* tree-ssa.c (warn_uninitialized_var): Use OPT_Wmaybe_uninitialized tag
[official-gcc.git] / gcc / rtl.def
blob6948bfe13ed72562cab9eaaf5b523379ef062507
1 /* This file contains the definitions and documentation for the
2 Register Transfer Expressions (rtx's) that make up the
3 Register Transfer Language (rtl) used in the Back End of the GNU compiler.
4 Copyright (C) 1987, 1988, 1992, 1994, 1995, 1997, 1998, 1999, 2000, 2004,
5 2005, 2006, 2007, 2008, 2009, 2010, 2011
6 Free Software Foundation, Inc.
8 This file is part of GCC.
10 GCC is free software; you can redistribute it and/or modify it under
11 the terms of the GNU General Public License as published by the Free
12 Software Foundation; either version 3, or (at your option) any later
13 version.
15 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
16 WARRANTY; without even the implied warranty of MERCHANTABILITY or
17 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 for more details.
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3. If not see
22 <http://www.gnu.org/licenses/>. */
25 /* Expression definitions and descriptions for all targets are in this file.
26 Some will not be used for some targets.
28 The fields in the cpp macro call "DEF_RTL_EXPR()"
29 are used to create declarations in the C source of the compiler.
31 The fields are:
33 1. The internal name of the rtx used in the C source.
34 It is a tag in the enumeration "enum rtx_code" defined in "rtl.h".
35 By convention these are in UPPER_CASE.
37 2. The name of the rtx in the external ASCII format read by
38 read_rtx(), and printed by print_rtx().
39 These names are stored in rtx_name[].
40 By convention these are the internal (field 1) names in lower_case.
42 3. The print format, and type of each rtx->u.fld[] (field) in this rtx.
43 These formats are stored in rtx_format[].
44 The meaning of the formats is documented in front of this array in rtl.c
46 4. The class of the rtx. These are stored in rtx_class and are accessed
47 via the GET_RTX_CLASS macro. They are defined as follows:
49 RTX_CONST_OBJ
50 an rtx code that can be used to represent a constant object
51 (e.g, CONST_INT)
52 RTX_OBJ
53 an rtx code that can be used to represent an object (e.g, REG, MEM)
54 RTX_COMPARE
55 an rtx code for a comparison (e.g, LT, GT)
56 RTX_COMM_COMPARE
57 an rtx code for a commutative comparison (e.g, EQ, NE, ORDERED)
58 RTX_UNARY
59 an rtx code for a unary arithmetic expression (e.g, NEG, NOT)
60 RTX_COMM_ARITH
61 an rtx code for a commutative binary operation (e.g,, PLUS, MULT)
62 RTX_TERNARY
63 an rtx code for a non-bitfield three input operation (IF_THEN_ELSE)
64 RTX_BIN_ARITH
65 an rtx code for a non-commutative binary operation (e.g., MINUS, DIV)
66 RTX_BITFIELD_OPS
67 an rtx code for a bit-field operation (ZERO_EXTRACT, SIGN_EXTRACT)
68 RTX_INSN
69 an rtx code for a machine insn (INSN, JUMP_INSN, CALL_INSN)
70 RTX_MATCH
71 an rtx code for something that matches in insns (e.g, MATCH_DUP)
72 RTX_AUTOINC
73 an rtx code for autoincrement addressing modes (e.g. POST_DEC)
74 RTX_EXTRA
75 everything else
77 All of the expressions that appear only in machine descriptions,
78 not in RTL used by the compiler itself, are at the end of the file. */
80 /* Unknown, or no such operation; the enumeration constant should have
81 value zero. */
82 DEF_RTL_EXPR(UNKNOWN, "UnKnown", "*", RTX_EXTRA)
84 /* Used in the cselib routines to describe a value. Objects of this
85 kind are only allocated in cselib.c, in an alloc pool instead of in
86 GC memory. The only operand of a VALUE is a cselib_val_struct.
87 var-tracking requires this to have a distinct integral value from
88 DECL codes in trees. */
89 DEF_RTL_EXPR(VALUE, "value", "0", RTX_OBJ)
91 /* The RTL generated for a DEBUG_EXPR_DECL. It links back to the
92 DEBUG_EXPR_DECL in the first operand. */
93 DEF_RTL_EXPR(DEBUG_EXPR, "debug_expr", "0", RTX_OBJ)
95 /* ---------------------------------------------------------------------
96 Expressions used in constructing lists.
97 --------------------------------------------------------------------- */
99 /* a linked list of expressions */
100 DEF_RTL_EXPR(EXPR_LIST, "expr_list", "ee", RTX_EXTRA)
102 /* a linked list of instructions.
103 The insns are represented in print by their uids. */
104 DEF_RTL_EXPR(INSN_LIST, "insn_list", "ue", RTX_EXTRA)
106 /* SEQUENCE appears in the result of a `gen_...' function
107 for a DEFINE_EXPAND that wants to make several insns.
108 Its elements are the bodies of the insns that should be made.
109 `emit_insn' takes the SEQUENCE apart and makes separate insns. */
110 DEF_RTL_EXPR(SEQUENCE, "sequence", "E", RTX_EXTRA)
112 /* Represents a non-global base address. This is only used in alias.c. */
113 DEF_RTL_EXPR(ADDRESS, "address", "i", RTX_EXTRA)
115 /* ----------------------------------------------------------------------
116 Expression types used for things in the instruction chain.
118 All formats must start with "iuu" to handle the chain.
119 Each insn expression holds an rtl instruction and its semantics
120 during back-end processing.
121 See macros's in "rtl.h" for the meaning of each rtx->u.fld[].
123 ---------------------------------------------------------------------- */
125 /* An annotation for variable assignment tracking. */
126 DEF_RTL_EXPR(DEBUG_INSN, "debug_insn", "iuuBeiie", RTX_INSN)
128 /* An instruction that cannot jump. */
129 DEF_RTL_EXPR(INSN, "insn", "iuuBeiie", RTX_INSN)
131 /* An instruction that can possibly jump.
132 Fields ( rtx->u.fld[] ) have exact same meaning as INSN's. */
133 DEF_RTL_EXPR(JUMP_INSN, "jump_insn", "iuuBeiie0", RTX_INSN)
135 /* An instruction that can possibly call a subroutine
136 but which will not change which instruction comes next
137 in the current function.
138 Field ( rtx->u.fld[8] ) is CALL_INSN_FUNCTION_USAGE.
139 All other fields ( rtx->u.fld[] ) have exact same meaning as INSN's. */
140 DEF_RTL_EXPR(CALL_INSN, "call_insn", "iuuBeiiee", RTX_INSN)
142 /* A marker that indicates that control will not flow through. */
143 DEF_RTL_EXPR(BARRIER, "barrier", "iuu00000", RTX_EXTRA)
145 /* Holds a label that is followed by instructions.
146 Operand:
147 4: is used in jump.c for the use-count of the label.
148 5: is used in the sh backend.
149 6: is a number that is unique in the entire compilation.
150 7: is the user-given name of the label, if any. */
151 DEF_RTL_EXPR(CODE_LABEL, "code_label", "iuuB00is", RTX_EXTRA)
153 /* Say where in the code a source line starts, for symbol table's sake.
154 Operand:
155 4: note-specific data
156 5: enum insn_note
157 6: unique number if insn_note == note_insn_deleted_label. */
158 DEF_RTL_EXPR(NOTE, "note", "iuuB0ni", RTX_EXTRA)
160 /* ----------------------------------------------------------------------
161 Top level constituents of INSN, JUMP_INSN and CALL_INSN.
162 ---------------------------------------------------------------------- */
164 /* Conditionally execute code.
165 Operand 0 is the condition that if true, the code is executed.
166 Operand 1 is the code to be executed (typically a SET).
168 Semantics are that there are no side effects if the condition
169 is false. This pattern is created automatically by the if_convert
170 pass run after reload or by target-specific splitters. */
171 DEF_RTL_EXPR(COND_EXEC, "cond_exec", "ee", RTX_EXTRA)
173 /* Several operations to be done in parallel (perhaps under COND_EXEC). */
174 DEF_RTL_EXPR(PARALLEL, "parallel", "E", RTX_EXTRA)
176 /* A string that is passed through to the assembler as input.
177 One can obviously pass comments through by using the
178 assembler comment syntax.
179 These occur in an insn all by themselves as the PATTERN.
180 They also appear inside an ASM_OPERANDS
181 as a convenient way to hold a string. */
182 DEF_RTL_EXPR(ASM_INPUT, "asm_input", "si", RTX_EXTRA)
184 /* An assembler instruction with operands.
185 1st operand is the instruction template.
186 2nd operand is the constraint for the output.
187 3rd operand is the number of the output this expression refers to.
188 When an insn stores more than one value, a separate ASM_OPERANDS
189 is made for each output; this integer distinguishes them.
190 4th is a vector of values of input operands.
191 5th is a vector of modes and constraints for the input operands.
192 Each element is an ASM_INPUT containing a constraint string
193 and whose mode indicates the mode of the input operand.
194 6th is a vector of labels that may be branched to by the asm.
195 7th is the source line number. */
196 DEF_RTL_EXPR(ASM_OPERANDS, "asm_operands", "ssiEEEi", RTX_EXTRA)
198 /* A machine-specific operation.
199 1st operand is a vector of operands being used by the operation so that
200 any needed reloads can be done.
201 2nd operand is a unique value saying which of a number of machine-specific
202 operations is to be performed.
203 (Note that the vector must be the first operand because of the way that
204 genrecog.c record positions within an insn.)
206 UNSPEC can occur all by itself in a PATTERN, as a component of a PARALLEL,
207 or inside an expression.
208 UNSPEC by itself or as a component of a PARALLEL
209 is currently considered not deletable.
211 FIXME: Replace all uses of UNSPEC that appears by itself or as a component
212 of a PARALLEL with USE.
214 DEF_RTL_EXPR(UNSPEC, "unspec", "Ei", RTX_EXTRA)
216 /* Similar, but a volatile operation and one which may trap. */
217 DEF_RTL_EXPR(UNSPEC_VOLATILE, "unspec_volatile", "Ei", RTX_EXTRA)
219 /* Vector of addresses, stored as full words. */
220 /* Each element is a LABEL_REF to a CODE_LABEL whose address we want. */
221 DEF_RTL_EXPR(ADDR_VEC, "addr_vec", "E", RTX_EXTRA)
223 /* Vector of address differences X0 - BASE, X1 - BASE, ...
224 First operand is BASE; the vector contains the X's.
225 The machine mode of this rtx says how much space to leave
226 for each difference and is adjusted by branch shortening if
227 CASE_VECTOR_SHORTEN_MODE is defined.
228 The third and fourth operands store the target labels with the
229 minimum and maximum addresses respectively.
230 The fifth operand stores flags for use by branch shortening.
231 Set at the start of shorten_branches:
232 min_align: the minimum alignment for any of the target labels.
233 base_after_vec: true iff BASE is after the ADDR_DIFF_VEC.
234 min_after_vec: true iff minimum addr target label is after the ADDR_DIFF_VEC.
235 max_after_vec: true iff maximum addr target label is after the ADDR_DIFF_VEC.
236 min_after_base: true iff minimum address target label is after BASE.
237 max_after_base: true iff maximum address target label is after BASE.
238 Set by the actual branch shortening process:
239 offset_unsigned: true iff offsets have to be treated as unsigned.
240 scale: scaling that is necessary to make offsets fit into the mode.
242 The third, fourth and fifth operands are only valid when
243 CASE_VECTOR_SHORTEN_MODE is defined, and only in an optimizing
244 compilation. */
246 DEF_RTL_EXPR(ADDR_DIFF_VEC, "addr_diff_vec", "eEee0", RTX_EXTRA)
248 /* Memory prefetch, with attributes supported on some targets.
249 Operand 1 is the address of the memory to fetch.
250 Operand 2 is 1 for a write access, 0 otherwise.
251 Operand 3 is the level of temporal locality; 0 means there is no
252 temporal locality and 1, 2, and 3 are for increasing levels of temporal
253 locality.
255 The attributes specified by operands 2 and 3 are ignored for targets
256 whose prefetch instructions do not support them. */
257 DEF_RTL_EXPR(PREFETCH, "prefetch", "eee", RTX_EXTRA)
259 /* ----------------------------------------------------------------------
260 At the top level of an instruction (perhaps under PARALLEL).
261 ---------------------------------------------------------------------- */
263 /* Assignment.
264 Operand 1 is the location (REG, MEM, PC, CC0 or whatever) assigned to.
265 Operand 2 is the value stored there.
266 ALL assignment must use SET.
267 Instructions that do multiple assignments must use multiple SET,
268 under PARALLEL. */
269 DEF_RTL_EXPR(SET, "set", "ee", RTX_EXTRA)
271 /* Indicate something is used in a way that we don't want to explain.
272 For example, subroutine calls will use the register
273 in which the static chain is passed.
275 USE can not appear as an operand of other rtx except for PARALLEL.
276 USE is not deletable, as it indicates that the operand
277 is used in some unknown way. */
278 DEF_RTL_EXPR(USE, "use", "e", RTX_EXTRA)
280 /* Indicate something is clobbered in a way that we don't want to explain.
281 For example, subroutine calls will clobber some physical registers
282 (the ones that are by convention not saved).
284 CLOBBER can not appear as an operand of other rtx except for PARALLEL.
285 CLOBBER of a hard register appearing by itself (not within PARALLEL)
286 is considered undeletable before reload. */
287 DEF_RTL_EXPR(CLOBBER, "clobber", "e", RTX_EXTRA)
289 /* Call a subroutine.
290 Operand 1 is the address to call.
291 Operand 2 is the number of arguments. */
293 DEF_RTL_EXPR(CALL, "call", "ee", RTX_EXTRA)
295 /* Return from a subroutine. */
297 DEF_RTL_EXPR(RETURN, "return", "", RTX_EXTRA)
299 /* Like RETURN, but truly represents only a function return, while
300 RETURN may represent an insn that also performs other functions
301 of the function epilogue. Like RETURN, this may also occur in
302 conditional jumps. */
303 DEF_RTL_EXPR(SIMPLE_RETURN, "simple_return", "", RTX_EXTRA)
305 /* Special for EH return from subroutine. */
307 DEF_RTL_EXPR(EH_RETURN, "eh_return", "", RTX_EXTRA)
309 /* Conditional trap.
310 Operand 1 is the condition.
311 Operand 2 is the trap code.
312 For an unconditional trap, make the condition (const_int 1). */
313 DEF_RTL_EXPR(TRAP_IF, "trap_if", "ee", RTX_EXTRA)
315 /* ----------------------------------------------------------------------
316 Primitive values for use in expressions.
317 ---------------------------------------------------------------------- */
319 /* numeric integer constant */
320 DEF_RTL_EXPR(CONST_INT, "const_int", "w", RTX_CONST_OBJ)
322 /* fixed-point constant */
323 DEF_RTL_EXPR(CONST_FIXED, "const_fixed", "www", RTX_CONST_OBJ)
325 /* numeric floating point or integer constant. If the mode is
326 VOIDmode it is an int otherwise it has a floating point mode and a
327 floating point value. Operands hold the value. They are all 'w'
328 and there may be from 2 to 6; see real.h. */
329 DEF_RTL_EXPR(CONST_DOUBLE, "const_double", CONST_DOUBLE_FORMAT, RTX_CONST_OBJ)
331 /* Describes a vector constant. */
332 DEF_RTL_EXPR(CONST_VECTOR, "const_vector", "E", RTX_CONST_OBJ)
334 /* String constant. Used for attributes in machine descriptions and
335 for special cases in DWARF2 debug output. NOT used for source-
336 language string constants. */
337 DEF_RTL_EXPR(CONST_STRING, "const_string", "s", RTX_OBJ)
339 /* This is used to encapsulate an expression whose value is constant
340 (such as the sum of a SYMBOL_REF and a CONST_INT) so that it will be
341 recognized as a constant operand rather than by arithmetic instructions. */
343 DEF_RTL_EXPR(CONST, "const", "e", RTX_CONST_OBJ)
345 /* program counter. Ordinary jumps are represented
346 by a SET whose first operand is (PC). */
347 DEF_RTL_EXPR(PC, "pc", "", RTX_OBJ)
349 /* A register. The "operand" is the register number, accessed with
350 the REGNO macro. If this number is less than FIRST_PSEUDO_REGISTER
351 than a hardware register is being referred to. The second operand
352 holds the original register number - this will be different for a
353 pseudo register that got turned into a hard register. The third
354 operand points to a reg_attrs structure.
355 This rtx needs to have as many (or more) fields as a MEM, since we
356 can change REG rtx's into MEMs during reload. */
357 DEF_RTL_EXPR(REG, "reg", "i00", RTX_OBJ)
359 /* A scratch register. This represents a register used only within a
360 single insn. It will be turned into a REG during register allocation
361 or reload unless the constraint indicates that the register won't be
362 needed, in which case it can remain a SCRATCH. This code is
363 marked as having one operand so it can be turned into a REG. */
364 DEF_RTL_EXPR(SCRATCH, "scratch", "0", RTX_OBJ)
366 /* A reference to a part of another value. The first operand is the
367 complete value and the second is the byte offset of the selected part. */
368 DEF_RTL_EXPR(SUBREG, "subreg", "ei", RTX_EXTRA)
370 /* This one-argument rtx is used for move instructions
371 that are guaranteed to alter only the low part of a destination.
372 Thus, (SET (SUBREG:HI (REG...)) (MEM:HI ...))
373 has an unspecified effect on the high part of REG,
374 but (SET (STRICT_LOW_PART (SUBREG:HI (REG...))) (MEM:HI ...))
375 is guaranteed to alter only the bits of REG that are in HImode.
377 The actual instruction used is probably the same in both cases,
378 but the register constraints may be tighter when STRICT_LOW_PART
379 is in use. */
381 DEF_RTL_EXPR(STRICT_LOW_PART, "strict_low_part", "e", RTX_EXTRA)
383 /* (CONCAT a b) represents the virtual concatenation of a and b
384 to make a value that has as many bits as a and b put together.
385 This is used for complex values. Normally it appears only
386 in DECL_RTLs and during RTL generation, but not in the insn chain. */
387 DEF_RTL_EXPR(CONCAT, "concat", "ee", RTX_OBJ)
389 /* (CONCATN [a1 a2 ... an]) represents the virtual concatenation of
390 all An to make a value. This is an extension of CONCAT to larger
391 number of components. Like CONCAT, it should not appear in the
392 insn chain. Every element of the CONCATN is the same size. */
393 DEF_RTL_EXPR(CONCATN, "concatn", "E", RTX_OBJ)
395 /* A memory location; operand is the address. The second operand is the
396 alias set to which this MEM belongs. We use `0' instead of `w' for this
397 field so that the field need not be specified in machine descriptions. */
398 DEF_RTL_EXPR(MEM, "mem", "e0", RTX_OBJ)
400 /* Reference to an assembler label in the code for this function.
401 The operand is a CODE_LABEL found in the insn chain. */
402 DEF_RTL_EXPR(LABEL_REF, "label_ref", "u", RTX_CONST_OBJ)
404 /* Reference to a named label:
405 Operand 0: label name
406 Operand 1: flags (see SYMBOL_FLAG_* in rtl.h)
407 Operand 2: tree from which this symbol is derived, or null.
408 This is either a DECL node, or some kind of constant. */
409 DEF_RTL_EXPR(SYMBOL_REF, "symbol_ref", "s00", RTX_CONST_OBJ)
411 /* The condition code register is represented, in our imagination,
412 as a register holding a value that can be compared to zero.
413 In fact, the machine has already compared them and recorded the
414 results; but instructions that look at the condition code
415 pretend to be looking at the entire value and comparing it. */
416 DEF_RTL_EXPR(CC0, "cc0", "", RTX_OBJ)
418 /* ----------------------------------------------------------------------
419 Expressions for operators in an rtl pattern
420 ---------------------------------------------------------------------- */
422 /* if_then_else. This is used in representing ordinary
423 conditional jump instructions.
424 Operand:
425 0: condition
426 1: then expr
427 2: else expr */
428 DEF_RTL_EXPR(IF_THEN_ELSE, "if_then_else", "eee", RTX_TERNARY)
430 /* Comparison, produces a condition code result. */
431 DEF_RTL_EXPR(COMPARE, "compare", "ee", RTX_BIN_ARITH)
433 /* plus */
434 DEF_RTL_EXPR(PLUS, "plus", "ee", RTX_COMM_ARITH)
436 /* Operand 0 minus operand 1. */
437 DEF_RTL_EXPR(MINUS, "minus", "ee", RTX_BIN_ARITH)
439 /* Minus operand 0. */
440 DEF_RTL_EXPR(NEG, "neg", "e", RTX_UNARY)
442 DEF_RTL_EXPR(MULT, "mult", "ee", RTX_COMM_ARITH)
444 /* Multiplication with signed saturation */
445 DEF_RTL_EXPR(SS_MULT, "ss_mult", "ee", RTX_COMM_ARITH)
446 /* Multiplication with unsigned saturation */
447 DEF_RTL_EXPR(US_MULT, "us_mult", "ee", RTX_COMM_ARITH)
449 /* Operand 0 divided by operand 1. */
450 DEF_RTL_EXPR(DIV, "div", "ee", RTX_BIN_ARITH)
451 /* Division with signed saturation */
452 DEF_RTL_EXPR(SS_DIV, "ss_div", "ee", RTX_BIN_ARITH)
453 /* Division with unsigned saturation */
454 DEF_RTL_EXPR(US_DIV, "us_div", "ee", RTX_BIN_ARITH)
456 /* Remainder of operand 0 divided by operand 1. */
457 DEF_RTL_EXPR(MOD, "mod", "ee", RTX_BIN_ARITH)
459 /* Unsigned divide and remainder. */
460 DEF_RTL_EXPR(UDIV, "udiv", "ee", RTX_BIN_ARITH)
461 DEF_RTL_EXPR(UMOD, "umod", "ee", RTX_BIN_ARITH)
463 /* Bitwise operations. */
464 DEF_RTL_EXPR(AND, "and", "ee", RTX_COMM_ARITH)
465 DEF_RTL_EXPR(IOR, "ior", "ee", RTX_COMM_ARITH)
466 DEF_RTL_EXPR(XOR, "xor", "ee", RTX_COMM_ARITH)
467 DEF_RTL_EXPR(NOT, "not", "e", RTX_UNARY)
469 /* Operand:
470 0: value to be shifted.
471 1: number of bits. */
472 DEF_RTL_EXPR(ASHIFT, "ashift", "ee", RTX_BIN_ARITH) /* shift left */
473 DEF_RTL_EXPR(ROTATE, "rotate", "ee", RTX_BIN_ARITH) /* rotate left */
474 DEF_RTL_EXPR(ASHIFTRT, "ashiftrt", "ee", RTX_BIN_ARITH) /* arithmetic shift right */
475 DEF_RTL_EXPR(LSHIFTRT, "lshiftrt", "ee", RTX_BIN_ARITH) /* logical shift right */
476 DEF_RTL_EXPR(ROTATERT, "rotatert", "ee", RTX_BIN_ARITH) /* rotate right */
478 /* Minimum and maximum values of two operands. We need both signed and
479 unsigned forms. (We cannot use MIN for SMIN because it conflicts
480 with a macro of the same name.) The signed variants should be used
481 with floating point. Further, if both operands are zeros, or if either
482 operand is NaN, then it is unspecified which of the two operands is
483 returned as the result. */
485 DEF_RTL_EXPR(SMIN, "smin", "ee", RTX_COMM_ARITH)
486 DEF_RTL_EXPR(SMAX, "smax", "ee", RTX_COMM_ARITH)
487 DEF_RTL_EXPR(UMIN, "umin", "ee", RTX_COMM_ARITH)
488 DEF_RTL_EXPR(UMAX, "umax", "ee", RTX_COMM_ARITH)
490 /* These unary operations are used to represent incrementation
491 and decrementation as they occur in memory addresses.
492 The amount of increment or decrement are not represented
493 because they can be understood from the machine-mode of the
494 containing MEM. These operations exist in only two cases:
495 1. pushes onto the stack.
496 2. created automatically by the auto-inc-dec pass. */
497 DEF_RTL_EXPR(PRE_DEC, "pre_dec", "e", RTX_AUTOINC)
498 DEF_RTL_EXPR(PRE_INC, "pre_inc", "e", RTX_AUTOINC)
499 DEF_RTL_EXPR(POST_DEC, "post_dec", "e", RTX_AUTOINC)
500 DEF_RTL_EXPR(POST_INC, "post_inc", "e", RTX_AUTOINC)
502 /* These binary operations are used to represent generic address
503 side-effects in memory addresses, except for simple incrementation
504 or decrementation which use the above operations. They are
505 created automatically by the life_analysis pass in flow.c.
506 The first operand is a REG which is used as the address.
507 The second operand is an expression that is assigned to the
508 register, either before (PRE_MODIFY) or after (POST_MODIFY)
509 evaluating the address.
510 Currently, the compiler can only handle second operands of the
511 form (plus (reg) (reg)) and (plus (reg) (const_int)), where
512 the first operand of the PLUS has to be the same register as
513 the first operand of the *_MODIFY. */
514 DEF_RTL_EXPR(PRE_MODIFY, "pre_modify", "ee", RTX_AUTOINC)
515 DEF_RTL_EXPR(POST_MODIFY, "post_modify", "ee", RTX_AUTOINC)
517 /* Comparison operations. The ordered comparisons exist in two
518 flavors, signed and unsigned. */
519 DEF_RTL_EXPR(NE, "ne", "ee", RTX_COMM_COMPARE)
520 DEF_RTL_EXPR(EQ, "eq", "ee", RTX_COMM_COMPARE)
521 DEF_RTL_EXPR(GE, "ge", "ee", RTX_COMPARE)
522 DEF_RTL_EXPR(GT, "gt", "ee", RTX_COMPARE)
523 DEF_RTL_EXPR(LE, "le", "ee", RTX_COMPARE)
524 DEF_RTL_EXPR(LT, "lt", "ee", RTX_COMPARE)
525 DEF_RTL_EXPR(GEU, "geu", "ee", RTX_COMPARE)
526 DEF_RTL_EXPR(GTU, "gtu", "ee", RTX_COMPARE)
527 DEF_RTL_EXPR(LEU, "leu", "ee", RTX_COMPARE)
528 DEF_RTL_EXPR(LTU, "ltu", "ee", RTX_COMPARE)
530 /* Additional floating point unordered comparison flavors. */
531 DEF_RTL_EXPR(UNORDERED, "unordered", "ee", RTX_COMM_COMPARE)
532 DEF_RTL_EXPR(ORDERED, "ordered", "ee", RTX_COMM_COMPARE)
534 /* These are equivalent to unordered or ... */
535 DEF_RTL_EXPR(UNEQ, "uneq", "ee", RTX_COMM_COMPARE)
536 DEF_RTL_EXPR(UNGE, "unge", "ee", RTX_COMPARE)
537 DEF_RTL_EXPR(UNGT, "ungt", "ee", RTX_COMPARE)
538 DEF_RTL_EXPR(UNLE, "unle", "ee", RTX_COMPARE)
539 DEF_RTL_EXPR(UNLT, "unlt", "ee", RTX_COMPARE)
541 /* This is an ordered NE, ie !UNEQ, ie false for NaN. */
542 DEF_RTL_EXPR(LTGT, "ltgt", "ee", RTX_COMM_COMPARE)
544 /* Represents the result of sign-extending the sole operand.
545 The machine modes of the operand and of the SIGN_EXTEND expression
546 determine how much sign-extension is going on. */
547 DEF_RTL_EXPR(SIGN_EXTEND, "sign_extend", "e", RTX_UNARY)
549 /* Similar for zero-extension (such as unsigned short to int). */
550 DEF_RTL_EXPR(ZERO_EXTEND, "zero_extend", "e", RTX_UNARY)
552 /* Similar but here the operand has a wider mode. */
553 DEF_RTL_EXPR(TRUNCATE, "truncate", "e", RTX_UNARY)
555 /* Similar for extending floating-point values (such as SFmode to DFmode). */
556 DEF_RTL_EXPR(FLOAT_EXTEND, "float_extend", "e", RTX_UNARY)
557 DEF_RTL_EXPR(FLOAT_TRUNCATE, "float_truncate", "e", RTX_UNARY)
559 /* Conversion of fixed point operand to floating point value. */
560 DEF_RTL_EXPR(FLOAT, "float", "e", RTX_UNARY)
562 /* With fixed-point machine mode:
563 Conversion of floating point operand to fixed point value.
564 Value is defined only when the operand's value is an integer.
565 With floating-point machine mode (and operand with same mode):
566 Operand is rounded toward zero to produce an integer value
567 represented in floating point. */
568 DEF_RTL_EXPR(FIX, "fix", "e", RTX_UNARY)
570 /* Conversion of unsigned fixed point operand to floating point value. */
571 DEF_RTL_EXPR(UNSIGNED_FLOAT, "unsigned_float", "e", RTX_UNARY)
573 /* With fixed-point machine mode:
574 Conversion of floating point operand to *unsigned* fixed point value.
575 Value is defined only when the operand's value is an integer. */
576 DEF_RTL_EXPR(UNSIGNED_FIX, "unsigned_fix", "e", RTX_UNARY)
578 /* Conversions involving fractional fixed-point types without saturation,
579 including:
580 fractional to fractional (of different precision),
581 signed integer to fractional,
582 fractional to signed integer,
583 floating point to fractional,
584 fractional to floating point.
585 NOTE: fractional can be either signed or unsigned for conversions. */
586 DEF_RTL_EXPR(FRACT_CONVERT, "fract_convert", "e", RTX_UNARY)
588 /* Conversions involving fractional fixed-point types and unsigned integer
589 without saturation, including:
590 unsigned integer to fractional,
591 fractional to unsigned integer.
592 NOTE: fractional can be either signed or unsigned for conversions. */
593 DEF_RTL_EXPR(UNSIGNED_FRACT_CONVERT, "unsigned_fract_convert", "e", RTX_UNARY)
595 /* Conversions involving fractional fixed-point types with saturation,
596 including:
597 fractional to fractional (of different precision),
598 signed integer to fractional,
599 floating point to fractional.
600 NOTE: fractional can be either signed or unsigned for conversions. */
601 DEF_RTL_EXPR(SAT_FRACT, "sat_fract", "e", RTX_UNARY)
603 /* Conversions involving fractional fixed-point types and unsigned integer
604 with saturation, including:
605 unsigned integer to fractional.
606 NOTE: fractional can be either signed or unsigned for conversions. */
607 DEF_RTL_EXPR(UNSIGNED_SAT_FRACT, "unsigned_sat_fract", "e", RTX_UNARY)
609 /* Absolute value */
610 DEF_RTL_EXPR(ABS, "abs", "e", RTX_UNARY)
612 /* Square root */
613 DEF_RTL_EXPR(SQRT, "sqrt", "e", RTX_UNARY)
615 /* Swap bytes. */
616 DEF_RTL_EXPR(BSWAP, "bswap", "e", RTX_UNARY)
618 /* Find first bit that is set.
619 Value is 1 + number of trailing zeros in the arg.,
620 or 0 if arg is 0. */
621 DEF_RTL_EXPR(FFS, "ffs", "e", RTX_UNARY)
623 /* Count number of leading redundant sign bits (number of leading
624 sign bits minus one). */
625 DEF_RTL_EXPR(CLRSB, "clrsb", "e", RTX_UNARY)
627 /* Count leading zeros. */
628 DEF_RTL_EXPR(CLZ, "clz", "e", RTX_UNARY)
630 /* Count trailing zeros. */
631 DEF_RTL_EXPR(CTZ, "ctz", "e", RTX_UNARY)
633 /* Population count (number of 1 bits). */
634 DEF_RTL_EXPR(POPCOUNT, "popcount", "e", RTX_UNARY)
636 /* Population parity (number of 1 bits modulo 2). */
637 DEF_RTL_EXPR(PARITY, "parity", "e", RTX_UNARY)
639 /* Reference to a signed bit-field of specified size and position.
640 Operand 0 is the memory unit (usually SImode or QImode) which
641 contains the field's first bit. Operand 1 is the width, in bits.
642 Operand 2 is the number of bits in the memory unit before the
643 first bit of this field.
644 If BITS_BIG_ENDIAN is defined, the first bit is the msb and
645 operand 2 counts from the msb of the memory unit.
646 Otherwise, the first bit is the lsb and operand 2 counts from
647 the lsb of the memory unit.
648 This kind of expression can not appear as an lvalue in RTL. */
649 DEF_RTL_EXPR(SIGN_EXTRACT, "sign_extract", "eee", RTX_BITFIELD_OPS)
651 /* Similar for unsigned bit-field.
652 But note! This kind of expression _can_ appear as an lvalue. */
653 DEF_RTL_EXPR(ZERO_EXTRACT, "zero_extract", "eee", RTX_BITFIELD_OPS)
655 /* For RISC machines. These save memory when splitting insns. */
657 /* HIGH are the high-order bits of a constant expression. */
658 DEF_RTL_EXPR(HIGH, "high", "e", RTX_CONST_OBJ)
660 /* LO_SUM is the sum of a register and the low-order bits
661 of a constant expression. */
662 DEF_RTL_EXPR(LO_SUM, "lo_sum", "ee", RTX_OBJ)
664 /* Describes a merge operation between two vector values.
665 Operands 0 and 1 are the vectors to be merged, operand 2 is a bitmask
666 that specifies where the parts of the result are taken from. Set bits
667 indicate operand 0, clear bits indicate operand 1. The parts are defined
668 by the mode of the vectors. */
669 DEF_RTL_EXPR(VEC_MERGE, "vec_merge", "eee", RTX_TERNARY)
671 /* Describes an operation that selects parts of a vector.
672 Operands 0 is the source vector, operand 1 is a PARALLEL that contains
673 a CONST_INT for each of the subparts of the result vector, giving the
674 number of the source subpart that should be stored into it. */
675 DEF_RTL_EXPR(VEC_SELECT, "vec_select", "ee", RTX_BIN_ARITH)
677 /* Describes a vector concat operation. Operands 0 and 1 are the source
678 vectors, the result is a vector that is as long as operands 0 and 1
679 combined and is the concatenation of the two source vectors. */
680 DEF_RTL_EXPR(VEC_CONCAT, "vec_concat", "ee", RTX_BIN_ARITH)
682 /* Describes an operation that converts a small vector into a larger one by
683 duplicating the input values. The output vector mode must have the same
684 submodes as the input vector mode, and the number of output parts must be
685 an integer multiple of the number of input parts. */
686 DEF_RTL_EXPR(VEC_DUPLICATE, "vec_duplicate", "e", RTX_UNARY)
688 /* Addition with signed saturation */
689 DEF_RTL_EXPR(SS_PLUS, "ss_plus", "ee", RTX_COMM_ARITH)
691 /* Addition with unsigned saturation */
692 DEF_RTL_EXPR(US_PLUS, "us_plus", "ee", RTX_COMM_ARITH)
694 /* Operand 0 minus operand 1, with signed saturation. */
695 DEF_RTL_EXPR(SS_MINUS, "ss_minus", "ee", RTX_BIN_ARITH)
697 /* Negation with signed saturation. */
698 DEF_RTL_EXPR(SS_NEG, "ss_neg", "e", RTX_UNARY)
699 /* Negation with unsigned saturation. */
700 DEF_RTL_EXPR(US_NEG, "us_neg", "e", RTX_UNARY)
702 /* Absolute value with signed saturation. */
703 DEF_RTL_EXPR(SS_ABS, "ss_abs", "e", RTX_UNARY)
705 /* Shift left with signed saturation. */
706 DEF_RTL_EXPR(SS_ASHIFT, "ss_ashift", "ee", RTX_BIN_ARITH)
708 /* Shift left with unsigned saturation. */
709 DEF_RTL_EXPR(US_ASHIFT, "us_ashift", "ee", RTX_BIN_ARITH)
711 /* Operand 0 minus operand 1, with unsigned saturation. */
712 DEF_RTL_EXPR(US_MINUS, "us_minus", "ee", RTX_BIN_ARITH)
714 /* Signed saturating truncate. */
715 DEF_RTL_EXPR(SS_TRUNCATE, "ss_truncate", "e", RTX_UNARY)
717 /* Unsigned saturating truncate. */
718 DEF_RTL_EXPR(US_TRUNCATE, "us_truncate", "e", RTX_UNARY)
720 /* Floating point multiply/add combined instruction. */
721 DEF_RTL_EXPR(FMA, "fma", "eee", RTX_TERNARY)
723 /* Information about the variable and its location. */
724 /* Changed 'te' to 'tei'; the 'i' field is for recording
725 initialization status of variables. */
726 DEF_RTL_EXPR(VAR_LOCATION, "var_location", "tei", RTX_EXTRA)
728 /* Used in VAR_LOCATION for a pointer to a decl that is no longer
729 addressable. */
730 DEF_RTL_EXPR(DEBUG_IMPLICIT_PTR, "debug_implicit_ptr", "t", RTX_OBJ)
732 /* Represents value that argument had on function entry. The
733 single argument is the DECL_INCOMING_RTL of the corresponding
734 parameter. */
735 DEF_RTL_EXPR(ENTRY_VALUE, "entry_value", "0", RTX_OBJ)
737 /* Used in VAR_LOCATION for a reference to a parameter that has
738 been optimized away completely. */
739 DEF_RTL_EXPR(DEBUG_PARAMETER_REF, "debug_parameter_ref", "t", RTX_OBJ)
741 /* All expressions from this point forward appear only in machine
742 descriptions. */
743 #ifdef GENERATOR_FILE
745 /* Pattern-matching operators: */
747 /* Use the function named by the second arg (the string)
748 as a predicate; if matched, store the structure that was matched
749 in the operand table at index specified by the first arg (the integer).
750 If the second arg is the null string, the structure is just stored.
752 A third string argument indicates to the register allocator restrictions
753 on where the operand can be allocated.
755 If the target needs no restriction on any instruction this field should
756 be the null string.
758 The string is prepended by:
759 '=' to indicate the operand is only written to.
760 '+' to indicate the operand is both read and written to.
762 Each character in the string represents an allocable class for an operand.
763 'g' indicates the operand can be any valid class.
764 'i' indicates the operand can be immediate (in the instruction) data.
765 'r' indicates the operand can be in a register.
766 'm' indicates the operand can be in memory.
767 'o' a subset of the 'm' class. Those memory addressing modes that
768 can be offset at compile time (have a constant added to them).
770 Other characters indicate target dependent operand classes and
771 are described in each target's machine description.
773 For instructions with more than one operand, sets of classes can be
774 separated by a comma to indicate the appropriate multi-operand constraints.
775 There must be a 1 to 1 correspondence between these sets of classes in
776 all operands for an instruction.
778 DEF_RTL_EXPR(MATCH_OPERAND, "match_operand", "iss", RTX_MATCH)
780 /* Match a SCRATCH or a register. When used to generate rtl, a
781 SCRATCH is generated. As for MATCH_OPERAND, the mode specifies
782 the desired mode and the first argument is the operand number.
783 The second argument is the constraint. */
784 DEF_RTL_EXPR(MATCH_SCRATCH, "match_scratch", "is", RTX_MATCH)
786 /* Apply a predicate, AND match recursively the operands of the rtx.
787 Operand 0 is the operand-number, as in match_operand.
788 Operand 1 is a predicate to apply (as a string, a function name).
789 Operand 2 is a vector of expressions, each of which must match
790 one subexpression of the rtx this construct is matching. */
791 DEF_RTL_EXPR(MATCH_OPERATOR, "match_operator", "isE", RTX_MATCH)
793 /* Match a PARALLEL of arbitrary length. The predicate is applied
794 to the PARALLEL and the initial expressions in the PARALLEL are matched.
795 Operand 0 is the operand-number, as in match_operand.
796 Operand 1 is a predicate to apply to the PARALLEL.
797 Operand 2 is a vector of expressions, each of which must match the
798 corresponding element in the PARALLEL. */
799 DEF_RTL_EXPR(MATCH_PARALLEL, "match_parallel", "isE", RTX_MATCH)
801 /* Match only something equal to what is stored in the operand table
802 at the index specified by the argument. Use with MATCH_OPERAND. */
803 DEF_RTL_EXPR(MATCH_DUP, "match_dup", "i", RTX_MATCH)
805 /* Match only something equal to what is stored in the operand table
806 at the index specified by the argument. Use with MATCH_OPERATOR. */
807 DEF_RTL_EXPR(MATCH_OP_DUP, "match_op_dup", "iE", RTX_MATCH)
809 /* Match only something equal to what is stored in the operand table
810 at the index specified by the argument. Use with MATCH_PARALLEL. */
811 DEF_RTL_EXPR(MATCH_PAR_DUP, "match_par_dup", "iE", RTX_MATCH)
813 /* Appears only in define_predicate/define_special_predicate
814 expressions. Evaluates true only if the operand has an RTX code
815 from the set given by the argument (a comma-separated list). If the
816 second argument is present and nonempty, it is a sequence of digits
817 and/or letters which indicates the subexpression to test, using the
818 same syntax as genextract/genrecog's location strings: 0-9 for
819 XEXP (op, n), a-z for XVECEXP (op, 0, n); each character applies to
820 the result of the one before it. */
821 DEF_RTL_EXPR(MATCH_CODE, "match_code", "ss", RTX_MATCH)
823 /* Used to inject a C conditional expression into an .md file. It can
824 appear in a predicate definition or an attribute expression. */
825 DEF_RTL_EXPR(MATCH_TEST, "match_test", "s", RTX_MATCH)
827 /* Insn (and related) definitions. */
829 /* Definition of the pattern for one kind of instruction.
830 Operand:
831 0: names this instruction.
832 If the name is the null string, the instruction is in the
833 machine description just to be recognized, and will never be emitted by
834 the tree to rtl expander.
835 1: is the pattern.
836 2: is a string which is a C expression
837 giving an additional condition for recognizing this pattern.
838 A null string means no extra condition.
839 3: is the action to execute if this pattern is matched.
840 If this assembler code template starts with a * then it is a fragment of
841 C code to run to decide on a template to use. Otherwise, it is the
842 template to use.
843 4: optionally, a vector of attributes for this insn.
845 DEF_RTL_EXPR(DEFINE_INSN, "define_insn", "sEsTV", RTX_EXTRA)
847 /* Definition of a peephole optimization.
848 1st operand: vector of insn patterns to match
849 2nd operand: C expression that must be true
850 3rd operand: template or C code to produce assembler output.
851 4: optionally, a vector of attributes for this insn.
853 This form is deprecated; use define_peephole2 instead. */
854 DEF_RTL_EXPR(DEFINE_PEEPHOLE, "define_peephole", "EsTV", RTX_EXTRA)
856 /* Definition of a split operation.
857 1st operand: insn pattern to match
858 2nd operand: C expression that must be true
859 3rd operand: vector of insn patterns to place into a SEQUENCE
860 4th operand: optionally, some C code to execute before generating the
861 insns. This might, for example, create some RTX's and store them in
862 elements of `recog_data.operand' for use by the vector of
863 insn-patterns.
864 (`operands' is an alias here for `recog_data.operand'). */
865 DEF_RTL_EXPR(DEFINE_SPLIT, "define_split", "EsES", RTX_EXTRA)
867 /* Definition of an insn and associated split.
868 This is the concatenation, with a few modifications, of a define_insn
869 and a define_split which share the same pattern.
870 Operand:
871 0: names this instruction.
872 If the name is the null string, the instruction is in the
873 machine description just to be recognized, and will never be emitted by
874 the tree to rtl expander.
875 1: is the pattern.
876 2: is a string which is a C expression
877 giving an additional condition for recognizing this pattern.
878 A null string means no extra condition.
879 3: is the action to execute if this pattern is matched.
880 If this assembler code template starts with a * then it is a fragment of
881 C code to run to decide on a template to use. Otherwise, it is the
882 template to use.
883 4: C expression that must be true for split. This may start with "&&"
884 in which case the split condition is the logical and of the insn
885 condition and what follows the "&&" of this operand.
886 5: vector of insn patterns to place into a SEQUENCE
887 6: optionally, some C code to execute before generating the
888 insns. This might, for example, create some RTX's and store them in
889 elements of `recog_data.operand' for use by the vector of
890 insn-patterns.
891 (`operands' is an alias here for `recog_data.operand').
892 7: optionally, a vector of attributes for this insn. */
893 DEF_RTL_EXPR(DEFINE_INSN_AND_SPLIT, "define_insn_and_split", "sEsTsESV", RTX_EXTRA)
895 /* Definition of an RTL peephole operation.
896 Follows the same arguments as define_split. */
897 DEF_RTL_EXPR(DEFINE_PEEPHOLE2, "define_peephole2", "EsES", RTX_EXTRA)
899 /* Define how to generate multiple insns for a standard insn name.
900 1st operand: the insn name.
901 2nd operand: vector of insn-patterns.
902 Use match_operand to substitute an element of `recog_data.operand'.
903 3rd operand: C expression that must be true for this to be available.
904 This may not test any operands.
905 4th operand: Extra C code to execute before generating the insns.
906 This might, for example, create some RTX's and store them in
907 elements of `recog_data.operand' for use by the vector of
908 insn-patterns.
909 (`operands' is an alias here for `recog_data.operand').
910 5th: optionally, a vector of attributes for this expand. */
911 DEF_RTL_EXPR(DEFINE_EXPAND, "define_expand", "sEssV", RTX_EXTRA)
913 /* Define a requirement for delay slots.
914 1st operand: Condition involving insn attributes that, if true,
915 indicates that the insn requires the number of delay slots
916 shown.
917 2nd operand: Vector whose length is the three times the number of delay
918 slots required.
919 Each entry gives three conditions, each involving attributes.
920 The first must be true for an insn to occupy that delay slot
921 location. The second is true for all insns that can be
922 annulled if the branch is true and the third is true for all
923 insns that can be annulled if the branch is false.
925 Multiple DEFINE_DELAYs may be present. They indicate differing
926 requirements for delay slots. */
927 DEF_RTL_EXPR(DEFINE_DELAY, "define_delay", "eE", RTX_EXTRA)
929 /* Define attribute computation for `asm' instructions. */
930 DEF_RTL_EXPR(DEFINE_ASM_ATTRIBUTES, "define_asm_attributes", "V", RTX_EXTRA)
932 /* Definition of a conditional execution meta operation. Automatically
933 generates new instances of DEFINE_INSN, selected by having attribute
934 "predicable" true. The new pattern will contain a COND_EXEC and the
935 predicate at top-level.
937 Operand:
938 0: The predicate pattern. The top-level form should match a
939 relational operator. Operands should have only one alternative.
940 1: A C expression giving an additional condition for recognizing
941 the generated pattern.
942 2: A template or C code to produce assembler output. */
943 DEF_RTL_EXPR(DEFINE_COND_EXEC, "define_cond_exec", "Ess", RTX_EXTRA)
945 /* Definition of an operand predicate. The difference between
946 DEFINE_PREDICATE and DEFINE_SPECIAL_PREDICATE is that genrecog will
947 not warn about a match_operand with no mode if it has a predicate
948 defined with DEFINE_SPECIAL_PREDICATE.
950 Operand:
951 0: The name of the predicate.
952 1: A boolean expression which computes whether or not the predicate
953 matches. This expression can use IOR, AND, NOT, MATCH_OPERAND,
954 MATCH_CODE, and MATCH_TEST. It must be specific enough that genrecog
955 can calculate the set of RTX codes that can possibly match.
956 2: A C function body which must return true for the predicate to match.
957 Optional. Use this when the test is too complicated to fit into a
958 match_test expression. */
959 DEF_RTL_EXPR(DEFINE_PREDICATE, "define_predicate", "ses", RTX_EXTRA)
960 DEF_RTL_EXPR(DEFINE_SPECIAL_PREDICATE, "define_special_predicate", "ses", RTX_EXTRA)
962 /* Definition of a register operand constraint. This simply maps the
963 constraint string to a register class.
965 Operand:
966 0: The name of the constraint (often, but not always, a single letter).
967 1: A C expression which evaluates to the appropriate register class for
968 this constraint. If this is not just a constant, it should look only
969 at -m switches and the like.
970 2: A docstring for this constraint, in Texinfo syntax; not currently
971 used, in future will be incorporated into the manual's list of
972 machine-specific operand constraints. */
973 DEF_RTL_EXPR(DEFINE_REGISTER_CONSTRAINT, "define_register_constraint", "sss", RTX_EXTRA)
975 /* Definition of a non-register operand constraint. These look at the
976 operand and decide whether it fits the constraint.
978 DEFINE_CONSTRAINT gets no special treatment if it fails to match.
979 It is appropriate for constant-only constraints, and most others.
981 DEFINE_MEMORY_CONSTRAINT tells reload that this constraint can be made
982 to match, if it doesn't already, by converting the operand to the form
983 (mem (reg X)) where X is a base register. It is suitable for constraints
984 that describe a subset of all memory references.
986 DEFINE_ADDRESS_CONSTRAINT tells reload that this constraint can be made
987 to match, if it doesn't already, by converting the operand to the form
988 (reg X) where X is a base register. It is suitable for constraints that
989 describe a subset of all address references.
991 When in doubt, use plain DEFINE_CONSTRAINT.
993 Operand:
994 0: The name of the constraint (often, but not always, a single letter).
995 1: A docstring for this constraint, in Texinfo syntax; not currently
996 used, in future will be incorporated into the manual's list of
997 machine-specific operand constraints.
998 2: A boolean expression which computes whether or not the constraint
999 matches. It should follow the same rules as a define_predicate
1000 expression, including the bit about specifying the set of RTX codes
1001 that could possibly match. MATCH_TEST subexpressions may make use of
1002 these variables:
1003 `op' - the RTL object defining the operand.
1004 `mode' - the mode of `op'.
1005 `ival' - INTVAL(op), if op is a CONST_INT.
1006 `hval' - CONST_DOUBLE_HIGH(op), if op is an integer CONST_DOUBLE.
1007 `lval' - CONST_DOUBLE_LOW(op), if op is an integer CONST_DOUBLE.
1008 `rval' - CONST_DOUBLE_REAL_VALUE(op), if op is a floating-point
1009 CONST_DOUBLE.
1010 Do not use ival/hval/lval/rval if op is not the appropriate kind of
1011 RTL object. */
1012 DEF_RTL_EXPR(DEFINE_CONSTRAINT, "define_constraint", "sse", RTX_EXTRA)
1013 DEF_RTL_EXPR(DEFINE_MEMORY_CONSTRAINT, "define_memory_constraint", "sse", RTX_EXTRA)
1014 DEF_RTL_EXPR(DEFINE_ADDRESS_CONSTRAINT, "define_address_constraint", "sse", RTX_EXTRA)
1017 /* Constructions for CPU pipeline description described by NDFAs. */
1019 /* (define_cpu_unit string [string]) describes cpu functional
1020 units (separated by comma).
1022 1st operand: Names of cpu functional units.
1023 2nd operand: Name of automaton (see comments for DEFINE_AUTOMATON).
1025 All define_reservations, define_cpu_units, and
1026 define_query_cpu_units should have unique names which may not be
1027 "nothing". */
1028 DEF_RTL_EXPR(DEFINE_CPU_UNIT, "define_cpu_unit", "sS", RTX_EXTRA)
1030 /* (define_query_cpu_unit string [string]) describes cpu functional
1031 units analogously to define_cpu_unit. The reservation of such
1032 units can be queried for automaton state. */
1033 DEF_RTL_EXPR(DEFINE_QUERY_CPU_UNIT, "define_query_cpu_unit", "sS", RTX_EXTRA)
1035 /* (exclusion_set string string) means that each CPU functional unit
1036 in the first string can not be reserved simultaneously with any
1037 unit whose name is in the second string and vise versa. CPU units
1038 in the string are separated by commas. For example, it is useful
1039 for description CPU with fully pipelined floating point functional
1040 unit which can execute simultaneously only single floating point
1041 insns or only double floating point insns. All CPU functional
1042 units in a set should belong to the same automaton. */
1043 DEF_RTL_EXPR(EXCLUSION_SET, "exclusion_set", "ss", RTX_EXTRA)
1045 /* (presence_set string string) means that each CPU functional unit in
1046 the first string can not be reserved unless at least one of pattern
1047 of units whose names are in the second string is reserved. This is
1048 an asymmetric relation. CPU units or unit patterns in the strings
1049 are separated by commas. Pattern is one unit name or unit names
1050 separated by white-spaces.
1052 For example, it is useful for description that slot1 is reserved
1053 after slot0 reservation for a VLIW processor. We could describe it
1054 by the following construction
1056 (presence_set "slot1" "slot0")
1058 Or slot1 is reserved only after slot0 and unit b0 reservation. In
1059 this case we could write
1061 (presence_set "slot1" "slot0 b0")
1063 All CPU functional units in a set should belong to the same
1064 automaton. */
1065 DEF_RTL_EXPR(PRESENCE_SET, "presence_set", "ss", RTX_EXTRA)
1067 /* (final_presence_set string string) is analogous to `presence_set'.
1068 The difference between them is when checking is done. When an
1069 instruction is issued in given automaton state reflecting all
1070 current and planned unit reservations, the automaton state is
1071 changed. The first state is a source state, the second one is a
1072 result state. Checking for `presence_set' is done on the source
1073 state reservation, checking for `final_presence_set' is done on the
1074 result reservation. This construction is useful to describe a
1075 reservation which is actually two subsequent reservations. For
1076 example, if we use
1078 (presence_set "slot1" "slot0")
1080 the following insn will be never issued (because slot1 requires
1081 slot0 which is absent in the source state).
1083 (define_reservation "insn_and_nop" "slot0 + slot1")
1085 but it can be issued if we use analogous `final_presence_set'. */
1086 DEF_RTL_EXPR(FINAL_PRESENCE_SET, "final_presence_set", "ss", RTX_EXTRA)
1088 /* (absence_set string string) means that each CPU functional unit in
1089 the first string can be reserved only if each pattern of units
1090 whose names are in the second string is not reserved. This is an
1091 asymmetric relation (actually exclusion set is analogous to this
1092 one but it is symmetric). CPU units or unit patterns in the string
1093 are separated by commas. Pattern is one unit name or unit names
1094 separated by white-spaces.
1096 For example, it is useful for description that slot0 can not be
1097 reserved after slot1 or slot2 reservation for a VLIW processor. We
1098 could describe it by the following construction
1100 (absence_set "slot2" "slot0, slot1")
1102 Or slot2 can not be reserved if slot0 and unit b0 are reserved or
1103 slot1 and unit b1 are reserved . In this case we could write
1105 (absence_set "slot2" "slot0 b0, slot1 b1")
1107 All CPU functional units in a set should to belong the same
1108 automaton. */
1109 DEF_RTL_EXPR(ABSENCE_SET, "absence_set", "ss", RTX_EXTRA)
1111 /* (final_absence_set string string) is analogous to `absence_set' but
1112 checking is done on the result (state) reservation. See comments
1113 for `final_presence_set'. */
1114 DEF_RTL_EXPR(FINAL_ABSENCE_SET, "final_absence_set", "ss", RTX_EXTRA)
1116 /* (define_bypass number out_insn_names in_insn_names) names bypass
1117 with given latency (the first number) from insns given by the first
1118 string (see define_insn_reservation) into insns given by the second
1119 string. Insn names in the strings are separated by commas. The
1120 third operand is optional name of function which is additional
1121 guard for the bypass. The function will get the two insns as
1122 parameters. If the function returns zero the bypass will be
1123 ignored for this case. Additional guard is necessary to recognize
1124 complicated bypasses, e.g. when consumer is load address. If there
1125 are more one bypass with the same output and input insns, the
1126 chosen bypass is the first bypass with a guard in description whose
1127 guard function returns nonzero. If there is no such bypass, then
1128 bypass without the guard function is chosen. */
1129 DEF_RTL_EXPR(DEFINE_BYPASS, "define_bypass", "issS", RTX_EXTRA)
1131 /* (define_automaton string) describes names of automata generated and
1132 used for pipeline hazards recognition. The names are separated by
1133 comma. Actually it is possibly to generate the single automaton
1134 but unfortunately it can be very large. If we use more one
1135 automata, the summary size of the automata usually is less than the
1136 single one. The automaton name is used in define_cpu_unit and
1137 define_query_cpu_unit. All automata should have unique names. */
1138 DEF_RTL_EXPR(DEFINE_AUTOMATON, "define_automaton", "s", RTX_EXTRA)
1140 /* (automata_option string) describes option for generation of
1141 automata. Currently there are the following options:
1143 o "no-minimization" which makes no minimization of automata. This
1144 is only worth to do when we are debugging the description and
1145 need to look more accurately at reservations of states.
1147 o "time" which means printing additional time statistics about
1148 generation of automata.
1150 o "v" which means generation of file describing the result
1151 automata. The file has suffix `.dfa' and can be used for the
1152 description verification and debugging.
1154 o "w" which means generation of warning instead of error for
1155 non-critical errors.
1157 o "ndfa" which makes nondeterministic finite state automata.
1159 o "progress" which means output of a progress bar showing how many
1160 states were generated so far for automaton being processed. */
1161 DEF_RTL_EXPR(AUTOMATA_OPTION, "automata_option", "s", RTX_EXTRA)
1163 /* (define_reservation string string) names reservation (the first
1164 string) of cpu functional units (the 2nd string). Sometimes unit
1165 reservations for different insns contain common parts. In such
1166 case, you can describe common part and use its name (the 1st
1167 parameter) in regular expression in define_insn_reservation. All
1168 define_reservations, define_cpu_units, and define_query_cpu_units
1169 should have unique names which may not be "nothing". */
1170 DEF_RTL_EXPR(DEFINE_RESERVATION, "define_reservation", "ss", RTX_EXTRA)
1172 /* (define_insn_reservation name default_latency condition regexpr)
1173 describes reservation of cpu functional units (the 3nd operand) for
1174 instruction which is selected by the condition (the 2nd parameter).
1175 The first parameter is used for output of debugging information.
1176 The reservations are described by a regular expression according
1177 the following syntax:
1179 regexp = regexp "," oneof
1180 | oneof
1182 oneof = oneof "|" allof
1183 | allof
1185 allof = allof "+" repeat
1186 | repeat
1188 repeat = element "*" number
1189 | element
1191 element = cpu_function_unit_name
1192 | reservation_name
1193 | result_name
1194 | "nothing"
1195 | "(" regexp ")"
1197 1. "," is used for describing start of the next cycle in
1198 reservation.
1200 2. "|" is used for describing the reservation described by the
1201 first regular expression *or* the reservation described by the
1202 second regular expression *or* etc.
1204 3. "+" is used for describing the reservation described by the
1205 first regular expression *and* the reservation described by the
1206 second regular expression *and* etc.
1208 4. "*" is used for convenience and simply means sequence in
1209 which the regular expression are repeated NUMBER times with
1210 cycle advancing (see ",").
1212 5. cpu functional unit name which means its reservation.
1214 6. reservation name -- see define_reservation.
1216 7. string "nothing" means no units reservation. */
1218 DEF_RTL_EXPR(DEFINE_INSN_RESERVATION, "define_insn_reservation", "sies", RTX_EXTRA)
1220 /* Expressions used for insn attributes. */
1222 /* Definition of an insn attribute.
1223 1st operand: name of the attribute
1224 2nd operand: comma-separated list of possible attribute values
1225 3rd operand: expression for the default value of the attribute. */
1226 DEF_RTL_EXPR(DEFINE_ATTR, "define_attr", "sse", RTX_EXTRA)
1228 /* Definition of an insn attribute that uses an existing enumerated type.
1229 1st operand: name of the attribute
1230 2nd operand: the name of the enumerated type
1231 3rd operand: expression for the default value of the attribute. */
1232 DEF_RTL_EXPR(DEFINE_ENUM_ATTR, "define_enum_attr", "sse", RTX_EXTRA)
1234 /* Marker for the name of an attribute. */
1235 DEF_RTL_EXPR(ATTR, "attr", "s", RTX_EXTRA)
1237 /* For use in the last (optional) operand of DEFINE_INSN or DEFINE_PEEPHOLE and
1238 in DEFINE_ASM_INSN to specify an attribute to assign to insns matching that
1239 pattern.
1241 (set_attr "name" "value") is equivalent to
1242 (set (attr "name") (const_string "value")) */
1243 DEF_RTL_EXPR(SET_ATTR, "set_attr", "ss", RTX_EXTRA)
1245 /* In the last operand of DEFINE_INSN and DEFINE_PEEPHOLE, this can be used to
1246 specify that attribute values are to be assigned according to the
1247 alternative matched.
1249 The following three expressions are equivalent:
1251 (set (attr "att") (cond [(eq_attrq "alternative" "1") (const_string "a1")
1252 (eq_attrq "alternative" "2") (const_string "a2")]
1253 (const_string "a3")))
1254 (set_attr_alternative "att" [(const_string "a1") (const_string "a2")
1255 (const_string "a3")])
1256 (set_attr "att" "a1,a2,a3")
1258 DEF_RTL_EXPR(SET_ATTR_ALTERNATIVE, "set_attr_alternative", "sE", RTX_EXTRA)
1260 /* A conditional expression true if the value of the specified attribute of
1261 the current insn equals the specified value. The first operand is the
1262 attribute name and the second is the comparison value. */
1263 DEF_RTL_EXPR(EQ_ATTR, "eq_attr", "ss", RTX_EXTRA)
1265 /* A special case of the above representing a set of alternatives. The first
1266 operand is bitmap of the set, the second one is the default value. */
1267 DEF_RTL_EXPR(EQ_ATTR_ALT, "eq_attr_alt", "ii", RTX_EXTRA)
1269 /* A conditional expression which is true if the specified flag is
1270 true for the insn being scheduled in reorg.
1272 genattr.c defines the following flags which can be tested by
1273 (attr_flag "foo") expressions in eligible_for_delay: forward, backward. */
1275 DEF_RTL_EXPR (ATTR_FLAG, "attr_flag", "s", RTX_EXTRA)
1277 /* General conditional. The first operand is a vector composed of pairs of
1278 expressions. The first element of each pair is evaluated, in turn.
1279 The value of the conditional is the second expression of the first pair
1280 whose first expression evaluates nonzero. If none of the expressions is
1281 true, the second operand will be used as the value of the conditional. */
1282 DEF_RTL_EXPR(COND, "cond", "Ee", RTX_EXTRA)
1284 DEF_RTL_EXPR(DEFINE_SUBST, "define_subst", "sEsE", RTX_EXTRA)
1285 DEF_RTL_EXPR(DEFINE_SUBST_ATTR, "define_subst_attr", "ssss", RTX_EXTRA)
1286 #endif /* GENERATOR_FILE */
1289 Local variables:
1290 mode:c
1291 End: