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 Free Software Foundation, Inc.
6 This file is part of GNU CC.
8 GNU CC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2, or (at your option)
13 GNU CC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GNU CC; see the file COPYING. If not, write to
20 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
23 /* Expression definitions and descriptions for all targets are in this file.
24 Some will not be used for some targets.
26 The fields in the cpp macro call "DEF_RTL_EXPR()"
27 are used to create declarations in the C source of the compiler.
31 1. The internal name of the rtx used in the C source.
32 It is a tag in the enumeration "enum rtx_code" defined in "rtl.h".
33 By convention these are in UPPER_CASE.
35 2. The name of the rtx in the external ASCII format read by
36 read_rtx(), and printed by print_rtx().
37 These names are stored in rtx_name[].
38 By convention these are the internal (field 1) names in lower_case.
40 3. The print format, and type of each rtx->fld[] (field) in this rtx.
41 These formats are stored in rtx_format[].
42 The meaning of the formats is documented in front of this array in rtl.c
44 4. The class of the rtx. These are stored in rtx_class and are accessed
45 via the GET_RTX_CLASS macro. They are defined as follows:
47 "o" an rtx code that can be used to represent an object (e.g, REG, MEM)
48 "<" an rtx code for a comparison (e.g, EQ, NE, LT)
49 "1" an rtx code for a unary arithmetic expression (e.g, NEG, NOT)
50 "c" an rtx code for a commutative binary operation (e.g,, PLUS, MULT)
51 "3" an rtx code for a non-bitfield three input operation (IF_THEN_ELSE)
52 "2" an rtx code for a non-commutative binary operation (e.g., MINUS, DIV)
53 "b" an rtx code for a bit-field operation (ZERO_EXTRACT, SIGN_EXTRACT)
54 "i" an rtx code for a machine insn (INSN, JUMP_INSN, CALL_INSN)
55 "m" an rtx code for something that matches in insns (e.g, MATCH_DUP)
60 /* ---------------------------------------------------------------------
61 Expressions (and "meta" expressions) used for structuring the
62 rtl representation of a program.
63 --------------------------------------------------------------------- */
65 /* an expression code name unknown to the reader */
66 DEF_RTL_EXPR(UNKNOWN, "UnKnown", "*", 'x')
68 /* (NIL) is used by rtl reader and printer to represent a null pointer. */
70 DEF_RTL_EXPR(NIL, "nil", "*", 'x')
72 /* ---------------------------------------------------------------------
73 Expressions used in constructing lists.
74 --------------------------------------------------------------------- */
76 /* a linked list of expressions */
77 DEF_RTL_EXPR(EXPR_LIST, "expr_list", "ee", 'x')
79 /* a linked list of instructions.
80 The insns are represented in print by their uids. */
81 DEF_RTL_EXPR(INSN_LIST, "insn_list", "ue", 'x')
83 /* ----------------------------------------------------------------------
84 Expression types for machine descriptions.
85 These do not appear in actual rtl code in the compiler.
86 ---------------------------------------------------------------------- */
88 /* Appears only in machine descriptions.
89 Means use the function named by the second arg (the string)
90 as a predicate; if matched, store the structure that was matched
91 in the operand table at index specified by the first arg (the integer).
92 If the second arg is the null string, the structure is just stored.
94 A third string argument indicates to the register allocator restrictions
95 on where the operand can be allocated.
97 If the target needs no restriction on any instruction this field should
100 The string is prepended by:
101 '=' to indicate the operand is only written to.
102 '+' to indicate the operand is both read and written to.
104 Each character in the string represents an allocatable class for an operand.
105 'g' indicates the operand can be any valid class.
106 'i' indicates the operand can be immediate (in the instruction) data.
107 'r' indicates the operand can be in a register.
108 'm' indicates the operand can be in memory.
109 'o' a subset of the 'm' class. Those memory addressing modes that
110 can be offset at compile time (have a constant added to them).
112 Other characters indicate target dependent operand classes and
113 are described in each target's machine description.
115 For instructions with more than one operand, sets of classes can be
116 separated by a comma to indicate the appropriate multi-operand constraints.
117 There must be a 1 to 1 correspondence between these sets of classes in
118 all operands for an instruction.
120 DEF_RTL_EXPR(MATCH_OPERAND, "match_operand", "iss", 'm')
122 /* Appears only in machine descriptions.
123 Means match a SCRATCH or a register. When used to generate rtl, a
124 SCRATCH is generated. As for MATCH_OPERAND, the mode specifies
125 the desired mode and the first argument is the operand number.
126 The second argument is the constraint. */
127 DEF_RTL_EXPR(MATCH_SCRATCH, "match_scratch", "is", 'm')
129 /* Appears only in machine descriptions.
130 Means match only something equal to what is stored in the operand table
131 at the index specified by the argument. */
132 DEF_RTL_EXPR(MATCH_DUP, "match_dup", "i", 'm')
134 /* Appears only in machine descriptions.
135 Means apply a predicate, AND match recursively the operands of the rtx.
136 Operand 0 is the operand-number, as in match_operand.
137 Operand 1 is a predicate to apply (as a string, a function name).
138 Operand 2 is a vector of expressions, each of which must match
139 one subexpression of the rtx this construct is matching. */
140 DEF_RTL_EXPR(MATCH_OPERATOR, "match_operator", "isE", 'm')
142 /* Appears only in machine descriptions.
143 Means to match a PARALLEL of arbitrary length. The predicate is applied
144 to the PARALLEL and the initial expressions in the PARALLEL are matched.
145 Operand 0 is the operand-number, as in match_operand.
146 Operand 1 is a predicate to apply to the PARALLEL.
147 Operand 2 is a vector of expressions, each of which must match the
148 corresponding element in the PARALLEL. */
149 DEF_RTL_EXPR(MATCH_PARALLEL, "match_parallel", "isE", 'm')
151 /* Appears only in machine descriptions.
152 Means match only something equal to what is stored in the operand table
153 at the index specified by the argument. For MATCH_OPERATOR. */
154 DEF_RTL_EXPR(MATCH_OP_DUP, "match_op_dup", "iE", 'm')
156 /* Appears only in machine descriptions.
157 Means match only something equal to what is stored in the operand table
158 at the index specified by the argument. For MATCH_PARALLEL. */
159 DEF_RTL_EXPR(MATCH_PAR_DUP, "match_par_dup", "iE", 'm')
161 /* Appears only in machine descriptions.
162 Defines the pattern for one kind of instruction.
164 0: names this instruction.
165 If the name is the null string, the instruction is in the
166 machine description just to be recognized, and will never be emitted by
167 the tree to rtl expander.
169 2: is a string which is a C expression
170 giving an additional condition for recognizing this pattern.
171 A null string means no extra condition.
172 3: is the action to execute if this pattern is matched.
173 If this assembler code template starts with a * then it is a fragment of
174 C code to run to decide on a template to use. Otherwise, it is the
176 4: optionally, a vector of attributes for this insn.
178 DEF_RTL_EXPR(DEFINE_INSN, "define_insn", "sEssV", 'x')
180 /* Definition of a peephole optimization.
181 1st operand: vector of insn patterns to match
182 2nd operand: C expression that must be true
183 3rd operand: template or C code to produce assembler output.
184 4: optionally, a vector of attributes for this insn.
186 DEF_RTL_EXPR(DEFINE_PEEPHOLE, "define_peephole", "EssV", 'x')
188 /* Definition of a split operation.
189 1st operand: insn pattern to match
190 2nd operand: C expression that must be true
191 3rd operand: vector of insn patterns to place into a SEQUENCE
192 4th operand: optionally, some C code to execute before generating the
193 insns. This might, for example, create some RTX's and store them in
194 elements of `recog_operand' for use by the vector of insn-patterns.
195 (`operands' is an alias here for `recog_operand'). */
196 DEF_RTL_EXPR(DEFINE_SPLIT, "define_split", "EsES", 'x')
198 /* Definition of a combiner pattern.
199 Operands not defined yet. */
200 DEF_RTL_EXPR(DEFINE_COMBINE, "define_combine", "Ess", 'x')
202 /* Define how to generate multiple insns for a standard insn name.
203 1st operand: the insn name.
204 2nd operand: vector of insn-patterns.
205 Use match_operand to substitute an element of `recog_operand'.
206 3rd operand: C expression that must be true for this to be available.
207 This may not test any operands.
208 4th operand: Extra C code to execute before generating the insns.
209 This might, for example, create some RTX's and store them in
210 elements of `recog_operand' for use by the vector of insn-patterns.
211 (`operands' is an alias here for `recog_operand'). */
212 DEF_RTL_EXPR(DEFINE_EXPAND, "define_expand", "sEss", 'x')
214 /* Define a requirement for delay slots.
215 1st operand: Condition involving insn attributes that, if true,
216 indicates that the insn requires the number of delay slots
218 2nd operand: Vector whose length is the three times the number of delay
220 Each entry gives three conditions, each involving attributes.
221 The first must be true for an insn to occupy that delay slot
222 location. The second is true for all insns that can be
223 annulled if the branch is true and the third is true for all
224 insns that can be annulled if the branch is false.
226 Multiple DEFINE_DELAYs may be present. They indicate differing
227 requirements for delay slots. */
228 DEF_RTL_EXPR(DEFINE_DELAY, "define_delay", "eE", 'x')
230 /* Define a set of insns that requires a function unit. This means that
231 these insns produce their result after a delay and that there may be
232 restrictions on the number of insns of this type that can be scheduled
235 More than one DEFINE_FUNCTION_UNIT can be specified for a function unit.
236 Each gives a set of operations and associated delays. The first three
237 operands must be the same for each operation for the same function unit.
239 All delays are specified in cycles.
241 1st operand: Name of function unit (mostly for documentation)
242 2nd operand: Number of identical function units in CPU
243 3rd operand: Total number of simultaneous insns that can execute on this
244 function unit; 0 if unlimited.
245 4th operand: Condition involving insn attribute, that, if true, specifies
246 those insns that this expression applies to.
247 5th operand: Constant delay after which insn result will be
249 6th operand: Delay until next insn can be scheduled on the function unit
250 executing this operation. The meaning depends on whether or
251 not the next operand is supplied.
252 7th operand: If this operand is not specified, the 6th operand gives the
253 number of cycles after the instruction matching the 4th
254 operand begins using the function unit until a subsequent
255 insn can begin. A value of zero should be used for a
256 unit with no issue constraints. If only one operation can
257 be executed a time and the unit is busy for the entire time,
258 the 3rd operand should be specified as 1, the 6th operand
259 sould be specified as 0, and the 7th operand should not
262 If this operand is specified, it is a list of attribute
263 expressions. If an insn for which any of these expressions
264 is true is currently executing on the function unit, the
265 issue delay will be given by the 6th operand. Otherwise,
266 the insn can be immediately scheduled (subject to the limit
267 on the number of simultaneous operations executing on the
269 DEF_RTL_EXPR(DEFINE_FUNCTION_UNIT, "define_function_unit", "siieiiV", 'x')
271 /* Define attribute computation for `asm' instructions. */
272 DEF_RTL_EXPR(DEFINE_ASM_ATTRIBUTES, "define_asm_attributes", "V", 'x' )
274 /* SEQUENCE appears in the result of a `gen_...' function
275 for a DEFINE_EXPAND that wants to make several insns.
276 Its elements are the bodies of the insns that should be made.
277 `emit_insn' takes the SEQUENCE apart and makes separate insns. */
278 DEF_RTL_EXPR(SEQUENCE, "sequence", "E", 'x')
280 /* Refers to the address of its argument.
281 This appears only in machine descriptions, indicating that
282 any expression that would be acceptable as the operand of MEM
283 should be matched. */
284 DEF_RTL_EXPR(ADDRESS, "address", "e", 'm')
286 /* ----------------------------------------------------------------------
287 Expressions used for insn attributes. These also do not appear in
288 actual rtl code in the compiler.
289 ---------------------------------------------------------------------- */
291 /* Definition of an insn attribute.
292 1st operand: name of the attribute
293 2nd operand: comma-separated list of possible attribute values
294 3rd operand: expression for the default value of the attribute. */
295 DEF_RTL_EXPR(DEFINE_ATTR, "define_attr", "sse", 'x')
297 /* Marker for the name of an attribute. */
298 DEF_RTL_EXPR(ATTR, "attr", "s", 'x')
300 /* For use in the last (optional) operand of DEFINE_INSN or DEFINE_PEEPHOLE and
301 in DEFINE_ASM_INSN to specify an attribute to assign to insns matching that
304 (set_attr "name" "value") is equivalent to
305 (set (attr "name") (const_string "value")) */
306 DEF_RTL_EXPR(SET_ATTR, "set_attr", "ss", 'x')
308 /* In the last operand of DEFINE_INSN and DEFINE_PEEPHOLE, this can be used to
309 specify that attribute values are to be assigned according to the
312 The following three expressions are equivalent:
314 (set (attr "att") (cond [(eq_attrq "alternative" "1") (const_string "a1")
315 (eq_attrq "alternative" "2") (const_string "a2")]
316 (const_string "a3")))
317 (set_attr_alternative "att" [(const_string "a1") (const_string "a2")
318 (const_string "a3")])
319 (set_attr "att" "a1,a2,a3")
321 DEF_RTL_EXPR(SET_ATTR_ALTERNATIVE, "set_attr_alternative", "sE", 'x')
323 /* A conditional expression true if the value of the specified attribute of
324 the current insn equals the specified value. The first operand is the
325 attribute name and the second is the comparison value. */
326 DEF_RTL_EXPR(EQ_ATTR, "eq_attr", "ss", 'x')
328 /* A conditional expression which is true if the specified flag is
329 true for the insn being scheduled in reorg.
331 genattr.c defines the following flags which can be tested by
332 (attr_flag "foo") expressions in eligible_for_delay.
334 forward, backward, very_likely, likely, very_unlikely, and unlikely. */
336 DEF_RTL_EXPR (ATTR_FLAG, "attr_flag", "s", 'x')
338 /* ----------------------------------------------------------------------
339 Expression types used for things in the instruction chain.
341 All formats must start with "iuu" to handle the chain.
342 Each insn expression holds an rtl instruction and its semantics
343 during back-end processing.
344 See macros's in "rtl.h" for the meaning of each rtx->fld[].
346 ---------------------------------------------------------------------- */
348 /* An instruction that cannot jump. */
349 DEF_RTL_EXPR(INSN, "insn", "iuueiee", 'i')
351 /* An instruction that can possibly jump.
352 Fields ( rtx->fld[] ) have exact same meaning as INSN's. */
353 DEF_RTL_EXPR(JUMP_INSN, "jump_insn", "iuueiee0", 'i')
355 /* An instruction that can possibly call a subroutine
356 but which will not change which instruction comes next
357 in the current function.
358 Fields ( rtx->fld[] ) have exact same meaning as INSN's. */
359 DEF_RTL_EXPR(CALL_INSN, "call_insn", "iuueiee", 'i')
361 /* A marker that indicates that control will not flow through. */
362 DEF_RTL_EXPR(BARRIER, "barrier", "iuu", 'x')
364 /* Holds a label that is followed by instructions.
366 3: is a number that is unique in the entire compilation.
367 4: is the user-given name of the label, if any.
368 5: is used in jump.c for the use-count of the label.
369 and in flow.c to point to the chain of label_ref's to this label. */
370 DEF_RTL_EXPR(CODE_LABEL, "code_label", "iuuis0", 'x')
372 /* Say where in the code a source line starts, for symbol table's sake.
373 Contains a filename and a line number. Line numbers <= 0 are special:
374 0 is used in a dummy placed at the front of every function
375 just so there will never be a need to delete the first insn;
376 -1 indicates a dummy; insns to be deleted by flow analysis and combining
377 are really changed to NOTEs with a number of -1.
378 -2 means beginning of a name binding contour; output N_LBRAC.
379 -3 means end of a contour; output N_RBRAC. */
380 DEF_RTL_EXPR(NOTE, "note", "iuusn", 'x')
382 /* INLINE_HEADER is use by inline function machinery. The information
383 it contains helps to build the mapping function between the rtx's of
384 the function to be inlined and the current function being expanded. */
386 DEF_RTL_EXPR(INLINE_HEADER, "inline_header", "iuuuiiiiiieiiEe", 'x')
388 /* ----------------------------------------------------------------------
389 Top level constituents of INSN, JUMP_INSN and CALL_INSN.
390 ---------------------------------------------------------------------- */
392 /* Several operations to be done in parallel. */
393 DEF_RTL_EXPR(PARALLEL, "parallel", "E", 'x')
395 /* A string that is passed through to the assembler as input.
396 One can obviously pass comments through by using the
397 assembler comment syntax.
398 These occur in an insn all by themselves as the PATTERN.
399 They also appear inside an ASM_OPERANDS
400 as a convenient way to hold a string. */
401 DEF_RTL_EXPR(ASM_INPUT, "asm_input", "s", 'x')
403 /* An assembler instruction with operands.
404 1st operand is the instruction template.
405 2nd operand is the constraint for the output.
406 3rd operand is the number of the output this expression refers to.
407 When an insn stores more than one value, a separate ASM_OPERANDS
408 is made for each output; this integer distinguishes them.
409 4th is a vector of values of input operands.
410 5th is a vector of modes and constraints for the input operands.
411 Each element is an ASM_INPUT containing a constraint string
412 and whose mode indicates the mode of the input operand.
413 6th is the name of the containing source file.
414 7th is the source line number. */
415 DEF_RTL_EXPR(ASM_OPERANDS, "asm_operands", "ssiEEsi", 'x')
417 /* A machine-specific operation.
418 1st operand is a vector of operands being used by the operation so that
419 any needed reloads can be done.
420 2nd operand is a unique value saying which of a number of machine-specific
421 operations is to be performed.
422 (Note that the vector must be the first operand because of the way that
423 genrecog.c record positions within an insn.)
424 This can occur all by itself in a PATTERN, as a component of a PARALLEL,
425 or inside an expression. */
426 DEF_RTL_EXPR(UNSPEC, "unspec", "Ei", 'x')
428 /* Similar, but a volatile operation and one which may trap. */
429 DEF_RTL_EXPR(UNSPEC_VOLATILE, "unspec_volatile", "Ei", 'x')
431 /* Vector of addresses, stored as full words. */
432 /* Each element is a LABEL_REF to a CODE_LABEL whose address we want. */
433 DEF_RTL_EXPR(ADDR_VEC, "addr_vec", "E", 'x')
435 /* Vector of address differences X0 - BASE, X1 - BASE, ...
436 First operand is BASE; the vector contains the X's.
437 The machine mode of this rtx says how much space to leave
438 for each difference. */
439 DEF_RTL_EXPR(ADDR_DIFF_VEC, "addr_diff_vec", "eE", 'x')
441 /* ----------------------------------------------------------------------
442 At the top level of an instruction (perhaps under PARALLEL).
443 ---------------------------------------------------------------------- */
446 Operand 1 is the location (REG, MEM, PC, CC0 or whatever) assigned to.
447 Operand 2 is the value stored there.
448 ALL assignment must use SET.
449 Instructions that do multiple assignments must use multiple SET,
451 DEF_RTL_EXPR(SET, "set", "ee", 'x')
453 /* Indicate something is used in a way that we don't want to explain.
454 For example, subroutine calls will use the register
455 in which the static chain is passed. */
456 DEF_RTL_EXPR(USE, "use", "e", 'x')
458 /* Indicate something is clobbered in a way that we don't want to explain.
459 For example, subroutine calls will clobber some physical registers
460 (the ones that are by convention not saved). */
461 DEF_RTL_EXPR(CLOBBER, "clobber", "e", 'x')
463 /* Call a subroutine.
464 Operand 1 is the address to call.
465 Operand 2 is the number of arguments. */
467 DEF_RTL_EXPR(CALL, "call", "ee", 'x')
469 /* Return from a subroutine. */
471 DEF_RTL_EXPR(RETURN, "return", "", 'x')
474 Operand 1 is the condition.
475 Operand 2 is the trap code.
476 For an unconditional trap, make the condition (const_int 1). */
477 DEF_RTL_EXPR(TRAP_IF, "trap_if", "ei", 'x')
479 /* ----------------------------------------------------------------------
480 Primitive values for use in expressions.
481 ---------------------------------------------------------------------- */
483 /* numeric integer constant */
484 DEF_RTL_EXPR(CONST_INT, "const_int", "w", 'o')
486 /* numeric double constant.
487 Operand 0 is the MEM that stores this constant in memory,
488 or various other things (see comments at immed_double_const in varasm.c).
489 Operand 1 is a chain of all CONST_DOUBLEs in use in the current function.
490 Remaining operands hold the actual value.
491 The number of operands may be more than 2 if cross-compiling;
493 DEF_RTL_EXPR(CONST_DOUBLE, "const_double", "e0ww", 'o')
495 /* String constant. Used only for attributes right now. */
496 DEF_RTL_EXPR(CONST_STRING, "const_string", "s", 'o')
498 /* This is used to encapsulate an expression whose value is constant
499 (such as the sum of a SYMBOL_REF and a CONST_INT) so that it will be
500 recognized as a constant operand rather than by arithmetic instructions. */
502 DEF_RTL_EXPR(CONST, "const", "e", 'o')
504 /* program counter. Ordinary jumps are represented
505 by a SET whose first operand is (PC). */
506 DEF_RTL_EXPR(PC, "pc", "", 'o')
508 /* A register. The "operand" is the register number, accessed
509 with the REGNO macro. If this number is less than FIRST_PSEUDO_REGISTER
510 than a hardware register is being referred to. */
511 DEF_RTL_EXPR(REG, "reg", "i", 'o')
513 /* A scratch register. This represents a register used only within a
514 single insn. It will be turned into a REG during register allocation
515 or reload unless the constraint indicates that the register won't be
516 needed, in which case it can remain a SCRATCH. This code is
517 marked as having one operand so it can be turned into a REG. */
518 DEF_RTL_EXPR(SCRATCH, "scratch", "0", 'o')
520 /* One word of a multi-word value.
521 The first operand is the complete value; the second says which word.
522 The WORDS_BIG_ENDIAN flag controls whether word number 0
523 (as numbered in a SUBREG) is the most or least significant word.
525 This is also used to refer to a value in a different machine mode.
526 For example, it can be used to refer to a SImode value as if it were
527 Qimode, or vice versa. Then the word number is always 0. */
528 DEF_RTL_EXPR(SUBREG, "subreg", "ei", 'x')
530 /* This one-argument rtx is used for move instructions
531 that are guaranteed to alter only the low part of a destination.
532 Thus, (SET (SUBREG:HI (REG...)) (MEM:HI ...))
533 has an unspecified effect on the high part of REG,
534 but (SET (STRICT_LOW_PART (SUBREG:HI (REG...))) (MEM:HI ...))
535 is guaranteed to alter only the bits of REG that are in HImode.
537 The actual instruction used is probably the same in both cases,
538 but the register constraints may be tighter when STRICT_LOW_PART
541 DEF_RTL_EXPR(STRICT_LOW_PART, "strict_low_part", "e", 'x')
543 /* (CONCAT a b) represents the virtual concatenation of a and b
544 to make a value that has as many bits as a and b put together.
545 This is used for complex values. Normally it appears only
546 in DECL_RTLs and during RTL generation, but not in the insn chain. */
547 DEF_RTL_EXPR(CONCAT, "concat", "ee", 'o')
549 /* A memory location; operand is the address.
550 Can be nested inside a VOLATILE. */
551 DEF_RTL_EXPR(MEM, "mem", "e", 'o')
553 /* Reference to an assembler label in the code for this function.
554 The operand is a CODE_LABEL found in the insn chain.
555 The unprinted fields 1 and 2 are used in flow.c for the
556 LABEL_NEXTREF and CONTAINING_INSN. */
557 DEF_RTL_EXPR(LABEL_REF, "label_ref", "u00", 'o')
559 /* Reference to a named label: the string that is the first operand,
560 with `_' added implicitly in front.
561 Exception: if the first character explicitly given is `*',
562 to give it to the assembler, remove the `*' and do not add `_'. */
563 DEF_RTL_EXPR(SYMBOL_REF, "symbol_ref", "s", 'o')
565 /* The condition code register is represented, in our imagination,
566 as a register holding a value that can be compared to zero.
567 In fact, the machine has already compared them and recorded the
568 results; but instructions that look at the condition code
569 pretend to be looking at the entire value and comparing it. */
570 DEF_RTL_EXPR(CC0, "cc0", "", 'o')
572 /* =====================================================================
573 A QUEUED expression really points to a member of the queue of instructions
574 to be output later for postincrement/postdecrement.
575 QUEUED expressions never become part of instructions.
576 When a QUEUED expression would be put into an instruction,
577 instead either the incremented variable or a copy of its previous
581 0. the variable to be incremented (a REG rtx).
582 1. the incrementing instruction, or 0 if it hasn't been output yet.
583 2. A REG rtx for a copy of the old value of the variable, or 0 if none yet.
584 3. the body to use for the incrementing instruction
585 4. the next QUEUED expression in the queue.
586 ====================================================================== */
588 DEF_RTL_EXPR(QUEUED, "queued", "eeeee", 'x')
590 /* ----------------------------------------------------------------------
591 Expressions for operators in an rtl pattern
592 ---------------------------------------------------------------------- */
594 /* if_then_else. This is used in representing ordinary
595 conditional jump instructions.
600 DEF_RTL_EXPR(IF_THEN_ELSE, "if_then_else", "eee", '3')
602 /* General conditional. The first operand is a vector composed of pairs of
603 expressions. The first element of each pair is evaluated, in turn.
604 The value of the conditional is the second expression of the first pair
605 whose first expression evaluates non-zero. If none of the expressions is
606 true, the second operand will be used as the value of the conditional.
608 This should be replaced with use of IF_THEN_ELSE. */
609 DEF_RTL_EXPR(COND, "cond", "Ee", 'x')
611 /* Comparison, produces a condition code result. */
612 DEF_RTL_EXPR(COMPARE, "compare", "ee", '2')
615 DEF_RTL_EXPR(PLUS, "plus", "ee", 'c')
617 /* Operand 0 minus operand 1. */
618 DEF_RTL_EXPR(MINUS, "minus", "ee", '2')
620 /* Minus operand 0. */
621 DEF_RTL_EXPR(NEG, "neg", "e", '1')
623 DEF_RTL_EXPR(MULT, "mult", "ee", 'c')
625 /* Operand 0 divided by operand 1. */
626 DEF_RTL_EXPR(DIV, "div", "ee", '2')
627 /* Remainder of operand 0 divided by operand 1. */
628 DEF_RTL_EXPR(MOD, "mod", "ee", '2')
630 /* Unsigned divide and remainder. */
631 DEF_RTL_EXPR(UDIV, "udiv", "ee", '2')
632 DEF_RTL_EXPR(UMOD, "umod", "ee", '2')
634 /* Bitwise operations. */
635 DEF_RTL_EXPR(AND, "and", "ee", 'c')
637 DEF_RTL_EXPR(IOR, "ior", "ee", 'c')
639 DEF_RTL_EXPR(XOR, "xor", "ee", 'c')
641 DEF_RTL_EXPR(NOT, "not", "e", '1')
644 0: value to be shifted.
646 ASHIFT and LSHIFT are distinguished because on some machines
647 these allow a negative operand and shift right in that case. */
648 DEF_RTL_EXPR(LSHIFT, "lshift", "ee", '2')
649 DEF_RTL_EXPR(ASHIFT, "ashift", "ee", '2')
650 DEF_RTL_EXPR(ROTATE, "rotate", "ee", '2')
652 /* Right shift operations, for machines where these are not the same
653 as left shifting with a negative argument. */
655 DEF_RTL_EXPR(ASHIFTRT, "ashiftrt", "ee", '2')
656 DEF_RTL_EXPR(LSHIFTRT, "lshiftrt", "ee", '2')
657 DEF_RTL_EXPR(ROTATERT, "rotatert", "ee", '2')
659 /* Minimum and maximum values of two operands. We need both signed and
660 unsigned forms. (We cannot use MIN for SMIN because it conflicts
661 with a macro of the same name.) */
663 DEF_RTL_EXPR(SMIN, "smin", "ee", 'c')
664 DEF_RTL_EXPR(SMAX, "smax", "ee", 'c')
665 DEF_RTL_EXPR(UMIN, "umin", "ee", 'c')
666 DEF_RTL_EXPR(UMAX, "umax", "ee", 'c')
668 /* These unary operations are used to represent incrementation
669 and decrementation as they occur in memory addresses.
670 The amount of increment or decrement are not represented
671 because they can be understood from the machine-mode of the
672 containing MEM. These operations exist in only two cases:
673 1. pushes onto the stack.
674 2. created automatically by the life_analysis pass in flow.c. */
675 DEF_RTL_EXPR(PRE_DEC, "pre_dec", "e", 'x')
676 DEF_RTL_EXPR(PRE_INC, "pre_inc", "e", 'x')
677 DEF_RTL_EXPR(POST_DEC, "post_dec", "e", 'x')
678 DEF_RTL_EXPR(POST_INC, "post_inc", "e", 'x')
680 /* Comparison operations. The ordered comparisons exist in two
681 flavors, signed and unsigned. */
682 DEF_RTL_EXPR(NE, "ne", "ee", '<')
683 DEF_RTL_EXPR(EQ, "eq", "ee", '<')
684 DEF_RTL_EXPR(GE, "ge", "ee", '<')
685 DEF_RTL_EXPR(GT, "gt", "ee", '<')
686 DEF_RTL_EXPR(LE, "le", "ee", '<')
687 DEF_RTL_EXPR(LT, "lt", "ee", '<')
688 DEF_RTL_EXPR(GEU, "geu", "ee", '<')
689 DEF_RTL_EXPR(GTU, "gtu", "ee", '<')
690 DEF_RTL_EXPR(LEU, "leu", "ee", '<')
691 DEF_RTL_EXPR(LTU, "ltu", "ee", '<')
693 /* Represents the result of sign-extending the sole operand.
694 The machine modes of the operand and of the SIGN_EXTEND expression
695 determine how much sign-extension is going on. */
696 DEF_RTL_EXPR(SIGN_EXTEND, "sign_extend", "e", '1')
698 /* Similar for zero-extension (such as unsigned short to int). */
699 DEF_RTL_EXPR(ZERO_EXTEND, "zero_extend", "e", '1')
701 /* Similar but here the operand has a wider mode. */
702 DEF_RTL_EXPR(TRUNCATE, "truncate", "e", '1')
704 /* Similar for extending floating-point values (such as SFmode to DFmode). */
705 DEF_RTL_EXPR(FLOAT_EXTEND, "float_extend", "e", '1')
706 DEF_RTL_EXPR(FLOAT_TRUNCATE, "float_truncate", "e", '1')
708 /* Conversion of fixed point operand to floating point value. */
709 DEF_RTL_EXPR(FLOAT, "float", "e", '1')
711 /* With fixed-point machine mode:
712 Conversion of floating point operand to fixed point value.
713 Value is defined only when the operand's value is an integer.
714 With floating-point machine mode (and operand with same mode):
715 Operand is rounded toward zero to produce an integer value
716 represented in floating point. */
717 DEF_RTL_EXPR(FIX, "fix", "e", '1')
719 /* Conversion of unsigned fixed point operand to floating point value. */
720 DEF_RTL_EXPR(UNSIGNED_FLOAT, "unsigned_float", "e", '1')
722 /* With fixed-point machine mode:
723 Conversion of floating point operand to *unsigned* fixed point value.
724 Value is defined only when the operand's value is an integer. */
725 DEF_RTL_EXPR(UNSIGNED_FIX, "unsigned_fix", "e", '1')
728 DEF_RTL_EXPR(ABS, "abs", "e", '1')
731 DEF_RTL_EXPR(SQRT, "sqrt", "e", '1')
733 /* Find first bit that is set.
734 Value is 1 + number of trailing zeros in the arg.,
736 DEF_RTL_EXPR(FFS, "ffs", "e", '1')
738 /* Reference to a signed bit-field of specified size and position.
739 Operand 0 is the memory unit (usually SImode or QImode) which
740 contains the field's first bit. Operand 1 is the width, in bits.
741 Operand 2 is the number of bits in the memory unit before the
742 first bit of this field.
743 If BITS_BIG_ENDIAN is defined, the first bit is the msb and
744 operand 2 counts from the msb of the memory unit.
745 Otherwise, the first bit is the lsb and operand 2 counts from
746 the lsb of the memory unit. */
747 DEF_RTL_EXPR(SIGN_EXTRACT, "sign_extract", "eee", 'b')
749 /* Similar for unsigned bit-field. */
750 DEF_RTL_EXPR(ZERO_EXTRACT, "zero_extract", "eee", 'b')
752 /* For RISC machines. These save memory when splitting insns. */
754 /* HIGH are the high-order bits of a constant expression. */
755 DEF_RTL_EXPR(HIGH, "high", "e", 'o')
757 /* LO_SUM is the sum of a register and the low-order bits
758 of a constant expression. */
759 DEF_RTL_EXPR(LO_SUM, "lo_sum", "ee", 'o')
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