| blob | 58b967e48fee11fee98436e14a50b61c4312fa65 |
1 /* Fold a constant sub-tree into a single node for C-compiler
2 Copyright (C) 1987-2019 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. */
87 /* Nonzero if we are folding constants inside an initializer; zero
88 otherwise. */
91 /* The following constants represent a bit based encoding of GCC's
92 comparison operators. This encoding simplifies transformations
93 on relational comparison operators, such as AND and OR. */
111 };
144 /* Return EXPR_LOCATION of T if it is not UNKNOWN_LOCATION.
145 Otherwise, return LOC. */
147 static location_t
149 {
152 }
154 /* Similar to protected_set_expr_location, but never modify x in place,
155 if location can and needs to be set, unshare it. */
159 {
165 {
168 }
170 }
171 \f
172 /* If ARG2 divides ARG1 with zero remainder, carries out the exact
173 division and returns the quotient. Otherwise returns
174 NULL_TREE. */
176 tree
178 {
179 widest_int quo;
186 }
187 \f
188 /* This is nonzero if we should defer warnings about undefined
189 overflow. This facility exists because these warnings are a
190 special case. The code to estimate loop iterations does not want
191 to issue any warnings, since it works with expressions which do not
192 occur in user code. Various bits of cleanup code call fold(), but
193 only use the result if it has certain characteristics (e.g., is a
194 constant); that code only wants to issue a warning if the result is
195 used. */
199 /* If a warning about undefined overflow is deferred, this is the
200 warning. Note that this may cause us to turn two warnings into
201 one, but that is fine since it is sufficient to only give one
202 warning per expression. */
206 /* If a warning about undefined overflow is deferred, this is the
207 level at which the warning should be emitted. */
211 /* Start deferring overflow warnings. We could use a stack here to
212 permit nested calls, but at present it is not necessary. */
214 void
216 {
218 }
220 /* Stop deferring overflow warnings. If there is a pending warning,
221 and ISSUE is true, then issue the warning if appropriate. STMT is
222 the statement with which the warning should be associated (used for
223 location information); STMT may be NULL. CODE is the level of the
224 warning--a warn_strict_overflow_code value. This function will use
225 the smaller of CODE and the deferred code when deciding whether to
226 issue the warning. CODE may be zero to mean to always use the
227 deferred code. */
229 void
231 {
233 location_t locus;
238 {
244 }
255 /* Use the smallest code level when deciding to issue the
256 warning. */
265 else
268 }
270 /* Stop deferring overflow warnings, ignoring any deferred
271 warnings. */
273 void
275 {
277 }
279 /* Whether we are deferring overflow warnings. */
281 bool
283 {
285 }
287 /* This is called when we fold something based on the fact that signed
288 overflow is undefined. */
290 void
292 {
294 {
297 {
300 }
301 }
304 }
305 \f
306 /* Return true if the built-in mathematical function specified by CODE
307 is odd, i.e. -f(x) == f(-x). */
309 bool
311 {
313 {
314 CASE_CFN_ASIN:
315 CASE_CFN_ASINH:
316 CASE_CFN_ATAN:
317 CASE_CFN_ATANH:
318 CASE_CFN_CASIN:
319 CASE_CFN_CASINH:
320 CASE_CFN_CATAN:
321 CASE_CFN_CATANH:
322 CASE_CFN_CBRT:
323 CASE_CFN_CPROJ:
324 CASE_CFN_CSIN:
325 CASE_CFN_CSINH:
326 CASE_CFN_CTAN:
327 CASE_CFN_CTANH:
328 CASE_CFN_ERF:
329 CASE_CFN_LLROUND:
330 CASE_CFN_LROUND:
331 CASE_CFN_ROUND:
332 CASE_CFN_ROUNDEVEN:
333 CASE_CFN_ROUNDEVEN_FN:
334 CASE_CFN_SIN:
335 CASE_CFN_SINH:
336 CASE_CFN_TAN:
337 CASE_CFN_TANH:
338 CASE_CFN_TRUNC:
341 CASE_CFN_LLRINT:
342 CASE_CFN_LRINT:
343 CASE_CFN_NEARBYINT:
344 CASE_CFN_RINT:
349 }
351 }
353 /* Check whether we may negate an integer constant T without causing
354 overflow. */
356 bool
358 {
359 tree type;
368 }
370 /* Determine whether an expression T can be cheaply negated using
371 the function negate_expr without introducing undefined overflow. */
373 static bool
375 {
376 tree type;
385 {
390 /* Check that -CST will not overflow type. */
403 /* We want to canonicalize to positive real constants. Pretend
404 that only negative ones can be easily negated. */
412 {
416 /* Steps don't prevent negation. */
423 }
438 /* -(A + B) -> (-B) - A. */
441 /* -(A + B) -> (-A) - B. */
445 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
454 /* INT_MIN/n * n doesn't overflow while negating one operand it does
455 if n is a (negative) power of two. */
466 /* Fall through. */
479 /* In general we can't negate A in A / B, because if A is INT_MIN and
480 B is not 1 we change the sign of the result. */
484 /* In general we can't negate B in A / B, because if A is INT_MIN and
485 B is 1, we may turn this into INT_MIN / -1 which is undefined
486 and actually traps on some architectures. */
495 /* Negate -((double)float) as (double)(-float). */
497 {
501 }
505 /* Negate -f(x) as f(-x). */
511 /* Optimize -((int)x >> 31) into (unsigned)x >> 31 for int. */
513 {
517 }
522 }
524 }
526 /* Given T, an expression, return a folded tree for -T or NULL_TREE, if no
527 simplification is possible.
528 If negate_expr_p would return true for T, NULL_TREE will never be
529 returned. */
531 static tree
533 {
535 tree tem;
538 {
539 /* Convert - (~A) to A + 1. */
563 {
568 }
572 {
573 tree_vector_builder elts;
577 {
582 }
585 }
608 {
609 /* -(A + B) -> (-B) - A. */
611 {
615 }
617 /* -(A + B) -> (-A) - B. */
619 {
623 }
624 }
628 /* - (A - B) -> B - A */
639 /* Fall through. */
643 {
652 }
660 /* In general we can't negate A in A / B, because if A is INT_MIN and
661 B is not 1 we change the sign of the result. */
667 /* In general we can't negate B in A / B, because if A is INT_MIN and
668 B is 1, we may turn this into INT_MIN / -1 which is undefined
669 and actually traps on some architectures. */
681 /* Convert -((double)float) into (double)(-float). */
683 {
687 }
691 /* Negate -f(x) as f(-x). */
694 {
700 }
704 /* Optimize -((int)x >> 31) into (unsigned)x >> 31 for int. */
706 {
709 {
716 }
717 }
722 }
725 }
727 /* A wrapper for fold_negate_expr_1. */
729 static tree
731 {
738 }
740 /* Like fold_negate_expr, but return a NEGATE_EXPR tree, if T cannot be
741 negated in a simpler way. Also allow for T to be NULL_TREE, in which case
742 return NULL_TREE. */
744 static tree
746 {
748 location_t loc;
761 }
762 \f
763 /* Split a tree IN into a constant, literal and variable parts that could be
764 combined with CODE to make IN. "constant" means an expression with
765 TREE_CONSTANT but that isn't an actual constant. CODE must be a
766 commutative arithmetic operation. Store the constant part into *CONP,
767 the literal in *LITP and return the variable part. If a part isn't
768 present, set it to null. If the tree does not decompose in this way,
769 return the entire tree as the variable part and the other parts as null.
771 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
772 case, we negate an operand that was subtracted. Except if it is a
773 literal for which we use *MINUS_LITP instead.
775 If NEGATE_P is true, we are negating all of IN, again except a literal
776 for which we use *MINUS_LITP instead. If a variable part is of pointer
777 type, it is negated after converting to TYPE. This prevents us from
778 generating illegal MINUS pointer expression. LOC is the location of
779 the converted variable part.
781 If IN is itself a literal or constant, return it as appropriate.
783 Note that we do not guarantee that any of the three values will be the
784 same type as IN, but they will have the same signedness and mode. */
786 static tree
790 {
798 /* Strip any conversions that don't change the machine mode or signedness. */
807 /* We can associate addition and subtraction together (even
808 though the C standard doesn't say so) for integers because
809 the value is not affected. For reals, the value might be
810 affected, so we can't. */
816 {
822 /* First see if either of the operands is a literal, then a constant. */
835 /* If we haven't dealt with either operand, this is not a case we can
836 decompose. Otherwise, VAR is either of the ones remaining, if any. */
841 else
844 /* Now do any needed negations. */
851 }
856 {
857 /* -1 - X is folded to ~X, undo that here. Do _not_ do this
858 when IN is constant. */
861 }
862 else
866 {
879 }
889 }
891 /* Re-associate trees split by the above function. T1 and T2 are
892 either expressions to associate or null. Return the new
893 expression, if any. LOC is the location of the new expression. If
894 we build an operation, do it in TYPE and with CODE. */
896 static tree
898 {
900 {
903 }
907 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
908 try to fold this since we will have infinite recursion. But do
909 deal with any NEGATE_EXPRs. */
913 {
915 {
928 }
930 {
933 }
937 }
941 }
942 \f
943 /* Check whether TYPE1 and TYPE2 are equivalent integer types, suitable
944 for use in int_const_binop, size_binop and size_diffop. */
946 static bool
948 {
955 {
964 }
969 }
971 /* Combine two wide ints ARG1 and ARG2 under operation CODE to produce
972 a new constant in RES. Return FALSE if we don't know how to
973 evaluate CODE at compile-time. */
975 bool
979 {
980 wide_int tmp;
983 {
999 {
1003 else
1005 }
1006 else
1010 /* It's unclear from the C standard whether shifts can overflow.
1011 The following code ignores overflow; perhaps a C standard
1012 interpretation ruling is needed. */
1014 else
1021 {
1025 else
1027 }
1028 else
1033 else
1112 }
1114 }
1116 /* Combine two poly int's ARG1 and ARG2 under operation CODE to
1117 produce a new constant in RES. Return FALSE if we don't know how
1118 to evaluate CODE at compile-time. */
1120 static bool
1124 {
1128 {
1146 else
1153 else
1166 }
1168 }
1170 /* Combine two integer constants ARG1 and ARG2 under operation CODE to
1171 produce a new constant. Return NULL_TREE if we don't know how to
1172 evaluate CODE at compile-time. */
1174 tree
1177 {
1178 poly_wide_int poly_res;
1184 {
1190 }
1199 }
1201 /* Return true if binary operation OP distributes over addition in operand
1202 OPNO, with the other operand being held constant. OPNO counts from 1. */
1204 static bool
1206 {
1208 {
1219 }
1220 }
1222 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1223 constant. We assume ARG1 and ARG2 have the same data type, or at least
1224 are the same kind of constant and the same machine mode. Return zero if
1225 combining the constants is not allowed in the current operating mode. */
1227 static tree
1229 {
1230 /* Sanity check for the recursive cases. */
1238 {
1244 }
1247 {
1248 machine_mode mode;
1249 REAL_VALUE_TYPE d1;
1250 REAL_VALUE_TYPE d2;
1251 REAL_VALUE_TYPE value;
1252 REAL_VALUE_TYPE result;
1256 /* The following codes are handled by real_arithmetic. */
1258 {
1269 }
1277 /* Don't perform operation if we honor signaling NaNs and
1278 either operand is a signaling NaN. */
1284 /* Don't perform operation if it would raise a division
1285 by zero exception. */
1291 /* If either operand is a NaN, just return it. Otherwise, set up
1292 for floating-point trap; we return an overflow. */
1294 {
1295 /* Make resulting NaN value to be qNaN when flag_signaling_nans
1296 is off. */
1300 }
1302 {
1303 /* Make resulting NaN value to be qNaN when flag_signaling_nans
1304 is off. */
1308 }
1313 /* Don't constant fold this floating point operation if
1314 the result has overflowed and flag_trapping_math. */
1322 /* Don't constant fold this floating point operation if the
1323 result may dependent upon the run-time rounding mode and
1324 flag_rounding_math is set, or if GCC's software emulation
1325 is unable to accurately represent the result. */
1335 }
1338 {
1339 FIXED_VALUE_TYPE f1;
1340 FIXED_VALUE_TYPE f2;
1341 FIXED_VALUE_TYPE result;
1346 /* The following codes are handled by fixed_arithmetic. */
1348 {
1360 {
1367 }
1372 }
1379 /* Propagate overflow flags. */
1383 }
1386 {
1395 {
1406 mpc_mul);
1420 mpc_div);
1421 /* Fallthru. */
1427 {
1428 /* Keep this algorithm in sync with
1429 tree-complex.c:expand_complex_div_straight().
1431 Expand complex division to scalars, straightforward algorithm.
1432 a / b = ((ar*br + ai*bi)/t) + i((ai*br - ar*bi)/t)
1433 t = br*br + bi*bi
1434 */
1435 tree magsquared
1439 tree t1
1443 tree t2
1450 }
1451 else
1452 {
1453 /* Keep this algorithm in sync with
1454 tree-complex.c:expand_complex_div_wide().
1456 Expand complex division to scalars, modified algorithm to minimize
1457 overflow with wide input ranges. */
1463 {
1464 /* In the TRUE branch, we compute
1465 ratio = br/bi;
1466 div = (br * ratio) + bi;
1467 tr = (ar * ratio) + ai;
1468 ti = (ai * ratio) - ar;
1469 tr = tr / div;
1470 ti = ti / div; */
1481 }
1482 else
1483 {
1484 /* In the FALSE branch, we compute
1485 ratio = d/c;
1486 divisor = (d * ratio) + c;
1487 tr = (b * ratio) + a;
1488 ti = b - (a * ratio);
1489 tr = tr / div;
1490 ti = ti / div; */
1502 }
1503 }
1508 }
1512 }
1518 {
1523 /* We can operate directly on the encoding if:
1525 a3 - a2 == a2 - a1 && b3 - b2 == b2 - b1
1526 implies
1527 (a3 op b3) - (a2 op b2) == (a2 op b2) - (a1 op b1)
1529 Addition and subtraction are the supported operators
1530 for which this is true. */
1533 /* We can operate directly on stepped encodings if:
1535 a3 - a2 == a2 - a1
1536 implies:
1537 (a3 op c) - (a2 op c) == (a2 op c) - (a1 op c)
1539 which is true if (x -> x op c) distributes over addition. */
1541 else
1542 /* Similarly in reverse. */
1544 tree_vector_builder elts;
1549 {
1555 /* It is possible that const_binop cannot handle the given
1556 code and return NULL_TREE */
1560 }
1563 }
1565 /* Shifts allow a scalar offset for a vector. */
1568 {
1571 tree_vector_builder elts;
1576 {
1581 /* It is possible that const_binop cannot handle the given
1582 code and return NULL_TREE. */
1586 }
1589 }
1591 }
1593 /* Overload that adds a TYPE parameter to be able to dispatch
1594 to fold_relational_const. */
1596 tree
1598 {
1602 /* ??? Until we make the const_binop worker take the type of the
1603 result as argument put those cases that need it here. */
1605 {
1622 {
1627 }
1633 {
1649 {
1654 ? NOP_EXPR
1661 }
1664 }
1670 {
1693 {
1706 }
1709 }
1712 }
1717 /* Make sure type and arg0 have the same saturating flag. */
1722 }
1724 /* Compute CODE ARG1 with resulting type TYPE with ARG1 being constant.
1725 Return zero if computing the constants is not possible. */
1727 tree
1729 {
1730 /* Don't perform the operation, other than NEGATE and ABS, if
1731 flag_signaling_nans is on and the operand is a signaling NaN. */
1741 {
1742 CASE_CONVERT:
1749 /* If the source address is 0, and the source address space
1750 cannot have a valid object at 0, fold to dest type null. */
1761 {
1762 /* Can't call fold_negate_const directly here as that doesn't
1763 handle all cases and we might not be able to negate some
1764 constants. */
1769 }
1779 {
1783 }
1791 /* Perform BIT_NOT_EXPR on each element individually. */
1793 {
1794 tree elem;
1796 /* This can cope with stepped encodings because ~x == -1 - x. */
1797 tree_vector_builder elements;
1801 {
1807 }
1810 }
1834 {
1857 else
1862 {
1868 }
1871 }
1880 }
1883 }
1885 /* Create a sizetype INT_CST node with NUMBER sign extended. KIND
1886 indicates which particular sizetype to create. */
1888 tree
1890 {
1892 }
1893 \f
1894 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1895 is a tree code. The type of the result is taken from the operands.
1896 Both must be equivalent integer types, ala int_binop_types_match_p.
1897 If the operands are constant, so is the result. */
1899 tree
1901 {
1910 /* Handle the special case of two poly_int constants faster. */
1912 {
1913 /* And some specific cases even faster than that. */
1915 {
1922 }
1924 {
1928 }
1930 {
1934 }
1936 /* Handle general case of two integer constants. For sizetype
1937 constant calculations we always want to know about overflow,
1938 even in the unsigned case. */
1942 }
1945 }
1947 /* Given two values, either both of sizetype or both of bitsizetype,
1948 compute the difference between the two values. Return the value
1949 in signed type corresponding to the type of the operands. */
1951 tree
1953 {
1955 tree ctype;
1960 /* If the type is already signed, just do the simple thing. */
1968 else
1971 /* If either operand is not a constant, do the conversions to the signed
1972 type and subtract. The hardware will do the right thing with any
1973 overflow in the subtraction. */
1979 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1980 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1981 overflow) and negate (which can't either). Special-case a result
1982 of zero while we're here. */
1988 else
1992 MINUS_EXPR,
1994 }
1995 \f
1996 /* A subroutine of fold_convert_const handling conversions of an
1997 INTEGER_CST to another integer type. */
1999 static tree
2001 {
2002 /* Given an integer constant, make new constant with new type,
2003 appropriately sign-extended or truncated. Use widest_int
2004 so that any extension is done according ARG1's type. */
2008 }
2010 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2011 to an integer type. */
2013 static tree
2015 {
2017 tree t;
2019 /* The following code implements the floating point to integer
2020 conversion rules required by the Java Language Specification,
2021 that IEEE NaNs are mapped to zero and values that overflow
2022 the target precision saturate, i.e. values greater than
2023 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
2024 are mapped to INT_MIN. These semantics are allowed by the
2025 C and C++ standards that simply state that the behavior of
2026 FP-to-integer conversion is unspecified upon overflow. */
2028 wide_int val;
2029 REAL_VALUE_TYPE r;
2033 {
2040 }
2042 /* If R is NaN, return zero and show we have an overflow. */
2044 {
2047 }
2049 /* See if R is less than the lower bound or greater than the
2050 upper bound. */
2053 {
2057 {
2060 }
2061 }
2064 {
2067 {
2070 {
2073 }
2074 }
2075 }
2082 }
2084 /* A subroutine of fold_convert_const handling conversions of a
2085 FIXED_CST to an integer type. */
2087 static tree
2089 {
2090 tree t;
2092 scalar_mode mode;
2094 /* Right shift FIXED_CST to temp by fbit. */
2098 {
2100 HOST_BITS_PER_DOUBLE_INT,
2103 /* Left shift temp to temp_trunc by fbit. */
2105 HOST_BITS_PER_DOUBLE_INT,
2107 }
2108 else
2109 {
2112 }
2114 /* If FIXED_CST is negative, we need to round the value toward 0.
2115 By checking if the fractional bits are not zero to add 1 to temp. */
2121 /* Given a fixed-point constant, make new constant with new type,
2122 appropriately sign-extended or truncated. */
2130 }
2132 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2133 to another floating point type. */
2135 static tree
2137 {
2138 REAL_VALUE_TYPE value;
2139 tree t;
2141 /* Don't perform the operation if flag_signaling_nans is on
2142 and the operand is a signaling NaN. */
2150 /* If converting an infinity or NAN to a representation that doesn't
2151 have one, set the overflow bit so that we can produce some kind of
2152 error message at the appropriate point if necessary. It's not the
2153 most user-friendly message, but it's better than nothing. */
2160 /* Regular overflow, conversion produced an infinity in a mode that
2161 can't represent them. */
2166 else
2169 }
2171 /* A subroutine of fold_convert_const handling conversions a FIXED_CST
2172 to a floating point type. */
2174 static tree
2176 {
2177 REAL_VALUE_TYPE value;
2178 tree t;
2186 }
2188 /* A subroutine of fold_convert_const handling conversions a FIXED_CST
2189 to another fixed-point type. */
2191 static tree
2193 {
2194 FIXED_VALUE_TYPE value;
2195 tree t;
2202 /* Propagate overflow flags. */
2206 }
2208 /* A subroutine of fold_convert_const handling conversions an INTEGER_CST
2209 to a fixed-point type. */
2211 static tree
2213 {
2214 FIXED_VALUE_TYPE value;
2215 tree t;
2217 double_int di;
2224 else
2232 /* Propagate overflow flags. */
2236 }
2238 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2239 to a fixed-point type. */
2241 static tree
2243 {
2244 FIXED_VALUE_TYPE value;
2245 tree t;
2253 /* Propagate overflow flags. */
2257 }
2259 /* Attempt to fold type conversion operation CODE of expression ARG1 to
2260 type TYPE. If no simplification can be done return NULL_TREE. */
2262 static tree
2264 {
2269 /* We can't widen types, since the runtime value could overflow the
2270 original type before being extended to the new type. */
2281 {
2288 }
2290 {
2297 }
2299 {
2306 }
2308 {
2311 {
2314 /* We can't handle steps directly when extending, since the
2315 values need to wrap at the original precision first. */
2316 bool step_ok_p
2320 tree_vector_builder v;
2325 {
2331 }
2333 }
2334 }
2336 }
2338 /* Construct a vector of zero elements of vector type TYPE. */
2340 static tree
2342 {
2343 tree t;
2347 }
2349 /* Returns true, if ARG is convertible to TYPE using a NOP_EXPR. */
2351 bool
2353 {
2368 {
2385 }
2386 }
2388 /* Convert expression ARG to type TYPE. Used by the middle-end for
2389 simple conversions in preference to calling the front-end's convert. */
2391 tree
2393 {
2395 tree tem;
2406 {
2409 /* Handle conversions between pointers to different address spaces. */
2414 /* fall through */
2419 {
2423 }
2437 {
2441 }
2443 {
2447 }
2449 {
2453 }
2456 {
2474 }
2479 {
2483 }
2486 {
2500 }
2504 {
2513 integer_zero_node));
2515 {
2519 {
2525 }
2533 }
2537 }
2555 }
2556 fold_convert_exit:
2559 }
2560 \f
2561 /* Return false if expr can be assumed not to be an lvalue, true
2562 otherwise. */
2564 static bool
2566 {
2567 /* We only need to wrap lvalue tree codes. */
2569 {
2600 /* Assume the worst for front-end tree codes. */
2604 }
2607 }
2609 /* Return an expr equal to X but certainly not valid as an lvalue. */
2611 tree
2613 {
2614 /* While we are in GIMPLE, NON_LVALUE_EXPR doesn't mean anything to
2615 us. */
2622 }
2624 /* When pedantic, return an expr equal to X but certainly not valid as a
2625 pedantic lvalue. Otherwise, return X. */
2627 static tree
2629 {
2631 }
2632 \f
2633 /* Given a tree comparison code, return the code that is the logical inverse.
2634 It is generally not safe to do this for floating-point comparisons, except
2635 for EQ_EXPR, NE_EXPR, ORDERED_EXPR and UNORDERED_EXPR, so we return
2636 ERROR_MARK in this case. */
2638 enum tree_code
2640 {
2646 {
2677 }
2678 }
2680 /* Similar, but return the comparison that results if the operands are
2681 swapped. This is safe for floating-point. */
2683 enum tree_code
2685 {
2687 {
2713 }
2714 }
2717 /* Convert a comparison tree code from an enum tree_code representation
2718 into a compcode bit-based encoding. This function is the inverse of
2719 compcode_to_comparison. */
2721 static enum comparison_code
2723 {
2725 {
2756 }
2757 }
2759 /* Convert a compcode bit-based encoding of a comparison operator back
2760 to GCC's enum tree_code representation. This function is the
2761 inverse of comparison_to_compcode. */
2763 static enum tree_code
2765 {
2767 {
2798 }
2799 }
2801 /* Return true if COND1 tests the opposite condition of COND2. */
2803 bool
2805 {
2808 && (invert_tree_comparison
2815 }
2817 /* Return a tree for the comparison which is the combination of
2818 doing the AND or OR (depending on CODE) of the two operations LCODE
2819 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2820 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2821 if this makes the transformation invalid. */
2823 tree
2828 {
2835 {
2846 }
2849 {
2850 /* Eliminate unordered comparisons, as well as LTGT and ORD
2851 which are not used unless the mode has NaNs. */
2857 }
2859 {
2860 /* Check that the original operation and the optimized ones will trap
2861 under the same condition. */
2872 /* In a short-circuited boolean expression the LHS might be
2873 such that the RHS, if evaluated, will never trap. For
2874 example, in ORD (x, y) && (x < y), we evaluate the RHS only
2875 if neither x nor y is NaN. (This is a mixed blessing: for
2876 example, the expression above will never trap, hence
2877 optimizing it to x < y would be invalid). */
2882 /* If the comparison was short-circuited, and only the RHS
2883 trapped, we may now generate a spurious trap. */
2888 /* If we changed the conditions that cause a trap, we lose. */
2891 }
2897 else
2898 {
2903 }
2904 }
2905 \f
2906 /* Return nonzero if two operands (typically of the same tree node)
2907 are necessarily equal. FLAGS modifies behavior as follows:
2909 If OEP_ONLY_CONST is set, only return nonzero for constants.
2910 This function tests whether the operands are indistinguishable;
2911 it does not test whether they are equal using C's == operation.
2912 The distinction is important for IEEE floating point, because
2913 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2914 (2) two NaNs may be indistinguishable, but NaN!=NaN.
2916 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
2917 even though it may hold multiple values during a function.
2918 This is because a GCC tree node guarantees that nothing else is
2919 executed between the evaluation of its "operands" (which may often
2920 be evaluated in arbitrary order). Hence if the operands themselves
2921 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
2922 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
2923 unset means assuming isochronic (or instantaneous) tree equivalence.
2924 Unless comparing arbitrary expression trees, such as from different
2925 statements, this flag can usually be left unset.
2927 If OEP_PURE_SAME is set, then pure functions with identical arguments
2928 are considered the same. It is used when the caller has other ways
2929 to ensure that global memory is unchanged in between.
2931 If OEP_ADDRESS_OF is set, we are actually comparing addresses of objects,
2932 not values of expressions.
2934 If OEP_LEXICOGRAPHIC is set, then also handle expressions with side-effects
2935 such as MODIFY_EXPR, RETURN_EXPR, as well as STATEMENT_LISTs.
2937 Unless OEP_MATCH_SIDE_EFFECTS is set, the function returns false on
2938 any operand with side effect. This is unnecesarily conservative in the
2939 case we know that arg0 and arg1 are in disjoint code paths (such as in
2940 ?: operator). In addition OEP_MATCH_SIDE_EFFECTS is used when comparing
2941 addresses with TREE_CONSTANT flag set so we know that &var == &var
2942 even if var is volatile. */
2944 bool
2946 {
2947 /* When checking, verify at the outermost operand_equal_p call that
2948 if operand_equal_p returns non-zero then ARG0 and ARG1 has the same
2949 hash value. */
2951 {
2953 {
2955 {
2962 }
2964 }
2965 else
2967 }
2972 /* If either is ERROR_MARK, they aren't equal. */
2978 /* Similar, if either does not have a type (like a template id),
2979 they aren't equal. */
2983 /* We cannot consider pointers to different address space equal. */
2990 /* Check equality of integer constants before bailing out due to
2991 precision differences. */
2993 {
2994 /* Address of INTEGER_CST is not defined; check that we did not forget
2995 to drop the OEP_ADDRESS_OF flags. */
2998 }
3001 {
3002 /* If both types don't have the same signedness, then we can't consider
3003 them equal. We must check this before the STRIP_NOPS calls
3004 because they may change the signedness of the arguments. As pointers
3005 strictly don't have a signedness, require either two pointers or
3006 two non-pointers as well. */
3012 /* If both types don't have the same precision, then it is not safe
3013 to strip NOPs. */
3020 }
3021 #if 0
3022 /* FIXME: Fortran FE currently produce ADDR_EXPR of NOP_EXPR. Enable the
3023 sanity check once the issue is solved. */
3024 else
3025 /* Addresses of conversions and SSA_NAMEs (and many other things)
3026 are not defined. Check that we did not forget to drop the
3027 OEP_ADDRESS_OF/OEP_CONSTANT_ADDRESS_OF flags. */
3030 #endif
3032 /* In case both args are comparisons but with different comparison
3033 code, try to swap the comparison operands of one arg to produce
3034 a match and compare that variant. */
3038 {
3046 }
3049 {
3050 /* NOP_EXPR and CONVERT_EXPR are considered equal. */
3052 ;
3054 {
3055 /* If we are interested in comparing addresses ignore
3056 MEM_REF wrappings of the base that can appear just for
3057 TBAA reasons. */
3071 }
3072 else
3074 }
3076 /* When not checking adddresses, this is needed for conversions and for
3077 COMPONENT_REF. Might as well play it safe and always test this. */
3084 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
3085 We don't care about side effects in that case because the SAVE_EXPR
3086 takes care of that for us. In all other cases, two expressions are
3087 equal if they have no side effects. If we have two identical
3088 expressions with side effects that should be treated the same due
3089 to the only side effects being identical SAVE_EXPR's, that will
3090 be detected in the recursive calls below.
3091 If we are taking an invariant address of two identical objects
3092 they are necessarily equal as well. */
3099 /* Next handle constant cases, those for which we can return 1 even
3100 if ONLY_CONST is set. */
3103 {
3117 {
3118 /* If we do not distinguish between signed and unsigned zero,
3119 consider them equal. */
3122 }
3126 {
3141 }
3145 flags)
3147 flags));
3158 flags | OEP_ADDRESS_OF
3161 /* In GIMPLE empty constructors are allowed in initializers of
3162 aggregates. */
3166 }
3171 /* Define macros to test an operand from arg0 and arg1 for equality and a
3172 variant that allows null and views null as being different from any
3173 non-null value. In the latter case, if either is null, the both
3174 must be; otherwise, do the normal comparison. */
3175 #define OP_SAME(N) operand_equal_p (TREE_OPERAND (arg0, N), \
3176 TREE_OPERAND (arg1, N), flags)
3178 #define OP_SAME_WITH_NULL(N) \
3179 ((!TREE_OPERAND (arg0, N) || !TREE_OPERAND (arg1, N)) \
3180 ? TREE_OPERAND (arg0, N) == TREE_OPERAND (arg1, N) : OP_SAME (N))
3183 {
3185 /* Two conversions are equal only if signedness and modes match. */
3187 {
3188 CASE_CONVERT:
3196 }
3206 /* For commutative ops, allow the other order. */
3214 /* If either of the pointer (or reference) expressions we are
3215 dereferencing contain a side effect, these cannot be equal,
3216 but their addresses can be. */
3223 {
3226 {
3230 /* Verify that the access types are compatible. */
3234 }
3239 /* Require the same offset. */
3245 /* Fallthru. */
3253 {
3254 /* Require equal access sizes */
3260 flags)))
3262 /* Verify that access happens in similar types. */
3265 /* Verify that accesses are TBAA compatible. */
3274 /* Verify that alignment is compatible. */
3278 }
3281 /* TARGET_MEM_REF require equal extra operands. */
3292 /* Compare the array index by value if it is constant first as we
3293 may have different types but same value here. */
3299 /* Compare low bound and element size as with OEP_ADDRESS_OF
3300 we have to account for the offset of the ref. */
3305 array_ref_low_bound
3309 array_ref_element_size
3311 flags))));
3314 /* Handle operand 2 the same as for ARRAY_REF. Operand 0
3315 may be NULL when we're called to compare MEM_EXPRs. */
3330 }
3334 {
3336 /* Be sure we pass right ADDRESS_OF flag. */
3353 /* The multiplcation operands are commutative. */
3354 /* FALLTHRU */
3362 /* Otherwise take into account this is a commutative operation. */
3375 /* BIT_INSERT_EXPR has an implict operand as the type precision
3376 of op1. Need to check to make sure they are the same. */
3382 /* FALLTHRU */
3408 }
3412 {
3416 /* If not both CALL_EXPRs are either internal or normal function
3417 functions, then they are not equal. */
3420 {
3421 /* If the CALL_EXPRs call different internal functions, then they
3422 are not equal. */
3425 }
3426 else
3427 {
3428 /* If the CALL_EXPRs call different functions, then they are not
3429 equal. */
3431 flags))
3433 }
3435 /* FIXME: We could skip this test for OEP_MATCH_SIDE_EFFECTS. */
3436 {
3440 else
3444 }
3446 /* Now see if all the arguments are the same. */
3447 {
3458 /* If we get here and both argument lists are exhausted
3459 then the CALL_EXPRs are equal. */
3461 }
3464 }
3467 /* Consider __builtin_sqrt equal to sqrt. */
3476 {
3477 /* In GIMPLE constructors are used only to build vectors from
3478 elements. Individual elements in the constructor must be
3479 indexed in increasing order and form an initial sequence.
3481 We make no effort to compare constructors in generic.
3482 (see sem_variable::equals in ipa-icf which can do so for
3483 constants). */
3488 /* Be sure that vectors constructed have the same representation.
3489 We only tested element precision and modes to match.
3490 Vectors may be BLKmode and thus also check that the number of
3491 parts match. */
3504 {
3509 /* In GIMPLE the indexes can be either NULL or matching i.
3510 Double check this so we won't get false
3511 positives for GENERIC. */
3519 }
3521 }
3524 {
3525 /* Compare the STATEMENT_LISTs. */
3531 {
3532 /* The lists don't have the same number of statements. */
3538 flags & (OEP_LEXICOGRAPHIC
3541 }
3542 }
3547 {
3558 }
3562 }
3564 #undef OP_SAME
3565 #undef OP_SAME_WITH_NULL
3566 }
3567 \f
3568 /* Similar to operand_equal_p, but see if ARG0 might be a variant of ARG1
3569 with a different signedness or a narrower precision. */
3571 static bool
3573 {
3581 /* Discard any conversions that don't change the modes of ARG0 and ARG1
3582 and see if the inner values are the same. This removes any
3583 signedness comparison, which doesn't matter here. */
3591 /* Discard a single widening conversion from ARG1 and see if the inner
3592 value is the same as ARG0. */
3601 }
3602 \f
3603 /* See if ARG is an expression that is either a comparison or is performing
3604 arithmetic on comparisons. The comparisons must only be comparing
3605 two different values, which will be stored in *CVAL1 and *CVAL2; if
3606 they are nonzero it means that some operands have already been found.
3607 No variables may be used anywhere else in the expression except in the
3608 comparisons.
3610 If this is true, return 1. Otherwise, return zero. */
3612 static bool
3614 {
3618 /* We can handle some of the tcc_expression cases here. */
3627 {
3646 /* First see if we can handle the first operand, then the second. For
3647 the second operand, we know *CVAL1 can't be zero. It must be that
3648 one side of the comparison is each of the values; test for the
3649 case where this isn't true by failing if the two operands
3650 are the same. */
3659 ;
3663 ;
3664 else
3668 ;
3672 ;
3673 else
3680 }
3681 }
3682 \f
3683 /* ARG is a tree that is known to contain just arithmetic operations and
3684 comparisons. Evaluate the operations in the tree substituting NEW0 for
3685 any occurrence of OLD0 as an operand of a comparison and likewise for
3686 NEW1 and OLD1. */
3688 static tree
3691 {
3696 /* We can handle some of the tcc_expression cases here. */
3704 {
3719 {
3738 }
3739 /* Fall through - ??? */
3742 {
3746 /* We need to check both for exact equality and tree equality. The
3747 former will be true if the operand has a side-effect. In that
3748 case, we know the operand occurred exactly once. */
3761 }
3765 }
3766 }
3767 \f
3768 /* Return a tree for the case when the result of an expression is RESULT
3769 converted to TYPE and OMITTED was previously an operand of the expression
3770 but is now not needed (e.g., we folded OMITTED * 0).
3772 If OMITTED has side effects, we must evaluate it. Otherwise, just do
3773 the conversion of RESULT to TYPE. */
3775 tree
3777 {
3780 /* If the resulting operand is an empty statement, just return the omitted
3781 statement casted to void. */
3791 }
3793 /* Return a tree for the case when the result of an expression is RESULT
3794 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
3795 of the expression but are now not needed.
3797 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
3798 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
3799 evaluated before OMITTED2. Otherwise, if neither has side effects,
3800 just do the conversion of RESULT to TYPE. */
3802 tree
3805 {
3814 }
3816 \f
3817 /* Return a simplified tree node for the truth-negation of ARG. This
3818 never alters ARG itself. We assume that ARG is an operation that
3819 returns a truth value (0 or 1).
3821 FIXME: one would think we would fold the result, but it causes
3822 problems with the dominator optimizer. */
3824 static tree
3826 {
3831 /* If this is a comparison, we can simply invert it, except for
3832 floating-point non-equality comparisons, in which case we just
3833 enclose a TRUTH_NOT_EXPR around what we have. */
3836 {
3839 && flag_trapping_math
3853 }
3856 {
3875 /* Here we can invert either operand. We invert the first operand
3876 unless the second operand is a TRUTH_NOT_EXPR in which case our
3877 result is the XOR of the first operand with the inside of the
3878 negation of the second operand. */
3883 else
3906 {
3913 /* A COND_EXPR may have a throw as one operand, which
3914 then has void type. Just leave void operands
3915 as they are. */
3921 }
3933 CASE_CONVERT:
3937 /* fall through */
3959 }
3960 }
3962 /* Fold the truth-negation of ARG. This never alters ARG itself. We
3963 assume that ARG is an operation that returns a truth value (0 or 1
3964 for scalars, 0 or -1 for vectors). Return the folded expression if
3965 folding is successful. Otherwise, return NULL_TREE. */
3967 static tree
3969 {
3972 ? BIT_NOT_EXPR
3975 }
3977 /* Return a simplified tree node for the truth-negation of ARG. This
3978 never alters ARG itself. We assume that ARG is an operation that
3979 returns a truth value (0 or 1 for scalars, 0 or -1 for vectors). */
3981 tree
3983 {
3989 ? BIT_NOT_EXPR
3992 }
3993 \f
3994 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
3995 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero
3996 and uses reverse storage order if REVERSEP is nonzero. ORIG_INNER
3997 is the original memory reference used to preserve the alias set of
3998 the access. */
4000 static tree
4004 {
4007 /* Attempt not to lose the access path if possible. */
4009 {
4011 machine_mode nmode;
4013 tree noffset;
4021 && !reversep
4022 && !nreversep
4024 {
4027 }
4028 }
4037 {
4044 }
4059 }
4061 /* Optimize a bit-field compare.
4063 There are two cases: First is a compare against a constant and the
4064 second is a comparison of two items where the fields are at the same
4065 bit position relative to the start of a chunk (byte, halfword, word)
4066 large enough to contain it. In these cases we can avoid the shift
4067 implicit in bitfield extractions.
4069 For constants, we emit a compare of the shifted constant with the
4070 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
4071 compared. For two fields at the same position, we do the ANDs with the
4072 similar mask and compare the result of the ANDs.
4074 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
4075 COMPARE_TYPE is the type of the comparison, and LHS and RHS
4076 are the left and right operands of the comparison, respectively.
4078 If the optimization described above can be done, we return the resulting
4079 tree. Otherwise we return zero. */
4081 static tree
4084 {
4088 tree unsigned_type;
4091 scalar_int_mode nmode;
4096 tree mask;
4097 tree offset;
4099 /* Get all the information about the extractions being done. If the bit size
4100 is the same as the size of the underlying object, we aren't doing an
4101 extraction at all and so can do nothing. We also don't want to
4102 do anything if the inner expression is a PLACEHOLDER_EXPR since we
4103 then will no longer be able to replace it. */
4118 else
4119 {
4120 /* If this is not a constant, we can only do something if bit positions,
4121 sizes, signedness and storage order are the same. */
4122 rinner
4135 }
4137 /* Honor the C++ memory model and mimic what RTL expansion does. */
4141 {
4145 }
4147 /* See if we can find a mode to refer to this field. We should be able to,
4148 but fail if we can't. */
4156 /* Set signed and unsigned types of the precision of this mode for the
4157 shifts below. */
4160 /* Compute the bit position and size for the new reference and our offset
4161 within it. If the new reference is the same size as the original, we
4162 won't optimize anything, so return zero. */
4172 /* Make the mask to be used against the extracted field. */
4179 {
4183 /* If not comparing with constant, just rework the comparison
4184 and return. */
4192 }
4194 /* Otherwise, we are handling the constant case. See if the constant is too
4195 big for the field. Warn and return a tree for 0 (false) if so. We do
4196 this not only for its own sake, but to avoid having to test for this
4197 error case below. If we didn't, we might generate wrong code.
4199 For unsigned fields, the constant shifted right by the field length should
4200 be all zero. For signed fields, the high-order bits should agree with
4201 the sign bit. */
4204 {
4206 {
4210 }
4211 }
4212 else
4213 {
4216 {
4220 }
4221 }
4226 /* Single-bit compares should always be against zero. */
4228 {
4231 }
4233 /* Make a new bitfield reference, shift the constant over the
4234 appropriate number of bits and mask it with the computed mask
4235 (in case this was a signed field). If we changed it, make a new one. */
4243 mask);
4248 }
4249 \f
4250 /* Subroutine for fold_truth_andor_1: decode a field reference.
4252 If EXP is a comparison reference, we return the innermost reference.
4254 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
4255 set to the starting bit number.
4257 If the innermost field can be completely contained in a mode-sized
4258 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
4260 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
4261 otherwise it is not changed.
4263 *PUNSIGNEDP is set to the signedness of the field.
4265 *PREVERSEP is set to the storage order of the field.
4267 *PMASK is set to the mask used. This is either contained in a
4268 BIT_AND_EXPR or derived from the width of the field.
4270 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
4272 Return 0 if this is not a component reference or is one that we can't
4273 do anything with. */
4275 static tree
4280 {
4285 tree unsigned_type;
4288 /* All the optimizations using this function assume integer fields.
4289 There are problems with FP fields since the type_for_size call
4290 below can fail for, e.g., XFmode. */
4294 /* We are interested in the bare arrangement of bits, so strip everything
4295 that doesn't affect the machine mode. However, record the type of the
4296 outermost expression if it may matter below. */
4303 {
4309 }
4320 /* Reject out-of-bound accesses (PR79731). */
4332 /* If the number of bits in the reference is the same as the bitsize of
4333 the outer type, then the outer type gives the signedness. Otherwise
4334 (in case of a small bitfield) the signedness is unchanged. */
4338 /* Compute the mask to access the bitfield. */
4346 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
4354 }
4356 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
4357 bit positions and MASK is SIGNED. */
4359 static bool
4361 {
4365 /* If this function returns true when the type of the mask is
4366 UNSIGNED, then there will be errors. In particular see
4367 gcc.c-torture/execute/990326-1.c. There does not appear to be
4368 any documentation paper trail as to why this is so. But the pre
4369 wide-int worked with that restriction and it has been preserved
4370 here. */
4375 }
4377 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
4378 represents the sign bit of EXP's type. If EXP represents a sign
4379 or zero extension, also test VAL against the unextended type.
4380 The return value is the (sub)expression whose sign bit is VAL,
4381 or NULL_TREE otherwise. */
4383 tree
4385 {
4387 tree t;
4389 /* Tree EXP must have an integral type. */
4394 /* Tree VAL must be an integer constant. */
4403 /* Handle extension from a narrower type. */
4409 }
4411 /* Subroutine for fold_truth_andor_1: determine if an operand is simple enough
4412 to be evaluated unconditionally. */
4414 static bool
4416 {
4417 /* Strip any conversions that don't change the machine mode. */
4426 /* Don't regard global variables as simple. They may be
4427 allocated in ways unknown to the compiler (shared memory,
4428 #pragma weak, etc). */
4431 /* Weakrefs are not safe to be read, since they can be NULL.
4432 They are !TREE_PUBLIC && !DECL_EXTERNAL but still
4433 have DECL_WEAK flag set. */
4435 /* Loading a static variable is unduly expensive, but global
4436 registers aren't expensive. */
4438 }
4440 /* Subroutine for fold_truth_andor: determine if an operand is simple enough
4441 to be evaluated unconditionally.
4442 I addition to simple_operand_p, we assume that comparisons, conversions,
4443 and logic-not operations are simple, if their operands are simple, too. */
4445 static bool
4447 {
4466 }
4468 \f
4469 /* The following functions are subroutines to fold_range_test and allow it to
4470 try to change a logical combination of comparisons into a range test.
4472 For example, both
4473 X == 2 || X == 3 || X == 4 || X == 5
4474 and
4475 X >= 2 && X <= 5
4476 are converted to
4477 (unsigned) (X - 2) <= 3
4479 We describe each set of comparisons as being either inside or outside
4480 a range, using a variable named like IN_P, and then describe the
4481 range with a lower and upper bound. If one of the bounds is omitted,
4482 it represents either the highest or lowest value of the type.
4484 In the comments below, we represent a range by two numbers in brackets
4485 preceded by a "+" to designate being inside that range, or a "-" to
4486 designate being outside that range, so the condition can be inverted by
4487 flipping the prefix. An omitted bound is represented by a "-". For
4488 example, "- [-, 10]" means being outside the range starting at the lowest
4489 possible value and ending at 10, in other words, being greater than 10.
4490 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
4491 always false.
4493 We set up things so that the missing bounds are handled in a consistent
4494 manner so neither a missing bound nor "true" and "false" need to be
4495 handled using a special case. */
4497 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
4498 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
4499 and UPPER1_P are nonzero if the respective argument is an upper bound
4500 and zero for a lower. TYPE, if nonzero, is the type of the result; it
4501 must be specified for a comparison. ARG1 will be converted to ARG0's
4502 type if both are specified. */
4504 static tree
4507 {
4508 tree tem;
4512 /* If neither arg represents infinity, do the normal operation.
4513 Else, if not a comparison, return infinity. Else handle the special
4514 comparison rules. Note that most of the cases below won't occur, but
4515 are handled for consistency. */
4518 {
4523 }
4528 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
4529 for neither. In real maths, we cannot assume open ended ranges are
4530 the same. But, this is computer arithmetic, where numbers are finite.
4531 We can therefore make the transformation of any unbounded range with
4532 the value Z, Z being greater than any representable number. This permits
4533 us to treat unbounded ranges as equal. */
4537 {
4558 }
4561 }
4562 \f
4563 /* Helper routine for make_range. Perform one step for it, return
4564 new expression if the loop should continue or NULL_TREE if it should
4565 stop. */
4567 tree
4571 {
4577 {
4579 /* We can only do something if the range is testing for zero. */
4588 /* We can only do something if the range is testing for zero
4589 and if the second operand is an integer constant. Note that
4590 saying something is "in" the range we make is done by
4591 complementing IN_P since it will set in the initial case of
4592 being not equal to zero; "out" is leaving it alone. */
4599 {
4620 }
4622 /* If this is an unsigned comparison, we also know that EXP is
4623 greater than or equal to zero. We base the range tests we make
4624 on that fact, so we record it here so we can parse existing
4625 range tests. We test arg0_type since often the return type
4626 of, e.g. EQ_EXPR, is boolean. */
4628 {
4632 NULL_TREE))
4637 /* If the high bound is missing, but we have a nonzero low
4638 bound, reverse the range so it goes from zero to the low bound
4639 minus 1. */
4641 {
4646 }
4647 }
4655 /* If flag_wrapv and ARG0_TYPE is signed, make sure
4656 low and high are non-NULL, then normalize will DTRT. */
4659 {
4664 }
4666 /* (-x) IN [a,b] -> x in [-b, -a] */
4678 /* ~ X -> -X - 1 */
4687 /* If flag_wrapv and ARG0_TYPE is signed, then we cannot
4688 move a constant to the other side. */
4693 /* If EXP is signed, any overflow in the computation is undefined,
4694 so we don't worry about it so long as our computations on
4695 the bounds don't overflow. For unsigned, overflow is defined
4696 and this is exactly the right thing. */
4708 normalize:
4709 /* Check for an unsigned range which has wrapped around the maximum
4710 value thus making n_high < n_low, and normalize it. */
4712 {
4718 /* If the range is of the form +/- [ x+1, x ], we won't
4719 be able to normalize it. But then, it represents the
4720 whole range or the empty set, so make it
4721 +/- [ -, - ]. */
4725 else
4727 }
4728 else
4736 CASE_CONVERT:
4754 /* If we're converting arg0 from an unsigned type, to exp,
4755 a signed type, we will be doing the comparison as unsigned.
4756 The tests above have already verified that LOW and HIGH
4757 are both positive.
4759 So we have to ensure that we will handle large unsigned
4760 values the same way that the current signed bounds treat
4761 negative values. */
4764 {
4765 tree high_positive;
4766 tree equiv_type;
4767 /* For fixed-point modes, we need to pass the saturating flag
4768 as the 2nd parameter. */
4770 equiv_type
4773 else
4774 equiv_type
4777 /* A range without an upper bound is, naturally, unbounded.
4778 Since convert would have cropped a very large value, use
4779 the max value for the destination type. */
4780 high_positive
4787 high_positive),
4790 /* If the low bound is specified, "and" the range with the
4791 range for which the original unsigned value will be
4792 positive. */
4794 {
4797 integer_zero_node),
4798 high_positive))
4802 }
4803 else
4804 {
4805 /* Otherwise, "or" the range with the range of the input
4806 that will be interpreted as negative. */
4809 integer_zero_node),
4810 high_positive))
4814 }
4815 }
4824 }
4825 }
4827 /* Given EXP, a logical expression, set the range it is testing into
4828 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
4829 actually being tested. *PLOW and *PHIGH will be made of the same
4830 type as the returned expression. If EXP is not a comparison, we
4831 will most likely not be returning a useful value and range. Set
4832 *STRICT_OVERFLOW_P to true if the return value is only valid
4833 because signed overflow is undefined; otherwise, do not change
4834 *STRICT_OVERFLOW_P. */
4836 tree
4839 {
4847 /* Start with simply saying "EXP != 0" and then look at the code of EXP
4848 and see if we can refine the range. Some of the cases below may not
4849 happen, but it doesn't seem worth worrying about this. We "continue"
4850 the outer loop when we've changed something; otherwise we "break"
4851 the switch, which will "break" the while. */
4857 {
4863 {
4871 }
4880 }
4882 /* If EXP is a constant, we can evaluate whether this is true or false. */
4884 {
4891 }
4895 }
4897 /* Returns TRUE if [LOW, HIGH] range check can be optimized to
4898 a bitwise check i.e. when
4899 LOW == 0xXX...X00...0
4900 HIGH == 0xXX...X11...1
4901 Return corresponding mask in MASK and stem in VALUE. */
4903 static bool
4906 {
4929 }
4930 \f
4931 /* Helper routine for build_range_check and match.pd. Return the type to
4932 perform the check or NULL if it shouldn't be optimized. */
4934 tree
4936 {
4937 /* First make sure that arithmetics in this type is valid, then make sure
4938 that it wraps around. */
4943 {
4946 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
4947 for the type in question, as we rely on this here. */
4957 else
4959 }
4963 }
4965 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
4966 type, TYPE, return an expression to test if EXP is in (or out of, depending
4967 on IN_P) the range. Return 0 if the test couldn't be created. */
4969 tree
4972 {
4975 /* Disable this optimization for function pointer expressions
4976 on targets that require function pointer canonicalization. */
4983 {
4989 }
5011 value);
5014 {
5016 {
5020 }
5022 }
5024 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
5026 {
5030 {
5032 {
5035 etype
5037 else
5040 }
5043 }
5044 }
5046 /* Optimize (c>=low) && (c<=high) into (c-low>=0) && (c-low<=high-low).
5047 This requires wrap-around arithmetics for the type of the expression. */
5064 }
5065 \f
5066 /* Return the predecessor of VAL in its type, handling the infinite case. */
5068 static tree
5070 {
5076 else
5079 }
5081 /* Return the successor of VAL in its type, handling the infinite case. */
5083 static tree
5085 {
5091 else
5094 }
5096 /* Given two ranges, see if we can merge them into one. Return 1 if we
5097 can, 0 if we can't. Set the output range into the specified parameters. */
5099 bool
5102 {
5106 tree tem;
5116 /* Make range 0 be the range that starts first, or ends last if they
5117 start at the same value. Swap them if it isn't. */
5120 || (lowequal
5123 {
5127 }
5129 /* If the second range is != high1 where high1 is the type maximum of
5130 the type, try first merging with < high1 range. */
5132 && high1
5139 {
5144 /* Similarly for the second range != low1 where low1 is the type minimum
5145 of the type, try first merging with > low1 range. */
5150 }
5152 /* Now flag two cases, whether the ranges are disjoint or whether the
5153 second range is totally subsumed in the first. Note that the tests
5154 below are simplified by the ones above. */
5160 /* We now have four cases, depending on whether we are including or
5161 excluding the two ranges. */
5163 {
5164 /* If they don't overlap, the result is false. If the second range
5165 is a subset it is the result. Otherwise, the range is from the start
5166 of the second to the end of the first. */
5171 else
5173 }
5176 {
5177 /* If they don't overlap, the result is the first range. If they are
5178 equal, the result is false. If the second range is a subset of the
5179 first, and the ranges begin at the same place, we go from just after
5180 the end of the second range to the end of the first. If the second
5181 range is not a subset of the first, or if it is a subset and both
5182 ranges end at the same place, the range starts at the start of the
5183 first range and ends just before the second range.
5184 Otherwise, we can't describe this as a single range. */
5190 {
5195 {
5196 /* We are in the weird situation where high0 > high1 but
5197 high1 has no successor. Punt. */
5199 }
5200 }
5202 {
5207 {
5208 /* low0 < low1 but low1 has no predecessor. Punt. */
5210 }
5211 }
5212 else
5214 }
5217 {
5218 /* If they don't overlap, the result is the second range. If the second
5219 is a subset of the first, the result is false. Otherwise,
5220 the range starts just after the first range and ends at the
5221 end of the second. */
5226 else
5227 {
5232 {
5233 /* high1 > high0 but high0 has no successor. Punt. */
5235 }
5236 }
5237 }
5239 else
5240 {
5241 /* The case where we are excluding both ranges. Here the complex case
5242 is if they don't overlap. In that case, the only time we have a
5243 range is if they are adjacent. If the second is a subset of the
5244 first, the result is the first. Otherwise, the range to exclude
5245 starts at the beginning of the first range and ends at the end of the
5246 second. */
5248 {
5253 else
5254 {
5255 /* Canonicalize - [min, x] into - [-, x]. */
5258 {
5261 GET_MODE_BITSIZE
5264 /* FALLTHROUGH */
5277 }
5279 /* Canonicalize - [x, max] into - [x, -]. */
5282 {
5285 GET_MODE_BITSIZE
5288 /* FALLTHROUGH */
5304 }
5306 /* The ranges might be also adjacent between the maximum and
5307 minimum values of the given type. For
5308 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
5309 return + [x + 1, y - 1]. */
5311 {
5318 }
5319 else
5321 }
5322 }
5325 else
5327 }
5331 }
5332 \f
5334 /* Subroutine of fold, looking inside expressions of the form
5335 A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
5336 of the COND_EXPR. This function is being used also to optimize
5337 A op B ? C : A, by reversing the comparison first.
5339 Return a folded expression whose code is not a COND_EXPR
5340 anymore, or NULL_TREE if no folding opportunity is found. */
5342 static tree
5345 {
5350 tree tem;
5355 /* If we have A op 0 ? A : -A, consider applying the following
5356 transformations:
5358 A == 0? A : -A same as -A
5359 A != 0? A : -A same as A
5360 A >= 0? A : -A same as abs (A)
5361 A > 0? A : -A same as abs (A)
5362 A <= 0? A : -A same as -abs (A)
5363 A < 0? A : -A same as -abs (A)
5365 None of these transformations work for modes with signed
5366 zeros. If A is +/-0, the first two transformations will
5367 change the sign of the result (from +0 to -0, or vice
5368 versa). The last four will fix the sign of the result,
5369 even though the original expressions could be positive or
5370 negative, depending on the sign of A.
5372 Note that all these transformations are correct if A is
5373 NaN, since the two alternatives (A and -A) are also NaNs. */
5380 /* In the case that A is of the form X-Y, '-A' (arg2) may
5381 have already been folded to Y-X, check for that. */
5389 {
5401 /* Fall through. */
5412 /* FALLTHRU */
5422 }
5424 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
5425 A == 0 ? A : 0 is always 0 unless A is -0. Note that
5426 both transformations are correct when A is NaN: A != 0
5427 is then true, and A == 0 is false. */
5431 {
5436 }
5438 /* Try some transformations of A op B ? A : B.
5440 A == B? A : B same as B
5441 A != B? A : B same as A
5442 A >= B? A : B same as max (A, B)
5443 A > B? A : B same as max (B, A)
5444 A <= B? A : B same as min (A, B)
5445 A < B? A : B same as min (B, A)
5447 As above, these transformations don't work in the presence
5448 of signed zeros. For example, if A and B are zeros of
5449 opposite sign, the first two transformations will change
5450 the sign of the result. In the last four, the original
5451 expressions give different results for (A=+0, B=-0) and
5452 (A=-0, B=+0), but the transformed expressions do not.
5454 The first two transformations are correct if either A or B
5455 is a NaN. In the first transformation, the condition will
5456 be false, and B will indeed be chosen. In the case of the
5457 second transformation, the condition A != B will be true,
5458 and A will be chosen.
5460 The conversions to max() and min() are not correct if B is
5461 a number and A is not. The conditions in the original
5462 expressions will be false, so all four give B. The min()
5463 and max() versions would give a NaN instead. */
5466 /* Avoid these transformations if the COND_EXPR may be used
5467 as an lvalue in the C++ front-end. PR c++/19199. */
5468 && (in_gimple_form
5474 {
5480 {
5489 /* In C++ a ?: expression can be an lvalue, so put the
5490 operand which will be used if they are equal first
5491 so that we can convert this back to the
5492 corresponding COND_EXPR. */
5494 {
5502 }
5509 {
5517 }
5530 }
5531 }
5534 }
5537 \f
5538 #ifndef LOGICAL_OP_NON_SHORT_CIRCUIT
5539 #define LOGICAL_OP_NON_SHORT_CIRCUIT \
5540 (BRANCH_COST (optimize_function_for_speed_p (cfun), \
5541 false) >= 2)
5542 #endif
5544 /* EXP is some logical combination of boolean tests. See if we can
5545 merge it into some range test. Return the new tree if so. */
5547 static tree
5550 {
5566 /* If this is an OR operation, invert both sides; we will invert
5567 again at the end. */
5571 /* If both expressions are the same, if we can merge the ranges, and we
5572 can build the range test, return it or it inverted. If one of the
5573 ranges is always true or always false, consider it to be the same
5574 expression as the other. */
5582 {
5586 }
5588 /* On machines where the branch cost is expensive, if this is a
5589 short-circuited branch and the underlying object on both sides
5590 is the same, make a non-short-circuit operation. */
5593 logical_op_non_short_circuit
5596 && !flag_sanitize_coverage
5600 {
5601 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
5602 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
5603 which cases we can't do this. */
5611 {
5620 {
5623 WARN_STRICT_OVERFLOW_COMPARISON);
5627 }
5628 }
5629 }
5632 }
5633 \f
5634 /* Subroutine for fold_truth_andor_1: C is an INTEGER_CST interpreted as a P
5635 bit value. Arrange things so the extra bits will be set to zero if and
5636 only if C is signed-extended to its full width. If MASK is nonzero,
5637 it is an INTEGER_CST that should be AND'ed with the extra bits. */
5639 static tree
5641 {
5644 tree temp;
5649 /* We work by getting just the sign bit into the low-order bit, then
5650 into the high-order bit, then sign-extend. We then XOR that value
5651 with C. */
5655 /* We must use a signed type in order to get an arithmetic right shift.
5656 However, we must also avoid introducing accidental overflows, so that
5657 a subsequent call to integer_zerop will work. Hence we must
5658 do the type conversion here. At this point, the constant is either
5659 zero or one, and the conversion to a signed type can never overflow.
5660 We could get an overflow if this conversion is done anywhere else. */
5669 /* If necessary, convert the type back to match the type of C. */
5674 }
5675 \f
5676 /* For an expression that has the form
5677 (A && B) || ~B
5678 or
5679 (A || B) && ~B,
5680 we can drop one of the inner expressions and simplify to
5681 A || ~B
5682 or
5683 A && ~B
5684 LOC is the location of the resulting expression. OP is the inner
5685 logical operation; the left-hand side in the examples above, while CMPOP
5686 is the right-hand side. RHS_ONLY is used to prevent us from accidentally
5687 removing a condition that guards another, as in
5688 (A != NULL && A->...) || A == NULL
5689 which we must not transform. If RHS_ONLY is true, only eliminate the
5690 right-most operand of the inner logical operation. */
5692 static tree
5695 {
5713 {
5716 {
5719 }
5720 }
5722 {
5725 {
5728 }
5729 }
5744 }
5746 /* Find ways of folding logical expressions of LHS and RHS:
5747 Try to merge two comparisons to the same innermost item.
5748 Look for range tests like "ch >= '0' && ch <= '9'".
5749 Look for combinations of simple terms on machines with expensive branches
5750 and evaluate the RHS unconditionally.
5752 For example, if we have p->a == 2 && p->b == 4 and we can make an
5753 object large enough to span both A and B, we can do this with a comparison
5754 against the object ANDed with the a mask.
5756 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
5757 operations to do this with one comparison.
5759 We check for both normal comparisons and the BIT_AND_EXPRs made this by
5760 function and the one above.
5762 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
5763 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
5765 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
5766 two operands.
5768 We return the simplified tree or 0 if no optimization is possible. */
5770 static tree
5773 {
5774 /* If this is the "or" of two comparisons, we can do something if
5775 the comparisons are NE_EXPR. If this is the "and", we can do something
5776 if the comparisons are EQ_EXPR. I.e.,
5777 (a->b == 2 && a->c == 4) can become (a->new == NEW).
5779 WANTED_CODE is this operation code. For single bit fields, we can
5780 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
5781 comparison for one-bit fields. */
5802 /* Start by getting the comparison codes. Fail if anything is volatile.
5803 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
5804 it were surrounded with a NE_EXPR. */
5813 {
5817 }
5820 {
5824 }
5835 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
5838 {
5841 {
5846 }
5849 {
5855 }
5856 }
5861 /* If the RHS can be evaluated unconditionally and its operands are
5862 simple, it wins to evaluate the RHS unconditionally on machines
5863 with expensive branches. In this case, this isn't a comparison
5864 that can be merged. */
5871 {
5872 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
5883 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
5893 }
5895 /* See if the comparisons can be merged. Then get all the parameters for
5896 each side. */
5921 /* It must be true that the inner operation on the lhs of each
5922 comparison must be the same if we are to be able to do anything.
5923 Then see if we have constants. If not, the same must be true for
5924 the rhs's. */
5933 {
5936 }
5941 else
5944 /* If either comparison code is not correct for our logical operation,
5945 fail. However, we can convert a one-bit comparison against zero into
5946 the opposite comparison against that bit being set in the field. */
5950 {
5952 {
5953 /* Make the left operand unsigned, since we are only interested
5954 in the value of one bit. Otherwise we are doing the wrong
5955 thing below. */
5958 }
5959 else
5961 }
5963 /* This is analogous to the code for l_const above. */
5965 {
5967 {
5970 }
5971 else
5973 }
5975 /* See if we can find a mode that contains both fields being compared on
5976 the left. If we can't, fail. Otherwise, update all constants and masks
5977 to be relative to a field of that size. */
5991 {
5994 }
6002 {
6009 {
6013 }
6014 }
6016 {
6023 {
6027 }
6028 }
6030 /* If the right sides are not constant, do the same for it. Also,
6031 disallow this optimization if a size, signedness or storage order
6032 mismatch occurs between the left and right sides. */
6034 {
6038 /* Make sure the two fields on the right
6039 correspond to the left without being swapped. */
6056 {
6059 }
6068 /* Make a mask that corresponds to both fields being compared.
6069 Do this for both items being compared. If the operands are the
6070 same size and the bits being compared are in the same position
6071 then we can do this by masking both and comparing the masked
6072 results. */
6079 {
6093 }
6095 /* There is still another way we can do something: If both pairs of
6096 fields being compared are adjacent, we may be able to make a wider
6097 field containing them both.
6099 Note that we still must mask the lhs/rhs expressions. Furthermore,
6100 the mask must be shifted to account for the shift done by
6101 make_bit_field_ref. */
6110 {
6111 tree type;
6127 /* Convert to the smaller type before masking out unwanted bits. */
6130 {
6132 {
6136 }
6138 {
6142 }
6143 }
6152 }
6155 }
6157 /* Handle the case of comparisons with constants. If there is something in
6158 common between the masks, those bits of the constants must be the same.
6159 If not, the condition is always false. Test for this to avoid generating
6160 incorrect code below. */
6165 {
6167 {
6170 }
6171 else
6172 {
6175 }
6176 }
6181 /* Construct the expression we will return. First get the component
6182 reference we will make. Unless the mask is all ones the width of
6183 that field, perform the mask operation. Then compare with the
6184 merged constant. */
6195 }
6196 \f
6197 /* T is an integer expression that is being multiplied, divided, or taken a
6198 modulus (CODE says which and what kind of divide or modulus) by a
6199 constant C. See if we can eliminate that operation by folding it with
6200 other operations already in T. WIDE_TYPE, if non-null, is a type that
6201 should be used for the computation if wider than our type.
6203 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
6204 (X * 2) + (Y * 4). We must, however, be assured that either the original
6205 expression would not overflow or that overflow is undefined for the type
6206 in the language in question.
6208 If we return a non-null expression, it is an equivalent form of the
6209 original computation, but need not be in the original type.
6211 We set *STRICT_OVERFLOW_P to true if the return values depends on
6212 signed overflow being undefined. Otherwise we do not change
6213 *STRICT_OVERFLOW_P. */
6215 static tree
6218 {
6219 /* To avoid exponential search depth, refuse to allow recursion past
6220 three levels. Beyond that (1) it's highly unlikely that we'll find
6221 something interesting and (2) we've probably processed it before
6222 when we built the inner expression. */
6225 tree ret;
6230 depth++;
6232 depth--;
6235 }
6237 static tree
6240 {
6252 /* Don't deal with constants of zero here; they confuse the code below. */
6262 /* Note that we need not handle conditional operations here since fold
6263 already handles those cases. So just do arithmetic here. */
6265 {
6267 /* For a constant, we can always simplify if we are a multiply
6268 or (for divide and modulus) if it is a multiple of our constant. */
6272 {
6275 /* If the multiplication overflowed, we lost information on it.
6276 See PR68142 and PR69845. */
6280 }
6284 /* If op0 is an expression ... */
6290 /* ... and has wrapping overflow, and its type is smaller
6291 than ctype, then we cannot pass through as widening. */
6296 /* ... or this is a truncation (t is narrower than op0),
6297 then we cannot pass through this narrowing. */
6300 /* ... or signedness changes for division or modulus,
6301 then we cannot pass through this conversion. */
6305 /* ... or has undefined overflow while the converted to
6306 type has not, we cannot do the operation in the inner type
6307 as that would introduce undefined overflow. */
6313 /* Pass the constant down and see if we can make a simplification. If
6314 we can, replace this expression with the inner simplification for
6315 possible later conversion to our or some other type. */
6326 /* If widening the type changes it from signed to unsigned, then we
6327 must avoid building ABS_EXPR itself as unsigned. */
6329 {
6333 {
6336 }
6338 }
6339 /* If the constant is negative, we cannot simplify this. */
6342 /* FALLTHROUGH */
6344 /* For division and modulus, type can't be unsigned, as e.g.
6345 (-(x / 2U)) / 2U isn't equal to -((x / 2U) / 2U) for x >= 2.
6346 For signed types, even with wrapping overflow, this is fine. */
6355 /* If widening the type changes the signedness, then we can't perform
6356 this optimization as that changes the result. */
6360 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
6366 {
6373 }
6377 /* If the second operand is constant, this is a multiplication
6378 or floor division, by a power of two, so we can treat it that
6379 way unless the multiplier or divisor overflows. Signed
6380 left-shift overflow is implementation-defined rather than
6381 undefined in C90, so do not convert signed left shift into
6382 multiplication. */
6385 /* const_binop may not detect overflow correctly,
6386 so check for it explicitly here. */
6395 ctype,
6397 t1),
6402 /* See if we can eliminate the operation on both sides. If we can, we
6403 can return a new PLUS or MINUS. If we can't, the only remaining
6404 cases where we can do anything are if the second operand is a
6405 constant. */
6412 /* If not multiplication, we can only do this if both operands
6413 are divisible by c. */
6416 {
6421 }
6423 /* If this was a subtraction, negate OP1 and set it to be an addition.
6424 This simplifies the logic below. */
6426 {
6428 /* If OP1 was not easily negatable, the constant may be OP0. */
6430 {
6433 }
6434 }
6439 /* If either OP1 or C are negative, this optimization is not safe for
6440 some of the division and remainder types while for others we need
6441 to change the code. */
6443 {
6451 }
6453 /* If it's a multiply or a division/modulus operation of a multiple
6454 of our constant, do the operation and verify it doesn't overflow. */
6458 {
6461 /* We allow the constant to overflow with wrapping semantics. */
6465 }
6466 else
6469 /* If we have an unsigned type, we cannot widen the operation since it
6470 will change the result if the original computation overflowed. */
6474 /* The last case is if we are a multiply. In that case, we can
6475 apply the distributive law to commute the multiply and addition
6476 if the multiplication of the constants doesn't overflow
6477 and overflow is defined. With undefined overflow
6478 op0 * c might overflow, while (op0 + orig_op1) * c doesn't.
6479 But fold_plusminus_mult_expr would factor back any power-of-two
6480 value so do not distribute in the first place in this case. */
6488 op1);
6493 /* We have a special case here if we are doing something like
6494 (C * 8) % 4 since we know that's zero. */
6497 /* If the multiplication can overflow we cannot optimize this. */
6502 {
6505 }
6507 /* ... fall through ... */
6511 /* If we can extract our operation from the LHS, do so and return a
6512 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
6513 do something only if the second operand is a constant. */
6529 /* If these are the same operation types, we can associate them
6530 assuming no overflow. */
6532 {
6547 }
6549 /* If these operations "cancel" each other, we have the main
6550 optimizations of this pass, which occur when either constant is a
6551 multiple of the other, in which case we replace this with either an
6552 operation or CODE or TCODE.
6554 If we have an unsigned type, we cannot do this since it will change
6555 the result if the original computation overflowed. */
6562 {
6565 {
6572 }
6575 {
6582 }
6583 }
6588 }
6591 }
6592 \f
6593 /* Return a node which has the indicated constant VALUE (either 0 or
6594 1 for scalars or {-1,-1,..} or {0,0,...} for vectors),
6595 and is of the indicated TYPE. */
6597 tree
6599 {
6608 else
6610 }
6613 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
6614 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
6615 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
6616 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
6617 COND is the first argument to CODE; otherwise (as in the example
6618 given here), it is the second argument. TYPE is the type of the
6619 original expression. Return NULL_TREE if no simplification is
6620 possible. */
6622 static tree
6627 {
6635 /* Do not move possibly trapping operations into the conditional as this
6636 pessimizes code and causes gimplification issues when applied late. */
6644 {
6648 /* If this operand throws an expression, then it does not make
6649 sense to try to perform a logical or arithmetic operation
6650 involving it. */
6655 }
6658 {
6663 }
6664 else
6665 /* Detect the case of mixing vector and scalar types - bail out. */
6671 /* This transformation is only worthwhile if we don't have to wrap ARG
6672 in a SAVE_EXPR and the operation can be simplified without recursing
6673 on at least one of the branches once its pushed inside the COND_EXPR. */
6682 {
6686 else
6688 }
6690 {
6694 else
6696 }
6698 /* Check that we have simplified at least one of the branches. */
6703 }
6705 \f
6706 /* Subroutine of fold() that checks for the addition of +/- 0.0.
6708 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
6709 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
6710 ADDEND is the same as X.
6712 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
6713 and finite. The problematic cases are when X is zero, and its mode
6714 has signed zeros. In the case of rounding towards -infinity,
6715 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
6716 modes, X + 0 is not the same as X because -0 + 0 is 0. */
6718 bool
6720 {
6724 /* Don't allow the fold with -fsignaling-nans. */
6728 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
6732 /* There is no case that is safe for all rounding modes. */
6736 /* In a vector or complex, we would need to check the sign of all zeros. */
6742 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
6746 /* The mode has signed zeros, and we have to honor their sign.
6747 In this situation, there is only one case we can return true for.
6748 X - 0 is the same as X with default rounding. */
6750 }
6752 /* Subroutine of match.pd that optimizes comparisons of a division by
6753 a nonzero integer constant against an integer constant, i.e.
6754 X/C1 op C2.
6756 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6757 GE_EXPR or LE_EXPR. ARG01 and ARG1 must be a INTEGER_CST. */
6759 enum tree_code
6762 {
6767 /* We have to do this the hard way to detect unsigned overflow.
6768 prod = int_const_binop (MULT_EXPR, c1, c2); */
6774 {
6778 /* Likewise *hi = int_const_binop (PLUS_EXPR, prod, tmp). */
6781 }
6783 {
6786 {
6805 }
6806 }
6807 else
6808 {
6809 /* A negative divisor reverses the relational operators. */
6814 {
6833 }
6834 }
6847 }
6850 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6851 equality/inequality test, then return a simplified form of the test
6852 using a sign testing. Otherwise return NULL. TYPE is the desired
6853 result type. */
6855 static tree
6858 tree result_type)
6859 {
6860 /* If this is testing a single bit, we can optimize the test. */
6864 {
6865 /* If we have (A & C) != 0 where C is the sign bit of A, convert
6866 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
6870 /* This is only a win if casting to a signed type is cheap,
6871 i.e. when arg00's type is not a partial mode. */
6873 {
6876 result_type,
6879 }
6880 }
6883 }
6885 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6886 equality/inequality test, then return a simplified form of
6887 the test using shifts and logical operations. Otherwise return
6888 NULL. TYPE is the desired result type. */
6890 tree
6893 {
6894 /* If this is testing a single bit, we can optimize the test. */
6898 {
6907 /* First, see if we can fold the single bit test into a sign-bit
6908 test. */
6910 result_type);
6914 /* Otherwise we have (A & C) != 0 where C is a single bit,
6915 convert that into ((A >> C2) & 1). Where C2 = log2(C).
6916 Similarly for (A & C) == 0. */
6918 /* If INNER is a right shift of a constant and it plus BITNUM does
6919 not overflow, adjust BITNUM and INNER. */
6925 {
6928 }
6930 /* If we are going to be able to omit the AND below, we must do our
6931 operations as unsigned. If we must use the AND, we have a choice.
6932 Normally unsigned is faster, but for some machines signed is. */
6950 /* Put the AND last so it can combine with more things. */
6953 /* Make sure to return the proper type. */
6957 }
6959 }
6961 /* Test whether it is preferable two swap two operands, ARG0 and
6962 ARG1, for example because ARG0 is an integer constant and ARG1
6963 isn't. */
6965 bool
6967 {
6981 /* It is preferable to swap two SSA_NAME to ensure a canonical form
6982 for commutative and comparison operators. Ensuring a canonical
6983 form allows the optimizers to find additional redundancies without
6984 having to explicitly check for both orderings. */
6990 /* Put SSA_NAMEs last. */
6996 /* Put variables last. */
7003 }
7006 /* Fold A < X && A + 1 > Y to A < X && A >= Y. Normally A + 1 > Y
7007 means A >= Y && A != MAX, but in this case we know that
7008 A < X <= MAX. INEQ is A + 1 > Y, BOUND is A < X. */
7010 static tree
7012 {
7019 else
7028 {
7031 }
7033 {
7036 }
7037 else
7044 {
7045 /* Convert the pointer types into integer before taking the difference. */
7049 }
7050 else
7057 }
7059 /* Fold a sum or difference of at least one multiplication.
7060 Returns the folded tree or NULL if no simplification could be made. */
7062 static tree
7065 {
7069 /* (A * C) +- (B * C) -> (A+-B) * C.
7070 (A * C) +- A -> A * (C+-1).
7071 We are most concerned about the case where C is a constant,
7072 but other combinations show up during loop reduction. Since
7073 it is not difficult, try all four possibilities. */
7076 {
7079 }
7081 {
7084 }
7085 else
7086 {
7087 /* We cannot generate constant 1 for fract. */
7092 }
7094 {
7097 }
7099 {
7101 /* As we canonicalize A - 2 to A + -2 get rid of that sign for
7102 the purpose of this canonicalization. */
7106 {
7109 }
7110 else
7112 }
7113 else
7114 {
7115 /* We cannot generate constant 1 for fract. */
7120 }
7123 /* Prefer factoring a common non-constant. */
7133 /* No identical multiplicands; see if we can find a common
7134 power-of-two factor in non-power-of-two multiplies. This
7135 can help in multi-dimensional array access. */
7137 {
7140 HOST_WIDE_INT tmp;
7142 tree maybe_same;
7144 /* Move min of absolute values to int11. */
7146 {
7151 }
7152 else
7159 /* The remainder should not be a constant, otherwise we
7160 end up folding i * 4 + 2 to (i * 2 + 1) * 2 which has
7161 increased the number of multiplications necessary. */
7163 {
7171 }
7172 }
7179 /* We are neither factoring zero nor minus one. */
7187 /* Same may be zero and thus the operation 'code' may overflow. Likewise
7188 same may be minus one and thus the multiplication may overflow. Perform
7189 the sum operation in an unsigned type. */
7194 /* If the sum evaluated to a constant that is not -INF the multiplication
7195 cannot overflow. */
7202 /* Do not resort to unsigned multiplication because
7203 we lose the no-overflow property of the expression. */
7205 }
7207 /* Subroutine of native_encode_expr. Encode the INTEGER_CST
7208 specified by EXPR into the buffer PTR of length LEN bytes.
7209 Return the number of bytes placed in the buffer, or zero
7210 upon failure. */
7212 static int
7214 {
7226 /* Dry run. */
7232 {
7234 /* Extend EXPR according to TYPE_SIGN if the precision isn't a whole
7235 number of bytes. */
7239 {
7246 else
7248 }
7249 else
7253 }
7255 }
7258 /* Subroutine of native_encode_expr. Encode the FIXED_CST
7259 specified by EXPR into the buffer PTR of length LEN bytes.
7260 Return the number of bytes placed in the buffer, or zero
7261 upon failure. */
7263 static int
7265 {
7269 FIXED_VALUE_TYPE value;
7284 }
7287 /* Subroutine of native_encode_expr. Encode the REAL_CST
7288 specified by EXPR into the buffer PTR of length LEN bytes.
7289 Return the number of bytes placed in the buffer, or zero
7290 upon failure. */
7292 static int
7294 {
7300 /* There are always 32 bits in each long, no matter the size of
7301 the hosts long. We handle floating point representations with
7302 up to 192 bits. */
7311 /* Dry run. */
7320 {
7325 {
7332 else
7334 }
7335 else
7336 {
7339 {
7340 /* Reverse bytes within each long, or within the entire float
7341 if it's smaller than a long (for HFmode). */
7344 }
7345 }
7350 }
7352 }
7354 /* Subroutine of native_encode_expr. Encode the COMPLEX_CST
7355 specified by EXPR into the buffer PTR of length LEN bytes.
7356 Return the number of bytes placed in the buffer, or zero
7357 upon failure. */
7359 static int
7361 {
7363 tree part;
7377 }
7380 /* Subroutine of native_encode_expr. Encode the VECTOR_CST
7381 specified by EXPR into the buffer PTR of length LEN bytes.
7382 Return the number of bytes placed in the buffer, or zero
7383 upon failure. */
7385 static int
7387 {
7398 {
7400 {
7403 }
7414 }
7416 }
7419 /* Subroutine of native_encode_expr. Encode the STRING_CST
7420 specified by EXPR into the buffer PTR of length LEN bytes.
7421 Return the number of bytes placed in the buffer, or zero
7422 upon failure. */
7424 static int
7426 {
7429 /* Wide-char strings are encoded in target byte-order so native
7430 encoding them is trivial. */
7445 {
7448 {
7451 }
7454 }
7455 else
7458 }
7461 /* Subroutine of fold_view_convert_expr. Encode the INTEGER_CST,
7462 REAL_CST, COMPLEX_CST or VECTOR_CST specified by EXPR into the
7463 buffer PTR of length LEN bytes. If PTR is NULL, don't actually store
7464 anything, just do a dry run. If OFF is not -1 then start
7465 the encoding at byte offset OFF and encode at most LEN bytes.
7466 Return the number of bytes placed in the buffer, or zero upon failure. */
7468 int
7470 {
7471 /* We don't support starting at negative offset and -1 is special. */
7476 {
7497 }
7498 }
7501 /* Subroutine of native_interpret_expr. Interpret the contents of
7502 the buffer PTR of length LEN as an INTEGER_CST of type TYPE.
7503 If the buffer cannot be interpreted, return NULL_TREE. */
7505 static tree
7507 {
7517 }
7520 /* Subroutine of native_interpret_expr. Interpret the contents of
7521 the buffer PTR of length LEN as a FIXED_CST of type TYPE.
7522 If the buffer cannot be interpreted, return NULL_TREE. */
7524 static tree
7526 {
7529 double_int result;
7530 FIXED_VALUE_TYPE fixed_value;
7540 }
7543 /* Subroutine of native_interpret_expr. Interpret the contents of
7544 the buffer PTR of length LEN as a REAL_CST of type TYPE.
7545 If the buffer cannot be interpreted, return NULL_TREE. */
7547 static tree
7549 {
7553 /* There are always 32 bits in each long, no matter the size of
7554 the hosts long. We handle floating point representations with
7555 up to 192 bits. */
7556 REAL_VALUE_TYPE r;
7566 {
7567 /* Both OFFSET and BYTE index within a long;
7568 bitpos indexes the whole float. */
7571 {
7578 else
7580 }
7581 else
7582 {
7585 {
7586 /* Reverse bytes within each long, or within the entire float
7587 if it's smaller than a long (for HFmode). */
7590 }
7591 }
7595 }
7599 }
7602 /* Subroutine of native_interpret_expr. Interpret the contents of
7603 the buffer PTR of length LEN as a COMPLEX_CST of type TYPE.
7604 If the buffer cannot be interpreted, return NULL_TREE. */
7606 static tree
7608 {
7623 }
7626 /* Subroutine of native_interpret_expr. Interpret the contents of
7627 the buffer PTR of length LEN as a VECTOR_CST of type TYPE.
7628 If the buffer cannot be interpreted, return NULL_TREE. */
7630 static tree
7632 {
7645 {
7650 }
7652 }
7655 /* Subroutine of fold_view_convert_expr. Interpret the contents of
7656 the buffer PTR of length LEN as a constant of type TYPE. For
7657 INTEGRAL_TYPE_P we return an INTEGER_CST, for SCALAR_FLOAT_TYPE_P
7658 we return a REAL_CST, etc... If the buffer cannot be interpreted,
7659 return NULL_TREE. */
7661 tree
7663 {
7665 {
7687 }
7688 }
7690 /* Returns true if we can interpret the contents of a native encoding
7691 as TYPE. */
7693 static bool
7695 {
7697 {
7710 }
7711 }
7714 /* Fold a VIEW_CONVERT_EXPR of a constant expression EXPR to type
7715 TYPE at compile-time. If we're unable to perform the conversion
7716 return NULL_TREE. */
7718 static tree
7720 {
7721 /* We support up to 512-bit values (for V8DFmode). */
7725 /* Check that the host and target are sane. */
7734 }
7736 /* Build an expression for the address of T. Folds away INDIRECT_REF
7737 to avoid confusing the gimplify process. */
7739 tree
7741 {
7742 /* The size of the object is not relevant when talking about its address. */
7747 {
7752 }
7762 {
7767 }
7768 else
7772 }
7774 /* Build an expression for the address of T. */
7776 tree
7778 {
7782 }
7784 /* Fold a unary expression of code CODE and type TYPE with operand
7785 OP0. Return the folded expression if folding is successful.
7786 Otherwise, return NULL_TREE. */
7788 tree
7790 {
7791 tree tem;
7792 tree arg0;
7800 {
7803 {
7804 /* Don't use STRIP_NOPS, because signedness of argument type
7805 matters. */
7807 }
7808 else
7809 {
7810 /* Strip any conversions that don't change the mode. This
7811 is safe for every expression, except for a comparison
7812 expression because its signedness is derived from its
7813 operands.
7815 Note that this is done as an internal manipulation within
7816 the constant folder, in order to find the simplest
7817 representation of the arguments so that their form can be
7818 studied. In any cases, the appropriate type conversions
7819 should be put back in the tree that will get out of the
7820 constant folder. */
7822 }
7825 {
7828 {
7832 }
7833 }
7834 }
7841 {
7848 {
7862 /* If this was a conversion, and all we did was to move into
7863 inside the COND_EXPR, bring it back out. But leave it if
7864 it is a conversion from integer to integer and the
7865 result precision is no wider than a word since such a
7866 conversion is cheap and may be optimized away by combine,
7867 while it couldn't if it were outside the COND_EXPR. Then return
7868 so we don't get into an infinite recursion loop taking the
7869 conversion out and then back in. */
7881 && (INTEGRAL_TYPE_P
7894 }
7895 }
7898 {
7904 CASE_CONVERT:
7908 {
7909 /* If we have (type) (a CMP b) and type is an integral type, return
7910 new expression involving the new type. Canonicalize
7911 (type) (a CMP b) to (a CMP b) ? (type) true : (type) false for
7912 non-integral type.
7913 Do not fold the result as that would not simplify further, also
7914 folding again results in recursions. */
7924 }
7926 /* Handle (T *)&A.B.C for A being of type T and B and C
7927 living at offset zero. This occurs frequently in
7928 C++ upcasting and then accessing the base. */
7932 {
7934 tree offset;
7935 machine_mode mode;
7937 tree base
7941 /* If the reference was to a (constant) zero offset, we can use
7942 the address of the base if it has the same base type
7943 as the result type and the pointer type is unqualified. */
7951 }
7955 /* Detect assigning a bitfield. */
7957 && DECL_BIT_FIELD
7959 {
7960 /* Don't leave an assignment inside a conversion
7961 unless assigning a bitfield. */
7963 /* First do the assignment, then return converted constant. */
7968 }
7970 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
7971 constants (if x has signed type, the sign bit cannot be set
7972 in c). This folds extension into the BIT_AND_EXPR.
7973 ??? We don't do it for BOOLEAN_TYPE or ENUMERAL_TYPE because they
7974 very likely don't have maximal range for their precision and this
7975 transformation effectively doesn't preserve non-maximal ranges. */
7979 {
7990 <= HOST_BITS_PER_WIDE_INT
7992 {
7996 cst &= HOST_WIDE_INT_M1U
8000 && !flag_syntax_only
8003 {
8007 }
8008 }
8010 {
8015 }
8016 }
8018 /* Convert (T1)(X p+ Y) into ((T1)X p+ Y), for pointer type, when the new
8019 cast (T1)X will fold away. We assume that this happens when X itself
8020 is a cast. */
8024 {
8028 return fold_build_pointer_plus_loc
8030 }
8032 /* Convert (T1)(~(T2)X) into ~(T1)X if T1 and T2 are integral types
8033 of the same precision, and X is an integer type not narrower than
8034 types T1 or T2, i.e. the cast (T2)X isn't an extension. */
8040 {
8046 }
8048 /* Convert (T1)(X * Y) into (T1)X * (T1)Y if T1 is narrower than the
8049 type of X and Y (integer types only). */
8054 {
8055 /* Be careful not to introduce new overflows. */
8056 tree mult_type;
8059 else
8063 {
8070 }
8071 }
8077 {
8084 }
8095 /* Convert fabs((double)float) into (double)fabsf(float). */
8098 {
8104 targ0));
8105 }
8109 /* Convert ~(X ^ Y) to ~X ^ Y or X ^ ~Y if ~X or ~Y simplify. */
8128 /* Note that the operand of this must be an int
8129 and its values must be 0 or 1.
8130 ("true" is a fixed value perhaps depending on the language,
8131 but we don't handle values other than 1 correctly yet.) */
8138 /* Fold *&X to X if X is an lvalue. */
8140 {
8147 }
8153 }
8156 /* If the operation was a conversion do _not_ mark a resulting constant
8157 with TREE_OVERFLOW if the original constant was not. These conversions
8158 have implementation defined behavior and retaining the TREE_OVERFLOW
8159 flag here would confuse later passes such as VRP. */
8160 tree
8163 {
8172 }
8174 /* Fold a binary bitwise/truth expression of code CODE and type TYPE with
8175 operands OP0 and OP1. LOC is the location of the resulting expression.
8176 ARG0 and ARG1 are the NOP_STRIPed results of OP0 and OP1.
8177 Return the folded expression if folding is successful. Otherwise,
8178 return NULL_TREE. */
8179 static tree
8182 {
8183 tree tem;
8185 /* We only do these simplifications if we are optimizing. */
8189 /* Check for things like (A || B) && (A || C). We can convert this
8190 to A || (B && C). Note that either operator can be any of the four
8191 truth and/or operations and the transformation will still be
8192 valid. Also note that we only care about order for the
8193 ANDIF and ORIF operators. If B contains side effects, this
8194 might change the truth-value of A. */
8201 {
8221 /* This case if tricky because we must either have commutative
8222 operators or else A10 must not have side-effects. */
8228 a01);
8229 }
8231 /* See if we can build a range comparison. */
8237 {
8241 }
8245 {
8249 }
8251 /* Check for the possibility of merging component references. If our
8252 lhs is another similar operation, try to merge its rhs with our
8253 rhs. Then try to merge our lhs and rhs. */
8264 logical_op_non_short_circuit
8267 && !flag_sanitize_coverage
8272 {
8279 /* Transform ((A AND-IF B) AND[-IF] C) into (A AND-IF (B AND C)),
8280 or ((A OR-IF B) OR[-IF] C) into (A OR-IF (B OR C))
8281 We don't want to pack more than two leafs to a non-IF AND/OR
8282 expression.
8283 If tree-code of left-hand operand isn't an AND/OR-IF code and not
8284 equal to IF-CODE, then we don't want to add right-hand operand.
8285 If the inner right-hand side of left-hand operand has
8286 side-effects, or isn't simple, then we can't add to it,
8287 as otherwise we might destroy if-sequence. */
8290 /* Needed for sequence points to handle trappings, and
8291 side-effects. */
8293 {
8295 arg1);
8297 tem);
8298 }
8299 /* Same as above but for (A AND[-IF] (B AND-IF C)) -> ((A AND B) AND-IF C),
8300 or (A OR[-IF] (B OR-IF C) -> ((A OR B) OR-IF C). */
8303 /* Needed for sequence points to handle trappings, and
8304 side-effects. */
8306 {
8311 }
8312 /* Transform (A AND-IF B) into (A AND B), or (A OR-IF B)
8313 into (A OR B).
8314 For sequence point consistancy, we need to check for trapping,
8315 and side-effects. */
8319 }
8322 }
8324 /* Helper that tries to canonicalize the comparison ARG0 CODE ARG1
8325 by changing CODE to reduce the magnitude of constants involved in
8326 ARG0 of the comparison.
8327 Returns a canonicalized comparison tree if a simplification was
8328 possible, otherwise returns NULL_TREE.
8329 Set *STRICT_OVERFLOW_P to true if the canonicalization is only
8330 valid if signed overflow is undefined. */
8332 static tree
8336 {
8341 /* Match A +- CST code arg1. We can change this only if overflow
8342 is undefined. */
8345 /* In principle pointers also have undefined overflow behavior,
8346 but that causes problems elsewhere. */
8353 /* Identify the constant in arg0 and its sign. */
8357 /* Overflowed constants and zero will cause problems. */
8362 /* See if we can reduce the magnitude of the constant in
8363 arg0 by changing the comparison code. */
8364 /* A - CST < arg1 -> A - CST-1 <= arg1. */
8368 /* A + CST > arg1 -> A + CST-1 >= arg1. */
8372 /* A + CST <= arg1 -> A + CST-1 < arg1. */
8376 /* A - CST >= arg1 -> A - CST-1 > arg1. */
8380 else
8384 /* Now build the constant reduced in magnitude. But not if that
8385 would produce one outside of its types range. */
8401 }
8403 /* Canonicalize the comparison ARG0 CODE ARG1 with type TYPE with undefined
8404 overflow further. Try to decrease the magnitude of constants involved
8405 by changing LE_EXPR and GE_EXPR to LT_EXPR and GT_EXPR or vice versa
8406 and put sole constants at the second argument position.
8407 Returns the canonicalized tree if changed, otherwise NULL_TREE. */
8409 static tree
8412 {
8413 tree t;
8418 /* Try canonicalization by simplifying arg0. */
8423 {
8427 }
8429 /* Try canonicalization by simplifying arg1 using the swapped
8430 comparison. */
8438 }
8440 /* Return whether BASE + OFFSET + BITPOS may wrap around the address
8441 space. This is used to avoid issuing overflow warnings for
8442 expressions like &p->x which cannot wrap. */
8444 static bool
8446 {
8453 poly_wide_int wi_offset;
8459 else
8464 precision);
8479 /* We can do slightly better for SIZE if we have an ADDR_EXPR of an
8480 array. */
8489 }
8491 /* Return a positive integer when the symbol DECL is known to have
8492 a nonzero address, zero when it's known not to (e.g., it's a weak
8493 symbol), and a negative integer when the symbol is not yet in the
8494 symbol table and so whether or not its address is zero is unknown.
8495 For function local objects always return positive integer. */
8496 static int
8498 {
8503 /* Function local objects are never NULL. */
8511 }
8513 /* Subroutine of fold_binary. This routine performs all of the
8514 transformations that are common to the equality/inequality
8515 operators (EQ_EXPR and NE_EXPR) and the ordering operators
8516 (LT_EXPR, LE_EXPR, GE_EXPR and GT_EXPR). Callers other than
8517 fold_binary should call fold_binary. Fold a comparison with
8518 tree code CODE and type TYPE with operands OP0 and OP1. Return
8519 the folded comparison or NULL_TREE. */
8521 static tree
8524 {
8534 /* For comparisons of pointers we can decompose it to a compile time
8535 comparison of the base objects and the offsets into the object.
8536 This requires at least one operand being an ADDR_EXPR or a
8537 POINTER_PLUS_EXPR to do more than the operand_equal_p test below. */
8543 {
8546 machine_mode mode;
8550 /* Get base and offset for the access. Strip ADDR_EXPR for
8551 get_inner_reference, but put it back by stripping INDIRECT_REF
8552 off the base object if possible. indirect_baseN will be true
8553 if baseN is not an address but refers to the object itself. */
8556 {
8557 base0
8563 else
8565 }
8567 {
8571 {
8572 base0
8578 else
8580 }
8583 else
8587 {
8594 }
8595 }
8599 {
8600 base1
8606 else
8608 }
8610 {
8614 {
8615 base1
8621 else
8623 }
8626 else
8630 {
8637 }
8638 }
8640 /* If we have equivalent bases we might be able to simplify. */
8644 {
8645 /* We can fold this expression to a constant if the non-constant
8646 offset parts are equal. */
8650 && (equality_code
8651 || (indirect_base0
8654 {
8660 "occur when comparing P +- C1 with "
8662 WARN_STRICT_OVERFLOW_CONDITIONAL);
8665 {
8703 }
8704 }
8705 /* We can simplify the comparison to a comparison of the variable
8706 offset parts if the constant offset parts are equal.
8707 Be careful to use signed sizetype here because otherwise we
8708 mess with array offsets in the wrong way. This is possible
8709 because pointer arithmetic is restricted to retain within an
8710 object and overflow on pointer differences is undefined as of
8711 6.5.6/8 and /9 with respect to the signed ptrdiff_t. */
8713 && (equality_code
8714 || (indirect_base0
8717 {
8718 /* By converting to signed sizetype we cover middle-end pointer
8719 arithmetic which operates on unsigned pointer types of size
8720 type size and ARRAY_REF offsets which are properly sign or
8721 zero extended from their type in case it is narrower than
8722 sizetype. */
8725 else
8729 else
8736 "occur when comparing P +- C1 with "
8738 WARN_STRICT_OVERFLOW_COMPARISON);
8741 }
8742 }
8743 /* For equal offsets we can simplify to a comparison of the
8744 base addresses. */
8746 && (indirect_base0
8748 && (indirect_base1
8753 {
8759 }
8760 /* Comparison between an ordinary (non-weak) symbol and a null
8761 pointer can be eliminated since such symbols must have a non
8762 null address. In C, relational expressions between pointers
8763 to objects and null pointers are undefined. The results
8764 below follow the C++ rules with the additional property that
8765 every object pointer compares greater than a null pointer.
8766 */
8769 /* Avoid folding references to struct members at offset 0 to
8770 prevent tests like '&ptr->firstmember == 0' from getting
8771 eliminated. When ptr is null, although the -> expression
8772 is strictly speaking invalid, GCC retains it as a matter
8773 of QoI. See PR c/44555. */
8776 && indirect_base0
8777 /* The caller guarantees that when one of the arguments is
8778 constant (i.e., null in this case) it is second. */
8780 {
8782 {
8793 }
8794 }
8795 }
8797 /* Transform comparisons of the form X +- C1 CMP Y +- C2 to
8798 X CMP Y +- C2 +- C1 for signed X, Y. This is valid if
8799 the resulting offset is smaller in absolute value than the
8800 original one and has the same sign. */
8809 {
8814 tree cst;
8816 "occur when combining constants around "
8819 /* Put the constant on the side where it doesn't overflow and is
8820 of lower absolute value and of same sign than before. */
8827 {
8830 variable1,
8834 }
8842 {
8848 variable2);
8849 }
8850 }
8856 /* If we are comparing an expression that just has comparisons
8857 of two integer values, arithmetic expressions of those comparisons,
8858 and constants, we can simplify it. There are only three cases
8859 to check: the two values can either be equal, the first can be
8860 greater, or the second can be greater. Fold the expression for
8861 those three values. Since each value must be 0 or 1, we have
8862 eight possibilities, each of which corresponds to the constant 0
8863 or 1 or one of the six possible comparisons.
8865 This handles common cases like (a > b) == 0 but also handles
8866 expressions like ((x > y) - (y > x)) > 0, which supposedly
8867 occur in macroized code. */
8870 {
8874 /* Don't handle degenerate cases here; they should already
8875 have been handled anyway. */
8884 {
8888 /* We can't just pass T to eval_subst in case cval1 or cval2
8889 was the same as ARG1. */
8891 tree high_result
8895 arg1);
8896 tree equal_result
8900 arg1);
8901 tree low_result
8905 arg1);
8907 /* All three of these results should be 0 or 1. Confirm they are.
8908 Then use those values to select the proper code to use. */
8913 {
8914 /* Make a 3-bit mask with the high-order bit being the
8915 value for `>', the next for '=', and the low for '<'. */
8919 {
8921 /* Always false. */
8942 /* Always true. */
8944 }
8947 }
8948 }
8949 }
8952 }
8955 /* Subroutine of fold_binary. Optimize complex multiplications of the
8956 form z * conj(z), as pow(realpart(z),2) + pow(imagpart(z),2). The
8957 argument EXPR represents the expression "z" of type TYPE. */
8959 static tree
8961 {
8966 {
8969 }
8971 {
8974 }
8975 else
8976 {
8980 }
8989 }
8992 /* Helper function for fold_vec_perm. Store elements of VECTOR_CST or
8993 CONSTRUCTOR ARG into array ELTS, which has NELTS elements, and return
8994 true if successful. */
8996 static bool
8998 {
9003 {
9006 }
9008 {
9014 else
9016 }
9017 else
9023 }
9025 /* Attempt to fold vector permutation of ARG0 and ARG1 vectors using SEL
9026 selector. Return the folded VECTOR_CST or CONSTRUCTOR if successful,
9027 NULL_TREE otherwise. */
9029 tree
9031 {
9052 {
9053 HOST_WIDE_INT index;
9059 }
9062 {
9068 }
9069 else
9071 }
9073 /* Try to fold a pointer difference of type TYPE two address expressions of
9074 array references AREF0 and AREF1 using location LOC. Return a
9075 simplified expression for the difference or NULL_TREE. */
9077 static tree
9081 {
9086 /* If the bases are array references as well, recurse. If the bases
9087 are pointer indirections compute the difference of the pointers.
9088 If the bases are equal, we are set. */
9091 && (base_offset
9093 use_pointer_diff)))
9096 && (base_offset
9097 = use_pointer_diff
9107 {
9113 base_offset,
9116 }
9118 }
9120 /* If the real or vector real constant CST of type TYPE has an exact
9121 inverse, return it, else return NULL. */
9123 tree
9125 {
9126 REAL_VALUE_TYPE r;
9127 tree unit_type;
9128 machine_mode mode;
9131 {
9141 {
9145 tree_vector_builder elts;
9150 {
9155 }
9158 }
9162 }
9163 }
9165 /* Mask out the tz least significant bits of X of type TYPE where
9166 tz is the number of trailing zeroes in Y. */
9167 static wide_int
9169 {
9174 }
9176 /* Return true when T is an address and is known to be nonzero.
9177 For floating point we further ensure that T is not denormal.
9178 Similar logic is present in nonzero_address in rtlanal.h.
9180 If the return value is based on the assumption that signed overflow
9181 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
9182 change *STRICT_OVERFLOW_P. */
9184 static bool
9186 {
9190 /* Doing something useful for floating point would need more work. */
9196 {
9199 strict_overflow_p);
9205 strict_overflow_p);
9213 }
9216 {
9219 strict_overflow_p);
9227 strict_overflow_p);
9242 strict_overflow_p);
9246 strict_overflow_p);
9249 {
9261 }
9265 }
9267 }
9269 /* Return true when T is an address and is known to be nonzero.
9270 Handle warnings about undefined signed overflow. */
9272 bool
9274 {
9281 "determining that expression is always "
9283 WARN_STRICT_OVERFLOW_MISC);
9285 }
9287 /* Return true if T is known not to be equal to an integer W. */
9289 bool
9291 {
9293 value_range_kind rtype;
9295 {
9304 {
9309 }
9314 /* If T has some known zero bits and W has any of those bits set,
9315 then T is known not to be equal to W. */
9323 }
9324 }
9326 /* Fold a binary expression of code CODE and type TYPE with operands
9327 OP0 and OP1. LOC is the location of the resulting expression.
9328 Return the folded expression if folding is successful. Otherwise,
9329 return NULL_TREE. */
9331 tree
9334 {
9349 /* Strip any conversions that don't change the mode. This is
9350 safe for every expression, except for a comparison expression
9351 because its signedness is derived from its operands. So, in
9352 the latter case, only strip conversions that don't change the
9353 signedness. MIN_EXPR/MAX_EXPR also need signedness of arguments
9354 preserved.
9356 Note that this is done as an internal manipulation within the
9357 constant folder, in order to find the simplest representation
9358 of the arguments so that their form can be studied. In any
9359 cases, the appropriate type conversions should be put back in
9360 the tree that will get out of the constant folder. */
9363 {
9366 }
9367 else
9368 {
9371 }
9373 /* Note that TREE_CONSTANT isn't enough: static var addresses are
9374 constant but we can't do arithmetic on them. */
9376 {
9379 {
9383 }
9384 }
9386 /* If this is a commutative operation, and ARG0 is a constant, move it
9387 to ARG1 to reduce the number of tests below. */
9392 /* Likewise if this is a comparison, and ARG0 is a constant, move it
9393 to ARG1 to reduce the number of tests below. */
9402 /* ARG0 is the first operand of EXPR, and ARG1 is the second operand.
9404 First check for cases where an arithmetic operation is applied to a
9405 compound, conditional, or comparison operation. Push the arithmetic
9406 operation inside the compound or conditional to see if any folding
9407 can then be done. Convert comparison to conditional for this purpose.
9408 The also optimizes non-constant cases that used to be done in
9409 expand_expr.
9411 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
9412 one of the operands is a comparison and the other is a comparison, a
9413 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
9414 code below would make the expression more complex. Change it to a
9415 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
9416 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
9429 {
9433 boolean_type_node,
9441 }
9445 {
9447 {
9452 tem);
9453 }
9455 {
9460 tem);
9461 }
9466 {
9472 }
9477 {
9483 }
9484 }
9487 {
9489 /* MEM[&MEM[p, CST1], CST2] -> MEM[p, CST1 + CST2]. */
9492 {
9498 }
9500 /* MEM[&a.b, CST2] -> MEM[&a, offsetof (a, b) + CST2]. */
9503 {
9504 tree base;
9505 poly_int64 coffset;
9514 }
9519 /* INT +p INT -> (PTR)(INT + INT). Stripping types allows for this. */
9525 arg1),
9527 arg0)));
9533 {
9534 /* X + (X / CST) * -CST is X % CST. */
9539 {
9548 cst0));
9549 }
9550 }
9552 /* Handle (A1 * C1) + (A2 * C2) with A1, A2 or C1, C2 being the same or
9553 one. Make sure the type is not saturating and has the signedness of
9554 the stripped operands, as fold_plusminus_mult_expr will re-associate.
9555 ??? The latter condition should use TYPE_OVERFLOW_* flags instead. */
9562 {
9566 }
9569 {
9570 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
9571 (plus (plus (mult) (mult)) (foo)) so that we can
9572 take advantage of the factoring cases below. */
9581 {
9587 else
9600 parg0),
9602 marg)),
9606 return
9612 parg1)));
9613 }
9614 }
9615 else
9616 {
9617 /* Fold __complex__ ( x, 0 ) + __complex__ ( 0, y )
9618 to __complex__ ( x, y ). This is not the same for SNaNs or
9619 if signed zeros are involved. */
9623 {
9630 {
9634 {
9640 }
9642 {
9648 }
9649 }
9650 }
9652 /* Convert a + (b*c + d*e) into (a + b*c) + d*e.
9653 We associate floats only if the user has specified
9654 -fassociative-math. */
9658 {
9663 {
9664 tree tree0;
9667 }
9668 }
9669 /* Convert (b*c + d*e) + a into b*c + (d*e +a).
9670 We associate floats only if the user has specified
9671 -fassociative-math. */
9675 {
9680 {
9681 tree tree0;
9684 }
9685 }
9686 }
9688 bit_rotate:
9689 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
9690 is a rotate of A by C1 bits. */
9691 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
9692 is a rotate of A by B bits.
9693 Similarly for (A << B) | (A >> (-B & C3)) where C3 is Z-1,
9694 though in this case CODE must be | and not + or ^, otherwise
9695 it doesn't return A when B is 0. */
9696 {
9698 tree rtype;
9707 /* Only create rotates in complete modes. Other cases are not
9708 expanded properly. */
9711 {
9724 {
9729 }
9734 {
9737 code0 == LSHIFT_EXPR
9740 }
9742 {
9752 {
9756 orig_tree01);
9758 }
9759 }
9763 {
9774 {
9778 orig_tree01);
9780 }
9781 }
9782 }
9783 }
9785 associate:
9786 /* In most languages, can't associate operations on floats through
9787 parentheses. Rather than remember where the parentheses were, we
9788 don't associate floats at all, unless the user has specified
9789 -fassociative-math.
9790 And, we need to make sure type is not saturating. */
9794 {
9800 /* Split both trees into variables, constants, and literals. Then
9801 associate each group together, the constants with literals,
9802 then the result with variables. This increases the chances of
9803 literals being recombined later and of generating relocatable
9804 expressions for the sum of a constant and literal. */
9812 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
9816 /* With undefined overflow prefer doing association in a type
9817 which wraps on overflow, if that is one of the operand types. */
9820 {
9828 }
9830 /* With undefined overflow we can only associate constants with one
9831 variable, and constants whose association doesn't overflow. */
9834 {
9836 {
9837 /* ??? If split_tree would handle NEGATE_EXPR we could
9838 simply reject these cases and the allowed cases would
9839 be the var0/minus_var1 ones. */
9845 {
9848 }
9855 {
9858 }
9864 /* The only case we can still associate with two variables
9865 is if they cancel out. */
9869 }
9875 }
9877 /* Only do something if we found more than two objects. Otherwise,
9878 nothing has changed and we risk infinite recursion. */
9886 {
9898 {
9902 }
9904 {
9908 }
9910 /* Preserve the MINUS_EXPR if the negative part of the literal is
9911 greater than the positive part. Otherwise, the multiplicative
9912 folding code (i.e extract_muldiv) may be fooled in case
9913 unsigned constants are subtracted, like in the following
9914 example: ((X*2 + 4) - 8U)/2. */
9916 {
9920 /* But avoid ending up with only negated parts. */
9922 {
9926 }
9927 else
9928 {
9932 }
9933 }
9935 /* Don't introduce overflows through reassociation. */
9940 /* Eliminate lit0 and minus_lit0 to con0 and minus_con0. */
9947 /* Eliminate minus_con0. */
9949 {
9956 else
9959 }
9961 /* Eliminate minus_var0. */
9963 {
9967 else
9970 }
9972 return
9975 }
9976 }
9982 /* Fold &a[i] - &a[j] to i-j. */
9987 {
9991 code
9995 }
9997 /* Further transformations are not for pointers. */
10001 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
10004 /* If arg0 is e.g. unsigned int and type is int, then this could
10005 introduce UB, because if A is INT_MIN at runtime, the original
10006 expression can be well defined while the latter is not.
10007 See PR83269. */
10016 /* Fold __complex__ ( x, 0 ) - __complex__ ( 0, y ) to
10017 __complex__ ( x, -y ). This is not the same for SNaNs or if
10018 signed zeros are involved. */
10022 {
10029 {
10033 {
10035 arg1r ? arg1r
10040 }
10042 {
10046 arg1i ? arg1i
10049 }
10050 }
10051 }
10053 /* A - B -> A + (-B) if B is easily negatable. */
10057 /* Avoid this transformation if B is a positive REAL_CST. */
10065 /* Handle (A1 * C1) - (A2 * C2) with A1, A2 or C1, C2 being the same or
10066 one. Make sure the type is not saturating and has the signedness of
10067 the stripped operands, as fold_plusminus_mult_expr will re-associate.
10068 ??? The latter condition should use TYPE_OVERFLOW_* flags instead. */
10075 {
10079 }
10085 {
10086 /* Transform x * -C into -x * C if x is easily negatable. */
10101 {
10104 "occur when simplifying "
10106 WARN_STRICT_OVERFLOW_MISC);
10108 }
10110 /* Optimize z * conj(z) for integer complex numbers. */
10117 }
10118 else
10119 {
10120 /* Fold z * +-I to __complex__ (-+__imag z, +-__real z).
10121 This is not the same for NaNs or if signed zeros are
10122 involved. */
10128 {
10131 return
10137 return
10142 }
10144 /* Optimize z * conj(z) for floating point complex numbers.
10145 Guarded by flag_unsafe_math_optimizations as non-finite
10146 imaginary components don't produce scalar results. */
10155 }
10159 /* Canonicalize (X & C1) | C2. */
10163 {
10168 /* If (C1&C2) == C1, then (X&C1)|C2 becomes (X,C2). */
10176 /* If (C1|C2) == ~0 then (X&C1)|C2 becomes X|C2. */
10178 {
10181 }
10183 /* Minimize the number of bits set in C1, i.e. C1 := C1 & ~C2,
10184 unless (C1 & ~C2) | (C2 & C3) for some C3 is a mask of some
10185 mode which allows further optimizations. */
10190 {
10195 {
10198 }
10199 }
10202 {
10207 }
10208 }
10210 /* See if this can be simplified into a rotate first. If that
10211 is unsuccessful continue in the association code. */
10215 /* Fold (X & 1) ^ 1 as (X & 1) == 0. */
10223 /* See if this can be simplified into a rotate first. If that
10224 is unsuccessful continue in the association code. */
10228 /* Fold (X ^ 1) & 1 as (X & 1) == 0. */
10233 {
10234 tree tem2;
10241 }
10242 /* Fold ~X & 1 as (X & 1) == 0. */
10246 {
10247 tree tem2;
10254 }
10255 /* Fold !X & 1 as X == 0. */
10258 {
10262 }
10264 /* Fold (X * Y) & -(1 << CST) to X * Y if Y is a constant
10265 multiple of 1 << CST. */
10267 {
10274 }
10276 /* Fold (X * CST1) & CST2 to zero if we can, or drop known zero
10277 bits from CST2. */
10281 {
10283 wide_int masked
10290 {
10291 /* Avoid the transform if arg1 is a mask of some
10292 mode which allows further optimizations. */
10299 }
10300 }
10302 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
10305 {
10310 return
10312 }
10317 /* Don't touch a floating-point divide by zero unless the mode
10318 of the constant can represent infinity. */
10324 /* (-A) / (-B) -> A / B */
10336 /* Fall through */
10339 /* Simplify A / (B << N) where A and B are positive and B is
10340 a power of 2, to A >> (N + log2(B)). */
10345 {
10348 {
10356 WARN_STRICT_OVERFLOW_MISC);
10362 }
10363 }
10365 /* Fall through */
10373 /* Convert -A / -B to A / B when the type is signed and overflow is
10374 undefined. */
10378 {
10381 "when distributing negation across "
10383 WARN_STRICT_OVERFLOW_MISC);
10388 }
10392 {
10395 "when distributing negation across "
10397 WARN_STRICT_OVERFLOW_MISC);
10402 }
10404 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
10405 operation, EXACT_DIV_EXPR.
10407 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
10408 At one time others generated faster code, it's not clear if they do
10409 after the last round to changes to the DIV code in expmed.c. */
10420 {
10424 WARN_STRICT_OVERFLOW_MISC);
10426 }
10438 {
10442 WARN_STRICT_OVERFLOW_MISC);
10444 }
10452 /* Since negative shift count is not well-defined,
10453 don't try to compute it in the compiler. */
10459 /* If we have a rotate of a bit operation with the rotate count and
10460 the second operand of the bit operation both constant,
10461 permute the two operations. */
10467 {
10475 }
10477 /* Two consecutive rotates adding up to the some integer
10478 multiple of the precision of the type can be ignored. */
10494 /* Note that the operands of this must be ints
10495 and their values must be 0 or 1.
10496 ("true" is a fixed value perhaps depending on the language.) */
10497 /* If first arg is constant zero, return it. */
10500 /* FALLTHRU */
10502 /* If either arg is constant true, drop it. */
10506 /* Preserve sequence points. */
10509 /* If second arg is constant zero, result is zero, but first arg
10510 must be evaluated. */
10513 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
10514 case will be handled here. */
10518 /* !X && X is always false. */
10522 /* X && !X is always false. */
10527 /* A < X && A + 1 > Y ==> A < X && A >= Y. Normally A + 1 > Y
10528 means A >= Y && A != MAX, but in this case we know that
10529 A < X <= MAX. */
10533 {
10541 }
10550 /* Note that the operands of this must be ints
10551 and their values must be 0 or true.
10552 ("true" is a fixed value perhaps depending on the language.) */
10553 /* If first arg is constant true, return it. */
10556 /* FALLTHRU */
10558 /* If either arg is constant zero, drop it. */
10562 /* Preserve sequence points. */
10565 /* If second arg is constant true, result is true, but we must
10566 evaluate first arg. */
10569 /* Likewise for first arg, but note this only occurs here for
10570 TRUTH_OR_EXPR. */
10574 /* !X || X is always true. */
10578 /* X || !X is always true. */
10583 /* (X && !Y) || (!X && Y) is X ^ Y */
10586 {
10603 }
10612 /* If the second arg is constant zero, drop it. */
10615 /* If the second arg is constant true, this is a logical inversion. */
10617 {
10620 }
10621 /* Identical arguments cancel to zero. */
10625 /* !X ^ X is always true. */
10630 /* X ^ !X is always true. */
10646 /* bool_var != 1 becomes !bool_var. */
10653 /* bool_var == 0 becomes !bool_var. */
10660 /* !exp != 0 becomes !exp */
10665 /* If this is an EQ or NE comparison with zero and ARG0 is
10666 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
10667 two operations, but the latter can be done in one less insn
10668 on machines that have only two-operand insns or on which a
10669 constant cannot be the first operand. */
10672 {
10677 {
10684 arg1);
10685 }
10688 {
10695 arg1);
10696 }
10697 }
10699 /* Fold ((X >> C1) & C2) == 0 and ((X >> C1) & C2) != 0 where
10700 C1 is a valid shift constant, and C2 is a power of two, i.e.
10701 a single bit. */
10705 == INTEGER_CST
10708 {
10713 /* Check for a valid shift count. */
10715 {
10719 /* If (C2 << C1) doesn't overflow, then ((X >> C1) & C2) != 0
10720 can be rewritten as (X & (C2 << C1)) != 0. */
10722 {
10727 }
10728 /* Otherwise, for signed (arithmetic) shifts,
10729 ((X >> C1) & C2) != 0 is rewritten as X < 0, and
10730 ((X >> C1) & C2) == 0 is rewritten as X >= 0. */
10734 /* Otherwise, of unsigned (logical) shifts,
10735 ((X >> C1) & C2) != 0 is rewritten as (X,false), and
10736 ((X >> C1) & C2) == 0 is rewritten as (X,true). */
10737 else
10741 arg000);
10742 }
10743 }
10745 /* If this is a comparison of a field, we may be able to simplify it. */
10748 /* Handle the constant case even without -O
10749 to make sure the warnings are given. */
10751 {
10755 }
10757 /* Optimize comparisons of strlen vs zero to a compare of the
10758 first character of the string vs zero. To wit,
10759 strlen(ptr) == 0 => *ptr == 0
10760 strlen(ptr) != 0 => *ptr != 0
10761 Other cases should reduce to one of these two (or a constant)
10762 due to the return value of strlen being unsigned. */
10764 {
10772 {
10773 tree ptrtype
10775 TYPE_QUAL_CONST));
10781 }
10782 }
10784 /* Fold (X >> C) != 0 into X < 0 if C is one less than the width
10785 of X. Similarly fold (X >> C) == 0 into X >= 0. */
10789 {
10794 {
10796 {
10799 }
10802 }
10803 }
10805 /* Fold (~X & C) == 0 into (X & C) != 0 and (~X & C) != 0 into
10806 (X & C) == 0 when C is a single bit. */
10811 {
10818 arg1));
10819 }
10821 /* Fold ((X & C) ^ C) eq/ne 0 into (X & C) ne/eq 0, when the
10822 constant C is a power of two, i.e. a single bit. */
10829 {
10833 }
10835 /* Likewise, fold ((X ^ C) & C) eq/ne 0 into (X & C) ne/eq 0,
10836 when is C is a power of two, i.e. a single bit. */
10843 {
10849 }
10853 {
10856 }
10858 /* Fold (X & C) op (Y & C) as (X ^ Y) & C op 0", and symmetries. */
10861 {
10869 {
10875 }
10877 {
10883 }
10885 {
10891 }
10893 {
10899 }
10900 }
10904 {
10911 /* Optimize (X ^ Z) op (Y ^ Z) as X op Y, and symmetries.
10912 operand_equal_p guarantees no side-effects so we don't need
10913 to use omit_one_operand on Z. */
10917 arg10));
10921 arg11));
10925 arg10));
10929 arg11));
10931 /* Optimize (X ^ C1) op (Y ^ C2) as (X ^ (C1 ^ C2)) op Y. */
10934 {
10940 }
10941 }
10943 /* Attempt to simplify equality/inequality comparisons of complex
10944 values. Only lower the comparison if the result is known or
10945 can be simplified to a single scalar comparison. */
10950 {
10955 {
10958 }
10959 else
10960 {
10963 }
10966 {
10969 }
10970 else
10971 {
10974 }
10978 {
10980 {
10985 }
10986 else
10987 {
10992 }
10993 }
10997 {
10999 {
11004 }
11005 else
11006 {
11011 }
11012 }
11013 }
11025 /* Transform comparisons of the form X +- C CMP X. */
11030 {
11035 /* (X - c) > X becomes false. */
11041 /* Likewise (X + c) < X becomes false. */
11047 /* Convert (X - c) <= X to true. */
11054 /* Convert (X + c) >= X to true. */
11060 }
11062 /* If we are comparing an ABS_EXPR with a constant, we can
11063 convert all the cases into explicit comparisons, but they may
11064 well not be faster than doing the ABS and one comparison.
11065 But ABS (X) <= C is a range comparison, which becomes a subtraction
11066 and a comparison, and is probably faster. */
11080 /* Convert ABS_EXPR<x> >= 0 to true. */
11087 {
11090 "when simplifying comparison of "
11092 WARN_STRICT_OVERFLOW_CONDITIONAL);
11095 arg0);
11096 }
11098 /* Convert ABS_EXPR<x> < 0 to false. */
11103 {
11106 "when simplifying comparison of "
11108 WARN_STRICT_OVERFLOW_CONDITIONAL);
11111 arg0);
11112 }
11114 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
11115 and similarly for >= into !=. */
11125 /* Similarly for X < (cast) (1 << Y). But cast can't be narrowing,
11126 otherwise Y might be >= # of bits in X's type and thus e.g.
11127 (unsigned char) (1 << Y) for Y 15 might be 0.
11128 If the cast is widening, then 1 << Y should have unsigned type,
11129 otherwise if Y is number of bits in the signed shift type minus 1,
11130 we can't optimize this. E.g. (unsigned long long) (1 << Y) for Y
11131 31 might be 0xffffffff80000000. */
11142 {
11148 }
11160 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
11161 {
11173 }
11178 /* When pedantic, a compound expression can be neither an lvalue
11179 nor an integer constant expression. */
11182 /* Don't let (0, 0) be null pointer constant. */
11188 /* An ASSERT_EXPR should never be passed to fold_binary. */
11194 }
11196 /* For constants M and N, if M == (1LL << cst) - 1 && (N & M) == M,
11197 ((A & N) + B) & M -> (A + B) & M
11198 Similarly if (N & M) == 0,
11199 ((A | N) + B) & M -> (A + B) & M
11200 and for - instead of + (or unary - instead of +)
11201 and/or ^ instead of |.
11202 If B is constant and (B & M) == 0, fold into A & M.
11204 This function is a helper for match.pd patterns. Return non-NULL
11205 type in which the simplified operation should be performed only
11206 if any optimization is possible.
11208 ARG1 is M above, ARG00 is left operand of +/-, if CODE00 is BIT_*_EXPR,
11209 then ARG00{0,1} are operands of that bitop, otherwise CODE00 is ERROR_MARK.
11210 Similarly for ARG01, CODE01 and ARG01{0,1}, just for the right operand of
11211 +/-. */
11212 tree
11217 {
11232 wide_int cst0;
11234 /* Now we know that arg0 is (C + D) or (C - D) or -C and
11235 arg1 (M) is == (1LL << cst) - 1.
11236 Store C into PMOP[0] and D into PMOP[1]. */
11243 {
11250 {
11253 }
11256 /* If C or D is of the form (A & N) where
11257 (N & M) == M, or of the form (A | N) or
11258 (A ^ N) where (N & M) == 0, replace it with A. */
11264 /* If C or D is a N where (N & M) == 0, it can be
11265 omitted (replaced with 0). */
11270 /* Similarly, with C - N where (-N & M) == 0. */
11278 }
11280 /* Only build anything new if we optimized one or both arguments above. */
11286 else
11288 }
11290 /* Used by contains_label_[p1]. */
11292 struct contains_label_data
11293 {
11296 };
11298 /* Callback for walk_tree, looking for LABEL_EXPR. Return *TP if it is
11299 a LABEL_EXPR or CASE_LABEL_EXPR not inside of another SWITCH_EXPR; otherwise
11300 return NULL_TREE. Do not check the subtrees of GOTO_EXPR. */
11302 static tree
11304 {
11307 {
11318 {
11326 }
11335 }
11336 }
11338 /* Return whether the sub-tree ST contains a label which is accessible from
11339 outside the sub-tree. */
11341 static bool
11343 {
11347 }
11349 /* Fold a ternary expression of code CODE and type TYPE with operands
11350 OP0, OP1, and OP2. Return the folded expression if folding is
11351 successful. Otherwise, return NULL_TREE. */
11353 tree
11356 {
11357 tree tem;
11364 /* If this is a commutative operation, and OP0 is a constant, move it
11365 to OP1 to reduce the number of tests below. */
11374 /* Strip any conversions that don't change the mode. This is safe
11375 for every expression, except for a comparison expression because
11376 its signedness is derived from its operands. So, in the latter
11377 case, only strip conversions that don't change the signedness.
11379 Note that this is done as an internal manipulation within the
11380 constant folder, in order to find the simplest representation of
11381 the arguments so that their form can be studied. In any cases,
11382 the appropriate type conversions should be put back in the tree
11383 that will get out of the constant folder. */
11385 {
11388 }
11391 {
11394 }
11397 {
11400 }
11403 {
11407 {
11413 }
11418 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
11419 so all simple results must be passed through pedantic_non_lvalue. */
11421 {
11424 /* Only optimize constant conditions when the selected branch
11425 has the same type as the COND_EXPR. This avoids optimizing
11426 away "c ? x : throw", where the throw has a void type.
11427 Avoid throwing away that operand which contains label. */
11434 }
11436 {
11443 {
11446 {
11454 }
11459 }
11460 }
11462 /* If we have A op B ? A : C, we may be able to convert this to a
11463 simpler expression, depending on the operation and the values
11464 of B and C. Signed zeros prevent all of these transformations,
11465 for reasons given above each one.
11467 Also try swapping the arguments and inverting the conditional. */
11471 {
11475 }
11480 {
11484 {
11488 }
11489 }
11491 /* If the second operand is simpler than the third, swap them
11492 since that produces better jump optimization results. */
11495 {
11497 /* See if this can be inverted. If it can't, possibly because
11498 it was a floating-point inequality comparison, don't do
11499 anything. */
11503 }
11505 /* Convert A ? 1 : 0 to simply A. */
11510 /* If we try to convert OP0 to our type, the
11511 call to fold will try to move the conversion inside
11512 a COND, which will recurse. In that case, the COND_EXPR
11513 is probably the best choice, so leave it alone. */
11517 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
11518 over COND_EXPR in cases such as floating point comparisons. */
11527 arg0)));
11529 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
11534 {
11535 /* sign_bit_p looks through both zero and sign extensions,
11536 but for this optimization only sign extensions are
11537 usable. */
11540 {
11543 {
11546 }
11548 }
11549 /* sign_bit_p only checks ARG1 bits within A's precision.
11550 If <sign bit of A> has wider type than A, bits outside
11551 of A's precision in <sign bit of A> need to be checked.
11552 If they are all 0, this optimization needs to be done
11553 in unsigned A's type, if they are all 1 in signed A's type,
11554 otherwise this can't be done. */
11560 {
11562 tree tem_type;
11575 {
11578 }
11580 {
11583 }
11584 else
11586 }
11589 return
11595 arg1)));
11596 }
11598 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
11599 already handled above. */
11604 {
11614 op1);
11615 }
11617 /* A & N ? N : 0 is simply A & N if N is a power of two. This
11618 is probably obsolete because the first operand should be a
11619 truth value (that's why we have the two cases above), but let's
11620 leave it in until we can confirm this for all front-ends. */
11628 /* operand_equal_p compares just value, not precision, so e.g.
11629 arg1 could be 8-bit -128 and be power of two, but BIT_AND_EXPR
11630 second operand 32-bit -128, which is not a power of two (or vice
11631 versa. */
11638 /* Disable the transformations below for vectors, since
11639 fold_binary_op_with_conditional_arg may undo them immediately,
11640 yielding an infinite loop. */
11644 /* Convert A ? B : 0 into A && B if A and B are truth values. */
11653 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
11658 {
11660 /* Only perform transformation if ARG0 is easily inverted. */
11664 ? BIT_IOR_EXPR
11667 op1);
11668 }
11670 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
11675 {
11677 /* Only perform transformation if ARG0 is easily inverted. */
11683 op2);
11684 }
11686 /* Convert A ? 1 : B into A || B if A and B are truth values. */
11698 /* CALL_EXPRs used to be ternary exprs. Catch any mistaken uses
11699 of fold_ternary on them. */
11709 {
11720 {
11725 {
11727 {
11732 }
11738 }
11739 }
11740 }
11742 /* On constants we can use native encode/interpret to constant
11743 fold (nearly) all BIT_FIELD_REFs. */
11749 {
11752 /* Limit us to a reasonable amount of work. To relax the
11753 other limitations we need bit-shifting of the buffer
11754 and rounding up the size. */
11758 {
11760 unsigned HOST_WIDE_INT len
11765 {
11770 }
11771 }
11772 }
11777 /* Perform constant folding of BIT_INSERT_EXPR. */
11781 {
11782 /* Build a vector of integers from the tree mask. */
11783 vec_perm_builder builder;
11787 /* Create a vec_perm_indices for the integer vector. */
11792 }
11796 /* Perform (partial) constant folding of BIT_INSERT_EXPR. */
11799 {
11805 wide_int tem2
11809 }
11814 {
11816 unsigned HOST_WIDE_INT elsize
11819 {
11825 {
11831 }
11832 }
11833 }
11839 }
11841 /* Gets the element ACCESS_INDEX from CTOR, which must be a CONSTRUCTOR
11842 of an array (or vector). *CTOR_IDX if non-NULL is updated with the
11843 constructor element index of the value returned. If the element is
11844 not found NULL_TREE is returned and *CTOR_IDX is updated to
11845 the index of the element after the ACCESS_INDEX position (which
11846 may be outside of the CTOR array). */
11848 tree
11851 {
11857 {
11860 {
11861 /* Static constructors for variably sized objects makes no sense. */
11864 /* ??? When it is obvious that the range is signed, treat it so. */
11869 {
11871 low_bound
11873 SIGNED);
11874 }
11875 else
11876 {
11879 }
11880 }
11881 }
11885 index_sgn);
11897 {
11898 /* Array constructor might explicitly set index, or specify a range,
11899 or leave index NULL meaning that it is next index after previous
11900 one. */
11902 {
11904 max_index = index
11906 else
11907 {
11910 index_sgn);
11911 max_index
11913 index_sgn);
11915 }
11916 }
11918 {
11924 }
11925 else
11928 /* Do we have match? */
11930 {
11932 {
11936 }
11937 }
11939 /* We're past the element we search for. Note during parsing
11940 the elements might not be sorted.
11941 ??? We should use a binary search and a flag on the
11942 CONSTRUCTOR as to whether elements are sorted in declaration
11943 order. */
11945 }
11949 }
11951 /* Perform constant folding and related simplification of EXPR.
11952 The related simplifications include x*1 => x, x*0 => 0, etc.,
11953 and application of the associative law.
11954 NOP_EXPR conversions may be removed freely (as long as we
11955 are careful not to change the type of the overall expression).
11956 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
11957 but we can constant-fold them if they have constant operands. */
11959 #ifdef ENABLE_FOLD_CHECKING
11960 # define fold(x) fold_1 (x)
11962 static
11963 #endif
11964 tree
11966 {
11970 tree tem;
11973 /* Return right away if a constant. */
11977 /* CALL_EXPR-like objects with variable numbers of operands are
11978 treated specially. */
11980 {
11982 {
11985 }
11987 }
11990 {
11995 {
12013 }
12014 }
12017 {
12019 {
12026 {
12031 }
12034 }
12036 /* Return a VECTOR_CST if possible. */
12038 {
12044 tree val;
12050 }
12058 }
12060 #ifdef ENABLE_FOLD_CHECKING
12061 #undef fold
12068 /* When --enable-checking=fold, compute a digest of expr before
12069 and after actual fold call to see if fold did not accidentally
12070 change original expr. */
12072 tree
12074 {
12075 tree ret;
12095 }
12097 void
12099 {
12110 }
12112 static void
12114 {
12116 }
12118 static void
12121 {
12127 recursive_label:
12137 {
12138 /* Allow DECL_ASSEMBLER_NAME and symtab_node to be modified. */
12146 }
12154 {
12155 /* Allow these fields to be modified. */
12156 tree tmp;
12167 {
12170 }
12171 }
12173 {
12174 /* Allow TREE_NO_WARNING to be set. Perhaps we shouldn't allow that
12175 and change builtins.c etc. instead - see PR89543. */
12181 }
12192 {
12195 {
12211 }
12215 {
12228 }
12245 {
12251 }
12254 {
12256 {
12259 }
12261 }
12272 {
12275 }
12285 }
12286 }
12288 /* Helper function for outputting the checksum of a tree T. When
12289 debugging with gdb, you can "define mynext" to be "next" followed
12290 by "call debug_fold_checksum (op0)", then just trace down till the
12291 outputs differ. */
12293 DEBUG_FUNCTION void
12295 {
12310 }
12312 #endif
12314 /* Fold a unary tree expression with code CODE of type TYPE with an
12315 operand OP0. LOC is the location of the resulting expression.
12316 Return a folded expression if successful. Otherwise, return a tree
12317 expression with code CODE of type TYPE with an operand OP0. */
12319 tree
12322 {
12323 tree tem;
12324 #ifdef ENABLE_FOLD_CHECKING
12333 #endif
12339 #ifdef ENABLE_FOLD_CHECKING
12346 #endif
12348 }
12350 /* Fold a binary tree expression with code CODE of type TYPE with
12351 operands OP0 and OP1. LOC is the location of the resulting
12352 expression. Return a folded expression if successful. Otherwise,
12353 return a tree expression with code CODE of type TYPE with operands
12354 OP0 and OP1. */
12356 tree
12359 MEM_STAT_DECL)
12360 {
12361 tree tem;
12362 #ifdef ENABLE_FOLD_CHECKING
12379 #endif
12385 #ifdef ENABLE_FOLD_CHECKING
12400 #endif
12402 }
12404 /* Fold a ternary tree expression with code CODE of type TYPE with
12405 operands OP0, OP1, and OP2. Return a folded expression if
12406 successful. Otherwise, return a tree expression with code CODE of
12407 type TYPE with operands OP0, OP1, and OP2. */
12409 tree
12412 {
12413 tree tem;
12414 #ifdef ENABLE_FOLD_CHECKING
12438 #endif
12445 #ifdef ENABLE_FOLD_CHECKING
12468 #endif
12470 }
12472 /* Fold a CALL_EXPR expression of type TYPE with operands FN and NARGS
12473 arguments in ARGARRAY, and a null static chain.
12474 Return a folded expression if successful. Otherwise, return a CALL_EXPR
12475 of type TYPE from the given operands as constructed by build_call_array. */
12477 tree
12480 {
12481 tree tem;
12482 #ifdef ENABLE_FOLD_CHECKING
12501 #endif
12507 #ifdef ENABLE_FOLD_CHECKING
12523 #endif
12525 }
12527 /* Perform constant folding and related simplification of initializer
12528 expression EXPR. These behave identically to "fold_buildN" but ignore
12529 potential run-time traps and exceptions that fold must preserve. */
12531 #define START_FOLD_INIT \
12532 int saved_signaling_nans = flag_signaling_nans;\
12533 int saved_trapping_math = flag_trapping_math;\
12534 int saved_rounding_math = flag_rounding_math;\
12535 int saved_trapv = flag_trapv;\
12536 int saved_folding_initializer = folding_initializer;\
12537 flag_signaling_nans = 0;\
12538 flag_trapping_math = 0;\
12539 flag_rounding_math = 0;\
12540 flag_trapv = 0;\
12541 folding_initializer = 1;
12543 #define END_FOLD_INIT \
12544 flag_signaling_nans = saved_signaling_nans;\
12545 flag_trapping_math = saved_trapping_math;\
12546 flag_rounding_math = saved_rounding_math;\
12547 flag_trapv = saved_trapv;\
12548 folding_initializer = saved_folding_initializer;
12550 tree
12553 {
12554 tree result;
12555 START_FOLD_INIT;
12559 END_FOLD_INIT;
12561 }
12563 tree
12566 {
12567 tree result;
12568 START_FOLD_INIT;
12572 END_FOLD_INIT;
12574 }
12576 tree
12579 {
12580 tree result;
12581 START_FOLD_INIT;
12585 END_FOLD_INIT;
12587 }
12589 #undef START_FOLD_INIT
12590 #undef END_FOLD_INIT
12592 /* Determine if first argument is a multiple of second argument. Return 0 if
12593 it is not, or we cannot easily determined it to be.
12595 An example of the sort of thing we care about (at this point; this routine
12596 could surely be made more general, and expanded to do what the *_DIV_EXPR's
12597 fold cases do now) is discovering that
12599 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
12601 is a multiple of
12603 SAVE_EXPR (J * 8)
12605 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
12607 This code also handles discovering that
12609 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
12611 is a multiple of 8 so we don't have to worry about dealing with a
12612 possible remainder.
12614 Note that we *look* inside a SAVE_EXPR only to determine how it was
12615 calculated; it is not safe for fold to do much of anything else with the
12616 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
12617 at run time. For example, the latter example above *cannot* be implemented
12618 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
12619 evaluation time of the original SAVE_EXPR is not necessarily the same at
12620 the time the new expression is evaluated. The only optimization of this
12621 sort that would be valid is changing
12623 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
12625 divided by 8 to
12627 SAVE_EXPR (I) * SAVE_EXPR (J)
12629 (where the same SAVE_EXPR (J) is used in the original and the
12630 transformed version). */
12632 int
12634 {
12645 {
12647 /* Bitwise and provides a power of two multiple. If the mask is
12648 a multiple of BOTTOM then TOP is a multiple of BOTTOM. */
12656 {
12662 {
12665 /* Handle multiple_of_p ((x * 2 + 2) * 4, 8). */
12667 {
12671 {
12674 }
12675 }
12677 }
12678 }
12683 /* It is impossible to prove if op0 - op1 is multiple of bottom
12684 precisely, so be conservative here checking if both op0 and op1
12685 are multiple of bottom. Note we check the second operand first
12686 since it's usually simpler. */
12691 /* The same as MINUS_EXPR, but handle cases like op0 + 0xfffffffd
12692 as op0 - 3 if the expression has unsigned type. For example,
12693 (X / 3) + 0xfffffffd is multiple of 3, but 0xfffffffd is not. */
12703 {
12705 /* const_binop may not detect overflow correctly,
12706 so check for it explicitly here. */
12714 }
12718 /* Can't handle conversions from non-integral or wider integral type. */
12724 /* fall through */
12741 SIGNED);
12747 {
12750 /* Check for special cases to see if top is defined as multiple
12751 of bottom:
12753 top = (X & ~(bottom - 1) ; bottom is power of 2
12755 or
12757 Y = X % bottom
12758 top = X - Y. */
12777 }
12779 /* fall through */
12787 }
12788 }
12790 #define tree_expr_nonnegative_warnv_p(X, Y) \
12793 #define RECURSE(X) \
12794 ((tree_expr_nonnegative_warnv_p) (X, strict_overflow_p, depth + 1))
12796 /* Return true if CODE or TYPE is known to be non-negative. */
12798 static bool
12800 {
12803 /* Truth values evaluate to 0 or 1, which is nonnegative unless we
12804 have a signed:1 type (where the value is -1 and 0). */
12807 }
12809 /* Return true if (CODE OP0) is known to be non-negative. If the return
12810 value is based on the assumption that signed overflow is undefined,
12811 set *STRICT_OVERFLOW_P to true; otherwise, don't change
12812 *STRICT_OVERFLOW_P. DEPTH is the current nesting depth of the query. */
12814 bool
12817 {
12822 {
12824 /* We can't return 1 if flag_wrapv is set because
12825 ABS_EXPR<INT_MIN> = INT_MIN. */
12829 {
12832 }
12840 CASE_CONVERT:
12841 {
12846 {
12850 {
12854 }
12855 }
12857 {
12863 }
12864 }
12869 }
12871 /* We don't know sign of `t', so be conservative and return false. */
12873 }
12875 /* Return true if (CODE OP0 OP1) is known to be non-negative. If the return
12876 value is based on the assumption that signed overflow is undefined,
12877 set *STRICT_OVERFLOW_P to true; otherwise, don't change
12878 *STRICT_OVERFLOW_P. DEPTH is the current nesting depth of the query. */
12880 bool
12884 {
12889 {
12895 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
12896 both unsigned and at least 2 bits shorter than the result. */
12900 {
12905 {
12909 }
12910 }
12915 {
12916 /* x * x is always non-negative for floating point x
12917 or without overflow. */
12920 {
12925 }
12926 }
12928 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
12929 both unsigned and their total bits is shorter than the result. */
12933 {
12952 {
12962 }
12963 }
12990 }
12992 /* We don't know sign of `t', so be conservative and return false. */
12994 }
12996 /* Return true if T is known to be non-negative. If the return
12997 value is based on the assumption that signed overflow is undefined,
12998 set *STRICT_OVERFLOW_P to true; otherwise, don't change
12999 *STRICT_OVERFLOW_P. DEPTH is the current nesting depth of the query. */
13001 bool
13003 {
13008 {
13022 /* Limit the depth of recursion to avoid quadratic behavior.
13023 This is expected to catch almost all occurrences in practice.
13024 If this code misses important cases that unbounded recursion
13025 would not, passes that need this information could be revised
13026 to provide it through dataflow propagation. */
13034 }
13035 }
13037 /* Return true if T is known to be non-negative. If the return
13038 value is based on the assumption that signed overflow is undefined,
13039 set *STRICT_OVERFLOW_P to true; otherwise, don't change
13040 *STRICT_OVERFLOW_P. DEPTH is the current nesting depth of the query. */
13042 bool
13045 {
13047 {
13048 CASE_CFN_ACOS:
13049 CASE_CFN_ACOSH:
13050 CASE_CFN_CABS:
13051 CASE_CFN_COSH:
13052 CASE_CFN_ERFC:
13053 CASE_CFN_EXP:
13054 CASE_CFN_EXP10:
13055 CASE_CFN_EXP2:
13056 CASE_CFN_FABS:
13057 CASE_CFN_FDIM:
13058 CASE_CFN_HYPOT:
13059 CASE_CFN_POW10:
13060 CASE_CFN_FFS:
13061 CASE_CFN_PARITY:
13062 CASE_CFN_POPCOUNT:
13063 CASE_CFN_CLZ:
13064 CASE_CFN_CLRSB:
13067 /* Always true. */
13070 CASE_CFN_SQRT:
13071 CASE_CFN_SQRT_FN:
13072 /* sqrt(-0.0) is -0.0. */
13077 CASE_CFN_ASINH:
13078 CASE_CFN_ATAN:
13079 CASE_CFN_ATANH:
13080 CASE_CFN_CBRT:
13081 CASE_CFN_CEIL:
13082 CASE_CFN_CEIL_FN:
13083 CASE_CFN_ERF:
13084 CASE_CFN_EXPM1:
13085 CASE_CFN_FLOOR:
13086 CASE_CFN_FLOOR_FN:
13087 CASE_CFN_FMOD:
13088 CASE_CFN_FREXP:
13089 CASE_CFN_ICEIL:
13090 CASE_CFN_IFLOOR:
13091 CASE_CFN_IRINT:
13092 CASE_CFN_IROUND:
13093 CASE_CFN_LCEIL:
13094 CASE_CFN_LDEXP:
13095 CASE_CFN_LFLOOR:
13096 CASE_CFN_LLCEIL:
13097 CASE_CFN_LLFLOOR:
13098 CASE_CFN_LLRINT:
13099 CASE_CFN_LLROUND:
13100 CASE_CFN_LRINT:
13101 CASE_CFN_LROUND:
13102 CASE_CFN_MODF:
13103 CASE_CFN_NEARBYINT:
13104 CASE_CFN_NEARBYINT_FN:
13105 CASE_CFN_RINT:
13106 CASE_CFN_RINT_FN:
13107 CASE_CFN_ROUND:
13108 CASE_CFN_ROUND_FN:
13109 CASE_CFN_ROUNDEVEN:
13110 CASE_CFN_ROUNDEVEN_FN:
13111 CASE_CFN_SCALB:
13112 CASE_CFN_SCALBLN:
13113 CASE_CFN_SCALBN:
13114 CASE_CFN_SIGNBIT:
13115 CASE_CFN_SIGNIFICAND:
13116 CASE_CFN_SINH:
13117 CASE_CFN_TANH:
13118 CASE_CFN_TRUNC:
13119 CASE_CFN_TRUNC_FN:
13120 /* True if the 1st argument is nonnegative. */
13123 CASE_CFN_FMAX:
13124 CASE_CFN_FMAX_FN:
13125 /* True if the 1st OR 2nd arguments are nonnegative. */
13128 CASE_CFN_FMIN:
13129 CASE_CFN_FMIN_FN:
13130 /* True if the 1st AND 2nd arguments are nonnegative. */
13133 CASE_CFN_COPYSIGN:
13134 CASE_CFN_COPYSIGN_FN:
13135 /* True if the 2nd argument is nonnegative. */
13138 CASE_CFN_POWI:
13139 /* True if the 1st argument is nonnegative or the second
13140 argument is an even integer. */
13146 CASE_CFN_POW:
13147 /* True if the 1st argument is nonnegative or the second
13148 argument is an even integer valued real. */
13150 {
13151 REAL_VALUE_TYPE c;
13152 HOST_WIDE_INT n;
13157 {
13158 REAL_VALUE_TYPE cint;
13162 }
13163 }
13168 }
13170 }
13172 /* Return true if T is known to be non-negative. If the return
13173 value is based on the assumption that signed overflow is undefined,
13174 set *STRICT_OVERFLOW_P to true; otherwise, don't change
13175 *STRICT_OVERFLOW_P. DEPTH is the current nesting depth of the query. */
13177 static bool
13179 {
13185 {
13187 {
13191 /* If the initializer is non-void, then it's a normal expression
13192 that will be assigned to the slot. */
13196 /* Otherwise, the initializer sets the slot in some way. One common
13197 way is an assignment statement at the end of the initializer. */
13199 {
13207 else
13209 }
13215 }
13218 {
13224 arg0,
13225 arg1,
13227 }
13240 }
13241 }
13243 #undef RECURSE
13244 #undef tree_expr_nonnegative_warnv_p
13246 /* Return true if T is known to be non-negative. If the return
13247 value is based on the assumption that signed overflow is undefined,
13248 set *STRICT_OVERFLOW_P to true; otherwise, don't change
13249 *STRICT_OVERFLOW_P. DEPTH is the current nesting depth of the query. */
13251 bool
13253 {
13260 {
13282 }
13285 {
13311 }
13312 }
13314 /* Return true if `t' is known to be non-negative. Handle warnings
13315 about undefined signed overflow. */
13317 bool
13319 {
13326 "determining that expression is always "
13328 WARN_STRICT_OVERFLOW_MISC);
13330 }
13333 /* Return true when (CODE OP0) is an address and is known to be nonzero.
13334 For floating point we further ensure that T is not denormal.
13335 Similar logic is present in nonzero_address in rtlanal.h.
13337 If the return value is based on the assumption that signed overflow
13338 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
13339 change *STRICT_OVERFLOW_P. */
13341 bool
13344 {
13346 {
13349 strict_overflow_p);
13352 {
13358 strict_overflow_p));
13359 }
13364 strict_overflow_p);
13368 }
13371 }
13373 /* Return true when (CODE OP0 OP1) is an address and is known to be nonzero.
13374 For floating point we further ensure that T is not denormal.
13375 Similar logic is present in nonzero_address in rtlanal.h.
13377 If the return value is based on the assumption that signed overflow
13378 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
13379 change *STRICT_OVERFLOW_P. */
13381 bool
13383 tree type,
13384 tree op0,
13386 {
13389 {
13393 {
13394 /* With the presence of negative values it is hard
13395 to say something. */
13402 /* One of operands must be positive and the other non-negative. */
13403 /* We don't set *STRICT_OVERFLOW_P here: even if this value
13404 overflows, on a twos-complement machine the sum of two
13405 nonnegative numbers can never be zero. */
13407 strict_overflow_p)
13409 strict_overflow_p));
13410 }
13415 {
13417 strict_overflow_p)
13419 strict_overflow_p))
13420 {
13423 }
13424 }
13433 {
13436 }
13443 {
13447 /* When both operands are nonzero, then MAX must be too. */
13449 strict_overflow_p))
13452 /* MAX where operand 0 is positive is positive. */
13454 strict_overflow_p);
13455 }
13456 /* MAX where operand 1 is positive is positive. */
13461 {
13465 }
13470 strict_overflow_p)
13472 strict_overflow_p));
13476 }
13479 }
13481 /* Return true when T is an address and is known to be nonzero.
13482 For floating point we further ensure that T is not denormal.
13483 Similar logic is present in nonzero_address in rtlanal.h.
13485 If the return value is based on the assumption that signed overflow
13486 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
13487 change *STRICT_OVERFLOW_P. */
13489 bool
13491 {
13494 {
13499 {
13511 /* For objects in symbol table check if we know they are non-zero.
13512 Don't do anything for variables and functions before symtab is built;
13513 it is quite possible that they will be declared weak later. */
13518 /* Constants are never weak. */
13523 }
13531 {
13535 }
13545 }
13547 }
13549 #define integer_valued_real_p(X) \
13552 #define RECURSE(X) \
13553 ((integer_valued_real_p) (X, depth + 1))
13555 /* Return true if the floating point result of (CODE OP0) has an
13556 integer value. We also allow +Inf, -Inf and NaN to be considered
13557 integer values. Return false for signaling NaN.
13559 DEPTH is the current nesting depth of the query. */
13561 bool
13563 {
13565 {
13572 CASE_CONVERT:
13573 {
13580 }
13584 }
13586 }
13588 /* Return true if the floating point result of (CODE OP0 OP1) has an
13589 integer value. We also allow +Inf, -Inf and NaN to be considered
13590 integer values. Return false for signaling NaN.
13592 DEPTH is the current nesting depth of the query. */
13594 bool
13596 {
13598 {
13608 }
13610 }
13612 /* Return true if the floating point result of calling FNDECL with arguments
13613 ARG0 and ARG1 has an integer value. We also allow +Inf, -Inf and NaN to be
13614 considered integer values. Return false for signaling NaN. If FNDECL
13615 takes fewer than 2 arguments, the remaining ARGn are null.
13617 DEPTH is the current nesting depth of the query. */
13619 bool
13621 {
13623 {
13624 CASE_CFN_CEIL:
13625 CASE_CFN_CEIL_FN:
13626 CASE_CFN_FLOOR:
13627 CASE_CFN_FLOOR_FN:
13628 CASE_CFN_NEARBYINT:
13629 CASE_CFN_NEARBYINT_FN:
13630 CASE_CFN_RINT:
13631 CASE_CFN_RINT_FN:
13632 CASE_CFN_ROUND:
13633 CASE_CFN_ROUND_FN:
13634 CASE_CFN_ROUNDEVEN:
13635 CASE_CFN_ROUNDEVEN_FN:
13636 CASE_CFN_TRUNC:
13637 CASE_CFN_TRUNC_FN:
13640 CASE_CFN_FMIN:
13641 CASE_CFN_FMIN_FN:
13642 CASE_CFN_FMAX:
13643 CASE_CFN_FMAX_FN:
13648 }
13650 }
13652 /* Return true if the floating point expression T (a GIMPLE_SINGLE_RHS)
13653 has an integer value. We also allow +Inf, -Inf and NaN to be
13654 considered integer values. Return false for signaling NaN.
13656 DEPTH is the current nesting depth of the query. */
13658 bool
13660 {
13662 {
13670 /* Limit the depth of recursion to avoid quadratic behavior.
13671 This is expected to catch almost all occurrences in practice.
13672 If this code misses important cases that unbounded recursion
13673 would not, passes that need this information could be revised
13674 to provide it through dataflow propagation. */
13678 depth));
13682 }
13684 }
13686 /* Return true if the floating point expression T (a GIMPLE_INVALID_RHS)
13687 has an integer value. We also allow +Inf, -Inf and NaN to be
13688 considered integer values. Return false for signaling NaN.
13690 DEPTH is the current nesting depth of the query. */
13692 static bool
13694 {
13696 {
13707 }
13709 }
13711 #undef RECURSE
13712 #undef integer_valued_real_p
13714 /* Return true if the floating point expression T has an integer value.
13715 We also allow +Inf, -Inf and NaN to be considered integer values.
13716 Return false for signaling NaN.
13718 DEPTH is the current nesting depth of the query. */
13720 bool
13722 {
13730 {
13746 }
13749 {
13755 {
13764 }
13768 }
13769 }
13771 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
13772 attempt to fold the expression to a constant without modifying TYPE,
13773 OP0 or OP1.
13775 If the expression could be simplified to a constant, then return
13776 the constant. If the expression would not be simplified to a
13777 constant, then return NULL_TREE. */
13779 tree
13781 {
13784 }
13786 /* Given the components of a unary expression CODE, TYPE and OP0,
13787 attempt to fold the expression to a constant without modifying
13788 TYPE or OP0.
13790 If the expression could be simplified to a constant, then return
13791 the constant. If the expression would not be simplified to a
13792 constant, then return NULL_TREE. */
13794 tree
13796 {
13799 }
13801 /* If EXP represents referencing an element in a constant string
13802 (either via pointer arithmetic or array indexing), return the
13803 tree representing the value accessed, otherwise return NULL. */
13805 tree
13807 {
13811 {
13813 tree index;
13814 tree string;
13819 else
13820 {
13824 /* Optimize the special-case of a zero lower bound.
13826 We convert the low_bound to sizetype to avoid some problems
13827 with constant folding. (E.g. suppose the lower bound is 1,
13828 and its mode is QI. Without the conversion,l (ARRAY
13829 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
13830 +INDEX), which becomes (ARRAY+255+INDEX). Oops!) */
13836 }
13838 scalar_int_mode char_mode;
13850 }
13852 }
13854 /* Folds a read from vector element at IDX of vector ARG. */
13856 tree
13858 {
13863 {
13867 {
13871 }
13872 }
13874 }
13876 /* Return the tree for neg (ARG0) when ARG0 is known to be either
13877 an integer constant, real, or fixed-point constant.
13879 TYPE is the type of the result. */
13881 static tree
13883 {
13887 {
13893 {
13894 FIXED_VALUE_TYPE f;
13899 /* Propagate overflow flags. */
13903 }
13907 {
13914 }
13917 }
13920 }
13922 /* Return the tree for abs (ARG0) when ARG0 is known to be either
13923 an integer constant or real constant.
13925 TYPE is the type of the result. */
13927 tree
13929 {
13933 {
13935 {
13936 /* If the value is unsigned or non-negative, then the absolute value
13937 is the same as the ordinary value. */
13941 ;
13943 /* If the value is negative, then the absolute value is
13944 its negation. */
13945 else
13948 /* Force to the destination type, set TREE_OVERFLOW for signed
13949 TYPE only. */
13951 }
13957 else
13963 }
13966 }
13968 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
13969 constant. TYPE is the type of the result. */
13971 static tree
13973 {
13977 }
13979 /* Given CODE, a relational operator, the target type, TYPE and two
13980 constant operands OP0 and OP1, return the result of the
13981 relational operation. If the result is not a compile time
13982 constant, then return NULL_TREE. */
13984 static tree
13986 {
13989 /* From here on, the only cases we handle are when the result is
13990 known to be a constant. */
13993 {
13997 /* Handle the cases where either operand is a NaN. */
13999 {
14001 {
14029 }
14032 }
14035 }
14038 {
14042 }
14044 /* Handle equality/inequality of complex constants. */
14046 {
14057 else
14059 }
14062 {
14064 {
14065 /* Have vector comparison with scalar boolean result. */
14073 {
14081 }
14083 }
14084 tree_vector_builder elts;
14089 {
14102 }
14105 }
14107 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
14109 To compute GT, swap the arguments and do LT.
14110 To compute GE, do LT and invert the result.
14111 To compute LE, swap the arguments, do LT and invert the result.
14112 To compute NE, do EQ and invert the result.
14114 Therefore, the code below must handle only EQ and LT. */
14117 {
14120 }
14122 /* Note that it is safe to invert for real values here because we
14123 have already handled the one case that it matters. */
14127 {
14130 }
14132 /* Compute a result for LT or EQ if args permit;
14133 Otherwise return T. */
14135 {
14138 else
14140 }
14141 else
14147 }
14149 /* If necessary, return a CLEANUP_POINT_EXPR for EXPR with the
14150 indicated TYPE. If no CLEANUP_POINT_EXPR is necessary, return EXPR
14151 itself. */
14153 tree
14155 {
14156 /* If the expression does not have side effects then we don't have to wrap
14157 it with a cleanup point expression. */
14161 /* If the expression is a return, check to see if the expression inside the
14162 return has no side effects or the right hand side of the modify expression
14163 inside the return. If either don't have side effects set we don't need to
14164 wrap the expression in a cleanup point expression. Note we don't check the
14165 left hand side of the modify because it should always be a return decl. */
14167 {
14174 }
14177 }
14179 /* Given a pointer value OP0 and a type TYPE, return a simplified version
14180 of an indirection through OP0, or NULL_TREE if no simplification is
14181 possible. */
14183 tree
14185 {
14187 tree subtype;
14188 poly_uint64 const_op01;
14197 {
14201 /* *&CONST_DECL -> to the value of the const decl. */
14204 /* *&p => p; make sure to handle *&"str"[cst] here. */
14206 {
14210 else
14212 }
14213 /* *(foo *)&fooarray => fooarray[0] */
14216 && (!in_gimple_form
14218 {
14228 }
14229 /* *(foo *)&complexfoo => __real__ complexfoo */
14233 /* *(foo *)&vectorfoo => BIT_FIELD_REF<vectorfoo,...> */
14236 {
14240 index);
14241 }
14242 }
14246 {
14252 {
14253 tree op00type;
14257 /* ((foo*)&vectorfoo)[1] => BIT_FIELD_REF<vectorfoo,...> */
14260 /* POINTER_PLUS_EXPR second operand is sizetype, unsigned,
14261 but we want to treat offsets with MSB set as negative.
14262 For the code below negative offsets are invalid and
14263 TYPE_SIZE of the element is something unsigned, so
14264 check whether op01 fits into poly_int64, which implies
14265 it is from 0 to INTTYPE_MAXIMUM (HOST_WIDE_INT), and
14266 then just use poly_uint64 because we want to treat the
14267 value as unsigned. */
14269 {
14271 poly_uint64 max_offset
14275 {
14280 }
14281 }
14282 /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */
14285 {
14287 const_op01))
14289 }
14290 /* ((foo *)&fooarray)[1] => fooarray[1] */
14293 {
14302 {
14307 }
14308 }
14309 }
14310 }
14312 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
14315 && (!in_gimple_form
14317 {
14318 tree type_domain;
14328 NULL_TREE);
14329 }
14332 }
14334 /* Builds an expression for an indirection through T, simplifying some
14335 cases. */
14337 tree
14339 {
14347 }
14349 /* Given an INDIRECT_REF T, return either T or a simplified version. */
14351 tree
14353 {
14358 else
14360 }
14362 /* Strip non-trapping, non-side-effecting tree nodes from an expression
14363 whose result is ignored. The type of the returned tree need not be
14364 the same as the original expression. */
14366 tree
14368 {
14374 {
14385 else
14391 {
14407 }
14412 }
14413 }
14415 /* Return the value of VALUE, rounded up to a multiple of DIVISOR. */
14417 tree
14419 {
14425 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
14426 have to do anything. Only do this when we are not given a const,
14427 because in that case, this check is more expensive than just
14428 doing it. */
14430 {
14435 }
14437 /* If divisor is a power of two, simplify this to bit manipulation. */
14439 {
14441 {
14455 }
14456 else
14457 {
14458 tree t;
14464 }
14465 }
14466 else
14467 {
14472 }
14475 }
14477 /* Likewise, but round down. */
14479 tree
14481 {
14488 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
14489 have to do anything. Only do this when we are not given a const,
14490 because in that case, this check is more expensive than just
14491 doing it. */
14493 {
14498 }
14500 /* If divisor is a power of two, simplify this to bit manipulation. */
14502 {
14503 tree t;
14507 }
14508 else
14509 {
14514 }
14517 }
14519 /* Returns the pointer to the base of the object addressed by EXP and
14520 extracts the information about the offset of the access, storing it
14521 to PBITPOS and POFFSET. */
14523 static tree
14526 {
14527 tree core;
14528 machine_mode mode;
14530 poly_int64 bitsize;
14534 {
14539 }
14541 {
14547 {
14548 poly_offset_int tem
14554 }
14555 }
14556 else
14557 {
14561 }
14564 }
14566 /* Returns true if addresses of E1 and E2 differ by a constant, false
14567 otherwise. If they do, E1 - E2 is stored in *DIFF. */
14569 bool
14571 {
14586 {
14596 }
14598 {
14599 /* If only one of the offsets is non-constant, the difference cannot
14600 be a constant. */
14602 }
14603 else
14608 }
14610 /* Return OFF converted to a pointer offset type suitable as offset for
14611 POINTER_PLUS_EXPR. Use location LOC for this conversion. */
14612 tree
14614 {
14616 }
14618 /* Build and fold a POINTER_PLUS_EXPR at LOC offsetting PTR by OFF. */
14619 tree
14621 {
14624 }
14626 /* Build and fold a POINTER_PLUS_EXPR at LOC offsetting PTR by OFF. */
14627 tree
14629 {
14632 }
14634 /* Return a pointer P to a NUL-terminated string representing the sequence
14635 of constant characters referred to by SRC (or a subsequence of such
14636 characters within it if SRC is a reference to a string plus some
14637 constant offset). If STRLEN is non-null, store the number of bytes
14638 in the string constant including the terminating NUL char. *STRLEN is
14639 typically strlen(P) + 1 in the absence of embedded NUL characters. */
14643 {
14644 tree offset_node;
14645 tree mem_size;
14656 {
14659 else
14661 }
14666 /* STRING_LENGTH is the size of the string literal, including any
14667 embedded NULs. STRING_SIZE is the size of the array the string
14668 literal is stored in. */
14672 /* Ideally this would turn into a gcc_checking_assert over time. */
14678 /* Ideally this would turn into a gcc_checking_assert over time. */
14687 {
14688 /* Compute and store the length of the substring at OFFSET.
14689 All offsets past the initial length refer to null strings. */
14692 else
14694 }
14695 else
14696 {
14698 /* Support only properly NUL-terminated single byte strings. */
14703 }
14706 }
14708 /* Given a tree T, compute which bits in T may be nonzero. */
14710 wide_int
14712 {
14714 {
14732 CASE_CONVERT:
14738 {
14743 }
14747 {
14755 }
14759 {
14767 }
14771 }
14774 }
14776 #if CHECKING_P
14780 /* Helper functions for writing tests of folding trees. */
14782 /* Verify that the binary op (LHS CODE RHS) folds to CONSTANT. */
14784 static void
14786 tree constant)
14787 {
14789 }
14791 /* Verify that the binary op (LHS CODE RHS) folds to an NON_LVALUE_EXPR
14792 wrapping WRAPPED_EXPR. */
14794 static void
14796 tree wrapped_expr)
14797 {
14802 }
14804 /* Verify that various arithmetic binary operations are folded
14805 correctly. */
14807 static void
14809 {
14815 /* Addition. */
14816 /* 1 <-- (0 + 1) */
14818 one);
14820 one);
14822 /* (nonlvalue)x <-- (x + 0) */
14824 x);
14826 /* Subtraction. */
14827 /* 0 <-- (x - x) */
14829 zero);
14831 x);
14833 /* Multiplication. */
14834 /* 0 <-- (x * 0) */
14836 zero);
14838 /* (nonlvalue)x <-- (x * 1) */
14840 x);
14841 }
14843 /* Verify that various binary operations on vectors are folded
14844 correctly. */
14846 static void
14848 {
14855 /* Verify equality tests that return a scalar boolean result. */
14868 }
14870 /* Verify folding of VEC_DUPLICATE_EXPRs. */
14872 static void
14874 {
14877 /* This will be 1 if VEC_MODE isn't a vector mode. */
14884 }
14886 /* Run all of the selftests within this file. */
14888 void
14890 {
14894 }