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1.1 root 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.
1.1.1.6 ! root 4: Copyright (C) 1987, 1988, 1992, 1994 Free Software Foundation, Inc.
1.1 root 5:
6: This file is part of GNU CC.
7:
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)
11: any later version.
12:
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.
17:
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. */
21:
22:
23: /* Expression definitions and descriptions for all targets are in this file.
24: Some will not be used for some targets.
25:
26: The fields in the cpp macro call "DEF_RTL_EXPR()"
27: are used to create declarations in the C source of the compiler.
28:
29: The fields are:
30:
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.
34:
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.
39:
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
43:
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:
46:
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)
56: "x" everything else
57:
58: */
59:
60: /* ---------------------------------------------------------------------
61: Expressions (and "meta" expressions) used for structuring the
62: rtl representation of a program.
63: --------------------------------------------------------------------- */
64:
65: /* an expression code name unknown to the reader */
66: DEF_RTL_EXPR(UNKNOWN, "UnKnown", "*", 'x')
67:
68: /* (NIL) is used by rtl reader and printer to represent a null pointer. */
69:
70: DEF_RTL_EXPR(NIL, "nil", "*", 'x')
71:
72: /* ---------------------------------------------------------------------
73: Expressions used in constructing lists.
74: --------------------------------------------------------------------- */
75:
76: /* a linked list of expressions */
77: DEF_RTL_EXPR(EXPR_LIST, "expr_list", "ee", 'x')
78:
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')
82:
83: /* ----------------------------------------------------------------------
1.1.1.2 root 84: Expression types for machine descriptions.
1.1 root 85: These do not appear in actual rtl code in the compiler.
86: ---------------------------------------------------------------------- */
87:
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.
93:
94: A third string argument indicates to the register allocator restrictions
95: on where the operand can be allocated.
96:
97: If the target needs no restriction on any instruction this field should
98: be the null string.
99:
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.
103:
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).
111:
112: Other characters indicate target dependent operand classes and
113: are described in each target's machine description.
114:
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.
119: */
120: DEF_RTL_EXPR(MATCH_OPERAND, "match_operand", "iss", 'm')
121:
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')
128:
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')
133:
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')
141:
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')
150:
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')
155:
156: /* Appears only in machine descriptions.
1.1.1.3 root 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')
160:
161: /* Appears only in machine descriptions.
1.1 root 162: Defines the pattern for one kind of instruction.
163: Operand:
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.
168: 1: is the pattern.
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
175: template to use.
176: 4: optionally, a vector of attributes for this insn.
177: */
178: DEF_RTL_EXPR(DEFINE_INSN, "define_insn", "sEssV", 'x')
179:
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.
185: */
186: DEF_RTL_EXPR(DEFINE_PEEPHOLE, "define_peephole", "EssV", 'x')
187:
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')
197:
198: /* Definition of a combiner pattern.
199: Operands not defined yet. */
200: DEF_RTL_EXPR(DEFINE_COMBINE, "define_combine", "Ess", 'x')
201:
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')
213:
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
217: shown.
218: 2nd operand: Vector whose length is the three times the number of delay
219: slots required.
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.
225:
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')
229:
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
233: simultaneously.
234:
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.
238:
1.1.1.3 root 239: All delays are specified in cycles.
1.1 root 240:
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
248: available.
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
1.1.1.3 root 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
260: be specified.
1.1 root 261:
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
1.1.1.3 root 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
1.1 root 268: unit.) */
269: DEF_RTL_EXPR(DEFINE_FUNCTION_UNIT, "define_function_unit", "siieiiV", 'x')
270:
271: /* Define attribute computation for `asm' instructions. */
272: DEF_RTL_EXPR(DEFINE_ASM_ATTRIBUTES, "define_asm_attributes", "V", 'x' )
273:
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')
279:
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')
285:
286: /* ----------------------------------------------------------------------
287: Expressions used for insn attributes. These also do not appear in
288: actual rtl code in the compiler.
289: ---------------------------------------------------------------------- */
290:
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')
296:
297: /* Marker for the name of an attribute. */
298: DEF_RTL_EXPR(ATTR, "attr", "s", 'x')
299:
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
302: pattern.
303:
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')
307:
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
310: alternative matched.
311:
312: The following three expressions are equivalent:
313:
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")
320: */
321: DEF_RTL_EXPR(SET_ATTR_ALTERNATIVE, "set_attr_alternative", "sE", 'x')
322:
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')
327:
1.1.1.4 root 328: /* A conditional expression which is true if the specified flag is
329: true for the insn being scheduled in reorg.
330:
331: genattr.c defines the following flags which can be tested by
332: (attr_flag "foo") expressions in eligible_for_delay.
333:
334: forward, backward, very_likely, likely, very_unlikely, and unlikely. */
335:
336: DEF_RTL_EXPR (ATTR_FLAG, "attr_flag", "s", 'x')
337:
1.1 root 338: /* ----------------------------------------------------------------------
339: Expression types used for things in the instruction chain.
340:
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[].
345:
346: ---------------------------------------------------------------------- */
347:
348: /* An instruction that cannot jump. */
349: DEF_RTL_EXPR(INSN, "insn", "iuueiee", 'i')
350:
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')
354:
355: /* An instruction that can possibly call a subroutine
356: but which will not change which instruction comes next
357: in the current function.
1.1.1.6 ! root 358: Field ( rtx->fld[7] ) is CALL_INSN_FUNCTION_USAGE.
! 359: All other fields ( rtx->fld[] ) have exact same meaning as INSN's. */
! 360: DEF_RTL_EXPR(CALL_INSN, "call_insn", "iuueieee", 'i')
1.1 root 361:
362: /* A marker that indicates that control will not flow through. */
363: DEF_RTL_EXPR(BARRIER, "barrier", "iuu", 'x')
364:
365: /* Holds a label that is followed by instructions.
366: Operand:
367: 3: is a number that is unique in the entire compilation.
368: 4: is the user-given name of the label, if any.
369: 5: is used in jump.c for the use-count of the label.
370: and in flow.c to point to the chain of label_ref's to this label. */
371: DEF_RTL_EXPR(CODE_LABEL, "code_label", "iuuis0", 'x')
372:
373: /* Say where in the code a source line starts, for symbol table's sake.
374: Contains a filename and a line number. Line numbers <= 0 are special:
375: 0 is used in a dummy placed at the front of every function
376: just so there will never be a need to delete the first insn;
377: -1 indicates a dummy; insns to be deleted by flow analysis and combining
378: are really changed to NOTEs with a number of -1.
379: -2 means beginning of a name binding contour; output N_LBRAC.
380: -3 means end of a contour; output N_RBRAC. */
381: DEF_RTL_EXPR(NOTE, "note", "iuusn", 'x')
382:
383: /* INLINE_HEADER is use by inline function machinery. The information
384: it contains helps to build the mapping function between the rtx's of
385: the function to be inlined and the current function being expanded. */
386:
387: DEF_RTL_EXPR(INLINE_HEADER, "inline_header", "iuuuiiiiiieiiEe", 'x')
388:
389: /* ----------------------------------------------------------------------
390: Top level constituents of INSN, JUMP_INSN and CALL_INSN.
391: ---------------------------------------------------------------------- */
392:
393: /* Several operations to be done in parallel. */
394: DEF_RTL_EXPR(PARALLEL, "parallel", "E", 'x')
395:
396: /* A string that is passed through to the assembler as input.
397: One can obviously pass comments through by using the
398: assembler comment syntax.
399: These occur in an insn all by themselves as the PATTERN.
400: They also appear inside an ASM_OPERANDS
401: as a convenient way to hold a string. */
402: DEF_RTL_EXPR(ASM_INPUT, "asm_input", "s", 'x')
403:
404: /* An assembler instruction with operands.
405: 1st operand is the instruction template.
406: 2nd operand is the constraint for the output.
407: 3rd operand is the number of the output this expression refers to.
408: When an insn stores more than one value, a separate ASM_OPERANDS
409: is made for each output; this integer distinguishes them.
410: 4th is a vector of values of input operands.
411: 5th is a vector of modes and constraints for the input operands.
412: Each element is an ASM_INPUT containing a constraint string
413: and whose mode indicates the mode of the input operand.
414: 6th is the name of the containing source file.
415: 7th is the source line number. */
416: DEF_RTL_EXPR(ASM_OPERANDS, "asm_operands", "ssiEEsi", 'x')
417:
418: /* A machine-specific operation.
419: 1st operand is a vector of operands being used by the operation so that
420: any needed reloads can be done.
421: 2nd operand is a unique value saying which of a number of machine-specific
422: operations is to be performed.
423: (Note that the vector must be the first operand because of the way that
424: genrecog.c record positions within an insn.)
425: This can occur all by itself in a PATTERN, as a component of a PARALLEL,
426: or inside an expression. */
427: DEF_RTL_EXPR(UNSPEC, "unspec", "Ei", 'x')
428:
1.1.1.2 root 429: /* Similar, but a volatile operation and one which may trap. */
1.1 root 430: DEF_RTL_EXPR(UNSPEC_VOLATILE, "unspec_volatile", "Ei", 'x')
431:
432: /* Vector of addresses, stored as full words. */
433: /* Each element is a LABEL_REF to a CODE_LABEL whose address we want. */
434: DEF_RTL_EXPR(ADDR_VEC, "addr_vec", "E", 'x')
435:
436: /* Vector of address differences X0 - BASE, X1 - BASE, ...
437: First operand is BASE; the vector contains the X's.
438: The machine mode of this rtx says how much space to leave
439: for each difference. */
440: DEF_RTL_EXPR(ADDR_DIFF_VEC, "addr_diff_vec", "eE", 'x')
441:
442: /* ----------------------------------------------------------------------
443: At the top level of an instruction (perhaps under PARALLEL).
444: ---------------------------------------------------------------------- */
445:
446: /* Assignment.
447: Operand 1 is the location (REG, MEM, PC, CC0 or whatever) assigned to.
448: Operand 2 is the value stored there.
449: ALL assignment must use SET.
450: Instructions that do multiple assignments must use multiple SET,
451: under PARALLEL. */
452: DEF_RTL_EXPR(SET, "set", "ee", 'x')
453:
454: /* Indicate something is used in a way that we don't want to explain.
455: For example, subroutine calls will use the register
456: in which the static chain is passed. */
457: DEF_RTL_EXPR(USE, "use", "e", 'x')
458:
459: /* Indicate something is clobbered in a way that we don't want to explain.
460: For example, subroutine calls will clobber some physical registers
461: (the ones that are by convention not saved). */
462: DEF_RTL_EXPR(CLOBBER, "clobber", "e", 'x')
463:
464: /* Call a subroutine.
465: Operand 1 is the address to call.
466: Operand 2 is the number of arguments. */
467:
468: DEF_RTL_EXPR(CALL, "call", "ee", 'x')
469:
470: /* Return from a subroutine. */
471:
472: DEF_RTL_EXPR(RETURN, "return", "", 'x')
473:
474: /* Conditional trap.
475: Operand 1 is the condition.
476: Operand 2 is the trap code.
477: For an unconditional trap, make the condition (const_int 1). */
478: DEF_RTL_EXPR(TRAP_IF, "trap_if", "ei", 'x')
479:
480: /* ----------------------------------------------------------------------
481: Primitive values for use in expressions.
482: ---------------------------------------------------------------------- */
483:
484: /* numeric integer constant */
1.1.1.3 root 485: DEF_RTL_EXPR(CONST_INT, "const_int", "w", 'o')
1.1 root 486:
487: /* numeric double constant.
488: Operand 0 is the MEM that stores this constant in memory,
489: or various other things (see comments at immed_double_const in varasm.c).
490: Operand 1 is a chain of all CONST_DOUBLEs in use in the current function.
491: Remaining operands hold the actual value.
492: The number of operands may be more than 2 if cross-compiling;
493: see init_rtl. */
1.1.1.3 root 494: DEF_RTL_EXPR(CONST_DOUBLE, "const_double", "e0ww", 'o')
1.1 root 495:
496: /* String constant. Used only for attributes right now. */
497: DEF_RTL_EXPR(CONST_STRING, "const_string", "s", 'o')
498:
499: /* This is used to encapsulate an expression whose value is constant
500: (such as the sum of a SYMBOL_REF and a CONST_INT) so that it will be
501: recognized as a constant operand rather than by arithmetic instructions. */
502:
503: DEF_RTL_EXPR(CONST, "const", "e", 'o')
504:
505: /* program counter. Ordinary jumps are represented
506: by a SET whose first operand is (PC). */
507: DEF_RTL_EXPR(PC, "pc", "", 'o')
508:
509: /* A register. The "operand" is the register number, accessed
510: with the REGNO macro. If this number is less than FIRST_PSEUDO_REGISTER
511: than a hardware register is being referred to. */
512: DEF_RTL_EXPR(REG, "reg", "i", 'o')
513:
514: /* A scratch register. This represents a register used only within a
515: single insn. It will be turned into a REG during register allocation
516: or reload unless the constraint indicates that the register won't be
517: needed, in which case it can remain a SCRATCH. This code is
518: marked as having one operand so it can be turned into a REG. */
519: DEF_RTL_EXPR(SCRATCH, "scratch", "0", 'o')
520:
521: /* One word of a multi-word value.
522: The first operand is the complete value; the second says which word.
523: The WORDS_BIG_ENDIAN flag controls whether word number 0
524: (as numbered in a SUBREG) is the most or least significant word.
525:
526: This is also used to refer to a value in a different machine mode.
527: For example, it can be used to refer to a SImode value as if it were
528: Qimode, or vice versa. Then the word number is always 0. */
529: DEF_RTL_EXPR(SUBREG, "subreg", "ei", 'x')
530:
531: /* This one-argument rtx is used for move instructions
532: that are guaranteed to alter only the low part of a destination.
533: Thus, (SET (SUBREG:HI (REG...)) (MEM:HI ...))
534: has an unspecified effect on the high part of REG,
535: but (SET (STRICT_LOW_PART (SUBREG:HI (REG...))) (MEM:HI ...))
536: is guaranteed to alter only the bits of REG that are in HImode.
537:
538: The actual instruction used is probably the same in both cases,
539: but the register constraints may be tighter when STRICT_LOW_PART
540: is in use. */
541:
542: DEF_RTL_EXPR(STRICT_LOW_PART, "strict_low_part", "e", 'x')
543:
1.1.1.5 root 544: /* (CONCAT a b) represents the virtual concatenation of a and b
545: to make a value that has as many bits as a and b put together.
546: This is used for complex values. Normally it appears only
547: in DECL_RTLs and during RTL generation, but not in the insn chain. */
548: DEF_RTL_EXPR(CONCAT, "concat", "ee", 'o')
549:
1.1 root 550: /* A memory location; operand is the address.
551: Can be nested inside a VOLATILE. */
552: DEF_RTL_EXPR(MEM, "mem", "e", 'o')
553:
554: /* Reference to an assembler label in the code for this function.
555: The operand is a CODE_LABEL found in the insn chain.
556: The unprinted fields 1 and 2 are used in flow.c for the
557: LABEL_NEXTREF and CONTAINING_INSN. */
558: DEF_RTL_EXPR(LABEL_REF, "label_ref", "u00", 'o')
559:
560: /* Reference to a named label: the string that is the first operand,
561: with `_' added implicitly in front.
562: Exception: if the first character explicitly given is `*',
563: to give it to the assembler, remove the `*' and do not add `_'. */
564: DEF_RTL_EXPR(SYMBOL_REF, "symbol_ref", "s", 'o')
565:
566: /* The condition code register is represented, in our imagination,
567: as a register holding a value that can be compared to zero.
568: In fact, the machine has already compared them and recorded the
569: results; but instructions that look at the condition code
570: pretend to be looking at the entire value and comparing it. */
571: DEF_RTL_EXPR(CC0, "cc0", "", 'o')
572:
573: /* =====================================================================
574: A QUEUED expression really points to a member of the queue of instructions
575: to be output later for postincrement/postdecrement.
576: QUEUED expressions never become part of instructions.
577: When a QUEUED expression would be put into an instruction,
578: instead either the incremented variable or a copy of its previous
579: value is used.
580:
581: Operands are:
582: 0. the variable to be incremented (a REG rtx).
583: 1. the incrementing instruction, or 0 if it hasn't been output yet.
584: 2. A REG rtx for a copy of the old value of the variable, or 0 if none yet.
585: 3. the body to use for the incrementing instruction
586: 4. the next QUEUED expression in the queue.
587: ====================================================================== */
588:
589: DEF_RTL_EXPR(QUEUED, "queued", "eeeee", 'x')
590:
591: /* ----------------------------------------------------------------------
592: Expressions for operators in an rtl pattern
593: ---------------------------------------------------------------------- */
594:
595: /* if_then_else. This is used in representing ordinary
596: conditional jump instructions.
597: Operand:
598: 0: condition
599: 1: then expr
600: 2: else expr */
601: DEF_RTL_EXPR(IF_THEN_ELSE, "if_then_else", "eee", '3')
602:
603: /* General conditional. The first operand is a vector composed of pairs of
604: expressions. The first element of each pair is evaluated, in turn.
605: The value of the conditional is the second expression of the first pair
606: whose first expression evaluates non-zero. If none of the expressions is
607: true, the second operand will be used as the value of the conditional.
608:
609: This should be replaced with use of IF_THEN_ELSE. */
610: DEF_RTL_EXPR(COND, "cond", "Ee", 'x')
611:
612: /* Comparison, produces a condition code result. */
613: DEF_RTL_EXPR(COMPARE, "compare", "ee", '2')
614:
615: /* plus */
616: DEF_RTL_EXPR(PLUS, "plus", "ee", 'c')
617:
618: /* Operand 0 minus operand 1. */
619: DEF_RTL_EXPR(MINUS, "minus", "ee", '2')
620:
621: /* Minus operand 0. */
622: DEF_RTL_EXPR(NEG, "neg", "e", '1')
623:
624: DEF_RTL_EXPR(MULT, "mult", "ee", 'c')
625:
626: /* Operand 0 divided by operand 1. */
627: DEF_RTL_EXPR(DIV, "div", "ee", '2')
628: /* Remainder of operand 0 divided by operand 1. */
629: DEF_RTL_EXPR(MOD, "mod", "ee", '2')
630:
631: /* Unsigned divide and remainder. */
632: DEF_RTL_EXPR(UDIV, "udiv", "ee", '2')
633: DEF_RTL_EXPR(UMOD, "umod", "ee", '2')
634:
635: /* Bitwise operations. */
636: DEF_RTL_EXPR(AND, "and", "ee", 'c')
637:
638: DEF_RTL_EXPR(IOR, "ior", "ee", 'c')
639:
640: DEF_RTL_EXPR(XOR, "xor", "ee", 'c')
641:
642: DEF_RTL_EXPR(NOT, "not", "e", '1')
643:
644: /* Operand:
645: 0: value to be shifted.
1.1.1.6 ! root 646: 1: number of bits. */
1.1 root 647: DEF_RTL_EXPR(ASHIFT, "ashift", "ee", '2')
648: DEF_RTL_EXPR(ROTATE, "rotate", "ee", '2')
649:
650: /* Right shift operations, for machines where these are not the same
651: as left shifting with a negative argument. */
652:
653: DEF_RTL_EXPR(ASHIFTRT, "ashiftrt", "ee", '2')
654: DEF_RTL_EXPR(LSHIFTRT, "lshiftrt", "ee", '2')
655: DEF_RTL_EXPR(ROTATERT, "rotatert", "ee", '2')
656:
657: /* Minimum and maximum values of two operands. We need both signed and
658: unsigned forms. (We cannot use MIN for SMIN because it conflicts
659: with a macro of the same name.) */
660:
661: DEF_RTL_EXPR(SMIN, "smin", "ee", 'c')
662: DEF_RTL_EXPR(SMAX, "smax", "ee", 'c')
663: DEF_RTL_EXPR(UMIN, "umin", "ee", 'c')
664: DEF_RTL_EXPR(UMAX, "umax", "ee", 'c')
665:
666: /* These unary operations are used to represent incrementation
667: and decrementation as they occur in memory addresses.
668: The amount of increment or decrement are not represented
669: because they can be understood from the machine-mode of the
670: containing MEM. These operations exist in only two cases:
671: 1. pushes onto the stack.
672: 2. created automatically by the life_analysis pass in flow.c. */
673: DEF_RTL_EXPR(PRE_DEC, "pre_dec", "e", 'x')
674: DEF_RTL_EXPR(PRE_INC, "pre_inc", "e", 'x')
675: DEF_RTL_EXPR(POST_DEC, "post_dec", "e", 'x')
676: DEF_RTL_EXPR(POST_INC, "post_inc", "e", 'x')
677:
678: /* Comparison operations. The ordered comparisons exist in two
679: flavors, signed and unsigned. */
680: DEF_RTL_EXPR(NE, "ne", "ee", '<')
681: DEF_RTL_EXPR(EQ, "eq", "ee", '<')
682: DEF_RTL_EXPR(GE, "ge", "ee", '<')
683: DEF_RTL_EXPR(GT, "gt", "ee", '<')
684: DEF_RTL_EXPR(LE, "le", "ee", '<')
685: DEF_RTL_EXPR(LT, "lt", "ee", '<')
686: DEF_RTL_EXPR(GEU, "geu", "ee", '<')
687: DEF_RTL_EXPR(GTU, "gtu", "ee", '<')
688: DEF_RTL_EXPR(LEU, "leu", "ee", '<')
689: DEF_RTL_EXPR(LTU, "ltu", "ee", '<')
690:
691: /* Represents the result of sign-extending the sole operand.
692: The machine modes of the operand and of the SIGN_EXTEND expression
693: determine how much sign-extension is going on. */
694: DEF_RTL_EXPR(SIGN_EXTEND, "sign_extend", "e", '1')
695:
696: /* Similar for zero-extension (such as unsigned short to int). */
697: DEF_RTL_EXPR(ZERO_EXTEND, "zero_extend", "e", '1')
698:
699: /* Similar but here the operand has a wider mode. */
700: DEF_RTL_EXPR(TRUNCATE, "truncate", "e", '1')
701:
702: /* Similar for extending floating-point values (such as SFmode to DFmode). */
703: DEF_RTL_EXPR(FLOAT_EXTEND, "float_extend", "e", '1')
704: DEF_RTL_EXPR(FLOAT_TRUNCATE, "float_truncate", "e", '1')
705:
706: /* Conversion of fixed point operand to floating point value. */
707: DEF_RTL_EXPR(FLOAT, "float", "e", '1')
708:
709: /* With fixed-point machine mode:
710: Conversion of floating point operand to fixed point value.
711: Value is defined only when the operand's value is an integer.
712: With floating-point machine mode (and operand with same mode):
713: Operand is rounded toward zero to produce an integer value
714: represented in floating point. */
715: DEF_RTL_EXPR(FIX, "fix", "e", '1')
716:
717: /* Conversion of unsigned fixed point operand to floating point value. */
718: DEF_RTL_EXPR(UNSIGNED_FLOAT, "unsigned_float", "e", '1')
719:
720: /* With fixed-point machine mode:
721: Conversion of floating point operand to *unsigned* fixed point value.
722: Value is defined only when the operand's value is an integer. */
723: DEF_RTL_EXPR(UNSIGNED_FIX, "unsigned_fix", "e", '1')
724:
725: /* Absolute value */
726: DEF_RTL_EXPR(ABS, "abs", "e", '1')
727:
728: /* Square root */
729: DEF_RTL_EXPR(SQRT, "sqrt", "e", '1')
730:
731: /* Find first bit that is set.
732: Value is 1 + number of trailing zeros in the arg.,
733: or 0 if arg is 0. */
734: DEF_RTL_EXPR(FFS, "ffs", "e", '1')
735:
736: /* Reference to a signed bit-field of specified size and position.
737: Operand 0 is the memory unit (usually SImode or QImode) which
738: contains the field's first bit. Operand 1 is the width, in bits.
739: Operand 2 is the number of bits in the memory unit before the
740: first bit of this field.
741: If BITS_BIG_ENDIAN is defined, the first bit is the msb and
742: operand 2 counts from the msb of the memory unit.
743: Otherwise, the first bit is the lsb and operand 2 counts from
744: the lsb of the memory unit. */
745: DEF_RTL_EXPR(SIGN_EXTRACT, "sign_extract", "eee", 'b')
746:
747: /* Similar for unsigned bit-field. */
748: DEF_RTL_EXPR(ZERO_EXTRACT, "zero_extract", "eee", 'b')
749:
750: /* For RISC machines. These save memory when splitting insns. */
751:
752: /* HIGH are the high-order bits of a constant expression. */
753: DEF_RTL_EXPR(HIGH, "high", "e", 'o')
754:
755: /* LO_SUM is the sum of a register and the low-order bits
756: of a constant expression. */
757: DEF_RTL_EXPR(LO_SUM, "lo_sum", "ee", 'o')
758:
759: /*
760: Local variables:
761: mode:c
762: version-control: t
763: End:
764: */
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