long;
8833 bitpos indexes the whole float. */
8836 {
8843 else
8845 }
8846 else
8847 {
8850 {
8851 /* Reverse bytes within each long, or within the entire float
8852 if it's smaller than a long (for HFmode). */
8855 }
8856 }
8860 }
8864 }
8867 /* Subroutine of native_interpret_expr. Interpret the contents of
8868 the buffer PTR of length LEN as a COMPLEX_CST of type TYPE.
8869 If the buffer cannot be interpreted, return NULL_TREE. */
8871 static tree
8873 {
8888 }
8890 /* Read a vector of type TYPE from the target memory image given by BYTES,
8891 which contains LEN bytes. The vector is known to be encodable using
8892 NPATTERNS interleaved patterns with NELTS_PER_PATTERN elements each.
8894 Return the vector on success, otherwise return null. */
8896 static tree
8900 {
8904 {
8905 /* This is the only case in which elements can be smaller than a byte.
8906 Element 0 is always in the lsb of the containing byte. */
8913 {
8920 }
8922 }
8930 {
8936 }
8938 }
8940 /* Subroutine of native_interpret_expr. Interpret the contents of
8941 the buffer PTR of length LEN as a VECTOR_CST of type TYPE.
8942 If the buffer cannot be interpreted, return NULL_TREE. */
8944 static tree
8946 {
8955 }
8958 /* Subroutine of fold_view_convert_expr. Interpret the contents of
8959 the buffer PTR of length LEN as a constant of type TYPE. For
8960 INTEGRAL_TYPE_P we return an INTEGER_CST, for SCALAR_FLOAT_TYPE_P
8961 we return a REAL_CST, etc... If the buffer cannot be interpreted,
8962 return NULL_TREE. */
8964 tree
8966 {
8968 {
8980 {
8981 /* For floating point values in composite modes, punt if this
8982 folding doesn't preserve bit representation. As the mode doesn't
8983 have fixed precision while GCC pretends it does, there could be
8984 valid values that GCC can't really represent accurately.
8985 See PR95450. Even for other modes, e.g. x86 XFmode can have some
8986 bit combinationations which GCC doesn't preserve. */
8996 }
9010 }
9011 }
9013 /* Returns true if we can interpret the contents of a native encoding
9014 as TYPE. */
9016 bool
9018 {
9020 {
9034 }
9035 }
9037 /* Attempt to interpret aggregate of TYPE from bytes encoded in target
9038 byte order at PTR + OFF with LEN bytes. Does not handle unions. */
9040 tree
9043 {
9046 {
9053 {
9057 }
9062 {
9067 {
9072 }
9076 eltsz);
9080 }
9082 }
9086 {
9095 {
9098 {
9099 poly_int64 bitoffset;
9104 else
9114 }
9115 else
9116 {
9134 HOST_WIDE_INT rpos;
9137 else
9138 {
9141 }
9150 }
9151 }
9154 {
9164 }
9168 {
9173 }
9180 {
9184 /* FIXME: Figure out how to handle PDP endian bitfields. */
9190 else
9194 }
9196 }
9198 }
9200 /* Routines for manipulation of native_encode_expr encoded data if the encoded
9201 or extracted constant positions and/or sizes aren't byte aligned. */
9203 /* Shift left the bytes in PTR of SZ elements by AMNT bits, carrying over the
9204 bits between adjacent elements. AMNT should be within
9205 [0, BITS_PER_UNIT).
9206 Example, AMNT = 2:
9207 00011111|11100000 << 2 = 01111111|10000000
9208 PTR[1] | PTR[0] PTR[1] | PTR[0]. */
9210 void
9213 {
9222 {
9228 {
9231 }
9232 }
9233 }
9235 /* Like shift_bytes_in_array_left but for big-endian.
9236 Shift right the bytes in PTR of SZ elements by AMNT bits, carrying over the
9237 bits between adjacent elements. AMNT should be within
9238 [0, BITS_PER_UNIT).
9239 Example, AMNT = 2:
9240 00011111|11100000 >> 2 = 00000111|11111000
9241 PTR[0] | PTR[1] PTR[0] | PTR[1]. */
9243 void
9246 {
9254 {
9261 }
9262 }
9264 /* Try to view-convert VECTOR_CST EXPR to VECTOR_TYPE TYPE by operating
9265 directly on the VECTOR_CST encoding, in a way that works for variable-
9266 length vectors. Return the resulting VECTOR_CST on success or null
9267 on failure. */
9269 static tree
9271 {
9283 /* We can only preserve the semantics of a stepped pattern if the new
9284 vector element is an integer of the same size. */
9289 /* The number of bits needed to encode one element from every pattern
9290 of the original vector. */
9291 unsigned int expr_sequence_bits
9294 /* The number of bits needed to encode one element from every pattern
9295 of the result. */
9296 unsigned int type_sequence_bits
9299 /* Don't try to read more bytes than are available, which can happen
9300 for constant-sized vectors if TYPE has larger elements than EXPR_TYPE.
9301 The general VIEW_CONVERT handling can cope with that case, so there's
9302 no point complicating things here. */
9305 BITS_PER_UNIT);
9310 /* Get enough bytes of EXPR to form the new encoding. */
9318 /* Reencode the bytes as TYPE. */
9322 }
9324 /* Fold a VIEW_CONVERT_EXPR of a constant expression EXPR to type
9325 TYPE at compile-time. If we're unable to perform the conversion
9326 return NULL_TREE. */
9328 static tree
9330 {
9334 HOST_WIDE_INT l;
9336 /* Check that the host and target are sane. */
9347 {
9350 }
9351 else
9352 {
9355 }
9361 }
9363 /* Build an expression for the address of T. Folds away INDIRECT_REF
9364 to avoid confusing the gimplify process. */
9366 tree
9368 {
9369 /* The size of the object is not relevant when talking about its address. */
9374 {
9379 }
9382 {
9387 }
9394 {
9399 }
9400 else
9404 }
9406 /* Build an expression for the address of T. */
9408 tree
9410 {
9414 }
9416 /* Fold a unary expression of code CODE and type TYPE with operand
9417 OP0. Return the folded expression if folding is successful.
9418 Otherwise, return NULL_TREE. */
9420 tree
9422 {
9423 tree tem;
9424 tree arg0;
9432 {
9435 {
9436 /* Don't use STRIP_NOPS, because signedness of argument type
9437 matters. */
9439 }
9440 else
9441 {
9442 /* Strip any conversions that don't change the mode. This
9443 is safe for every expression, except for a comparison
9444 expression because its signedness is derived from its
9445 operands.
9447 Note that this is done as an internal manipulation within
9448 the constant folder, in order to find the simplest
9449 representation of the arguments so that their form can be
9450 studied. In any cases, the appropriate type conversions
9451 should be put back in the tree that will get out of the
9452 constant folder. */
9454 }
9457 {
9460 {
9464 }
9465 }
9466 }
9473 {
9480 {
9494 /* If this was a conversion, and all we did was to move into
9495 inside the COND_EXPR, bring it back out. But leave it if
9496 it is a conversion from integer to integer and the
9497 result precision is no wider than a word since such a
9498 conversion is cheap and may be optimized away by combine,
9499 while it couldn't if it were outside the COND_EXPR. Then return
9500 so we don't get into an infinite recursion loop taking the
9501 conversion out and then back in. */
9513 && (INTEGRAL_TYPE_P
9526 }
9527 }
9530 {
9536 CASE_CONVERT:
9540 {
9541 /* If we have (type) (a CMP b) and type is an integral type, return
9542 new expression involving the new type. Canonicalize
9543 (type) (a CMP b) to (a CMP b) ? (type) true : (type) false for
9544 non-integral type.
9545 Do not fold the result as that would not simplify further, also
9546 folding again results in recursions. */
9556 }
9558 /* Handle (T *)&A.B.C for A being of type T and B and C
9559 living at offset zero. This occurs frequently in
9560 C++ upcasting and then accessing the base. */
9564 {
9566 tree offset;
9567 machine_mode mode;
9569 tree base
9573 /* If the reference was to a (constant) zero offset, we can use
9574 the address of the base if it has the same base type
9575 as the result type and the pointer type is unqualified. */
9583 }
9587 /* Detect assigning a bitfield. */
9589 && DECL_BIT_FIELD
9591 {
9592 /* Don't leave an assignment inside a conversion
9593 unless assigning a bitfield. */
9595 /* First do the assignment, then return converted constant. */
9600 }
9602 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
9603 constants (if x has signed type, the sign bit cannot be set
9604 in c). This folds extension into the BIT_AND_EXPR.
9605 ??? We don't do it for BOOLEAN_TYPE or ENUMERAL_TYPE because they
9606 very likely don't have maximal range for their precision and this
9607 transformation effectively doesn't preserve non-maximal ranges. */
9611 {
9622 <= HOST_BITS_PER_WIDE_INT
9624 {
9628 cst &= HOST_WIDE_INT_M1U
9632 && !flag_syntax_only
9635 {
9639 }
9640 }
9642 {
9652 }
9653 }
9655 /* Convert (T1)(X p+ Y) into ((T1)X p+ Y), for pointer type, when the new
9656 cast (T1)X will fold away. We assume that this happens when X itself
9657 is a cast. */
9661 {
9665 /* If -fsanitize=alignment, avoid this optimization in GENERIC
9666 when the pointed type needs higher alignment than
9667 the p+ first operand's pointed type. */
9674 /* Similarly, avoid this optimization in GENERIC for -fsanitize=null
9675 when type is a reference type and arg00's type is not,
9676 because arg00 could be validly nullptr and if arg01 doesn't return,
9677 we don't want false positive binding of reference to nullptr. */
9679 && !in_gimple_form
9686 }
9688 /* Convert (T1)(~(T2)X) into ~(T1)X if T1 and T2 are integral types
9689 of the same precision, and X is an integer type not narrower than
9690 types T1 or T2, i.e. the cast (T2)X isn't an extension. */
9696 {
9702 }
9704 /* Convert (T1)(X * Y) into (T1)X * (T1)Y if T1 is narrower than the
9705 type of X and Y (integer types only). */
9712 {
9713 /* Be careful not to introduce new overflows. */
9714 tree mult_type;
9717 else
9721 {
9728 }
9729 }
9735 {
9742 }
9753 /* Convert fabs((double)float) into (double)fabsf(float). */
9756 {
9762 targ0));
9763 }
9767 /* Convert ~(X ^ Y) to ~X ^ Y or X ^ ~Y if ~X or ~Y simplify. */
9786 /* Note that the operand of this must be an int
9787 and its values must be 0 or 1.
9788 ("true" is a fixed value perhaps depending on the language,
9789 but we don't handle values other than 1 correctly yet.) */
9796 /* Fold *&X to X if X is an lvalue. */
9798 {
9805 }
9811 }
9814 /* If the operation was a conversion do _not_ mark a resulting constant
9815 with TREE_OVERFLOW if the original constant was not. These conversions
9816 have implementation defined behavior and retaining the TREE_OVERFLOW
9817 flag here would confuse later passes such as VRP. */
9818 tree
9821 {
9830 }
9832 /* Fold a binary bitwise/truth expression of code CODE and type TYPE with
9833 operands OP0 and OP1. LOC is the location of the resulting expression.
9834 ARG0 and ARG1 are the NOP_STRIPed results of OP0 and OP1.
9835 Return the folded expression if folding is successful. Otherwise,
9836 return NULL_TREE. */
9837 static tree
9840 {
9841 tree tem;
9843 /* We only do these simplifications if we are optimizing. */
9847 /* Check for things like (A || B) && (A || C). We can convert this
9848 to A || (B && C). Note that either operator can be any of the four
9849 truth and/or operations and the transformation will still be
9850 valid. Also note that we only care about order for the
9851 ANDIF and ORIF operators. If B contains side effects, this
9852 might change the truth-value of A. */
9859 {
9879 /* This case if tricky because we must either have commutative
9880 operators or else A10 must not have side-effects. */
9886 a01);
9887 }
9889 /* See if we can build a range comparison. */
9895 {
9899 }
9903 {
9907 }
9909 /* Check for the possibility of merging component references. If our
9910 lhs is another similar operation, try to merge its rhs with our
9911 rhs. Then try to merge our lhs and rhs. */
9922 logical_op_non_short_circuit
9930 {
9937 /* Transform ((A AND-IF B) AND[-IF] C) into (A AND-IF (B AND C)),
9938 or ((A OR-IF B) OR[-IF] C) into (A OR-IF (B OR C))
9939 We don't want to pack more than two leafs to a non-IF AND/OR
9940 expression.
9941 If tree-code of left-hand operand isn't an AND/OR-IF code and not
9942 equal to IF-CODE, then we don't want to add right-hand operand.
9943 If the inner right-hand side of left-hand operand has
9944 side-effects, or isn't simple, then we can't add to it,
9945 as otherwise we might destroy if-sequence. */
9948 /* Needed for sequence points to handle trappings, and
9949 side-effects. */
9951 {
9953 arg1);
9955 tem);
9956 }
9957 /* Same as above but for (A AND[-IF] (B AND-IF C)) -> ((A AND B) AND-IF C),
9958 or (A OR[-IF] (B OR-IF C) -> ((A OR B) OR-IF C). */
9961 /* Needed for sequence points to handle trappings, and
9962 side-effects. */
9964 {
9969 }
9970 /* Transform (A AND-IF B) into (A AND B), or (A OR-IF B)
9971 into (A OR B).
9972 For sequence point consistancy, we need to check for trapping,
9973 and side-effects. */
9977 }
9980 }
9982 /* Helper that tries to canonicalize the comparison ARG0 CODE ARG1
9983 by changing CODE to reduce the magnitude of constants involved in
9984 ARG0 of the comparison.
9985 Returns a canonicalized comparison tree if a simplification was
9986 possible, otherwise returns NULL_TREE.
9987 Set *STRICT_OVERFLOW_P to true if the canonicalization is only
9988 valid if signed overflow is undefined. */
9990 static tree
9994 {
9999 /* Match A +- CST code arg1. We can change this only if overflow
10000 is undefined. */
10003 /* In principle pointers also have undefined overflow behavior,
10004 but that causes problems elsewhere. */
10011 /* Identify the constant in arg0 and its sign. */
10015 /* Overflowed constants and zero will cause problems. */
10020 /* See if we can reduce the magnitude of the constant in
10021 arg0 by changing the comparison code. */
10022 /* A - CST < arg1 -> A - CST-1 <= arg1. */
10026 /* A + CST > arg1 -> A + CST-1 >= arg1. */
10030 /* A + CST <= arg1 -> A + CST-1 < arg1. */
10034 /* A - CST >= arg1 -> A - CST-1 > arg1. */
10038 else
10042 /* Now build the constant reduced in magnitude. But not if that
10043 would produce one outside of its types range. */
10059 }
10061 /* Canonicalize the comparison ARG0 CODE ARG1 with type TYPE with undefined
10062 overflow further. Try to decrease the magnitude of constants involved
10063 by changing LE_EXPR and GE_EXPR to LT_EXPR and GT_EXPR or vice versa
10064 and put sole constants at the second argument position.
10065 Returns the canonicalized tree if changed, otherwise NULL_TREE. */
10067 static tree
10070 {
10071 tree t;
10076 /* Try canonicalization by simplifying arg0. */
10081 {
10085 }
10087 /* Try canonicalization by simplifying arg1 using the swapped
10088 comparison. */
10096 }
10098 /* Return whether BASE + OFFSET + BITPOS may wrap around the address
10099 space. This is used to avoid issuing overflow warnings for
10100 expressions like &p->x which cannot wrap. */
10102 static bool
10104 {
10111 poly_wide_int wi_offset;
10117 else
10122 precision);
10137 /* We can do slightly better for SIZE if we have an ADDR_EXPR of an
10138 array. */
10147 }
10149 /* Return a positive integer when the symbol DECL is known to have
10150 a nonzero address, zero when it's known not to (e.g., it's a weak
10151 symbol), and a negative integer when the symbol is not yet in the
10152 symbol table and so whether or not its address is zero is unknown.
10153 For function local objects always return positive integer. */
10154 static int
10156 {
10157 /* Normally, don't do anything for variables and functions before symtab is
10158 built; it is quite possible that DECL will be declared weak later.
10159 But if folding_initializer, we need a constant answer now, so create
10160 the symtab entry and prevent later weak declaration. */
10163 = (folding_initializer
10168 /* Function local objects are never NULL. */
10176 }
10178 /* Subroutine of fold_binary. This routine performs all of the
10179 transformations that are common to the equality/inequality
10180 operators (EQ_EXPR and NE_EXPR) and the ordering operators
10181 (LT_EXPR, LE_EXPR, GE_EXPR and GT_EXPR). Callers other than
10182 fold_binary should call fold_binary. Fold a comparison with
10183 tree code CODE and type TYPE with operands OP0 and OP1. Return
10184 the folded comparison or NULL_TREE. */
10186 static tree
10189 {
10199 /* For comparisons of pointers we can decompose it to a compile time
10200 comparison of the base objects and the offsets into the object.
10201 This requires at least one operand being an ADDR_EXPR or a
10202 POINTER_PLUS_EXPR to do more than the operand_equal_p test below. */
10208 {
10211 machine_mode mode;
10215 /* Get base and offset for the access. Strip ADDR_EXPR for
10216 get_inner_reference, but put it back by stripping INDIRECT_REF
10217 off the base object if possible. indirect_baseN will be true
10218 if baseN is not an address but refers to the object itself. */
10221 {
10222 base0
10228 else
10230 }
10232 {
10236 {
10237 base0
10243 else
10245 }
10248 else
10252 {
10259 }
10260 }
10264 {
10265 base1
10271 else
10273 }
10275 {
10279 {
10280 base1
10286 else
10288 }
10291 else
10295 {
10302 }
10303 }
10305 /* If we have equivalent bases we might be able to simplify. */
10309 {
10310 /* We can fold this expression to a constant if the non-constant
10311 offset parts are equal. */
10315 && (equality_code
10316 || (indirect_base0
10319 {
10325 "occur when comparing P +- C1 with "
10327 WARN_STRICT_OVERFLOW_CONDITIONAL);
10330 {
10368 }
10369 }
10370 /* We can simplify the comparison to a comparison of the variable
10371 offset parts if the constant offset parts are equal.
10372 Be careful to use signed sizetype here because otherwise we
10373 mess with array offsets in the wrong way. This is possible
10374 because pointer arithmetic is restricted to retain within an
10375 object and overflow on pointer differences is undefined as of
10376 6.5.6/8 and /9 with respect to the signed ptrdiff_t. */
10378 && (equality_code
10379 || (indirect_base0
10382 {
10383 /* By converting to signed sizetype we cover middle-end pointer
10384 arithmetic which operates on unsigned pointer types of size
10385 type size and ARRAY_REF offsets which are properly sign or
10386 zero extended from their type in case it is narrower than
10387 sizetype. */
10390 else
10394 else
10401 "occur when comparing P +- C1 with "
10403 WARN_STRICT_OVERFLOW_COMPARISON);
10406 }
10407 }
10408 /* For equal offsets we can simplify to a comparison of the
10409 base addresses. */
10411 && (indirect_base0
10413 && (indirect_base1
10418 {
10424 }
10425 /* Comparison between an ordinary (non-weak) symbol and a null
10426 pointer can be eliminated since such symbols must have a non
10427 null address. In C, relational expressions between pointers
10428 to objects and null pointers are undefined. The results
10429 below follow the C++ rules with the additional property that
10430 every object pointer compares greater than a null pointer.
10431 */
10434 /* Avoid folding references to struct members at offset 0 to
10435 prevent tests like '&ptr->firstmember == 0' from getting
10436 eliminated. When ptr is null, although the -> expression
10437 is strictly speaking invalid, GCC retains it as a matter
10438 of QoI. See PR c/44555. */
10441 && indirect_base0
10442 /* The caller guarantees that when one of the arguments is
10443 constant (i.e., null in this case) it is second. */
10445 {
10447 {
10458 }
10459 }
10460 }
10462 /* Transform comparisons of the form X +- C1 CMP Y +- C2 to
10463 X CMP Y +- C2 +- C1 for signed X, Y. This is valid if
10464 the resulting offset is smaller in absolute value than the
10465 original one and has the same sign. */
10474 {
10479 tree cst;
10481 "occur when combining constants around "
10484 /* Put the constant on the side where it doesn't overflow and is
10485 of lower absolute value and of same sign than before. */
10492 {
10495 variable1,
10499 }
10507 {
10513 variable2);
10514 }
10515 }
10521 /* If we are comparing an expression that just has comparisons
10522 of two integer values, arithmetic expressions of those comparisons,
10523 and constants, we can simplify it. There are only three cases
10524 to check: the two values can either be equal, the first can be
10525 greater, or the second can be greater. Fold the expression for
10526 those three values. Since each value must be 0 or 1, we have
10527 eight possibilities, each of which corresponds to the constant 0
10528 or 1 or one of the six possible comparisons.
10530 This handles common cases like (a > b) == 0 but also handles
10531 expressions like ((x > y) - (y > x)) > 0, which supposedly
10532 occur in macroized code. */
10535 {
10539 /* Don't handle degenerate cases here; they should already
10540 have been handled anyway. */
10549 {
10553 /* We can't just pass T to eval_subst in case cval1 or cval2
10554 was the same as ARG1. */
10556 tree high_result
10560 arg1);
10561 tree equal_result
10565 arg1);
10566 tree low_result
10570 arg1);
10572 /* All three of these results should be 0 or 1. Confirm they are.
10573 Then use those values to select the proper code to use. */
10578 {
10579 /* Make a 3-bit mask with the high-order bit being the
10580 value for `>', the next for '=', and the low for '<'. */
10584 {
10586 /* Always false. */
10607 /* Always true. */
10609 }
10612 }
10613 }
10614 }
10617 }
10620 /* Subroutine of fold_binary. Optimize complex multiplications of the
10621 form z * conj(z), as pow(realpart(z),2) + pow(imagpart(z),2). The
10622 argument EXPR represents the expression "z" of type TYPE. */
10624 static tree
10626 {
10631 {
10634 }
10636 {
10639 }
10640 else
10641 {
10645 }
10654 }
10657 /* Helper function for fold_vec_perm. Store elements of VECTOR_CST or
10658 CONSTRUCTOR ARG into array ELTS, which has NELTS elements, and return
10659 true if successful. */
10661 static bool
10663 {
10668 {
10671 }
10673 {
10679 else
10681 }
10682 else
10688 }
10690 /* Helper routine for fold_vec_perm_cst to check if SEL is a suitable
10691 mask for VLA vec_perm folding.
10692 REASON if specified, will contain the reason why SEL is not suitable.
10693 Used only for debugging and unit-testing. */
10695 static bool
10699 {
10706 {
10710 }
10712 /* We want to avoid cases where sel.length is not a multiple of npatterns.
10713 For eg: sel.length = 2 + 2x, and sel npatterns = 4. */
10714 poly_uint64 esel;
10716 {
10720 }
10726 {
10729 HOST_WIDE_INT step;
10731 {
10735 }
10736 // FIXME: Punt on step < 0 for now, revisit later.
10743 {
10747 }
10749 /* Ensure that stepped sequence of the pattern selects elements
10750 only from the same input vector. */
10759 {
10763 }
10765 /* Ensure that the stepped sequence always selects from the same
10766 input pattern. */
10771 {
10775 }
10777 /* If a1 chooses base element from arg, ensure that it's a natural
10778 stepped sequence, ie, (arg[2] - arg[1]) == (arg[1] - arg[0])
10779 to preserve arg's encoding. */
10782 {
10795 {
10799 }
10800 }
10801 }
10804 }
10806 /* Try to fold permutation of ARG0 and ARG1 with SEL selector when
10807 the input vectors are VECTOR_CST. Return NULL_TREE otherwise.
10808 REASON has same purpose as described in
10809 valid_mask_for_fold_vec_perm_cst_p. */
10811 static tree
10814 {
10818 /* First try to implement the fold in a VLA-friendly way.
10820 (1) If the selector is simply a duplication of N elements, the
10821 result is likewise a duplication of N elements.
10823 (2) If the selector is N elements followed by a duplication
10824 of N elements, the result is too.
10826 (3) If the selector is N elements followed by an interleaving
10827 of N linear series, the situation is more complex.
10829 valid_mask_for_fold_vec_perm_cst_p detects whether we
10830 can handle this case. If we can, then each of the N linear
10831 series either (a) selects the same element each time or
10832 (b) selects a linear series from one of the input patterns.
10834 If (b) holds for one of the linear series, the result
10835 will contain a linear series, and so the result will have
10836 the same shape as the selector. If (a) holds for all of
10837 the linear series, the result will be the same as (2) above.
10839 (b) can only hold if one of the input patterns has a
10840 stepped encoding. */
10843 {
10851 }
10853 {
10856 }
10857 else
10862 {
10865 poly_uint64 r;
10868 /* Punt if sel[i] /trunc_div len cannot be determined,
10869 because the input vector to be chosen will depend on
10870 runtime vector length.
10871 For example if len == 4 + 4x, and sel[i] == 4,
10872 If len at runtime equals 4, we choose arg1[0].
10873 For any other value of len > 4 at runtime, we choose arg0[4].
10874 which makes the element choice dependent on runtime vector length. */
10876 {
10880 }
10882 /* sel[i] % len will give the index of element in the chosen input
10883 vector. For example if sel[i] == 5 + 4x and len == 4 + 4x,
10884 we will choose arg1[1] since (5 + 4x) % (4 + 4x) == 1. */
10886 {
10890 }
10895 }
10898 }
10900 /* Attempt to fold vector permutation of ARG0 and ARG1 vectors using SEL
10901 selector. Return the folded VECTOR_CST or CONSTRUCTOR if successful,
10902 NULL_TREE otherwise. */
10904 tree
10906 {
10922 /* For fall back case, we want to ensure we have VLS vectors
10923 with equal length. */
10937 {
10938 HOST_WIDE_INT index;
10942 }
10944 }
10946 /* Try to fold a pointer difference of type TYPE two address expressions of
10947 array references AREF0 and AREF1 using location LOC. Return a
10948 simplified expression for the difference or NULL_TREE. */
10950 static tree
10954 {
10959 /* If the bases are array references as well, recurse. If the bases
10960 are pointer indirections compute the difference of the pointers.
10961 If the bases are equal, we are set. */
10964 && (base_offset
10966 use_pointer_diff)))
10969 && (base_offset
10970 = use_pointer_diff
10980 {
10986 base_offset,
10989 }
10991 }
10993 /* If the real or vector real constant CST of type TYPE has an exact
10994 inverse, return it, else return NULL. */
10996 tree
10998 {
10999 REAL_VALUE_TYPE r;
11000 tree unit_type;
11001 machine_mode mode;
11004 {
11014 {
11018 tree_vector_builder elts;
11023 {
11028 }
11031 }
11035 }
11036 }
11038 /* Mask out the tz least significant bits of X of type TYPE where
11039 tz is the number of trailing zeroes in Y. */
11040 static wide_int
11042 {
11047 }
11049 /* Return true when T is an address and is known to be nonzero.
11050 For floating point we further ensure that T is not denormal.
11051 Similar logic is present in nonzero_address in rtlanal.h.
11053 If the return value is based on the assumption that signed overflow
11054 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
11055 change *STRICT_OVERFLOW_P. */
11057 static bool
11059 {
11063 /* Doing something useful for floating point would need more work. */
11069 {
11072 strict_overflow_p);
11078 strict_overflow_p);
11086 }
11089 {
11092 strict_overflow_p);
11100 strict_overflow_p);
11114 strict_overflow_p);
11118 strict_overflow_p);
11121 {
11133 }
11137 }
11139 }
11141 /* Return true when T is an address and is known to be nonzero.
11142 Handle warnings about undefined signed overflow. */
11144 bool
11146 {
11153 "determining that expression is always "
11155 WARN_STRICT_OVERFLOW_MISC);
11157 }
11159 /* Return true if T is known not to be equal to an integer W. */
11161 bool
11163 {
11164 int_range_max vr;
11166 {
11177 /* If T has some known zero bits and W has any of those bits set,
11178 then T is known not to be equal to W. */
11186 }
11187 }
11189 /* Fold a binary expression of code CODE and type TYPE with operands
11190 OP0 and OP1. LOC is the location of the resulting expression.
11191 Return the folded expression if folding is successful. Otherwise,
11192 return NULL_TREE. */
11194 tree
11197 {
11212 /* Strip any conversions that don't change the mode. This is
11213 safe for every expression, except for a comparison expression
11214 because its signedness is derived from its operands. So, in
11215 the latter case, only strip conversions that don't change the
11216 signedness. MIN_EXPR/MAX_EXPR also need signedness of arguments
11217 preserved.
11219 Note that this is done as an internal manipulation within the
11220 constant folder, in order to find the simplest representation
11221 of the arguments so that their form can be studied. In any
11222 cases, the appropriate type conversions should be put back in
11223 the tree that will get out of the constant folder. */
11226 {
11229 }
11230 else
11231 {
11234 }
11236 /* Note that TREE_CONSTANT isn't enough: static var addresses are
11237 constant but we can't do arithmetic on them. */
11239 {
11242 {
11246 }
11247 }
11249 /* If this is a commutative operation, and ARG0 is a constant, move it
11250 to ARG1 to reduce the number of tests below. */
11255 /* Likewise if this is a comparison, and ARG0 is a constant, move it
11256 to ARG1 to reduce the number of tests below. */
11265 /* ARG0 is the first operand of EXPR, and ARG1 is the second operand.
11267 First check for cases where an arithmetic operation is applied to a
11268 compound, conditional, or comparison operation. Push the arithmetic
11269 operation inside the compound or conditional to see if any folding
11270 can then be done. Convert comparison to conditional for this purpose.
11271 The also optimizes non-constant cases that used to be done in
11272 expand_expr.
11274 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
11275 one of the operands is a comparison and the other is a comparison, a
11276 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
11277 code below would make the expression more complex. Change it to a
11278 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
11279 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
11292 {
11296 boolean_type_node,
11304 }
11308 {
11310 {
11315 tem);
11316 }
11318 {
11323 tem);
11324 }
11329 {
11335 }
11340 {
11346 }
11347 }
11350 {
11352 /* MEM[&MEM[p, CST1], CST2] -> MEM[p, CST1 + CST2]. */
11355 {
11361 }
11363 /* MEM[&a.b, CST2] -> MEM[&a, offsetof (a, b) + CST2]. */
11366 {
11367 tree base;
11368 poly_int64 coffset;
11377 }
11382 /* INT +p INT -> (PTR)(INT + INT). Stripping types allows for this. */
11388 arg1),
11390 arg0)));
11396 {
11397 /* X + (X / CST) * -CST is X % CST. */
11402 {
11411 cst0));
11412 }
11413 }
11415 /* Handle (A1 * C1) + (A2 * C2) with A1, A2 or C1, C2 being the same or
11416 one. Make sure the type is not saturating and has the signedness of
11417 the stripped operands, as fold_plusminus_mult_expr will re-associate.
11418 ??? The latter condition should use TYPE_OVERFLOW_* flags instead. */
11425 {
11429 }
11432 {
11433 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
11434 (plus (plus (mult) (mult)) (foo)) so that we can
11435 take advantage of the factoring cases below. */
11444 {
11450 else
11463 parg0),
11465 marg)),
11469 return
11475 parg1)));
11476 }
11477 }
11478 else
11479 {
11480 /* Fold __complex__ ( x, 0 ) + __complex__ ( 0, y )
11481 to __complex__ ( x, y ). This is not the same for SNaNs or
11482 if signed zeros are involved. */
11486 {
11493 {
11497 {
11503 }
11505 {
11511 }
11512 }
11513 }
11515 /* Convert a + (b*c + d*e) into (a + b*c) + d*e.
11516 We associate floats only if the user has specified
11517 -fassociative-math. */
11521 {
11526 {
11527 tree tree0;
11530 }
11531 }
11532 /* Convert (b*c + d*e) + a into b*c + (d*e +a).
11533 We associate floats only if the user has specified
11534 -fassociative-math. */
11538 {
11543 {
11544 tree tree0;
11547 }
11548 }
11549 }
11551 bit_rotate:
11552 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
11553 is a rotate of A by C1 bits. */
11554 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
11555 is a rotate of A by B bits.
11556 Similarly for (A << B) | (A >> (-B & C3)) where C3 is Z-1,
11557 though in this case CODE must be | and not + or ^, otherwise
11558 it doesn't return A when B is 0. */
11559 {
11561 tree rtype;
11570 /* Only create rotates in complete modes. Other cases are not
11571 expanded properly. */
11574 {
11587 {
11592 }
11597 {
11600 code0 == LSHIFT_EXPR
11603 }
11605 {
11615 {
11619 orig_tree01);
11621 }
11622 }
11626 {
11637 {
11641 orig_tree01);
11643 }
11644 }
11645 }
11646 }
11648 associate:
11649 /* In most languages, can't associate operations on floats through
11650 parentheses. Rather than remember where the parentheses were, we
11651 don't associate floats at all, unless the user has specified
11652 -fassociative-math.
11653 And, we need to make sure type is not saturating. */
11658 {
11664 /* Split both trees into variables, constants, and literals. Then
11665 associate each group together, the constants with literals,
11666 then the result with variables. This increases the chances of
11667 literals being recombined later and of generating relocatable
11668 expressions for the sum of a constant and literal. */
11676 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
11680 /* With undefined overflow prefer doing association in a type
11681 which wraps on overflow, if that is one of the operand types. */
11684 {
11692 }
11694 /* With undefined overflow we can only associate constants with one
11695 variable, and constants whose association doesn't overflow. */
11698 {
11700 {
11701 /* ??? If split_tree would handle NEGATE_EXPR we could
11702 simply reject these cases and the allowed cases would
11703 be the var0/minus_var1 ones. */
11709 {
11712 }
11719 {
11722 }
11728 /* The only case we can still associate with two variables
11729 is if they cancel out. */
11733 }
11739 }
11741 /* Only do something if we found more than two objects. Otherwise,
11742 nothing has changed and we risk infinite recursion. */
11750 {
11762 {
11766 }
11768 {
11772 }
11774 /* Preserve the MINUS_EXPR if the negative part of the literal is
11775 greater than the positive part. Otherwise, the multiplicative
11776 folding code (i.e extract_muldiv) may be fooled in case
11777 unsigned constants are subtracted, like in the following
11778 example: ((X*2 + 4) - 8U)/2. */
11780 {
11784 /* But avoid ending up with only negated parts. */
11786 {
11790 }
11791 else
11792 {
11796 }
11797 }
11799 /* Don't introduce overflows through reassociation. */
11804 /* Eliminate lit0 and minus_lit0 to con0 and minus_con0. */
11811 /* Eliminate minus_con0. */
11813 {
11820 else
11823 }
11825 /* Eliminate minus_var0. */
11827 {
11831 else
11834 }
11836 return
11839 }
11840 }
11846 /* Fold &a[i] - &a[j] to i-j. */
11851 {
11855 code
11859 }
11861 /* Further transformations are not for pointers. */
11865 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
11868 /* If arg0 is e.g. unsigned int and type is int, then this could
11869 introduce UB, because if A is INT_MIN at runtime, the original
11870 expression can be well defined while the latter is not.
11871 See PR83269. */
11880 /* Fold __complex__ ( x, 0 ) - __complex__ ( 0, y ) to
11881 __complex__ ( x, -y ). This is not the same for SNaNs or if
11882 signed zeros are involved. */
11886 {
11893 {
11897 {
11899 arg1r ? arg1r
11904 }
11906 {
11910 arg1i ? arg1i
11913 }
11914 }
11915 }
11917 /* A - B -> A + (-B) if B is easily negatable. */
11921 /* Avoid this transformation if B is a positive REAL_CST. */
11929 /* Handle (A1 * C1) - (A2 * C2) with A1, A2 or C1, C2 being the same or
11930 one. Make sure the type is not saturating and has the signedness of
11931 the stripped operands, as fold_plusminus_mult_expr will re-associate.
11932 ??? The latter condition should use TYPE_OVERFLOW_* flags instead. */
11939 {
11943 }
11949 {
11950 /* Transform x * -C into -x * C if x is easily negatable. */
11965 {
11968 "occur when simplifying "
11970 WARN_STRICT_OVERFLOW_MISC);
11972 }
11974 /* Optimize z * conj(z) for integer complex numbers. */
11981 }
11982 else
11983 {
11984 /* Fold z * +-I to __complex__ (-+__imag z, +-__real z).
11985 This is not the same for NaNs or if signed zeros are
11986 involved. */
11992 {
11995 return
12001 return
12006 }
12008 /* Optimize z * conj(z) for floating point complex numbers.
12009 Guarded by flag_unsafe_math_optimizations as non-finite
12010 imaginary components don't produce scalar results. */
12019 }
12023 /* Canonicalize (X & C1) | C2. */
12027 {
12032 /* If (C1&C2) == C1, then (X&C1)|C2 becomes (X,C2). */
12040 /* If (C1|C2) == ~0 then (X&C1)|C2 becomes X|C2. */
12042 {
12045 }
12047 /* Minimize the number of bits set in C1, i.e. C1 := C1 & ~C2,
12048 unless (C1 & ~C2) | (C2 & C3) for some C3 is a mask of some
12049 mode which allows further optimizations. */
12054 {
12059 {
12062 }
12063 }
12066 {
12071 }
12072 }
12074 /* See if this can be simplified into a rotate first. If that
12075 is unsuccessful continue in the association code. */
12079 /* Fold (X & 1) ^ 1 as (X & 1) == 0. */
12087 /* See if this can be simplified into a rotate first. If that
12088 is unsuccessful continue in the association code. */
12092 /* Fold !X & 1 as X == 0. */
12095 {
12099 }
12101 /* Fold (X * Y) & -(1 << CST) to X * Y if Y is a constant
12102 multiple of 1 << CST. */
12104 {
12111 }
12113 /* Fold (X * CST1) & CST2 to zero if we can, or drop known zero
12114 bits from CST2. */
12118 {
12120 wide_int masked
12127 {
12128 /* Avoid the transform if arg1 is a mask of some
12129 mode which allows further optimizations. */
12136 }
12137 }
12139 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
12142 {
12147 return
12149 }
12154 /* Don't touch a floating-point divide by zero unless the mode
12155 of the constant can represent infinity. */
12161 /* (-A) / (-B) -> A / B */
12173 /* Fall through */
12176 /* Simplify A / (B << N) where A and B are positive and B is
12177 a power of 2, to A >> (N + log2(B)). */
12182 {
12185 {
12193 WARN_STRICT_OVERFLOW_MISC);
12199 }
12200 }
12202 /* Fall through */
12210 /* Convert -A / -B to A / B when the type is signed and overflow is
12211 undefined. */
12215 {
12218 "when distributing negation across "
12220 WARN_STRICT_OVERFLOW_MISC);
12225 }
12229 {
12232 "when distributing negation across "
12234 WARN_STRICT_OVERFLOW_MISC);
12239 }
12241 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
12242 operation, EXACT_DIV_EXPR.
12244 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
12245 At one time others generated faster code, it's not clear if they do
12246 after the last round to changes to the DIV code in expmed.cc. */
12257 {
12261 WARN_STRICT_OVERFLOW_MISC);
12263 }
12275 {
12279 WARN_STRICT_OVERFLOW_MISC);
12281 }
12289 /* Since negative shift count is not well-defined,
12290 don't try to compute it in the compiler. */
12296 /* If we have a rotate of a bit operation with the rotate count and
12297 the second operand of the bit operation both constant,
12298 permute the two operations. */
12304 {
12312 }
12314 /* Two consecutive rotates adding up to the some integer
12315 multiple of the precision of the type can be ignored. */
12331 /* Note that the operands of this must be ints
12332 and their values must be 0 or 1.
12333 ("true" is a fixed value perhaps depending on the language.) */
12334 /* If first arg is constant zero, return it. */
12337 /* FALLTHRU */
12339 /* If either arg is constant true, drop it. */
12343 /* Preserve sequence points. */
12346 /* If second arg is constant zero, result is zero, but first arg
12347 must be evaluated. */
12350 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
12351 case will be handled here. */
12355 /* !X && X is always false. */
12359 /* X && !X is always false. */
12364 /* A < X && A + 1 > Y ==> A < X && A >= Y. Normally A + 1 > Y
12365 means A >= Y && A != MAX, but in this case we know that
12366 A < X <= MAX. */
12370 {
12382 }
12391 /* Note that the operands of this must be ints
12392 and their values must be 0 or true.
12393 ("true" is a fixed value perhaps depending on the language.) */
12394 /* If first arg is constant true, return it. */
12397 /* FALLTHRU */
12399 /* If either arg is constant zero, drop it. */
12403 /* Preserve sequence points. */
12406 /* If second arg is constant true, result is true, but we must
12407 evaluate first arg. */
12410 /* Likewise for first arg, but note this only occurs here for
12411 TRUTH_OR_EXPR. */
12415 /* !X || X is always true. */
12419 /* X || !X is always true. */
12424 /* (X && !Y) || (!X && Y) is X ^ Y */
12427 {
12444 }
12453 /* If the second arg is constant zero, drop it. */
12456 /* If the second arg is constant true, this is a logical inversion. */
12458 {
12461 }
12462 /* Identical arguments cancel to zero. */
12466 /* !X ^ X is always true. */
12471 /* X ^ !X is always true. */
12487 /* bool_var != 1 becomes !bool_var. */
12494 /* bool_var == 0 becomes !bool_var. */
12501 /* !exp != 0 becomes !exp */
12506 /* If this is an EQ or NE comparison with zero and ARG0 is
12507 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
12508 two operations, but the latter can be done in one less insn
12509 on machines that have only two-operand insns or on which a
12510 constant cannot be the first operand. */
12513 {
12518 {
12526 }
12529 {
12537 }
12538 }
12540 /* If this is a comparison of a field, we may be able to simplify it. */
12543 /* Handle the constant case even without -O
12544 to make sure the warnings are given. */
12546 {
12550 }
12552 /* Optimize comparisons of strlen vs zero to a compare of the
12553 first character of the string vs zero. To wit,
12554 strlen(ptr) == 0 => *ptr == 0
12555 strlen(ptr) != 0 => *ptr != 0
12556 Other cases should reduce to one of these two (or a constant)
12557 due to the return value of strlen being unsigned. */
12559 {
12567 {
12568 tree ptrtype
12570 TYPE_QUAL_CONST));
12576 }
12577 }
12579 /* Fold (X >> C) != 0 into X < 0 if C is one less than the width
12580 of X. Similarly fold (X >> C) == 0 into X >= 0. */
12584 {
12589 {
12591 {
12594 }
12597 }
12598 }
12600 /* Fold (~X & C) == 0 into (X & C) != 0 and (~X & C) != 0 into
12601 (X & C) == 0 when C is a single bit. */
12606 {
12613 arg1));
12614 }
12616 /* Fold ((X & C) ^ C) eq/ne 0 into (X & C) ne/eq 0, when the
12617 constant C is a power of two, i.e. a single bit. */
12624 {
12628 }
12630 /* Likewise, fold ((X ^ C) & C) eq/ne 0 into (X & C) ne/eq 0,
12631 when is C is a power of two, i.e. a single bit. */
12638 {
12644 }
12648 {
12655 /* Optimize (X ^ Z) op (Y ^ Z) as X op Y, and symmetries.
12656 operand_equal_p guarantees no side-effects so we don't need
12657 to use omit_one_operand on Z. */
12661 arg10));
12665 arg11));
12669 arg10));
12673 arg11));
12675 /* Optimize (X ^ C1) op (Y ^ C2) as (X ^ (C1 ^ C2)) op Y. */
12678 {
12684 }
12685 }
12687 /* Attempt to simplify equality/inequality comparisons of complex
12688 values. Only lower the comparison if the result is known or
12689 can be simplified to a single scalar comparison. */
12694 {
12699 {
12702 }
12703 else
12704 {
12707 }
12710 {
12713 }
12714 else
12715 {
12718 }
12722 {
12724 {
12729 }
12730 else
12731 {
12736 }
12737 }
12741 {
12743 {
12748 }
12749 else
12750 {
12755 }
12756 }
12757 }
12769 /* Transform comparisons of the form X +- C CMP X. */
12774 {
12779 /* (X - c) > X becomes false. */
12785 /* Likewise (X + c) < X becomes false. */
12791 /* Convert (X - c) <= X to true. */
12798 /* Convert (X + c) >= X to true. */
12804 }
12806 /* If we are comparing an ABS_EXPR with a constant, we can
12807 convert all the cases into explicit comparisons, but they may
12808 well not be faster than doing the ABS and one comparison.
12809 But ABS (X) <= C is a range comparison, which becomes a subtraction
12810 and a comparison, and is probably faster. */
12824 /* Convert ABS_EXPR<x> >= 0 to true. */
12831 {
12834 "when simplifying comparison of "
12836 WARN_STRICT_OVERFLOW_CONDITIONAL);
12839 arg0);
12840 }
12842 /* Convert ABS_EXPR<x> < 0 to false. */
12847 {
12850 "when simplifying comparison of "
12852 WARN_STRICT_OVERFLOW_CONDITIONAL);
12855 arg0);
12856 }
12858 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
12859 and similarly for >= into !=. */
12869 /* Similarly for X < (cast) (1 << Y). But cast can't be narrowing,
12870 otherwise Y might be >= # of bits in X's type and thus e.g.
12871 (unsigned char) (1 << Y) for Y 15 might be 0.
12872 If the cast is widening, then 1 << Y should have unsigned type,
12873 otherwise if Y is number of bits in the signed shift type minus 1,
12874 we can't optimize this. E.g. (unsigned long long) (1 << Y) for Y
12875 31 might be 0xffffffff80000000. */
12888 {
12894 }
12906 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
12907 {
12920 }
12925 /* When pedantic, a compound expression can be neither an lvalue
12926 nor an integer constant expression. */
12929 /* Don't let (0, 0) be null pointer constant. */
12937 }
12939 /* For constants M and N, if M == (1LL << cst) - 1 && (N & M) == M,
12940 ((A & N) + B) & M -> (A + B) & M
12941 Similarly if (N & M) == 0,
12942 ((A | N) + B) & M -> (A + B) & M
12943 and for - instead of + (or unary - instead of +)
12944 and/or ^ instead of |.
12945 If B is constant and (B & M) == 0, fold into A & M.
12947 This function is a helper for match.pd patterns. Return non-NULL
12948 type in which the simplified operation should be performed only
12949 if any optimization is possible.
12951 ARG1 is M above, ARG00 is left operand of +/-, if CODE00 is BIT_*_EXPR,
12952 then ARG00{0,1} are operands of that bitop, otherwise CODE00 is ERROR_MARK.
12953 Similarly for ARG01, CODE01 and ARG01{0,1}, just for the right operand of
12954 +/-. */
12955 tree
12960 {
12975 wide_int cst0;
12977 /* Now we know that arg0 is (C + D) or (C - D) or -C and
12978 arg1 (M) is == (1LL << cst) - 1.
12979 Store C into PMOP[0] and D into PMOP[1]. */
12986 {
12993 {
12996 }
12999 /* If C or D is of the form (A & N) where
13000 (N & M) == M, or of the form (A | N) or
13001 (A ^ N) where (N & M) == 0, replace it with A. */
13007 /* If C or D is a N where (N & M) == 0, it can be
13008 omitted (replaced with 0). */
13013 /* Similarly, with C - N where (-N & M) == 0. */
13021 }
13023 /* Only build anything new if we optimized one or both arguments above. */
13029 else
13031 }
13033 /* Used by contains_label_[p1]. */
13035 struct contains_label_data
13036 {
13039 };
13041 /* Callback for walk_tree, looking for LABEL_EXPR. Return *TP if it is
13042 a LABEL_EXPR or CASE_LABEL_EXPR not inside of another SWITCH_EXPR; otherwise
13043 return NULL_TREE. Do not check the subtrees of GOTO_EXPR. */
13045 static tree
13047 {
13050 {
13061 {
13069 }
13078 }
13079 }
13081 /* Return whether the sub-tree ST contains a label which is accessible from
13082 outside the sub-tree. */
13084 static bool
13086 {
13090 }
13092 /* Fold a ternary expression of code CODE and type TYPE with operands
13093 OP0, OP1, and OP2. Return the folded expression if folding is
13094 successful. Otherwise, return NULL_TREE. */
13096 tree
13099 {
13100 tree tem;
13107 /* If this is a commutative operation, and OP0 is a constant, move it
13108 to OP1 to reduce the number of tests below. */
13117 /* Strip any conversions that don't change the mode. This is safe
13118 for every expression, except for a comparison expression because
13119 its signedness is derived from its operands. So, in the latter
13120 case, only strip conversions that don't change the signedness.
13122 Note that this is done as an internal manipulation within the
13123 constant folder, in order to find the simplest representation of
13124 the arguments so that their form can be studied. In any cases,
13125 the appropriate type conversions should be put back in the tree
13126 that will get out of the constant folder. */
13128 {
13131 }
13134 {
13137 }
13140 {
13143 }
13146 {
13150 {
13156 }
13161 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
13162 so all simple results must be passed through pedantic_non_lvalue. */
13164 {
13167 /* Only optimize constant conditions when the selected branch
13168 has the same type as the COND_EXPR. This avoids optimizing
13169 away "c ? x : throw", where the throw has a void type.
13170 Avoid throwing away that operand which contains label. */
13177 }
13179 {
13186 {
13189 {
13197 }
13202 }
13203 }
13205 /* If we have A op B ? A : C, we may be able to convert this to a
13206 simpler expression, depending on the operation and the values
13207 of B and C. Signed zeros prevent all of these transformations,
13208 for reasons given above each one.
13210 Also try swapping the arguments and inverting the conditional. */
13214 {
13221 }
13226 {
13233 arg00,
13234 arg01,
13238 }
13240 /* If the second operand is simpler than the third, swap them
13241 since that produces better jump optimization results. */
13244 {
13246 /* See if this can be inverted. If it can't, possibly because
13247 it was a floating-point inequality comparison, don't do
13248 anything. */
13252 }
13254 /* Convert A ? 1 : 0 to simply A. */
13259 /* If we try to convert OP0 to our type, the
13260 call to fold will try to move the conversion inside
13261 a COND, which will recurse. In that case, the COND_EXPR
13262 is probably the best choice, so leave it alone. */
13266 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
13267 over COND_EXPR in cases such as floating point comparisons. */
13276 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
13281 {
13282 /* sign_bit_p looks through both zero and sign extensions,
13283 but for this optimization only sign extensions are
13284 usable. */
13287 {
13290 {
13293 }
13295 }
13296 /* sign_bit_p only checks ARG1 bits within A's precision.
13297 If <sign bit of A> has wider type than A, bits outside
13298 of A's precision in <sign bit of A> need to be checked.
13299 If they are all 0, this optimization needs to be done
13300 in unsigned A's type, if they are all 1 in signed A's type,
13301 otherwise this can't be done. */
13307 {
13309 tree tem_type;
13322 {
13325 }
13327 {
13330 }
13331 else
13333 }
13336 return
13342 arg1)));
13343 }
13345 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
13346 already handled above. */
13351 {
13361 op1);
13362 }
13364 /* A & N ? N : 0 is simply A & N if N is a power of two. This
13365 is probably obsolete because the first operand should be a
13366 truth value (that's why we have the two cases above), but let's
13367 leave it in until we can confirm this for all front-ends. */
13375 /* operand_equal_p compares just value, not precision, so e.g.
13376 arg1 could be 8-bit -128 and be power of two, but BIT_AND_EXPR
13377 second operand 32-bit -128, which is not a power of two (or vice
13378 versa. */
13382 /* Disable the transformations below for vectors, since
13383 fold_binary_op_with_conditional_arg may undo them immediately,
13384 yielding an infinite loop. */
13388 /* Convert A ? B : 0 into A && B if A and B are truth values. */
13397 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
13402 {
13404 /* Only perform transformation if ARG0 is easily inverted. */
13408 ? BIT_IOR_EXPR
13411 op1);
13412 }
13414 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
13419 {
13421 /* Only perform transformation if ARG0 is easily inverted. */
13427 op2);
13428 }
13430 /* Convert A ? 1 : B into A || B if A and B are truth values. */
13442 /* CALL_EXPRs used to be ternary exprs. Catch any mistaken uses
13443 of fold_ternary on them. */
13453 {
13455 unsigned HOST_WIDE_INT width
13466 {
13471 {
13473 {
13478 }
13484 }
13485 }
13486 }
13488 /* On constants we can use native encode/interpret to constant
13489 fold (nearly) all BIT_FIELD_REFs. */
13495 {
13498 /* Limit us to a reasonable amount of work. To relax the
13499 other limitations we need bit-shifting of the buffer
13500 and rounding up the size. */
13504 {
13506 unsigned HOST_WIDE_INT len
13511 {
13516 }
13517 }
13518 }
13523 /* Perform constant folding of BIT_INSERT_EXPR. */
13527 {
13528 /* Build a vector of integers from the tree mask. */
13529 vec_perm_builder builder;
13533 /* Create a vec_perm_indices for the integer vector. */
13538 }
13542 /* Perform (partial) constant folding of BIT_INSERT_EXPR. */
13545 {
13551 wide_int tem2
13555 }
13560 {
13562 unsigned HOST_WIDE_INT elsize
13565 {
13571 {
13577 }
13578 }
13579 }
13585 }
13587 /* Gets the element ACCESS_INDEX from CTOR, which must be a CONSTRUCTOR
13588 of an array (or vector). *CTOR_IDX if non-NULL is updated with the
13589 constructor element index of the value returned. If the element is
13590 not found NULL_TREE is returned and *CTOR_IDX is updated to
13591 the index of the element after the ACCESS_INDEX position (which
13592 may be outside of the CTOR array). */
13594 tree
13597 {
13603 {
13606 {
13607 /* Static constructors for variably sized objects makes no sense. */
13610 /* ??? When it is obvious that the range is signed, treat it so. */
13615 {
13617 low_bound
13619 SIGNED);
13620 }
13621 else
13622 {
13625 }
13626 }
13627 }
13631 index_sgn);
13643 {
13644 /* Array constructor might explicitly set index, or specify a range,
13645 or leave index NULL meaning that it is next index after previous
13646 one. */
13648 {
13650 max_index = index
13652 else
13653 {
13656 index_sgn);
13657 max_index
13659 index_sgn);
13661 }
13662 }
13664 {
13670 }
13671 else
13674 /* Do we have match? */
13676 {
13678 {
13682 }
13683 }
13685 /* We're past the element we search for. Note during parsing
13686 the elements might not be sorted.
13687 ??? We should use a binary search and a flag on the
13688 CONSTRUCTOR as to whether elements are sorted in declaration
13689 order. */
13691 }
13695 }
13697 /* Perform constant folding and related simplification of EXPR.
13698 The related simplifications include x*1 => x, x*0 => 0, etc.,
13699 and application of the associative law.
13700 NOP_EXPR conversions may be removed freely (as long as we
13701 are careful not to change the type of the overall expression).
13702 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
13703 but we can constant-fold them if they have constant operands. */
13705 #ifdef ENABLE_FOLD_CHECKING
13706 # define fold(x) fold_1 (x)
13708 static
13709 #endif
13710 tree
13712 {
13716 tree tem;
13719 /* Return right away if a constant. */
13723 /* CALL_EXPR-like objects with variable numbers of operands are
13724 treated specially. */
13726 {
13728 {
13731 }
13733 }
13736 {
13741 {
13759 }
13760 }
13763 {
13765 {
13772 {
13777 }
13780 }
13782 /* Return a VECTOR_CST if possible. */
13784 {
13790 tree val;
13796 }
13804 }
13806 #ifdef ENABLE_FOLD_CHECKING
13807 #undef fold
13814 /* When --enable-checking=fold, compute a digest of expr before
13815 and after actual fold call to see if fold did not accidentally
13816 change original expr. */
13818 tree
13820 {
13821 tree ret;
13841 }
13843 void
13845 {
13856 }
13858 static void
13860 {
13862 }
13864 static void
13867 {
13873 recursive_label:
13883 {
13884 /* Allow DECL_ASSEMBLER_NAME and symtab_node to be modified. */
13892 }
13900 {
13901 /* Allow these fields to be modified. */
13902 tree tmp;
13913 {
13916 }
13917 }
13919 {
13920 /* Allow the no-warning bit to be set. Perhaps we shouldn't allow
13921 that and change builtins.cc etc. instead - see PR89543. */
13927 }
13938 {
13941 {
13957 }
13961 {
13974 }
13991 {
13997 }
14000 {
14002 {
14005 }
14007 }
14018 {
14021 }
14029 }
14030 }
14032 /* Helper function for outputting the checksum of a tree T. When
14033 debugging with gdb, you can "define mynext" to be "next" followed
14034 by "call debug_fold_checksum (op0)", then just trace down till the
14035 outputs differ. */
14037 DEBUG_FUNCTION void
14039 {
14054 }
14056 #endif
14058 /* Fold a unary tree expression with code CODE of type TYPE with an
14059 operand OP0. LOC is the location of the resulting expression.
14060 Return a folded expression if successful. Otherwise, return a tree
14061 expression with code CODE of type TYPE with an operand OP0. */
14063 tree
14066 {
14067 tree tem;
14068 #ifdef ENABLE_FOLD_CHECKING
14077 #endif
14083 #ifdef ENABLE_FOLD_CHECKING
14090 #endif
14092 }
14094 /* Fold a binary tree expression with code CODE of type TYPE with
14095 operands OP0 and OP1. LOC is the location of the resulting
14096 expression. Return a folded expression if successful. Otherwise,
14097 return a tree expression with code CODE of type TYPE with operands
14098 OP0 and OP1. */
14100 tree
14103 MEM_STAT_DECL)
14104 {
14105 tree tem;
14106 #ifdef ENABLE_FOLD_CHECKING
14123 #endif
14129 #ifdef ENABLE_FOLD_CHECKING
14144 #endif
14146 }
14148 /* Fold a ternary tree expression with code CODE of type TYPE with
14149 operands OP0, OP1, and OP2. Return a folded expression if
14150 successful. Otherwise, return a tree expression with code CODE of
14151 type TYPE with operands OP0, OP1, and OP2. */
14153 tree
14156 {
14157 tree tem;
14158 #ifdef ENABLE_FOLD_CHECKING
14182 #endif
14189 #ifdef ENABLE_FOLD_CHECKING
14212 #endif
14214 }
14216 /* Fold a CALL_EXPR expression of type TYPE with operands FN and NARGS
14217 arguments in ARGARRAY, and a null static chain.
14218 Return a folded expression if successful. Otherwise, return a CALL_EXPR
14219 of type TYPE from the given operands as constructed by build_call_array. */
14221 tree
14224 {
14225 tree tem;
14226 #ifdef ENABLE_FOLD_CHECKING
14245 #endif
14251 #ifdef ENABLE_FOLD_CHECKING
14267 #endif
14269 }
14271 /* Perform constant folding and related simplification of initializer
14272 expression EXPR. These behave identically to "fold_buildN" but ignore
14273 potential run-time traps and exceptions that fold must preserve. */
14275 #define START_FOLD_INIT \
14276 int saved_signaling_nans = flag_signaling_nans;\
14277 int saved_trapping_math = flag_trapping_math;\
14278 int saved_rounding_math = flag_rounding_math;\
14279 int saved_trapv = flag_trapv;\
14280 int saved_folding_initializer = folding_initializer;\
14281 flag_signaling_nans = 0;\
14282 flag_trapping_math = 0;\
14283 flag_rounding_math = 0;\
14284 flag_trapv = 0;\
14285 folding_initializer = 1;
14287 #define END_FOLD_INIT \
14288 flag_signaling_nans = saved_signaling_nans;\
14289 flag_trapping_math = saved_trapping_math;\
14290 flag_rounding_math = saved_rounding_math;\
14291 flag_trapv = saved_trapv;\
14292 folding_initializer = saved_folding_initializer;
14294 tree
14296 {
14297 tree result;
14298 START_FOLD_INIT;
14302 END_FOLD_INIT;
14304 }
14306 tree
14309 {
14310 tree result;
14311 START_FOLD_INIT;
14315 END_FOLD_INIT;
14317 }
14319 tree
14322 {
14323 tree result;
14324 START_FOLD_INIT;
14328 END_FOLD_INIT;
14330 }
14332 tree
14335 {
14336 tree result;
14337 START_FOLD_INIT;
14341 END_FOLD_INIT;
14343 }
14345 tree
14348 {
14349 tree result;
14350 START_FOLD_INIT;
14354 END_FOLD_INIT;
14356 }
14358 #undef START_FOLD_INIT
14359 #undef END_FOLD_INIT
14361 /* Determine if first argument is a multiple of second argument. Return
14362 false if it is not, or we cannot easily determined it to be.
14364 An example of the sort of thing we care about (at this point; this routine
14365 could surely be made more general, and expanded to do what the *_DIV_EXPR's
14366 fold cases do now) is discovering that
14368 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
14370 is a multiple of
14372 SAVE_EXPR (J * 8)
14374 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
14376 This code also handles discovering that
14378 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
14380 is a multiple of 8 so we don't have to worry about dealing with a
14381 possible remainder.
14383 Note that we *look* inside a SAVE_EXPR only to determine how it was
14384 calculated; it is not safe for fold to do much of anything else with the
14385 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
14386 at run time. For example, the latter example above *cannot* be implemented
14387 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
14388 evaluation time of the original SAVE_EXPR is not necessarily the same at
14389 the time the new expression is evaluated. The only optimization of this
14390 sort that would be valid is changing
14392 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
14394 divided by 8 to
14396 SAVE_EXPR (I) * SAVE_EXPR (J)
14398 (where the same SAVE_EXPR (J) is used in the original and the
14399 transformed version).
14401 NOWRAP specifies whether all outer operations in TYPE should
14402 be considered not wrapping. Any type conversion within TOP acts
14403 as a barrier and we will fall back to NOWRAP being false.
14404 NOWRAP is mostly used to treat expressions in TYPE_SIZE and friends
14405 as not wrapping even though they are generally using unsigned arithmetic. */
14407 bool
14409 {
14420 {
14422 /* Bitwise and provides a power of two multiple. If the mask is
14423 a multiple of BOTTOM then TOP is a multiple of BOTTOM. */
14430 /* If the multiplication can wrap we cannot recurse further unless
14431 the bottom is a power of two which is where wrapping does not
14432 matter. */
14438 {
14444 {
14447 /* Handle multiple_of_p ((x * 2 + 2) * 4, 8). */
14449 {
14453 {
14456 }
14457 }
14459 }
14460 }
14465 /* Handle X << CST as X * (1 << CST) and only process the constant. */
14467 {
14470 {
14471 wide_int mul_op
14475 nowrap);
14476 }
14477 }
14482 /* If the addition or subtraction can wrap we cannot recurse further
14483 unless bottom is a power of two which is where wrapping does not
14484 matter. */
14490 /* Handle cases like op0 + 0xfffffffd as op0 - 3 if the expression has
14491 unsigned type. For example, (X / 3) + 0xfffffffd is multiple of 3,
14492 but 0xfffffffd is not. */
14495 && nowrap
14500 /* It is impossible to prove if op0 +- op1 is multiple of bottom
14501 precisely, so be conservative here checking if both op0 and op1
14502 are multiple of bottom. Note we check the second operand first
14503 since it's usually simpler. */
14507 CASE_CONVERT:
14508 /* Can't handle conversions from non-integral or wider integral type. */
14513 /* NOWRAP only extends to operations in the outermost type so
14514 make sure to strip it off here. */
14529 SIGNED);
14535 {
14538 /* Check for special cases to see if top is defined as multiple
14539 of bottom:
14541 top = (X & ~(bottom - 1) ; bottom is power of 2
14543 or
14545 Y = X % bottom
14546 top = X - Y. */
14565 }
14567 /* fall through */
14575 }
14576 }
14578 /* Return true if expression X cannot be (or contain) a NaN or infinity.
14579 This function returns true for integer expressions, and returns
14580 false if uncertain. */
14582 bool
14584 {
14589 {
14612 {
14613 CASE_CFN_FABS:
14614 CASE_CFN_FABS_FN:
14616 CASE_CFN_FMAX:
14617 CASE_CFN_FMAX_FN:
14618 CASE_CFN_FMIN:
14619 CASE_CFN_FMIN_FN:
14624 }
14628 }
14629 }
14631 /* Return true if expression X evaluates to an infinity.
14632 This function returns false for integer expressions. */
14634 bool
14636 {
14640 {
14653 }
14654 }
14656 /* Return true if expression X could evaluate to an infinity.
14657 This function returns false for integer expressions, and returns
14658 true if uncertain. */
14660 bool
14662 {
14666 {
14679 }
14680 }
14682 /* Return true if expression X evaluates to a signaling NaN.
14683 This function returns false for integer expressions. */
14685 bool
14687 {
14691 {
14702 }
14703 }
14705 /* Return true if expression X could evaluate to a signaling NaN.
14706 This function returns false for integer expressions, and returns
14707 true if uncertain. */
14709 bool
14711 {
14715 {
14735 {
14736 CASE_CFN_FABS:
14737 CASE_CFN_FABS_FN:
14739 CASE_CFN_FMAX:
14740 CASE_CFN_FMAX_FN:
14741 CASE_CFN_FMIN:
14742 CASE_CFN_FMIN_FN:
14747 }
14750 }
14751 }
14753 /* Return true if expression X evaluates to a NaN.
14754 This function returns false for integer expressions. */
14756 bool
14758 {
14762 {
14773 }
14774 }
14776 /* Return true if expression X could evaluate to a NaN.
14777 This function returns false for integer expressions, and returns
14778 true if uncertain. */
14780 bool
14782 {
14786 {
14811 {
14812 CASE_CFN_FABS:
14813 CASE_CFN_FABS_FN:
14815 CASE_CFN_FMAX:
14816 CASE_CFN_FMAX_FN:
14817 CASE_CFN_FMIN:
14818 CASE_CFN_FMIN_FN:
14823 }
14826 }
14827 }
14829 /* Return true if expression X could evaluate to -0.0.
14830 This function returns true if uncertain. */
14832 bool
14834 {
14838 {
14853 {
14854 CASE_CFN_FABS:
14855 CASE_CFN_FABS_FN:
14859 }
14862 }
14863 /* Ideally !(tree_expr_nonzero_p (X) || tree_expr_nonnegative_p (X))
14864 * but currently those predicates require tree and not const_tree. */
14866 }
14868 #define tree_expr_nonnegative_warnv_p(X, Y) \
14871 #define RECURSE(X) \
14872 ((tree_expr_nonnegative_warnv_p) (X, strict_overflow_p, depth + 1))
14874 /* Return true if CODE or TYPE is known to be non-negative. */
14876 static bool
14878 {
14882 /* Truth values evaluate to 0 or 1, which is nonnegative unless we
14883 have a signed:1 type (where the value is -1 and 0). */
14886 }
14888 /* Return true if (CODE OP0) is known to be non-negative. If the return
14889 value is based on the assumption that signed overflow is undefined,
14890 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14891 *STRICT_OVERFLOW_P. DEPTH is the current nesting depth of the query. */
14893 bool
14896 {
14901 {
14903 /* We can't return 1 if flag_wrapv is set because
14904 ABS_EXPR<INT_MIN> = INT_MIN. */
14908 {
14911 }
14919 CASE_CONVERT:
14920 {
14925 {
14929 {
14933 }
14934 }
14936 {
14942 }
14943 }
14948 }
14950 /* We don't know sign of `t', so be conservative and return false. */
14952 }
14954 /* Return true if (CODE OP0 OP1) is known to be non-negative. If the return
14955 value is based on the assumption that signed overflow is undefined,
14956 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14957 *STRICT_OVERFLOW_P. DEPTH is the current nesting depth of the query. */
14959 bool
14963 {
14968 {
14974 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
14975 both unsigned and at least 2 bits shorter than the result. */
14979 {
14984 {
14988 }
14989 }
14994 {
14995 /* x * x is always non-negative for floating point x
14996 or without overflow. */
14999 {
15004 }
15005 }
15007 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
15008 both unsigned and their total bits is shorter than the result. */
15012 {
15031 {
15041 }
15042 }
15049 /* Usually RECURSE (op0) || RECURSE (op1) but NaNs complicate
15050 things. */
15075 }
15077 /* We don't know sign of `t', so be conservative and return false. */
15079 }
15081 /* Return true if T is known to be non-negative. If the return
15082 value is based on the assumption that signed overflow is undefined,
15083 set *STRICT_OVERFLOW_P to true; otherwise, don't change
15084 *STRICT_OVERFLOW_P. DEPTH is the current nesting depth of the query. */
15086 bool
15088 {
15093 {
15107 /* Limit the depth of recursion to avoid quadratic behavior.
15108 This is expected to catch almost all occurrences in practice.
15109 If this code misses important cases that unbounded recursion
15110 would not, passes that need this information could be revised
15111 to provide it through dataflow propagation. */
15119 }
15120 }
15122 /* Return true if T is known to be non-negative. If the return
15123 value is based on the assumption that signed overflow is undefined,
15124 set *STRICT_OVERFLOW_P to true; otherwise, don't change
15125 *STRICT_OVERFLOW_P. DEPTH is the current nesting depth of the query. */
15127 bool
15130 {
15132 {
15133 CASE_CFN_ACOS:
15134 CASE_CFN_ACOS_FN:
15135 CASE_CFN_ACOSH:
15136 CASE_CFN_ACOSH_FN:
15137 CASE_CFN_CABS:
15138 CASE_CFN_CABS_FN:
15139 CASE_CFN_COSH:
15140 CASE_CFN_COSH_FN:
15141 CASE_CFN_ERFC:
15142 CASE_CFN_ERFC_FN:
15143 CASE_CFN_EXP:
15144 CASE_CFN_EXP_FN:
15145 CASE_CFN_EXP10:
15146 CASE_CFN_EXP2:
15147 CASE_CFN_EXP2_FN:
15148 CASE_CFN_FABS:
15149 CASE_CFN_FABS_FN:
15150 CASE_CFN_FDIM:
15151 CASE_CFN_FDIM_FN:
15152 CASE_CFN_HYPOT:
15153 CASE_CFN_HYPOT_FN:
15154 CASE_CFN_POW10:
15155 CASE_CFN_FFS:
15156 CASE_CFN_PARITY:
15157 CASE_CFN_POPCOUNT:
15158 CASE_CFN_CLZ:
15159 CASE_CFN_CLRSB:
15164 /* Always true. */
15167 CASE_CFN_SQRT:
15168 CASE_CFN_SQRT_FN:
15169 /* sqrt(-0.0) is -0.0. */
15174 CASE_CFN_ASINH:
15175 CASE_CFN_ASINH_FN:
15176 CASE_CFN_ATAN:
15177 CASE_CFN_ATAN_FN:
15178 CASE_CFN_ATANH:
15179 CASE_CFN_ATANH_FN:
15180 CASE_CFN_CBRT:
15181 CASE_CFN_CBRT_FN:
15182 CASE_CFN_CEIL:
15183 CASE_CFN_CEIL_FN:
15184 CASE_CFN_ERF:
15185 CASE_CFN_ERF_FN:
15186 CASE_CFN_EXPM1:
15187 CASE_CFN_EXPM1_FN:
15188 CASE_CFN_FLOOR:
15189 CASE_CFN_FLOOR_FN:
15190 CASE_CFN_FMOD:
15191 CASE_CFN_FMOD_FN:
15192 CASE_CFN_FREXP:
15193 CASE_CFN_FREXP_FN:
15194 CASE_CFN_ICEIL:
15195 CASE_CFN_IFLOOR:
15196 CASE_CFN_IRINT:
15197 CASE_CFN_IROUND:
15198 CASE_CFN_LCEIL:
15199 CASE_CFN_LDEXP:
15200 CASE_CFN_LFLOOR:
15201 CASE_CFN_LLCEIL:
15202 CASE_CFN_LLFLOOR:
15203 CASE_CFN_LLRINT:
15204 CASE_CFN_LLRINT_FN:
15205 CASE_CFN_LLROUND:
15206 CASE_CFN_LLROUND_FN:
15207 CASE_CFN_LRINT:
15208 CASE_CFN_LRINT_FN:
15209 CASE_CFN_LROUND:
15210 CASE_CFN_LROUND_FN:
15211 CASE_CFN_MODF:
15212 CASE_CFN_MODF_FN:
15213 CASE_CFN_NEARBYINT:
15214 CASE_CFN_NEARBYINT_FN:
15215 CASE_CFN_RINT:
15216 CASE_CFN_RINT_FN:
15217 CASE_CFN_ROUND:
15218 CASE_CFN_ROUND_FN:
15219 CASE_CFN_ROUNDEVEN:
15220 CASE_CFN_ROUNDEVEN_FN:
15221 CASE_CFN_SCALB:
15222 CASE_CFN_SCALBLN:
15223 CASE_CFN_SCALBLN_FN:
15224 CASE_CFN_SCALBN:
15225 CASE_CFN_SCALBN_FN:
15226 CASE_CFN_SIGNBIT:
15227 CASE_CFN_SIGNIFICAND:
15228 CASE_CFN_SINH:
15229 CASE_CFN_SINH_FN:
15230 CASE_CFN_TANH:
15231 CASE_CFN_TANH_FN:
15232 CASE_CFN_TRUNC:
15233 CASE_CFN_TRUNC_FN:
15234 /* True if the 1st argument is nonnegative. */
15237 CASE_CFN_FMAX:
15238 CASE_CFN_FMAX_FN:
15239 /* Usually RECURSE (arg0) || RECURSE (arg1) but NaNs complicate
15240 things. In the presence of sNaNs, we're only guaranteed to be
15241 non-negative if both operands are non-negative. In the presence
15242 of qNaNs, we're non-negative if either operand is non-negative
15243 and can't be a qNaN, or if both operands are non-negative. */
15252 CASE_CFN_FMIN:
15253 CASE_CFN_FMIN_FN:
15254 /* True if the 1st AND 2nd arguments are nonnegative. */
15257 CASE_CFN_COPYSIGN:
15258 CASE_CFN_COPYSIGN_FN:
15259 /* True if the 2nd argument is nonnegative. */
15262 CASE_CFN_POWI:
15263 /* True if the 1st argument is nonnegative or the second
15264 argument is an even integer. */
15270 CASE_CFN_POW:
15271 CASE_CFN_POW_FN:
15272 /* True if the 1st argument is nonnegative or the second
15273 argument is an even integer valued real. */
15275 {
15276 REAL_VALUE_TYPE c;
15277 HOST_WIDE_INT n;
15282 {
15283 REAL_VALUE_TYPE cint;
15287 }
15288 }
15293 }
15295 }
15297 /* Return true if T is known to be non-negative. If the return
15298 value is based on the assumption that signed overflow is undefined,
15299 set *STRICT_OVERFLOW_P to true; otherwise, don't change
15300 *STRICT_OVERFLOW_P. DEPTH is the current nesting depth of the query. */
15302 static bool
15304 {
15310 {
15312 {
15316 /* If the initializer is non-void, then it's a normal expression
15317 that will be assigned to the slot. */
15321 /* Otherwise, the initializer sets the slot in some way. One common
15322 way is an assignment statement at the end of the initializer. */
15324 {
15332 else
15334 }
15340 }
15343 {
15349 arg0,
15350 arg1,
15352 }
15365 }
15366 }
15368 #undef RECURSE
15369 #undef tree_expr_nonnegative_warnv_p
15371 /* Return true if T is known to be non-negative. If the return
15372 value is based on the assumption that signed overflow is undefined,
15373 set *STRICT_OVERFLOW_P to true; otherwise, don't change
15374 *STRICT_OVERFLOW_P. DEPTH is the current nesting depth of the query. */
15376 bool
15378 {
15385 {
15407 }
15410 {
15435 }
15436 }
15438 /* Return true if `t' is known to be non-negative. Handle warnings
15439 about undefined signed overflow. */
15441 bool
15443 {
15450 "determining that expression is always "
15452 WARN_STRICT_OVERFLOW_MISC);
15454 }
15457 /* Return true when (CODE OP0) is an address and is known to be nonzero.
15458 For floating point we further ensure that T is not denormal.
15459 Similar logic is present in nonzero_address in rtlanal.h.
15461 If the return value is based on the assumption that signed overflow
15462 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
15463 change *STRICT_OVERFLOW_P. */
15465 bool
15468 {
15470 {
15473 strict_overflow_p);
15476 {
15482 strict_overflow_p));
15483 }
15488 strict_overflow_p);
15492 }
15495 }
15497 /* Return true when (CODE OP0 OP1) is an address and is known to be nonzero.
15498 For floating point we further ensure that T is not denormal.
15499 Similar logic is present in nonzero_address in rtlanal.h.
15501 If the return value is based on the assumption that signed overflow
15502 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
15503 change *STRICT_OVERFLOW_P. */
15505 bool
15507 tree type,
15508 tree op0,
15510 {
15513 {
15517 {
15518 /* With the presence of negative values it is hard
15519 to say something. */
15526 /* One of operands must be positive and the other non-negative. */
15527 /* We don't set *STRICT_OVERFLOW_P here: even if this value
15528 overflows, on a twos-complement machine the sum of two
15529 nonnegative numbers can never be zero. */
15531 strict_overflow_p)
15533 strict_overflow_p));
15534 }
15539 {
15541 strict_overflow_p)
15543 strict_overflow_p))
15544 {
15547 }
15548 }
15557 {
15560 }
15567 {
15571 /* When both operands are nonzero, then MAX must be too. */
15573 strict_overflow_p))
15576 /* MAX where operand 0 is positive is positive. */
15578 strict_overflow_p);
15579 }
15580 /* MAX where operand 1 is positive is positive. */
15585 {
15589 }
15594 strict_overflow_p)
15596 strict_overflow_p));
15600 }
15603 }
15605 /* Return true when T is an address and is known to be nonzero.
15606 For floating point we further ensure that T is not denormal.
15607 Similar logic is present in nonzero_address in rtlanal.h.
15609 If the return value is based on the assumption that signed overflow
15610 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
15611 change *STRICT_OVERFLOW_P. */
15613 bool
15615 {
15618 {
15623 {
15635 /* For objects in symbol table check if we know they are non-zero.
15636 Don't do anything for variables and functions before symtab is built;
15637 it is quite possible that they will be declared weak later. */
15642 /* Constants are never weak. */
15647 }
15655 {
15659 }
15669 }
15671 }
15673 #define integer_valued_real_p(X) \
15676 #define RECURSE(X) \
15677 ((integer_valued_real_p) (X, depth + 1))
15679 /* Return true if the floating point result of (CODE OP0) has an
15680 integer value. We also allow +Inf, -Inf and NaN to be considered
15681 integer values. Return false for signaling NaN.
15683 DEPTH is the current nesting depth of the query. */
15685 bool
15687 {
15689 {
15696 CASE_CONVERT:
15697 {
15704 }
15708 }
15710 }
15712 /* Return true if the floating point result of (CODE OP0 OP1) has an
15713 integer value. We also allow +Inf, -Inf and NaN to be considered
15714 integer values. Return false for signaling NaN.
15716 DEPTH is the current nesting depth of the query. */
15718 bool
15720 {
15722 {
15732 }
15734 }
15736 /* Return true if the floating point result of calling FNDECL with arguments
15737 ARG0 and ARG1 has an integer value. We also allow +Inf, -Inf and NaN to be
15738 considered integer values. Return false for signaling NaN. If FNDECL
15739 takes fewer than 2 arguments, the remaining ARGn are null.
15741 DEPTH is the current nesting depth of the query. */
15743 bool
15745 {
15747 {
15748 CASE_CFN_CEIL:
15749 CASE_CFN_CEIL_FN:
15750 CASE_CFN_FLOOR:
15751 CASE_CFN_FLOOR_FN:
15752 CASE_CFN_NEARBYINT:
15753 CASE_CFN_NEARBYINT_FN:
15754 CASE_CFN_RINT:
15755 CASE_CFN_RINT_FN:
15756 CASE_CFN_ROUND:
15757 CASE_CFN_ROUND_FN:
15758 CASE_CFN_ROUNDEVEN:
15759 CASE_CFN_ROUNDEVEN_FN:
15760 CASE_CFN_TRUNC:
15761 CASE_CFN_TRUNC_FN:
15764 CASE_CFN_FMIN:
15765 CASE_CFN_FMIN_FN:
15766 CASE_CFN_FMAX:
15767 CASE_CFN_FMAX_FN:
15772 }
15774 }
15776 /* Return true if the floating point expression T (a GIMPLE_SINGLE_RHS)
15777 has an integer value. We also allow +Inf, -Inf and NaN to be
15778 considered integer values. Return false for signaling NaN.
15780 DEPTH is the current nesting depth of the query. */
15782 bool
15784 {
15786 {
15794 /* Limit the depth of recursion to avoid quadratic behavior.
15795 This is expected to catch almost all occurrences in practice.
15796 If this code misses important cases that unbounded recursion
15797 would not, passes that need this information could be revised
15798 to provide it through dataflow propagation. */
15802 depth));
15806 }
15808 }
15810 /* Return true if the floating point expression T (a GIMPLE_INVALID_RHS)
15811 has an integer value. We also allow +Inf, -Inf and NaN to be
15812 considered integer values. Return false for signaling NaN.
15814 DEPTH is the current nesting depth of the query. */
15816 static bool
15818 {
15820 {
15831 }
15833 }
15835 #undef RECURSE
15836 #undef integer_valued_real_p
15838 /* Return true if the floating point expression T has an integer value.
15839 We also allow +Inf, -Inf and NaN to be considered integer values.
15840 Return false for signaling NaN.
15842 DEPTH is the current nesting depth of the query. */
15844 bool
15846 {
15854 {
15870 }
15873 {
15879 {
15888 }
15892 }
15893 }
15895 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
15896 attempt to fold the expression to a constant without modifying TYPE,
15897 OP0 or OP1.
15899 If the expression could be simplified to a constant, then return
15900 the constant. If the expression would not be simplified to a
15901 constant, then return NULL_TREE. */
15903 tree
15905 {
15908 }
15910 /* Given the components of a unary expression CODE, TYPE and OP0,
15911 attempt to fold the expression to a constant without modifying
15912 TYPE or OP0.
15914 If the expression could be simplified to a constant, then return
15915 the constant. If the expression would not be simplified to a
15916 constant, then return NULL_TREE. */
15918 tree
15920 {
15923 }
15925 /* If EXP represents referencing an element in a constant string
15926 (either via pointer arithmetic or array indexing), return the
15927 tree representing the value accessed, otherwise return NULL. */
15929 tree
15931 {
15935 {
15937 tree index;
15938 tree string;
15943 else
15944 {
15948 /* Optimize the special-case of a zero lower bound.
15950 We convert the low_bound to sizetype to avoid some problems
15951 with constant folding. (E.g. suppose the lower bound is 1,
15952 and its mode is QI. Without the conversion,l (ARRAY
15953 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
15954 +INDEX), which becomes (ARRAY+255+INDEX). Oops!) */
15960 }
15962 scalar_int_mode char_mode;
15974 }
15976 }
15978 /* Folds a read from vector element at IDX of vector ARG. */
15980 tree
15982 {
15987 {
15991 {
15998 }
15999 }
16001 }
16003 /* Return the tree for neg (ARG0) when ARG0 is known to be either
16004 an integer constant, real, or fixed-point constant.
16006 TYPE is the type of the result. */
16008 static tree
16010 {
16014 {
16020 {
16021 FIXED_VALUE_TYPE f;
16026 /* Propagate overflow flags. */
16030 }
16034 {
16041 }
16044 }
16047 }
16049 /* Return the tree for abs (ARG0) when ARG0 is known to be either
16050 an integer constant or real constant.
16052 TYPE is the type of the result. */
16054 tree
16056 {
16060 {
16062 {
16063 /* If the value is unsigned or non-negative, then the absolute value
16064 is the same as the ordinary value. */
16068 ;
16070 /* If the value is negative, then the absolute value is
16071 its negation. */
16072 else
16075 /* Force to the destination type, set TREE_OVERFLOW for signed
16076 TYPE only. */
16078 }
16084 else
16090 }
16093 }
16095 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
16096 constant. TYPE is the type of the result. */
16098 static tree
16100 {
16104 }
16106 /* Given CODE, a relational operator, the target type, TYPE and two
16107 constant operands OP0 and OP1, return the result of the
16108 relational operation. If the result is not a compile time
16109 constant, then return NULL_TREE. */
16111 static tree
16113 {
16116 /* From here on, the only cases we handle are when the result is
16117 known to be a constant. */
16120 {
16124 /* Handle the cases where either operand is a NaN. */
16126 {
16128 {
16156 }
16159 }
16162 }
16165 {
16169 }
16171 /* Handle equality/inequality of complex constants. */
16173 {
16184 else
16186 }
16189 {
16191 {
16192 /* Have vector comparison with scalar boolean result. */
16200 {
16208 }
16210 }
16211 tree_vector_builder elts;
16216 {
16229 }
16232 }
16234 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
16236 To compute GT, swap the arguments and do LT.
16237 To compute GE, do LT and invert the result.
16238 To compute LE, swap the arguments, do LT and invert the result.
16239 To compute NE, do EQ and invert the result.
16241 Therefore, the code below must handle only EQ and LT. */
16244 {
16247 }
16249 /* Note that it is safe to invert for real values here because we
16250 have already handled the one case that it matters. */
16254 {
16257 }
16259 /* Compute a result for LT or EQ if args permit;
16260 Otherwise return T. */
16262 {
16265 else
16267 }
16268 else
16274 }
16276 /* If necessary, return a CLEANUP_POINT_EXPR for EXPR with the
16277 indicated TYPE. If no CLEANUP_POINT_EXPR is necessary, return EXPR
16278 itself. */
16280 tree
16282 {
16283 /* If the expression does not have side effects then we don't have to wrap
16284 it with a cleanup point expression. */
16288 /* If the expression is a return, check to see if the expression inside the
16289 return has no side effects or the right hand side of the modify expression
16290 inside the return. If either don't have side effects set we don't need to
16291 wrap the expression in a cleanup point expression. Note we don't check the
16292 left hand side of the modify because it should always be a return decl. */
16294 {
16301 }
16304 }
16306 /* Given a pointer value OP0 and a type TYPE, return a simplified version
16307 of an indirection through OP0, or NULL_TREE if no simplification is
16308 possible. */
16310 tree
16312 {
16314 tree subtype;
16315 poly_uint64 const_op01;
16324 {
16328 /* *&CONST_DECL -> to the value of the const decl. */
16331 /* *&p => p; make sure to handle *&"str"[cst] here. */
16333 {
16337 else
16339 }
16340 /* *(foo *)&fooarray => fooarray[0] */
16343 && (!in_gimple_form
16345 {
16355 }
16356 /* *(foo *)&complexfoo => __real__ complexfoo */
16360 /* *(foo *)&vectorfoo => BIT_FIELD_REF<vectorfoo,...> */
16363 {
16367 index);
16368 }
16369 }
16373 {
16379 {
16380 tree op00type;
16384 /* ((foo*)&vectorfoo)[1] => BIT_FIELD_REF<vectorfoo,...> */
16387 /* POINTER_PLUS_EXPR second operand is sizetype, unsigned,
16388 but we want to treat offsets with MSB set as negative.
16389 For the code below negative offsets are invalid and
16390 TYPE_SIZE of the element is something unsigned, so
16391 check whether op01 fits into poly_int64, which implies
16392 it is from 0 to INTTYPE_MAXIMUM (HOST_WIDE_INT), and
16393 then just use poly_uint64 because we want to treat the
16394 value as unsigned. */
16396 {
16398 poly_uint64 max_offset
16402 {
16407 }
16408 }
16409 /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */
16412 {
16414 const_op01))
16416 }
16417 /* ((foo *)&fooarray)[1] => fooarray[1] */
16420 {
16429 {
16434 }
16435 }
16436 }
16437 }
16439 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
16442 && (!in_gimple_form
16444 {
16445 tree type_domain;
16455 NULL_TREE);
16456 }
16459 }
16461 /* Builds an expression for an indirection through T, simplifying some
16462 cases. */
16464 tree
16466 {
16474 }
16476 /* Given an INDIRECT_REF T, return either T or a simplified version. */
16478 tree
16480 {
16485 else
16487 }
16489 /* Strip non-trapping, non-side-effecting tree nodes from an expression
16490 whose result is ignored. The type of the returned tree need not be
16491 the same as the original expression. */
16493 tree
16495 {
16501 {
16512 else
16518 {
16534 }
16539 }
16540 }
16542 /* Return the value of VALUE, rounded up to a multiple of DIVISOR. */
16544 tree
16546 {
16552 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
16553 have to do anything. Only do this when we are not given a const,
16554 because in that case, this check is more expensive than just
16555 doing it. */
16557 {
16562 }
16564 /* If divisor is a power of two, simplify this to bit manipulation. */
16566 {
16568 {
16582 }
16583 else
16584 {
16585 tree t;
16591 }
16592 }
16593 else
16594 {
16599 }
16602 }
16604 /* Likewise, but round down. */
16606 tree
16608 {
16615 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
16616 have to do anything. Only do this when we are not given a const,
16617 because in that case, this check is more expensive than just
16618 doing it. */
16620 {
16625 }
16627 /* If divisor is a power of two, simplify this to bit manipulation. */
16629 {
16630 tree t;
16634 }
16635 else
16636 {
16641 }
16644 }
16646 /* Returns the pointer to the base of the object addressed by EXP and
16647 extracts the information about the offset of the access, storing it
16648 to PBITPOS and POFFSET. */
16650 static tree
16653 {
16654 tree core;
16655 machine_mode mode;
16657 poly_int64 bitsize;
16666 {
16671 }
16673 {
16679 {
16680 poly_offset_int tem
16686 }
16687 }
16688 else
16689 {
16693 }
16696 }
16698 /* Returns true if addresses of E1 and E2 differ by a constant, false
16699 otherwise. If they do, E1 - E2 is stored in *DIFF. */
16701 bool
16703 {
16718 {
16728 }
16730 {
16731 /* If only one of the offsets is non-constant, the difference cannot
16732 be a constant. */
16734 }
16735 else
16740 }
16742 /* Return OFF converted to a pointer offset type suitable as offset for
16743 POINTER_PLUS_EXPR. Use location LOC for this conversion. */
16744 tree
16746 {
16750 }
16752 /* Build and fold a POINTER_PLUS_EXPR at LOC offsetting PTR by OFF. */
16753 tree
16755 {
16758 }
16760 /* Build and fold a POINTER_PLUS_EXPR at LOC offsetting PTR by OFF. */
16761 tree
16763 {
16766 }
16768 /* Return a pointer to a NUL-terminated string containing the sequence
16769 of bytes corresponding to the representation of the object referred to
16770 by SRC (or a subsequence of such bytes within it if SRC is a reference
16771 to an initialized constant array plus some constant offset).
16772 Set *STRSIZE the number of bytes in the constant sequence including
16773 the terminating NUL byte. *STRSIZE is equal to sizeof(A) - OFFSET
16774 where A is the array that stores the constant sequence that SRC points
16775 to and OFFSET is the byte offset of SRC from the beginning of A. SRC
16776 need not point to a string or even an array of characters but may point
16777 to an object of any type. */
16781 {
16782 /* The offset into the array A storing the string, and A's byte size. */
16783 tree offset_node;
16784 tree mem_size;
16791 else
16798 {
16801 else
16803 }
16808 /* ARRAY_SIZE is the byte size of the array the constant sequence
16809 is stored in and equal to sizeof A. INIT_BYTES is the number
16810 of bytes in the constant sequence used to initialize the array,
16811 including any embedded NULs as well as the terminating NUL (for
16812 strings), but not including any trailing zeros/NULs past
16813 the terminating one appended implicitly to a string literal to
16814 zero out the remainder of the array it's stored in. For example,
16815 given:
16816 const char a[7] = "abc\0d";
16817 n = strlen (a + 1);
16818 ARRAY_SIZE is 7, INIT_BYTES is 6, and OFFSET is 1. For a valid
16819 (i.e., nul-terminated) string with no embedded nuls, INIT_BYTES
16820 is equal to strlen (A) + 1. */
16825 /* Ideally this would turn into a gcc_checking_assert over time. */
16833 {
16834 /* Compute and store the number of characters from the beginning
16835 of the substring at OFFSET to the end, including the terminating
16836 nul. Offsets past the initial length refer to null strings. */
16839 else
16841 }
16842 else
16843 {
16845 /* Support only properly NUL-terminated single byte strings. */
16850 }
16853 }
16855 /* Return a pointer to a NUL-terminated string corresponding to
16856 the expression STR referencing a constant string, possibly
16857 involving a constant offset. Return null if STR either doesn't
16858 reference a constant string or if it involves a nonconstant
16859 offset. */
16863 {
16865 }
16867 /* Given a tree T, compute which bits in T may be nonzero. */
16869 wide_int
16871 {
16873 {
16891 CASE_CONVERT:
16897 {
16902 }
16906 {
16914 }
16918 {
16926 }
16930 }
16933 }
16935 /* Helper function for address compare simplifications in match.pd.
16936 OP0 and OP1 are ADDR_EXPR operands being compared by CODE.
16937 TYPE is the type of comparison operands.
16938 BASE0, BASE1, OFF0 and OFF1 are set by the function.
16939 GENERIC is true if GENERIC folding and false for GIMPLE folding.
16940 Returns 0 if OP0 is known to be unequal to OP1 regardless of OFF{0,1},
16941 1 if bases are known to be equal and OP0 cmp OP1 depends on OFF0 cmp OFF1,
16942 and 2 if unknown. */
16944 int
16948 {
16958 {
16961 }
16963 {
16966 }
16971 /* Punt in GENERIC on variables with value expressions;
16972 the value expressions might point to fields/elements
16973 of other vars etc. */
16979 {
16983 }
16991 /* Assume different STRING_CSTs with the same content will be
16992 merged. */
17001 {
17004 /* If the offsets are equal we can ignore overflow. */
17007 /* Or if we compare using pointers to decls or strings. */
17012 }
17018 /* At this point we know (or assume) the two pointers point at
17019 different objects. */
17023 /* Punt on non-zero offsets from functions. */
17027 /* Or if the bases are neither decls nor string literals. */
17032 /* For initializers, assume addresses of different functions are
17033 different. */
17039 /* Compute whether one address points to the start of one
17040 object and another one to the end of another one. */
17043 {
17046 else
17048 }
17051 else
17052 {
17056 else
17058 }
17060 {
17063 else
17065 }
17068 else
17069 {
17073 else
17075 }
17077 {
17078 /* If one offset is pointing (or could be) to the beginning of one
17079 object and the other is pointing to one past the last byte of the
17080 other object, punt. */
17085 /* If both offsets are the same, there are some cases we know that are
17086 ok. Either if we know they aren't zero, or if we know both sizes
17087 are no zero. */
17093 }
17095 /* At this point, equal is 2 if either one or both pointers are out of
17096 bounds of their object, or one points to start of its object and the
17097 other points to end of its object. This is unspecified behavior
17098 e.g. in C++. Otherwise equal is 0. */
17102 /* When both pointers point to string literals, even when equal is 0,
17103 due to tail merging of string literals the pointers might be the same. */
17105 {
17112 /* If the bytes in the string literals starting at the pointers
17113 differ, the pointers need to be different. */
17118 {
17123 /* If even the bytes in the string literal before the
17124 pointers are the same, the string literals could be
17125 tail merged. */
17127 }
17129 }
17134 /* If this is a pointer comparison, ignore for now even
17135 valid equalities where one pointer is the offset zero
17136 of one object and the other to one past end of another one. */
17140 /* Assume that string literals can't be adjacent to variables
17141 (automatic or global). */
17145 /* Assume that automatic variables can't be adjacent to global
17146 variables. */
17151 }
17153 /* Return the single non-zero element of a CONSTRUCTOR or NULL_TREE. */
17154 tree
17156 {
17165 {
17169 }
17171 }
17173 #if CHECKING_P
17177 /* Helper functions for writing tests of folding trees. */
17179 /* Verify that the binary op (LHS CODE RHS) folds to CONSTANT. */
17181 static void
17183 tree constant)
17184 {
17186 }
17188 /* Verify that the binary op (LHS CODE RHS) folds to an NON_LVALUE_EXPR
17189 wrapping WRAPPED_EXPR. */
17191 static void
17193 tree wrapped_expr)
17194 {
17199 }
17201 /* Verify that various arithmetic binary operations are folded
17202 correctly. */
17204 static void
17206 {
17212 /* Addition. */
17213 /* 1 <-- (0 + 1) */
17215 one);
17217 one);
17219 /* (nonlvalue)x <-- (x + 0) */
17221 x);
17223 /* Subtraction. */
17224 /* 0 <-- (x - x) */
17226 zero);
17228 x);
17230 /* Multiplication. */
17231 /* 0 <-- (x * 0) */
17233 zero);
17235 /* (nonlvalue)x <-- (x * 1) */
17237 x);
17238 }
17242 /* Build a VECTOR_CST corresponding to VMODE, and has
17243 encoding given by NPATTERNS, NELTS_PER_PATTERN and STEP.
17244 Fill it with randomized elements, using rand() % THRESHOLD. */
17246 static tree
17251 {
17256 // Fill a0 for each pattern
17263 // Fill a1 for each pattern
17265 {
17266 tree a1;
17268 {
17273 }
17274 else
17277 }
17282 {
17287 }
17290 }
17292 /* Validate result of VEC_PERM_EXPR folding for the unit-tests below,
17293 when result is VLA. */
17295 static void
17298 {
17299 /* Actual npatterns and encoded_elts in res may be less than expected due
17300 to canonicalization. */
17307 }
17309 /* Validate result of VEC_PERM_EXPR folding for the unit-tests below,
17310 when the result is VLS. */
17312 static void
17314 {
17318 }
17320 /* Helper routine to push multiple elements into BUILDER. */
17324 {
17327 }
17329 #define ARG0(index) vector_cst_elt (arg0, index)
17330 #define ARG1(index) vector_cst_elt (arg1, index)
17332 /* Test cases where result is VNx4SI and input vectors are V4SI. */
17334 static void
17336 {
17338 {
17339 /* Case 1:
17340 sel = { 0, 4, 1, 5, ... }
17341 res = { arg[0], arg1[0], arg0[1], arg1[1], ...} // (4, 1) */
17342 {
17346 tree inner_type
17360 }
17362 /* Case 2: Same as case 1, but contains an out of bounds access which
17363 should wrap around.
17364 sel = {0, 8, 4, 12, ...} (4, 1)
17365 res = { arg0[0], arg0[0], arg1[0], arg1[0], ... } (4, 1). */
17366 {
17370 tree inner_type
17384 }
17385 }
17386 }
17388 /* Test cases where result is V4SI and input vectors are VNx4SI. */
17390 static void
17392 {
17394 {
17395 /* Case 1:
17396 sel = { 0, 1, 2, 3}
17397 res = { arg0[0], arg0[1], arg0[2], arg0[3] }. */
17398 {
17402 tree inner_type
17416 }
17418 /* Case 2: Same as Case 1, but crossing input vector.
17419 sel = {0, 2, 4, 6}
17420 In this case,the index 4 is ambiguous since len = 4 + 4x.
17421 Since we cannot determine, which vector to choose from during
17422 compile time, should return NULL_TREE. */
17423 {
17427 tree inner_type
17442 }
17443 }
17444 }
17446 /* Test all input vectors. */
17448 static void
17450 {
17451 /* Test with 10 different inputs. */
17453 {
17458 /* Case 1: mask = {0, ...} // (1, 1)
17459 res = { arg0[0], ... } // (1, 1) */
17460 {
17467 }
17469 /* Case 2: mask = {len, ...} // (1, 1)
17470 res = { arg1[0], ... } // (1, 1) */
17471 {
17479 }
17480 }
17481 }
17483 /* Test all vectors which contain at-least 2 elements. */
17485 static void
17487 {
17489 {
17490 /* Case 1: mask = { 0, len, ... } // (2, 1)
17491 res = { arg0[0], arg1[0], ... } // (2, 1) */
17492 {
17506 }
17508 /* Case 2: mask = { 0, len, 1, len+1, ... } // (2, 2)
17509 res = { arg0[0], arg1[0], arg0[1], arg1[1], ... } // (2, 2) */
17510 {
17524 }
17526 /* Case 4: mask = {0, 0, 1, ...} // (1, 3)
17527 Test that the stepped sequence of the pattern selects from
17528 same input pattern. Since input vectors have npatterns = 2,
17529 and step (a2 - a1) = 1, step is not a multiple of npatterns
17530 in input vector. So return NULL_TREE. */
17531 {
17546 }
17548 /* Case 5: mask = {len, 0, 1, ...} // (1, 3)
17549 Test that stepped sequence of the pattern selects from arg0.
17550 res = { arg1[0], arg0[0], arg0[1], ... } // (1, 3) */
17551 {
17565 }
17567 /* Case 6: PR111648 - a1 chooses base element from input vector arg.
17568 In this case ensure that arg has a natural stepped sequence
17569 to preserve arg's encoding.
17571 As a concrete example, consider:
17572 arg0: { -16, -9, -10, ... } // (1, 3)
17573 arg1: { -12, -5, -6, ... } // (1, 3)
17574 sel = { 0, len, len + 1, ... } // (1, 3)
17576 This will create res with following encoding:
17577 res = { arg0[0], arg1[0], arg1[1], ... } // (1, 3)
17578 = { -16, -12, -5, ... }
17580 The step in above encoding would be: (-5) - (-12) = 7
17581 And hence res[3] would be computed as -5 + 7 = 2.
17582 instead of arg1[2], ie, -6.
17583 Ensure that valid_mask_for_fold_vec_perm_cst returns false
17584 for this case. */
17585 {
17596 /* FIXME: It may happen that build_vec_cst_rand may build a natural
17597 stepped pattern, even if we didn't explicitly tell it to. So folding
17598 may not always fail, but if it does, ensure that's because arg1 does
17599 not have a natural stepped sequence (and not due to other reason) */
17603 }
17605 /* Case 7: Same as Case 6, except that arg1 contains natural stepped
17606 sequence and thus folding should be valid for this case. */
17607 {
17621 }
17623 /* Case 8: Same as aarch64/sve/slp_3.c:
17624 arg0, arg1 are dup vectors.
17625 sel = { 0, len, 1, len+1, 2, len+2, ... } // (2, 3)
17626 So res = { arg0[0], arg1[0], ... } // (2, 1)
17628 In this case, since the input vectors are dup, only the first two
17629 elements per pattern in sel are considered significant. */
17630 {
17644 }
17645 }
17646 }
17648 /* Test all vectors which contain at-least 4 elements. */
17650 static void
17652 {
17654 {
17655 /* Case 1: mask = { 0, len, 1, len+1, ... } // (4, 1)
17656 res: { arg0[0], arg1[0], arg0[1], arg1[1], ... } // (4, 1) */
17657 {
17671 }
17673 /* Case 2: sel = {0, 1, 2, ...} // (1, 3)
17674 res: { arg0[0], arg0[1], arg0[2], ... } // (1, 3) */
17675 {
17688 }
17690 /* Case 3: sel = {len, len+1, len+2, ...} // (1, 3)
17691 res: { arg1[0], arg1[1], arg1[2], ... } // (1, 3) */
17692 {
17705 }
17707 /* Case 4:
17708 sel = { len, 0, 2, ... } // (1, 3)
17709 This should return NULL because we cross the input vectors.
17710 Because,
17711 Let's assume len = C + Cx
17712 a1 = 0
17713 S = 2
17714 esel = arg0_len / sel_npatterns = C + Cx
17715 ae = 0 + (esel - 2) * S
17716 = 0 + (C + Cx - 2) * 2
17717 = 2(C-2) + 2Cx
17719 For C >= 4:
17720 Let q1 = a1 / arg0_len = 0 / (C + Cx) = 0
17721 Let qe = ae / arg0_len = (2(C-2) + 2Cx) / (C + Cx) = 1
17722 Since q1 != qe, we cross input vectors.
17723 So return NULL_TREE. */
17724 {
17738 }
17740 /* Case 5: npatterns(arg0) = 4 > npatterns(sel) = 2
17741 mask = { 0, len, 1, len + 1, ...} // (2, 2)
17742 res = { arg0[0], arg1[0], arg0[1], arg1[1], ... } // (2, 2)
17744 Note that fold_vec_perm_cst will set
17745 res_npatterns = max(4, max(4, 2)) = 4
17746 However after canonicalizing, we will end up with shape (2, 2). */
17747 {
17760 }
17762 /* Case 6: Test combination in sel, where one pattern is dup and other
17763 is stepped sequence.
17764 sel = { 0, 0, 0, 1, 0, 2, ... } // (2, 3)
17765 res = { arg0[0], arg0[0], arg0[0],
17766 arg0[1], arg0[0], arg0[2], ... } // (2, 3) */
17767 {
17782 }
17784 /* Case 7: PR111048: Check that we set arg_npatterns correctly,
17785 when arg0, arg1 and sel have different number of patterns.
17786 arg0 is of shape (1, 1)
17787 arg1 is of shape (4, 1)
17788 sel is of shape (2, 3) = {1, len, 2, len+1, 3, len+2, ...}
17790 In this case the pattern: {len, len+1, len+2, ...} chooses arg1.
17791 However,
17792 step = (len+2) - (len+1) = 1
17793 arg_npatterns = VECTOR_CST_NPATTERNS (arg1) = 4
17794 Since step is not a multiple of arg_npatterns,
17795 valid_mask_for_fold_vec_perm_cst should return false,
17796 and thus fold_vec_perm_cst should return NULL_TREE. */
17797 {
17812 }
17814 /* Case 8: PR111754: When input vector is not a stepped sequence,
17815 check that the result is not a stepped sequence either, even
17816 if sel has a stepped sequence. */
17817 {
17830 }
17832 /* Case 9: If sel doesn't contain a stepped sequence,
17833 check that the result has same encoding as sel, irrespective
17834 of shape of input vectors. */
17835 {
17850 }
17851 }
17852 }
17854 /* Test all vectors which contain at-least 8 elements. */
17856 static void
17858 {
17860 {
17861 /* Case 1: sel_npatterns (4) > input npatterns (2)
17862 sel: { 0, 0, 1, len, 2, 0, 3, len, 4, 0, 5, len, ...} // (4, 3)
17863 res: { arg0[0], arg0[0], arg0[0], arg1[0],
17864 arg0[2], arg0[0], arg0[3], arg1[0],
17865 arg0[4], arg0[0], arg0[5], arg1[0], ... } // (4, 3) */
17866 {
17883 }
17884 }
17885 }
17887 /* Test vectors for which nunits[0] <= 4. */
17889 static void
17891 {
17892 /* Case 1: mask = {0, 4, ...} // (1, 2)
17893 This should return NULL_TREE because the index 4 may choose
17894 from either arg0 or arg1 depending on vector length. */
17895 {
17910 }
17911 }
17913 #undef ARG0
17914 #undef ARG1
17916 /* Return true if SIZE is of the form C + Cx and C is power of 2. */
17918 static bool
17920 {
17928 }
17930 /* Execute fold_vec_perm_cst unit tests. */
17932 static void
17934 {
17938 machine_mode vmode;
17940 {
17941 /* Obtain modes corresponding to VNx4SI and V4SI,
17942 to call mixed mode tests below.
17943 FIXME: Is there a better way to do this ? */
17945 {
17952 }
17969 }
17974 {
17977 }
17978 }
17981 /* Verify that various binary operations on vectors are folded
17982 correctly. */
17984 static void
17986 {
17993 /* Verify equality tests that return a scalar boolean result. */
18006 }
18008 /* Verify folding of VEC_DUPLICATE_EXPRs. */
18010 static void
18012 {
18015 /* This will be 1 if VEC_MODE isn't a vector mode. */
18022 }
18024 /* Run all of the selftests within this file. */
18026 void
18028 {
18033 }