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, 88, 92, 94, 95, 97, 98, 1999, 2000
5 Free Software Foundation, Inc.
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify it under
10 the terms of the GNU General Public License as published by the Free
11 Software Foundation; either version 2, or (at your option) any later
14 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
15 WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING. If not, write to the Free
21 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
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.
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->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 "o" an rtx code that can be used to represent an object (e.g, REG, MEM)
50 "<" an rtx code for a comparison (e.g, EQ, NE, LT)
51 "1" an rtx code for a unary arithmetic expression (e.g, NEG, NOT)
52 "c" an rtx code for a commutative binary operation (e.g,, PLUS, MULT)
53 "3" an rtx code for a non-bitfield three input operation (IF_THEN_ELSE)
54 "2" an rtx code for a non-commutative binary operation (e.g., MINUS, DIV)
55 "b" an rtx code for a bit-field operation (ZERO_EXTRACT, SIGN_EXTRACT)
56 "i" an rtx code for a machine insn (INSN, JUMP_INSN, CALL_INSN)
57 "m" an rtx code for something that matches in insns (e.g, MATCH_DUP)
58 "g" an rtx code for grouping insns together (e.g, GROUP_PARALLEL)
59 "a" an rtx code for autoincrement addressing modes (e.g. POST_DEC)
64 /* ---------------------------------------------------------------------
65 Expressions (and "meta" expressions) used for structuring the
66 rtl representation of a program.
67 --------------------------------------------------------------------- */
69 /* an expression code name unknown to the reader */
70 DEF_RTL_EXPR(UNKNOWN, "UnKnown", "*", 'x')
72 /* (NIL) is used by rtl reader and printer to represent a null pointer. */
74 DEF_RTL_EXPR(NIL, "nil", "*", 'x')
79 DEF_RTL_EXPR(INCLUDE, "include", "s", 'x')
81 /* ---------------------------------------------------------------------
82 Expressions used in constructing lists.
83 --------------------------------------------------------------------- */
85 /* a linked list of expressions */
86 DEF_RTL_EXPR(EXPR_LIST, "expr_list", "ee", 'x')
88 /* a linked list of instructions.
89 The insns are represented in print by their uids. */
90 DEF_RTL_EXPR(INSN_LIST, "insn_list", "ue", 'x')
92 /* ----------------------------------------------------------------------
93 Expression types for machine descriptions.
94 These do not appear in actual rtl code in the compiler.
95 ---------------------------------------------------------------------- */
97 /* Appears only in machine descriptions.
98 Means use the function named by the second arg (the string)
99 as a predicate; if matched, store the structure that was matched
100 in the operand table at index specified by the first arg (the integer).
101 If the second arg is the null string, the structure is just stored.
103 A third string argument indicates to the register allocator restrictions
104 on where the operand can be allocated.
106 If the target needs no restriction on any instruction this field should
109 The string is prepended by:
110 '=' to indicate the operand is only written to.
111 '+' to indicate the operand is both read and written to.
113 Each character in the string represents an allocable class for an operand.
114 'g' indicates the operand can be any valid class.
115 'i' indicates the operand can be immediate (in the instruction) data.
116 'r' indicates the operand can be in a register.
117 'm' indicates the operand can be in memory.
118 'o' a subset of the 'm' class. Those memory addressing modes that
119 can be offset at compile time (have a constant added to them).
121 Other characters indicate target dependent operand classes and
122 are described in each target's machine description.
124 For instructions with more than one operand, sets of classes can be
125 separated by a comma to indicate the appropriate multi-operand constraints.
126 There must be a 1 to 1 correspondence between these sets of classes in
127 all operands for an instruction.
129 DEF_RTL_EXPR(MATCH_OPERAND, "match_operand", "iss", 'm')
131 /* Appears only in machine descriptions.
132 Means match a SCRATCH or a register. When used to generate rtl, a
133 SCRATCH is generated. As for MATCH_OPERAND, the mode specifies
134 the desired mode and the first argument is the operand number.
135 The second argument is the constraint. */
136 DEF_RTL_EXPR(MATCH_SCRATCH, "match_scratch", "is", 'm')
138 /* Appears only in machine descriptions.
139 Means match only something equal to what is stored in the operand table
140 at the index specified by the argument. */
141 DEF_RTL_EXPR(MATCH_DUP, "match_dup", "i", 'm')
143 /* Appears only in machine descriptions.
144 Means apply a predicate, AND match recursively the operands of the rtx.
145 Operand 0 is the operand-number, as in match_operand.
146 Operand 1 is a predicate to apply (as a string, a function name).
147 Operand 2 is a vector of expressions, each of which must match
148 one subexpression of the rtx this construct is matching. */
149 DEF_RTL_EXPR(MATCH_OPERATOR, "match_operator", "isE", 'm')
151 /* Appears only in machine descriptions.
152 Means to match a PARALLEL of arbitrary length. The predicate is applied
153 to the PARALLEL and the initial expressions in the PARALLEL are matched.
154 Operand 0 is the operand-number, as in match_operand.
155 Operand 1 is a predicate to apply to the PARALLEL.
156 Operand 2 is a vector of expressions, each of which must match the
157 corresponding element in the PARALLEL. */
158 DEF_RTL_EXPR(MATCH_PARALLEL, "match_parallel", "isE", 'm')
160 /* Appears only in machine descriptions.
161 Means match only something equal to what is stored in the operand table
162 at the index specified by the argument. For MATCH_OPERATOR. */
163 DEF_RTL_EXPR(MATCH_OP_DUP, "match_op_dup", "iE", 'm')
165 /* Appears only in machine descriptions.
166 Means match only something equal to what is stored in the operand table
167 at the index specified by the argument. For MATCH_PARALLEL. */
168 DEF_RTL_EXPR(MATCH_PAR_DUP, "match_par_dup", "iE", 'm')
170 /* Appears only in machine descriptions.
171 Operand 0 is the operand number, as in match_operand.
172 Operand 1 is the predicate to apply to the insn. */
173 DEF_RTL_EXPR(MATCH_INSN, "match_insn", "is", 'm')
175 /* Appears only in machine descriptions.
176 Defines the pattern for one kind of instruction.
178 0: names this instruction.
179 If the name is the null string, the instruction is in the
180 machine description just to be recognized, and will never be emitted by
181 the tree to rtl expander.
183 2: is a string which is a C expression
184 giving an additional condition for recognizing this pattern.
185 A null string means no extra condition.
186 3: is the action to execute if this pattern is matched.
187 If this assembler code template starts with a * then it is a fragment of
188 C code to run to decide on a template to use. Otherwise, it is the
190 4: optionally, a vector of attributes for this insn.
192 DEF_RTL_EXPR(DEFINE_INSN, "define_insn", "sEsTV", 'x')
194 /* Definition of a peephole optimization.
195 1st operand: vector of insn patterns to match
196 2nd operand: C expression that must be true
197 3rd operand: template or C code to produce assembler output.
198 4: optionally, a vector of attributes for this insn.
200 DEF_RTL_EXPR(DEFINE_PEEPHOLE, "define_peephole", "EsTV", 'x')
202 /* Definition of a split operation.
203 1st operand: insn pattern to match
204 2nd operand: C expression that must be true
205 3rd operand: vector of insn patterns to place into a SEQUENCE
206 4th operand: optionally, some C code to execute before generating the
207 insns. This might, for example, create some RTX's and store them in
208 elements of `recog_data.operand' for use by the vector of
210 (`operands' is an alias here for `recog_data.operand'). */
211 DEF_RTL_EXPR(DEFINE_SPLIT, "define_split", "EsES", 'x')
213 /* Definition of an insn and associated split.
214 This is the concatenation, with a few modifications, of a define_insn
215 and a define_split which share the same pattern.
217 0: names this instruction.
218 If the name is the null string, the instruction is in the
219 machine description just to be recognized, and will never be emitted by
220 the tree to rtl expander.
222 2: is a string which is a C expression
223 giving an additional condition for recognizing this pattern.
224 A null string means no extra condition.
225 3: is the action to execute if this pattern is matched.
226 If this assembler code template starts with a * then it is a fragment of
227 C code to run to decide on a template to use. Otherwise, it is the
229 4: C expression that must be true for split. This may start with "&&"
230 in which case the split condition is the logical and of the insn
231 condition and what follows the "&&" of this operand.
232 5: vector of insn patterns to place into a SEQUENCE
233 6: optionally, some C code to execute before generating the
234 insns. This might, for example, create some RTX's and store them in
235 elements of `recog_data.operand' for use by the vector of
237 (`operands' is an alias here for `recog_data.operand').
238 7: optionally, a vector of attributes for this insn. */
239 DEF_RTL_EXPR(DEFINE_INSN_AND_SPLIT, "define_insn_and_split", "sEsTsESV", 'x')
241 /* Definition of an RTL peephole operation.
242 Follows the same arguments as define_split. */
243 DEF_RTL_EXPR(DEFINE_PEEPHOLE2, "define_peephole2", "EsES", 'x')
245 /* Definition of a combiner pattern.
246 Operands not defined yet. */
247 DEF_RTL_EXPR(DEFINE_COMBINE, "define_combine", "Ess", 'x')
249 /* Define how to generate multiple insns for a standard insn name.
250 1st operand: the insn name.
251 2nd operand: vector of insn-patterns.
252 Use match_operand to substitute an element of `recog_data.operand'.
253 3rd operand: C expression that must be true for this to be available.
254 This may not test any operands.
255 4th operand: Extra C code to execute before generating the insns.
256 This might, for example, create some RTX's and store them in
257 elements of `recog_data.operand' for use by the vector of
259 (`operands' is an alias here for `recog_data.operand'). */
260 DEF_RTL_EXPR(DEFINE_EXPAND, "define_expand", "sEss", 'x')
262 /* Define a requirement for delay slots.
263 1st operand: Condition involving insn attributes that, if true,
264 indicates that the insn requires the number of delay slots
266 2nd operand: Vector whose length is the three times the number of delay
268 Each entry gives three conditions, each involving attributes.
269 The first must be true for an insn to occupy that delay slot
270 location. The second is true for all insns that can be
271 annulled if the branch is true and the third is true for all
272 insns that can be annulled if the branch is false.
274 Multiple DEFINE_DELAYs may be present. They indicate differing
275 requirements for delay slots. */
276 DEF_RTL_EXPR(DEFINE_DELAY, "define_delay", "eE", 'x')
278 /* Define a set of insns that requires a function unit. This means that
279 these insns produce their result after a delay and that there may be
280 restrictions on the number of insns of this type that can be scheduled
283 More than one DEFINE_FUNCTION_UNIT can be specified for a function unit.
284 Each gives a set of operations and associated delays. The first three
285 operands must be the same for each operation for the same function unit.
287 All delays are specified in cycles.
289 1st operand: Name of function unit (mostly for documentation)
290 2nd operand: Number of identical function units in CPU
291 3rd operand: Total number of simultaneous insns that can execute on this
292 function unit; 0 if unlimited.
293 4th operand: Condition involving insn attribute, that, if true, specifies
294 those insns that this expression applies to.
295 5th operand: Constant delay after which insn result will be
297 6th operand: Delay until next insn can be scheduled on the function unit
298 executing this operation. The meaning depends on whether or
299 not the next operand is supplied.
300 7th operand: If this operand is not specified, the 6th operand gives the
301 number of cycles after the instruction matching the 4th
302 operand begins using the function unit until a subsequent
303 insn can begin. A value of zero should be used for a
304 unit with no issue constraints. If only one operation can
305 be executed a time and the unit is busy for the entire time,
306 the 3rd operand should be specified as 1, the 6th operand
307 should be specified as 0, and the 7th operand should not
310 If this operand is specified, it is a list of attribute
311 expressions. If an insn for which any of these expressions
312 is true is currently executing on the function unit, the
313 issue delay will be given by the 6th operand. Otherwise,
314 the insn can be immediately scheduled (subject to the limit
315 on the number of simultaneous operations executing on the
317 DEF_RTL_EXPR(DEFINE_FUNCTION_UNIT, "define_function_unit", "siieiiV", 'x')
319 /* Define attribute computation for `asm' instructions. */
320 DEF_RTL_EXPR(DEFINE_ASM_ATTRIBUTES, "define_asm_attributes", "V", 'x' )
322 /* Definition of a conditional execution meta operation. Automatically
323 generates new instances of DEFINE_INSN, selected by having attribute
324 "predicable" true. The new pattern will contain a COND_EXEC and the
325 predicate at top-level.
328 0: The predicate pattern. The top-level form should match a
329 relational operator. Operands should have only one alternative.
330 1: A C expression giving an additional condition for recognizing
331 the generated pattern.
332 2: A template or C code to produce assembler output. */
333 DEF_RTL_EXPR(DEFINE_COND_EXEC, "define_cond_exec", "Ess", 'x')
335 /* SEQUENCE appears in the result of a `gen_...' function
336 for a DEFINE_EXPAND that wants to make several insns.
337 Its elements are the bodies of the insns that should be made.
338 `emit_insn' takes the SEQUENCE apart and makes separate insns. */
339 DEF_RTL_EXPR(SEQUENCE, "sequence", "E", 'x')
341 /* Refers to the address of its argument. This is only used in alias.c. */
342 DEF_RTL_EXPR(ADDRESS, "address", "e", 'm')
344 /* ----------------------------------------------------------------------
345 Expressions used for insn attributes. These also do not appear in
346 actual rtl code in the compiler.
347 ---------------------------------------------------------------------- */
349 /* Definition of an insn attribute.
350 1st operand: name of the attribute
351 2nd operand: comma-separated list of possible attribute values
352 3rd operand: expression for the default value of the attribute. */
353 DEF_RTL_EXPR(DEFINE_ATTR, "define_attr", "sse", 'x')
355 /* Marker for the name of an attribute. */
356 DEF_RTL_EXPR(ATTR, "attr", "s", 'x')
358 /* For use in the last (optional) operand of DEFINE_INSN or DEFINE_PEEPHOLE and
359 in DEFINE_ASM_INSN to specify an attribute to assign to insns matching that
362 (set_attr "name" "value") is equivalent to
363 (set (attr "name") (const_string "value")) */
364 DEF_RTL_EXPR(SET_ATTR, "set_attr", "ss", 'x')
366 /* In the last operand of DEFINE_INSN and DEFINE_PEEPHOLE, this can be used to
367 specify that attribute values are to be assigned according to the
370 The following three expressions are equivalent:
372 (set (attr "att") (cond [(eq_attrq "alternative" "1") (const_string "a1")
373 (eq_attrq "alternative" "2") (const_string "a2")]
374 (const_string "a3")))
375 (set_attr_alternative "att" [(const_string "a1") (const_string "a2")
376 (const_string "a3")])
377 (set_attr "att" "a1,a2,a3")
379 DEF_RTL_EXPR(SET_ATTR_ALTERNATIVE, "set_attr_alternative", "sE", 'x')
381 /* A conditional expression true if the value of the specified attribute of
382 the current insn equals the specified value. The first operand is the
383 attribute name and the second is the comparison value. */
384 DEF_RTL_EXPR(EQ_ATTR, "eq_attr", "ss", 'x')
386 /* A conditional expression which is true if the specified flag is
387 true for the insn being scheduled in reorg.
389 genattr.c defines the following flags which can be tested by
390 (attr_flag "foo") expressions in eligible_for_delay.
392 forward, backward, very_likely, likely, very_unlikely, and unlikely. */
394 DEF_RTL_EXPR (ATTR_FLAG, "attr_flag", "s", 'x')
396 /* ----------------------------------------------------------------------
397 Expression types used for things in the instruction chain.
399 All formats must start with "iuu" to handle the chain.
400 Each insn expression holds an rtl instruction and its semantics
401 during back-end processing.
402 See macros's in "rtl.h" for the meaning of each rtx->fld[].
404 ---------------------------------------------------------------------- */
406 /* An instruction that cannot jump. */
407 DEF_RTL_EXPR(INSN, "insn", "iuueiee", 'i')
409 /* An instruction that can possibly jump.
410 Fields ( rtx->fld[] ) have exact same meaning as INSN's. */
411 DEF_RTL_EXPR(JUMP_INSN, "jump_insn", "iuueiee0", 'i')
413 /* An instruction that can possibly call a subroutine
414 but which will not change which instruction comes next
415 in the current function.
416 Field ( rtx->fld[7] ) is CALL_INSN_FUNCTION_USAGE.
417 All other fields ( rtx->fld[] ) have exact same meaning as INSN's. */
418 DEF_RTL_EXPR(CALL_INSN, "call_insn", "iuueieee", 'i')
420 /* A marker that indicates that control will not flow through. */
421 DEF_RTL_EXPR(BARRIER, "barrier", "iuu", 'x')
423 /* Holds a label that is followed by instructions.
425 3: is used in jump.c for the use-count of the label.
426 4: is used in flow.c to point to the chain of label_ref's to this label.
427 5: is a number that is unique in the entire compilation.
428 6: is the user-given name of the label, if any.
429 7: is the alternate label name. */
430 DEF_RTL_EXPR(CODE_LABEL, "code_label", "iuu00iss", 'x')
432 /* Say where in the code a source line starts, for symbol table's sake.
434 3: filename, if line number > 0, note-specific data otherwise.
435 4: line number if > 0, enum note_insn otherwise.
436 5: unique number if line number == note_insn_deleted_label. */
437 DEF_RTL_EXPR(NOTE, "note", "iuu0ni", 'x')
439 /* ----------------------------------------------------------------------
440 Top level constituents of INSN, JUMP_INSN and CALL_INSN.
441 ---------------------------------------------------------------------- */
443 /* Conditionally execute code.
444 Operand 0 is the condition that if true, the code is executed.
445 Operand 1 is the code to be executed (typically a SET).
447 Semantics are that there are no side effects if the condition
448 is false. This pattern is created automatically by the if_convert
449 pass run after reload or by target-specific splitters. */
450 DEF_RTL_EXPR(COND_EXEC, "cond_exec", "ee", 'x')
452 /* Several operations to be done in parallel (perhaps under COND_EXEC). */
453 DEF_RTL_EXPR(PARALLEL, "parallel", "E", 'x')
455 /* A string that is passed through to the assembler as input.
456 One can obviously pass comments through by using the
457 assembler comment syntax.
458 These occur in an insn all by themselves as the PATTERN.
459 They also appear inside an ASM_OPERANDS
460 as a convenient way to hold a string. */
461 DEF_RTL_EXPR(ASM_INPUT, "asm_input", "s", 'x')
463 /* An assembler instruction with operands.
464 1st operand is the instruction template.
465 2nd operand is the constraint for the output.
466 3rd operand is the number of the output this expression refers to.
467 When an insn stores more than one value, a separate ASM_OPERANDS
468 is made for each output; this integer distinguishes them.
469 4th is a vector of values of input operands.
470 5th is a vector of modes and constraints for the input operands.
471 Each element is an ASM_INPUT containing a constraint string
472 and whose mode indicates the mode of the input operand.
473 6th is the name of the containing source file.
474 7th is the source line number. */
475 DEF_RTL_EXPR(ASM_OPERANDS, "asm_operands", "ssiEEsi", 'x')
477 /* A machine-specific operation.
478 1st operand is a vector of operands being used by the operation so that
479 any needed reloads can be done.
480 2nd operand is a unique value saying which of a number of machine-specific
481 operations is to be performed.
482 (Note that the vector must be the first operand because of the way that
483 genrecog.c record positions within an insn.)
484 This can occur all by itself in a PATTERN, as a component of a PARALLEL,
485 or inside an expression. */
486 DEF_RTL_EXPR(UNSPEC, "unspec", "Ei", 'x')
488 /* Similar, but a volatile operation and one which may trap. */
489 DEF_RTL_EXPR(UNSPEC_VOLATILE, "unspec_volatile", "Ei", 'x')
491 /* Vector of addresses, stored as full words. */
492 /* Each element is a LABEL_REF to a CODE_LABEL whose address we want. */
493 DEF_RTL_EXPR(ADDR_VEC, "addr_vec", "E", 'x')
495 /* Vector of address differences X0 - BASE, X1 - BASE, ...
496 First operand is BASE; the vector contains the X's.
497 The machine mode of this rtx says how much space to leave
498 for each difference and is adjusted by branch shortening if
499 CASE_VECTOR_SHORTEN_MODE is defined.
500 The third and fourth operands store the target labels with the
501 minimum and maximum addresses respectively.
502 The fifth operand stores flags for use by branch shortening.
503 Set at the start of shorten_branches:
504 min_align: the minimum alignment for any of the target labels.
505 base_after_vec: true iff BASE is after the ADDR_DIFF_VEC.
506 min_after_vec: true iff minimum addr target label is after the ADDR_DIFF_VEC.
507 max_after_vec: true iff maximum addr target label is after the ADDR_DIFF_VEC.
508 min_after_base: true iff minimum address target label is after BASE.
509 max_after_base: true iff maximum address target label is after BASE.
510 Set by the actual branch shortening process:
511 offset_unsigned: true iff offsets have to be treated as unsigned.
512 scale: scaling that is necessary to make offsets fit into the mode.
514 The third, fourth and fifth operands are only valid when
515 CASE_VECTOR_SHORTEN_MODE is defined, and only in an optimizing
518 DEF_RTL_EXPR(ADDR_DIFF_VEC, "addr_diff_vec", "eEee0", 'x')
520 /* Memory prefetch, with attributes supported on some targets.
521 Operand 1 is the address of the memory to fetch.
522 Operand 2 is 1 for a write access, 0 otherwise.
523 Operand 3 is the level of temporal locality; 0 means there is no
524 temporal locality and 1, 2, and 3 are for increasing levels of temporal
527 The attributes specified by operands 2 and 3 are ignored for targets
528 whose prefetch instructions do not support them. */
529 DEF_RTL_EXPR(PREFETCH, "prefetch", "eee", 'x')
531 /* ----------------------------------------------------------------------
532 At the top level of an instruction (perhaps under PARALLEL).
533 ---------------------------------------------------------------------- */
536 Operand 1 is the location (REG, MEM, PC, CC0 or whatever) assigned to.
537 Operand 2 is the value stored there.
538 ALL assignment must use SET.
539 Instructions that do multiple assignments must use multiple SET,
541 DEF_RTL_EXPR(SET, "set", "ee", 'x')
543 /* Indicate something is used in a way that we don't want to explain.
544 For example, subroutine calls will use the register
545 in which the static chain is passed. */
546 DEF_RTL_EXPR(USE, "use", "e", 'x')
548 /* Indicate something is clobbered in a way that we don't want to explain.
549 For example, subroutine calls will clobber some physical registers
550 (the ones that are by convention not saved). */
551 DEF_RTL_EXPR(CLOBBER, "clobber", "e", 'x')
553 /* Call a subroutine.
554 Operand 1 is the address to call.
555 Operand 2 is the number of arguments. */
557 DEF_RTL_EXPR(CALL, "call", "ee", 'x')
559 /* Return from a subroutine. */
561 DEF_RTL_EXPR(RETURN, "return", "", 'x')
564 Operand 1 is the condition.
565 Operand 2 is the trap code.
566 For an unconditional trap, make the condition (const_int 1). */
567 DEF_RTL_EXPR(TRAP_IF, "trap_if", "ee", 'x')
569 /* Placeholder for _Unwind_Resume before we know if a function call
570 or a branch is needed. Operand 1 is the exception region from
571 which control is flowing. */
572 DEF_RTL_EXPR(RESX, "resx", "i", 'x')
574 /* ----------------------------------------------------------------------
575 Primitive values for use in expressions.
576 ---------------------------------------------------------------------- */
578 /* numeric integer constant */
579 DEF_RTL_EXPR(CONST_INT, "const_int", "w", 'o')
581 /* numeric floating point constant.
582 Operand 0 ('0') is a chain of all CONST_DOUBLEs in use in the
584 Remaining operands hold the actual value. They are all 'w' and
585 there may be from 1 to 4; see rtl.c. */
586 DEF_RTL_EXPR(CONST_DOUBLE, "const_double", CONST_DOUBLE_FORMAT, 'o')
588 /* Describes a vector constant. */
589 DEF_RTL_EXPR(CONST_VECTOR, "const_vector", "E", 'x')
591 /* String constant. Used only for attributes right now. */
592 DEF_RTL_EXPR(CONST_STRING, "const_string", "s", 'o')
594 /* This is used to encapsulate an expression whose value is constant
595 (such as the sum of a SYMBOL_REF and a CONST_INT) so that it will be
596 recognized as a constant operand rather than by arithmetic instructions. */
598 DEF_RTL_EXPR(CONST, "const", "e", 'o')
600 /* program counter. Ordinary jumps are represented
601 by a SET whose first operand is (PC). */
602 DEF_RTL_EXPR(PC, "pc", "", 'o')
604 /* Used in the cselib routines to describe a value. */
605 DEF_RTL_EXPR(VALUE, "value", "0", 'o')
607 /* A register. The "operand" is the register number, accessed with
608 the REGNO macro. If this number is less than FIRST_PSEUDO_REGISTER
609 than a hardware register is being referred to. The second operand
610 holds the original register number - this will be different for a
611 pseudo register that got turned into a hard register.
612 This rtx needs to have as many (or more) fields as a MEM, since we
613 can change REG rtx's into MEMs during reload. */
614 DEF_RTL_EXPR(REG, "reg", "i0", 'o')
616 /* A scratch register. This represents a register used only within a
617 single insn. It will be turned into a REG during register allocation
618 or reload unless the constraint indicates that the register won't be
619 needed, in which case it can remain a SCRATCH. This code is
620 marked as having one operand so it can be turned into a REG. */
621 DEF_RTL_EXPR(SCRATCH, "scratch", "0", 'o')
623 /* One word of a multi-word value.
624 The first operand is the complete value; the second says which word.
625 The WORDS_BIG_ENDIAN flag controls whether word number 0
626 (as numbered in a SUBREG) is the most or least significant word.
628 This is also used to refer to a value in a different machine mode.
629 For example, it can be used to refer to a SImode value as if it were
630 Qimode, or vice versa. Then the word number is always 0. */
631 DEF_RTL_EXPR(SUBREG, "subreg", "ei", 'x')
633 /* This one-argument rtx is used for move instructions
634 that are guaranteed to alter only the low part of a destination.
635 Thus, (SET (SUBREG:HI (REG...)) (MEM:HI ...))
636 has an unspecified effect on the high part of REG,
637 but (SET (STRICT_LOW_PART (SUBREG:HI (REG...))) (MEM:HI ...))
638 is guaranteed to alter only the bits of REG that are in HImode.
640 The actual instruction used is probably the same in both cases,
641 but the register constraints may be tighter when STRICT_LOW_PART
644 DEF_RTL_EXPR(STRICT_LOW_PART, "strict_low_part", "e", 'x')
646 /* (CONCAT a b) represents the virtual concatenation of a and b
647 to make a value that has as many bits as a and b put together.
648 This is used for complex values. Normally it appears only
649 in DECL_RTLs and during RTL generation, but not in the insn chain. */
650 DEF_RTL_EXPR(CONCAT, "concat", "ee", 'o')
652 /* A memory location; operand is the address. The second operand is the
653 alias set to which this MEM belongs. We use `0' instead of `w' for this
654 field so that the field need not be specified in machine descriptions. */
655 DEF_RTL_EXPR(MEM, "mem", "e0", 'o')
657 /* Reference to an assembler label in the code for this function.
658 The operand is a CODE_LABEL found in the insn chain.
659 The unprinted fields 1 and 2 are used in flow.c for the
660 LABEL_NEXTREF and CONTAINING_INSN. */
661 DEF_RTL_EXPR(LABEL_REF, "label_ref", "u00", 'o')
663 /* Reference to a named label: the string that is the first operand,
664 with `_' added implicitly in front.
665 Exception: if the first character explicitly given is `*',
666 to give it to the assembler, remove the `*' and do not add `_'. */
667 DEF_RTL_EXPR(SYMBOL_REF, "symbol_ref", "s", 'o')
669 /* The condition code register is represented, in our imagination,
670 as a register holding a value that can be compared to zero.
671 In fact, the machine has already compared them and recorded the
672 results; but instructions that look at the condition code
673 pretend to be looking at the entire value and comparing it. */
674 DEF_RTL_EXPR(CC0, "cc0", "", 'o')
676 /* Reference to the address of a register. Removed by purge_addressof after
677 CSE has elided as many as possible.
678 1st operand: the register we may need the address of.
679 2nd operand: the original pseudo regno we were generated for.
680 3rd operand: the decl for the object in the register, for
683 DEF_RTL_EXPR(ADDRESSOF, "addressof", "eit", 'o')
685 /* =====================================================================
686 A QUEUED expression really points to a member of the queue of instructions
687 to be output later for postincrement/postdecrement.
688 QUEUED expressions never become part of instructions.
689 When a QUEUED expression would be put into an instruction,
690 instead either the incremented variable or a copy of its previous
694 0. the variable to be incremented (a REG rtx).
695 1. the incrementing instruction, or 0 if it hasn't been output yet.
696 2. A REG rtx for a copy of the old value of the variable, or 0 if none yet.
697 3. the body to use for the incrementing instruction
698 4. the next QUEUED expression in the queue.
699 ====================================================================== */
701 DEF_RTL_EXPR(QUEUED, "queued", "eeeee", 'x')
703 /* ----------------------------------------------------------------------
704 Expressions for operators in an rtl pattern
705 ---------------------------------------------------------------------- */
707 /* if_then_else. This is used in representing ordinary
708 conditional jump instructions.
713 DEF_RTL_EXPR(IF_THEN_ELSE, "if_then_else", "eee", '3')
715 /* General conditional. The first operand is a vector composed of pairs of
716 expressions. The first element of each pair is evaluated, in turn.
717 The value of the conditional is the second expression of the first pair
718 whose first expression evaluates non-zero. If none of the expressions is
719 true, the second operand will be used as the value of the conditional.
721 This should be replaced with use of IF_THEN_ELSE. */
722 DEF_RTL_EXPR(COND, "cond", "Ee", 'x')
724 /* Comparison, produces a condition code result. */
725 DEF_RTL_EXPR(COMPARE, "compare", "ee", '2')
728 DEF_RTL_EXPR(PLUS, "plus", "ee", 'c')
730 /* Operand 0 minus operand 1. */
731 DEF_RTL_EXPR(MINUS, "minus", "ee", '2')
733 /* Minus operand 0. */
734 DEF_RTL_EXPR(NEG, "neg", "e", '1')
736 DEF_RTL_EXPR(MULT, "mult", "ee", 'c')
738 /* Operand 0 divided by operand 1. */
739 DEF_RTL_EXPR(DIV, "div", "ee", '2')
740 /* Remainder of operand 0 divided by operand 1. */
741 DEF_RTL_EXPR(MOD, "mod", "ee", '2')
743 /* Unsigned divide and remainder. */
744 DEF_RTL_EXPR(UDIV, "udiv", "ee", '2')
745 DEF_RTL_EXPR(UMOD, "umod", "ee", '2')
747 /* Bitwise operations. */
748 DEF_RTL_EXPR(AND, "and", "ee", 'c')
750 DEF_RTL_EXPR(IOR, "ior", "ee", 'c')
752 DEF_RTL_EXPR(XOR, "xor", "ee", 'c')
754 DEF_RTL_EXPR(NOT, "not", "e", '1')
757 0: value to be shifted.
758 1: number of bits. */
759 DEF_RTL_EXPR(ASHIFT, "ashift", "ee", '2') /* shift left */
760 DEF_RTL_EXPR(ROTATE, "rotate", "ee", '2') /* rotate left */
761 DEF_RTL_EXPR(ASHIFTRT, "ashiftrt", "ee", '2') /* arithmetic shift right */
762 DEF_RTL_EXPR(LSHIFTRT, "lshiftrt", "ee", '2') /* logical shift right */
763 DEF_RTL_EXPR(ROTATERT, "rotatert", "ee", '2') /* rotate right */
765 /* Minimum and maximum values of two operands. We need both signed and
766 unsigned forms. (We cannot use MIN for SMIN because it conflicts
767 with a macro of the same name.) */
769 DEF_RTL_EXPR(SMIN, "smin", "ee", 'c')
770 DEF_RTL_EXPR(SMAX, "smax", "ee", 'c')
771 DEF_RTL_EXPR(UMIN, "umin", "ee", 'c')
772 DEF_RTL_EXPR(UMAX, "umax", "ee", 'c')
774 /* These unary operations are used to represent incrementation
775 and decrementation as they occur in memory addresses.
776 The amount of increment or decrement are not represented
777 because they can be understood from the machine-mode of the
778 containing MEM. These operations exist in only two cases:
779 1. pushes onto the stack.
780 2. created automatically by the life_analysis pass in flow.c. */
781 DEF_RTL_EXPR(PRE_DEC, "pre_dec", "e", 'a')
782 DEF_RTL_EXPR(PRE_INC, "pre_inc", "e", 'a')
783 DEF_RTL_EXPR(POST_DEC, "post_dec", "e", 'a')
784 DEF_RTL_EXPR(POST_INC, "post_inc", "e", 'a')
786 /* These binary operations are used to represent generic address
787 side-effects in memory addresses, except for simple incrementation
788 or decrementation which use the above operations. They are
789 created automatically by the life_analysis pass in flow.c.
790 The first operand is a REG which is used as the address.
791 The second operand is an expression that is assigned to the
792 register, either before (PRE_MODIFY) or after (POST_MODIFY)
793 evaluating the address.
794 Currently, the compiler can only handle second operands of the
795 form (plus (reg) (reg)) and (plus (reg) (const_int)), where
796 the first operand of the PLUS has to be the same register as
797 the first operand of the *_MODIFY. */
798 DEF_RTL_EXPR(PRE_MODIFY, "pre_modify", "ee", 'a')
799 DEF_RTL_EXPR(POST_MODIFY, "post_modify", "ee", 'a')
801 /* Comparison operations. The ordered comparisons exist in two
802 flavors, signed and unsigned. */
803 DEF_RTL_EXPR(NE, "ne", "ee", '<')
804 DEF_RTL_EXPR(EQ, "eq", "ee", '<')
805 DEF_RTL_EXPR(GE, "ge", "ee", '<')
806 DEF_RTL_EXPR(GT, "gt", "ee", '<')
807 DEF_RTL_EXPR(LE, "le", "ee", '<')
808 DEF_RTL_EXPR(LT, "lt", "ee", '<')
809 DEF_RTL_EXPR(GEU, "geu", "ee", '<')
810 DEF_RTL_EXPR(GTU, "gtu", "ee", '<')
811 DEF_RTL_EXPR(LEU, "leu", "ee", '<')
812 DEF_RTL_EXPR(LTU, "ltu", "ee", '<')
814 /* Additional floating point unordered comparision flavors. */
815 DEF_RTL_EXPR(UNORDERED, "unordered", "ee", '<')
816 DEF_RTL_EXPR(ORDERED, "ordered", "ee", '<')
818 /* These are equivalent to unordered or ... */
819 DEF_RTL_EXPR(UNEQ, "uneq", "ee", '<')
820 DEF_RTL_EXPR(UNGE, "unge", "ee", '<')
821 DEF_RTL_EXPR(UNGT, "ungt", "ee", '<')
822 DEF_RTL_EXPR(UNLE, "unle", "ee", '<')
823 DEF_RTL_EXPR(UNLT, "unlt", "ee", '<')
825 /* This is an ordered NE, ie !UNEQ, ie false for NaN. */
826 DEF_RTL_EXPR(LTGT, "ltgt", "ee", '<')
828 /* Represents the result of sign-extending the sole operand.
829 The machine modes of the operand and of the SIGN_EXTEND expression
830 determine how much sign-extension is going on. */
831 DEF_RTL_EXPR(SIGN_EXTEND, "sign_extend", "e", '1')
833 /* Similar for zero-extension (such as unsigned short to int). */
834 DEF_RTL_EXPR(ZERO_EXTEND, "zero_extend", "e", '1')
836 /* Similar but here the operand has a wider mode. */
837 DEF_RTL_EXPR(TRUNCATE, "truncate", "e", '1')
839 /* Similar for extending floating-point values (such as SFmode to DFmode). */
840 DEF_RTL_EXPR(FLOAT_EXTEND, "float_extend", "e", '1')
841 DEF_RTL_EXPR(FLOAT_TRUNCATE, "float_truncate", "e", '1')
843 /* Conversion of fixed point operand to floating point value. */
844 DEF_RTL_EXPR(FLOAT, "float", "e", '1')
846 /* With fixed-point machine mode:
847 Conversion of floating point operand to fixed point value.
848 Value is defined only when the operand's value is an integer.
849 With floating-point machine mode (and operand with same mode):
850 Operand is rounded toward zero to produce an integer value
851 represented in floating point. */
852 DEF_RTL_EXPR(FIX, "fix", "e", '1')
854 /* Conversion of unsigned fixed point operand to floating point value. */
855 DEF_RTL_EXPR(UNSIGNED_FLOAT, "unsigned_float", "e", '1')
857 /* With fixed-point machine mode:
858 Conversion of floating point operand to *unsigned* fixed point value.
859 Value is defined only when the operand's value is an integer. */
860 DEF_RTL_EXPR(UNSIGNED_FIX, "unsigned_fix", "e", '1')
863 DEF_RTL_EXPR(ABS, "abs", "e", '1')
866 DEF_RTL_EXPR(SQRT, "sqrt", "e", '1')
868 /* Find first bit that is set.
869 Value is 1 + number of trailing zeros in the arg.,
871 DEF_RTL_EXPR(FFS, "ffs", "e", '1')
873 /* Reference to a signed bit-field of specified size and position.
874 Operand 0 is the memory unit (usually SImode or QImode) which
875 contains the field's first bit. Operand 1 is the width, in bits.
876 Operand 2 is the number of bits in the memory unit before the
877 first bit of this field.
878 If BITS_BIG_ENDIAN is defined, the first bit is the msb and
879 operand 2 counts from the msb of the memory unit.
880 Otherwise, the first bit is the lsb and operand 2 counts from
881 the lsb of the memory unit. */
882 DEF_RTL_EXPR(SIGN_EXTRACT, "sign_extract", "eee", 'b')
884 /* Similar for unsigned bit-field. */
885 DEF_RTL_EXPR(ZERO_EXTRACT, "zero_extract", "eee", 'b')
887 /* For RISC machines. These save memory when splitting insns. */
889 /* HIGH are the high-order bits of a constant expression. */
890 DEF_RTL_EXPR(HIGH, "high", "e", 'o')
892 /* LO_SUM is the sum of a register and the low-order bits
893 of a constant expression. */
894 DEF_RTL_EXPR(LO_SUM, "lo_sum", "ee", 'o')
896 /* Header for range information. Operand 0 is the NOTE_INSN_RANGE_BEG insn.
897 Operand 1 is the NOTE_INSN_RANGE_END insn. Operand 2 is a vector of all of
898 the registers that can be substituted within this range. Operand 3 is the
899 number of calls in the range. Operand 4 is the number of insns in the
900 range. Operand 5 is the unique range number for this range. Operand 6 is
901 the basic block # of the start of the live range. Operand 7 is the basic
902 block # of the end of the live range. Operand 8 is the loop depth. Operand
903 9 is a bitmap of the registers live at the start of the range. Operand 10
904 is a bitmap of the registers live at the end of the range. Operand 11 is
905 marker number for the start of the range. Operand 12 is the marker number
906 for the end of the range. */
907 DEF_RTL_EXPR(RANGE_INFO, "range_info", "uuEiiiiiibbii", 'x')
909 /* Registers that can be substituted within the range. Operand 0 is the
910 original pseudo register number. Operand 1 will be filled in with the
911 pseudo register the value is copied for the duration of the range. Operand
912 2 is the number of references within the range to the register. Operand 3
913 is the number of sets or clobbers of the register in the range. Operand 4
914 is the number of deaths the register has. Operand 5 is the copy flags that
915 give the status of whether a copy is needed from the original register to
916 the new register at the beginning of the range, or whether a copy from the
917 new register back to the original at the end of the range. Operand 6 is the
918 live length. Operand 7 is the number of calls that this register is live
919 across. Operand 8 is the symbol node of the variable if the register is a
920 user variable. Operand 9 is the block node that the variable is declared
921 in if the register is a user variable. */
922 DEF_RTL_EXPR(RANGE_REG, "range_reg", "iiiiiiiitt", 'x')
924 /* Information about a local variable's ranges. Operand 0 is an EXPR_LIST of
925 the different ranges a variable is in where it is copied to a different
926 pseudo register. Operand 1 is the block that the variable is declared in.
927 Operand 2 is the number of distinct ranges. */
928 DEF_RTL_EXPR(RANGE_VAR, "range_var", "eti", 'x')
930 /* Information about the registers that are live at the current point. Operand
931 0 is the live bitmap. Operand 1 is the original block number. */
932 DEF_RTL_EXPR(RANGE_LIVE, "range_live", "bi", 'x')
934 /* A unary `__builtin_constant_p' expression. These are only emitted
935 during RTL generation, and then only if optimize > 0. They are
936 eliminated by the first CSE pass. */
937 DEF_RTL_EXPR(CONSTANT_P_RTX, "constant_p_rtx", "e", 'x')
939 /* A placeholder for a CALL_INSN which may be turned into a normal call,
940 a sibling (tail) call or tail recursion.
942 Immediately after RTL generation, this placeholder will be replaced
943 by the insns to perform the call, sibcall or tail recursion.
945 This RTX has 4 operands. The first three are lists of instructions to
946 perform the call as a normal call, sibling call and tail recursion
947 respectively. The latter two lists may be NULL, the first may never
950 The last operand is the tail recursion CODE_LABEL, which may be NULL if no
951 potential tail recursive calls were found.
953 The tail recursion label is needed so that we can clear LABEL_PRESERVE_P
954 after we select a call method.
956 This method of tail-call elimination is intended to be replaced by
957 tree-based optimizations once front-end conversions are complete. */
958 DEF_RTL_EXPR(CALL_PLACEHOLDER, "call_placeholder", "uuuu", 'x')
960 /* Describes a merge operation between two vector values.
961 Operands 0 and 1 are the vectors to be merged, operand 2 is a bitmask
962 that specifies where the parts of the result are taken from. Set bits
963 indicate operand 0, clear bits indicate operand 1. The parts are defined
964 by the mode of the vectors. */
965 DEF_RTL_EXPR(VEC_MERGE, "vec_merge", "eee", 'x')
967 /* Describes an operation that selects parts of a vector.
968 Operands 0 is the source vector, operand 1 is a PARALLEL that contains
969 a CONST_INT for each of the subparts of the result vector, giving the
970 number of the source subpart that should be stored into it. */
971 DEF_RTL_EXPR(VEC_SELECT, "vec_select", "ee", 'x')
973 /* Describes a vector concat operation. Operands 0 and 1 are the source
974 vectors, the result is a vector that is as long as operands 0 and 1
975 combined and is the concatenation of the two source vectors. */
976 DEF_RTL_EXPR(VEC_CONCAT, "vec_concat", "ee", 'x')
978 /* Describes an operation that converts a small vector into a larger one by
979 duplicating the input values. The output vector mode must have the same
980 submodes as the input vector mode, and the number of output parts must be
981 an integer multiple of the number of input parts. */
982 DEF_RTL_EXPR(VEC_DUPLICATE, "vec_duplicate", "e", 'x')
984 /* Addition with signed saturation */
985 DEF_RTL_EXPR(SS_PLUS, "ss_plus", "ee", 'c')
987 /* Addition with unsigned saturation */
988 DEF_RTL_EXPR(US_PLUS, "us_plus", "ee", 'c')
990 /* Operand 0 minus operand 1, with signed saturation. */
991 DEF_RTL_EXPR(SS_MINUS, "ss_minus", "ee", '2')
993 /* Operand 0 minus operand 1, with unsigned saturation. */
994 DEF_RTL_EXPR(US_MINUS, "us_minus", "ee", '2')
996 /* Signed saturating truncate. */
997 DEF_RTL_EXPR(SS_TRUNCATE, "ss_truncate", "e", '1')
999 /* Unsigned saturating truncate. */
1000 DEF_RTL_EXPR(US_TRUNCATE, "us_truncate", "e", '1')
1002 /* The SSA phi operator.
1004 The argument is a vector of 2N rtxes. Element 2N+1 is a CONST_INT
1005 containing the block number of the predecessor through which control
1006 has passed when the register at element 2N is used.
1008 Note that PHI may only appear at the beginning of a basic block.
1010 ??? There may be multiple PHI insns, but they are all evaluated
1011 in parallel. This probably ought to be changed to use a real
1012 PARALLEL, as that would be less confusing and more in the spirit
1013 of canonical RTL. It is, however, easier to manipulate this way. */
1014 DEF_RTL_EXPR(PHI, "phi", "E", 'x')
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