rtl.def revision 259563
1/* This file contains the definitions and documentation for the
2   Register Transfer Expressions (rtx's) that make up the
3   Register Transfer Language (rtl) used in the Back End of the GNU compiler.
4   Copyright (C) 1987, 1988, 1992, 1994, 1995, 1997, 1998, 1999, 2000, 2004,
5   2005, 2006
6   Free Software Foundation, Inc.
7
8This file is part of GCC.
9
10GCC is free software; you can redistribute it and/or modify it under
11the terms of the GNU General Public License as published by the Free
12Software Foundation; either version 2, or (at your option) any later
13version.
14
15GCC is distributed in the hope that it will be useful, but WITHOUT ANY
16WARRANTY; without even the implied warranty of MERCHANTABILITY or
17FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
18for more details.
19
20You should have received a copy of the GNU General Public License
21along with GCC; see the file COPYING.  If not, write to the Free
22Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
2302110-1301, USA.  */
24
25
26/* Expression definitions and descriptions for all targets are in this file.
27   Some will not be used for some targets.
28
29   The fields in the cpp macro call "DEF_RTL_EXPR()"
30   are used to create declarations in the C source of the compiler.
31
32   The fields are:
33
34   1.  The internal name of the rtx used in the C source.
35   It is a tag in the enumeration "enum rtx_code" defined in "rtl.h".
36   By convention these are in UPPER_CASE.
37
38   2.  The name of the rtx in the external ASCII format read by
39   read_rtx(), and printed by print_rtx().
40   These names are stored in rtx_name[].
41   By convention these are the internal (field 1) names in lower_case.
42
43   3.  The print format, and type of each rtx->u.fld[] (field) in this rtx.
44   These formats are stored in rtx_format[].
45   The meaning of the formats is documented in front of this array in rtl.c
46   
47   4.  The class of the rtx.  These are stored in rtx_class and are accessed
48   via the GET_RTX_CLASS macro.  They are defined as follows:
49
50     RTX_CONST_OBJ
51         an rtx code that can be used to represent a constant object
52         (e.g, CONST_INT)
53     RTX_OBJ
54         an rtx code that can be used to represent an object (e.g, REG, MEM)
55     RTX_COMPARE
56         an rtx code for a comparison (e.g, LT, GT)
57     RTX_COMM_COMPARE
58         an rtx code for a commutative comparison (e.g, EQ, NE, ORDERED)
59     RTX_UNARY
60         an rtx code for a unary arithmetic expression (e.g, NEG, NOT)
61     RTX_COMM_ARITH
62         an rtx code for a commutative binary operation (e.g,, PLUS, MULT)
63     RTX_TERNARY
64         an rtx code for a non-bitfield three input operation (IF_THEN_ELSE)
65     RTX_BIN_ARITH
66         an rtx code for a non-commutative binary operation (e.g., MINUS, DIV)
67     RTX_BITFIELD_OPS
68         an rtx code for a bit-field operation (ZERO_EXTRACT, SIGN_EXTRACT)
69     RTX_INSN
70         an rtx code for a machine insn (INSN, JUMP_INSN, CALL_INSN)
71     RTX_MATCH
72         an rtx code for something that matches in insns (e.g, MATCH_DUP)
73     RTX_AUTOINC
74         an rtx code for autoincrement addressing modes (e.g. POST_DEC)
75     RTX_EXTRA
76         everything else
77
78   All of the expressions that appear only in machine descriptions,
79   not in RTL used by the compiler itself, are at the end of the file.  */
80
81/* Unknown, or no such operation; the enumeration constant should have
82   value zero.  */
83DEF_RTL_EXPR(UNKNOWN, "UnKnown", "*", RTX_EXTRA)
84
85/* ---------------------------------------------------------------------
86   Expressions used in constructing lists.
87   --------------------------------------------------------------------- */
88
89/* a linked list of expressions */
90DEF_RTL_EXPR(EXPR_LIST, "expr_list", "ee", RTX_EXTRA)
91
92/* a linked list of instructions.
93   The insns are represented in print by their uids.  */
94DEF_RTL_EXPR(INSN_LIST, "insn_list", "ue", RTX_EXTRA)
95
96/* a linked list of dependencies. 
97   The insns are represented in print by their uids. 
98   Operand 2 is the status of a dependence (see sched-int.h for more).  */
99DEF_RTL_EXPR(DEPS_LIST, "deps_list", "uei", RTX_EXTRA)
100
101/* SEQUENCE appears in the result of a `gen_...' function
102   for a DEFINE_EXPAND that wants to make several insns.
103   Its elements are the bodies of the insns that should be made.
104   `emit_insn' takes the SEQUENCE apart and makes separate insns.  */
105DEF_RTL_EXPR(SEQUENCE, "sequence", "E", RTX_EXTRA)
106
107/* Refers to the address of its argument.  This is only used in alias.c.  */
108DEF_RTL_EXPR(ADDRESS, "address", "e", RTX_MATCH)
109
110/* ----------------------------------------------------------------------
111   Expression types used for things in the instruction chain.
112
113   All formats must start with "iuu" to handle the chain.
114   Each insn expression holds an rtl instruction and its semantics
115   during back-end processing.
116   See macros's in "rtl.h" for the meaning of each rtx->u.fld[].
117
118   ---------------------------------------------------------------------- */
119
120/* An instruction that cannot jump.  */
121DEF_RTL_EXPR(INSN, "insn", "iuuBieiee", RTX_INSN)
122
123/* An instruction that can possibly jump.
124   Fields ( rtx->u.fld[] ) have exact same meaning as INSN's.  */
125DEF_RTL_EXPR(JUMP_INSN, "jump_insn", "iuuBieiee0", RTX_INSN)
126
127/* An instruction that can possibly call a subroutine
128   but which will not change which instruction comes next
129   in the current function.
130   Field ( rtx->u.fld[9] ) is CALL_INSN_FUNCTION_USAGE.
131   All other fields ( rtx->u.fld[] ) have exact same meaning as INSN's.  */
132DEF_RTL_EXPR(CALL_INSN, "call_insn", "iuuBieieee", RTX_INSN)
133
134/* A marker that indicates that control will not flow through.  */
135DEF_RTL_EXPR(BARRIER, "barrier", "iuu000000", RTX_EXTRA)
136
137/* Holds a label that is followed by instructions.
138   Operand:
139   4: is used in jump.c for the use-count of the label.
140   5: is used in flow.c to point to the chain of label_ref's to this label.
141   6: is a number that is unique in the entire compilation.
142   7: is the user-given name of the label, if any.  */
143DEF_RTL_EXPR(CODE_LABEL, "code_label", "iuuB00is", RTX_EXTRA)
144
145#ifdef USE_MAPPED_LOCATION
146/* Say where in the code a source line starts, for symbol table's sake.
147   Operand:
148   4: unused if line number > 0, note-specific data otherwise.
149   5: line number if > 0, enum note_insn otherwise.
150   6: CODE_LABEL_NUMBER if line number == NOTE_INSN_DELETED_LABEL.  */
151#else
152/* Say where in the code a source line starts, for symbol table's sake.
153   Operand:
154   4: filename, if line number > 0, note-specific data otherwise.
155   5: line number if > 0, enum note_insn otherwise.
156   6: unique number if line number == note_insn_deleted_label.  */
157#endif
158DEF_RTL_EXPR(NOTE, "note", "iuuB0ni", RTX_EXTRA)
159
160/* ----------------------------------------------------------------------
161   Top level constituents of INSN, JUMP_INSN and CALL_INSN.
162   ---------------------------------------------------------------------- */
163   
164/* Conditionally execute code.
165   Operand 0 is the condition that if true, the code is executed.
166   Operand 1 is the code to be executed (typically a SET). 
167
168   Semantics are that there are no side effects if the condition
169   is false.  This pattern is created automatically by the if_convert
170   pass run after reload or by target-specific splitters.  */
171DEF_RTL_EXPR(COND_EXEC, "cond_exec", "ee", RTX_EXTRA)
172
173/* Several operations to be done in parallel (perhaps under COND_EXEC).  */
174DEF_RTL_EXPR(PARALLEL, "parallel", "E", RTX_EXTRA)
175
176/* A string that is passed through to the assembler as input.
177     One can obviously pass comments through by using the
178     assembler comment syntax.
179     These occur in an insn all by themselves as the PATTERN.
180     They also appear inside an ASM_OPERANDS
181     as a convenient way to hold a string.  */
182DEF_RTL_EXPR(ASM_INPUT, "asm_input", "s", RTX_EXTRA)
183
184#ifdef USE_MAPPED_LOCATION
185/* An assembler instruction with operands.
186   1st operand is the instruction template.
187   2nd operand is the constraint for the output.
188   3rd operand is the number of the output this expression refers to.
189     When an insn stores more than one value, a separate ASM_OPERANDS
190     is made for each output; this integer distinguishes them.
191   4th is a vector of values of input operands.
192   5th is a vector of modes and constraints for the input operands.
193     Each element is an ASM_INPUT containing a constraint string
194     and whose mode indicates the mode of the input operand.
195   6th is the source line number.  */
196DEF_RTL_EXPR(ASM_OPERANDS, "asm_operands", "ssiEEi", RTX_EXTRA)
197#else
198/* An assembler instruction with operands.
199   1st operand is the instruction template.
200   2nd operand is the constraint for the output.
201   3rd operand is the number of the output this expression refers to.
202     When an insn stores more than one value, a separate ASM_OPERANDS
203     is made for each output; this integer distinguishes them.
204   4th is a vector of values of input operands.
205   5th is a vector of modes and constraints for the input operands.
206     Each element is an ASM_INPUT containing a constraint string
207     and whose mode indicates the mode of the input operand.
208   6th is the name of the containing source file.
209   7th is the source line number.  */
210DEF_RTL_EXPR(ASM_OPERANDS, "asm_operands", "ssiEEsi", RTX_EXTRA)
211#endif
212
213/* A machine-specific operation.
214   1st operand is a vector of operands being used by the operation so that
215     any needed reloads can be done.
216   2nd operand is a unique value saying which of a number of machine-specific
217     operations is to be performed.
218   (Note that the vector must be the first operand because of the way that
219   genrecog.c record positions within an insn.)
220   This can occur all by itself in a PATTERN, as a component of a PARALLEL,
221   or inside an expression.  */
222DEF_RTL_EXPR(UNSPEC, "unspec", "Ei", RTX_EXTRA)
223
224/* Similar, but a volatile operation and one which may trap.  */
225DEF_RTL_EXPR(UNSPEC_VOLATILE, "unspec_volatile", "Ei", RTX_EXTRA)
226
227/* Vector of addresses, stored as full words.  */
228/* Each element is a LABEL_REF to a CODE_LABEL whose address we want.  */
229DEF_RTL_EXPR(ADDR_VEC, "addr_vec", "E", RTX_EXTRA)
230
231/* Vector of address differences X0 - BASE, X1 - BASE, ...
232   First operand is BASE; the vector contains the X's.
233   The machine mode of this rtx says how much space to leave
234   for each difference and is adjusted by branch shortening if
235   CASE_VECTOR_SHORTEN_MODE is defined.
236   The third and fourth operands store the target labels with the
237   minimum and maximum addresses respectively.
238   The fifth operand stores flags for use by branch shortening.
239  Set at the start of shorten_branches:
240   min_align: the minimum alignment for any of the target labels.
241   base_after_vec: true iff BASE is after the ADDR_DIFF_VEC.
242   min_after_vec: true iff minimum addr target label is after the ADDR_DIFF_VEC.
243   max_after_vec: true iff maximum addr target label is after the ADDR_DIFF_VEC.
244   min_after_base: true iff minimum address target label is after BASE.
245   max_after_base: true iff maximum address target label is after BASE.
246  Set by the actual branch shortening process:
247   offset_unsigned: true iff offsets have to be treated as unsigned.
248   scale: scaling that is necessary to make offsets fit into the mode.
249
250   The third, fourth and fifth operands are only valid when
251   CASE_VECTOR_SHORTEN_MODE is defined, and only in an optimizing
252   compilations.  */
253     
254DEF_RTL_EXPR(ADDR_DIFF_VEC, "addr_diff_vec", "eEee0", RTX_EXTRA)
255
256/* Memory prefetch, with attributes supported on some targets.
257   Operand 1 is the address of the memory to fetch.
258   Operand 2 is 1 for a write access, 0 otherwise.
259   Operand 3 is the level of temporal locality; 0 means there is no
260   temporal locality and 1, 2, and 3 are for increasing levels of temporal
261   locality.
262
263   The attributes specified by operands 2 and 3 are ignored for targets
264   whose prefetch instructions do not support them.  */
265DEF_RTL_EXPR(PREFETCH, "prefetch", "eee", RTX_EXTRA)
266
267/* ----------------------------------------------------------------------
268   At the top level of an instruction (perhaps under PARALLEL).
269   ---------------------------------------------------------------------- */
270
271/* Assignment.
272   Operand 1 is the location (REG, MEM, PC, CC0 or whatever) assigned to.
273   Operand 2 is the value stored there.
274   ALL assignment must use SET.
275   Instructions that do multiple assignments must use multiple SET,
276   under PARALLEL.  */
277DEF_RTL_EXPR(SET, "set", "ee", RTX_EXTRA)
278
279/* Indicate something is used in a way that we don't want to explain.
280   For example, subroutine calls will use the register
281   in which the static chain is passed.  */
282DEF_RTL_EXPR(USE, "use", "e", RTX_EXTRA)
283
284/* Indicate something is clobbered in a way that we don't want to explain.
285   For example, subroutine calls will clobber some physical registers
286   (the ones that are by convention not saved).  */
287DEF_RTL_EXPR(CLOBBER, "clobber", "e", RTX_EXTRA)
288
289/* Call a subroutine.
290   Operand 1 is the address to call.
291   Operand 2 is the number of arguments.  */
292
293DEF_RTL_EXPR(CALL, "call", "ee", RTX_EXTRA)
294
295/* Return from a subroutine.  */
296
297DEF_RTL_EXPR(RETURN, "return", "", RTX_EXTRA)
298
299/* Conditional trap.
300   Operand 1 is the condition.
301   Operand 2 is the trap code.
302   For an unconditional trap, make the condition (const_int 1).  */
303DEF_RTL_EXPR(TRAP_IF, "trap_if", "ee", RTX_EXTRA)
304
305/* Placeholder for _Unwind_Resume before we know if a function call
306   or a branch is needed.  Operand 1 is the exception region from
307   which control is flowing.  */
308DEF_RTL_EXPR(RESX, "resx", "i", RTX_EXTRA)
309
310/* ----------------------------------------------------------------------
311   Primitive values for use in expressions.
312   ---------------------------------------------------------------------- */
313
314/* numeric integer constant */
315DEF_RTL_EXPR(CONST_INT, "const_int", "w", RTX_CONST_OBJ)
316
317/* numeric floating point constant.
318   Operands hold the value.  They are all 'w' and there may be from 2 to 6;
319   see real.h.  */
320DEF_RTL_EXPR(CONST_DOUBLE, "const_double", CONST_DOUBLE_FORMAT, RTX_CONST_OBJ)
321
322/* Describes a vector constant.  */
323DEF_RTL_EXPR(CONST_VECTOR, "const_vector", "E", RTX_CONST_OBJ)
324
325/* String constant.  Used for attributes in machine descriptions and
326   for special cases in DWARF2 debug output.  NOT used for source-
327   language string constants.  */
328DEF_RTL_EXPR(CONST_STRING, "const_string", "s", RTX_OBJ)
329
330/* This is used to encapsulate an expression whose value is constant
331   (such as the sum of a SYMBOL_REF and a CONST_INT) so that it will be
332   recognized as a constant operand rather than by arithmetic instructions.  */
333
334DEF_RTL_EXPR(CONST, "const", "e", RTX_CONST_OBJ)
335
336/* program counter.  Ordinary jumps are represented
337   by a SET whose first operand is (PC).  */
338DEF_RTL_EXPR(PC, "pc", "", RTX_OBJ)
339
340/* Used in the cselib routines to describe a value.  Objects of this
341   kind are only allocated in cselib.c, in an alloc pool instead of
342   in GC memory.  The only operand of a VALUE is a cselib_val_struct.  */
343DEF_RTL_EXPR(VALUE, "value", "0", RTX_OBJ)
344
345/* A register.  The "operand" is the register number, accessed with
346   the REGNO macro.  If this number is less than FIRST_PSEUDO_REGISTER
347   than a hardware register is being referred to.  The second operand
348   holds the original register number - this will be different for a
349   pseudo register that got turned into a hard register.  The third
350   operand points to a reg_attrs structure.
351   This rtx needs to have as many (or more) fields as a MEM, since we
352   can change REG rtx's into MEMs during reload.  */
353DEF_RTL_EXPR(REG, "reg", "i00", RTX_OBJ)
354
355/* A scratch register.  This represents a register used only within a
356   single insn.  It will be turned into a REG during register allocation
357   or reload unless the constraint indicates that the register won't be
358   needed, in which case it can remain a SCRATCH.  This code is
359   marked as having one operand so it can be turned into a REG.  */
360DEF_RTL_EXPR(SCRATCH, "scratch", "0", RTX_OBJ)
361
362/* One word of a multi-word value.
363   The first operand is the complete value; the second says which word.
364   The WORDS_BIG_ENDIAN flag controls whether word number 0
365   (as numbered in a SUBREG) is the most or least significant word.
366
367   This is also used to refer to a value in a different machine mode.
368   For example, it can be used to refer to a SImode value as if it were
369   Qimode, or vice versa.  Then the word number is always 0.  */
370DEF_RTL_EXPR(SUBREG, "subreg", "ei", RTX_EXTRA)
371
372/* This one-argument rtx is used for move instructions
373   that are guaranteed to alter only the low part of a destination.
374   Thus, (SET (SUBREG:HI (REG...)) (MEM:HI ...))
375   has an unspecified effect on the high part of REG,
376   but (SET (STRICT_LOW_PART (SUBREG:HI (REG...))) (MEM:HI ...))
377   is guaranteed to alter only the bits of REG that are in HImode.
378
379   The actual instruction used is probably the same in both cases,
380   but the register constraints may be tighter when STRICT_LOW_PART
381   is in use.  */
382
383DEF_RTL_EXPR(STRICT_LOW_PART, "strict_low_part", "e", RTX_EXTRA)
384
385/* (CONCAT a b) represents the virtual concatenation of a and b
386   to make a value that has as many bits as a and b put together.
387   This is used for complex values.  Normally it appears only
388   in DECL_RTLs and during RTL generation, but not in the insn chain.  */
389DEF_RTL_EXPR(CONCAT, "concat", "ee", RTX_OBJ)
390
391/* A memory location; operand is the address.  The second operand is the
392   alias set to which this MEM belongs.  We use `0' instead of `w' for this
393   field so that the field need not be specified in machine descriptions.  */
394DEF_RTL_EXPR(MEM, "mem", "e0", RTX_OBJ)
395
396/* Reference to an assembler label in the code for this function.
397   The operand is a CODE_LABEL found in the insn chain.  */
398DEF_RTL_EXPR(LABEL_REF, "label_ref", "u", RTX_CONST_OBJ)
399
400/* Reference to a named label: 
401   Operand 0: label name
402   Operand 1: flags (see SYMBOL_FLAG_* in rtl.h)
403   Operand 2: tree from which this symbol is derived, or null.
404   This is either a DECL node, or some kind of constant.  */
405DEF_RTL_EXPR(SYMBOL_REF, "symbol_ref", "s00", RTX_CONST_OBJ)
406
407/* The condition code register is represented, in our imagination,
408   as a register holding a value that can be compared to zero.
409   In fact, the machine has already compared them and recorded the
410   results; but instructions that look at the condition code
411   pretend to be looking at the entire value and comparing it.  */
412DEF_RTL_EXPR(CC0, "cc0", "", RTX_OBJ)
413
414/* ----------------------------------------------------------------------
415   Expressions for operators in an rtl pattern
416   ---------------------------------------------------------------------- */
417
418/* if_then_else.  This is used in representing ordinary
419   conditional jump instructions.
420     Operand:
421     0:  condition
422     1:  then expr
423     2:  else expr */
424DEF_RTL_EXPR(IF_THEN_ELSE, "if_then_else", "eee", RTX_TERNARY)
425
426/* Comparison, produces a condition code result.  */
427DEF_RTL_EXPR(COMPARE, "compare", "ee", RTX_BIN_ARITH)
428
429/* plus */
430DEF_RTL_EXPR(PLUS, "plus", "ee", RTX_COMM_ARITH)
431
432/* Operand 0 minus operand 1.  */
433DEF_RTL_EXPR(MINUS, "minus", "ee", RTX_BIN_ARITH)
434
435/* Minus operand 0.  */
436DEF_RTL_EXPR(NEG, "neg", "e", RTX_UNARY)
437
438DEF_RTL_EXPR(MULT, "mult", "ee", RTX_COMM_ARITH)
439
440/* Operand 0 divided by operand 1.  */
441DEF_RTL_EXPR(DIV, "div", "ee", RTX_BIN_ARITH)
442/* Remainder of operand 0 divided by operand 1.  */
443DEF_RTL_EXPR(MOD, "mod", "ee", RTX_BIN_ARITH)
444
445/* Unsigned divide and remainder.  */
446DEF_RTL_EXPR(UDIV, "udiv", "ee", RTX_BIN_ARITH)
447DEF_RTL_EXPR(UMOD, "umod", "ee", RTX_BIN_ARITH)
448
449/* Bitwise operations.  */
450DEF_RTL_EXPR(AND, "and", "ee", RTX_COMM_ARITH)
451DEF_RTL_EXPR(IOR, "ior", "ee", RTX_COMM_ARITH)
452DEF_RTL_EXPR(XOR, "xor", "ee", RTX_COMM_ARITH)
453DEF_RTL_EXPR(NOT, "not", "e", RTX_UNARY)
454
455/* Operand:
456     0:  value to be shifted.
457     1:  number of bits.  */
458DEF_RTL_EXPR(ASHIFT, "ashift", "ee", RTX_BIN_ARITH) /* shift left */
459DEF_RTL_EXPR(ROTATE, "rotate", "ee", RTX_BIN_ARITH) /* rotate left */
460DEF_RTL_EXPR(ASHIFTRT, "ashiftrt", "ee", RTX_BIN_ARITH) /* arithmetic shift right */
461DEF_RTL_EXPR(LSHIFTRT, "lshiftrt", "ee", RTX_BIN_ARITH) /* logical shift right */
462DEF_RTL_EXPR(ROTATERT, "rotatert", "ee", RTX_BIN_ARITH) /* rotate right */
463
464/* Minimum and maximum values of two operands.  We need both signed and
465   unsigned forms.  (We cannot use MIN for SMIN because it conflicts
466   with a macro of the same name.)   The signed variants should be used
467   with floating point.  Further, if both operands are zeros, or if either
468   operand is NaN, then it is unspecified which of the two operands is
469   returned as the result.  */
470
471DEF_RTL_EXPR(SMIN, "smin", "ee", RTX_COMM_ARITH)
472DEF_RTL_EXPR(SMAX, "smax", "ee", RTX_COMM_ARITH)
473DEF_RTL_EXPR(UMIN, "umin", "ee", RTX_COMM_ARITH)
474DEF_RTL_EXPR(UMAX, "umax", "ee", RTX_COMM_ARITH)
475
476/* These unary operations are used to represent incrementation
477   and decrementation as they occur in memory addresses.
478   The amount of increment or decrement are not represented
479   because they can be understood from the machine-mode of the
480   containing MEM.  These operations exist in only two cases:
481   1. pushes onto the stack.
482   2. created automatically by the life_analysis pass in flow.c.  */
483DEF_RTL_EXPR(PRE_DEC, "pre_dec", "e", RTX_AUTOINC)
484DEF_RTL_EXPR(PRE_INC, "pre_inc", "e", RTX_AUTOINC)
485DEF_RTL_EXPR(POST_DEC, "post_dec", "e", RTX_AUTOINC)
486DEF_RTL_EXPR(POST_INC, "post_inc", "e", RTX_AUTOINC)
487
488/* These binary operations are used to represent generic address
489   side-effects in memory addresses, except for simple incrementation
490   or decrementation which use the above operations.  They are
491   created automatically by the life_analysis pass in flow.c.
492   The first operand is a REG which is used as the address.
493   The second operand is an expression that is assigned to the
494   register, either before (PRE_MODIFY) or after (POST_MODIFY)
495   evaluating the address.
496   Currently, the compiler can only handle second operands of the
497   form (plus (reg) (reg)) and (plus (reg) (const_int)), where
498   the first operand of the PLUS has to be the same register as
499   the first operand of the *_MODIFY.  */
500DEF_RTL_EXPR(PRE_MODIFY, "pre_modify", "ee", RTX_AUTOINC)
501DEF_RTL_EXPR(POST_MODIFY, "post_modify", "ee", RTX_AUTOINC)
502
503/* Comparison operations.  The ordered comparisons exist in two
504   flavors, signed and unsigned.  */
505DEF_RTL_EXPR(NE, "ne", "ee", RTX_COMM_COMPARE)
506DEF_RTL_EXPR(EQ, "eq", "ee", RTX_COMM_COMPARE)
507DEF_RTL_EXPR(GE, "ge", "ee", RTX_COMPARE)
508DEF_RTL_EXPR(GT, "gt", "ee", RTX_COMPARE)
509DEF_RTL_EXPR(LE, "le", "ee", RTX_COMPARE)
510DEF_RTL_EXPR(LT, "lt", "ee", RTX_COMPARE)
511DEF_RTL_EXPR(GEU, "geu", "ee", RTX_COMPARE)
512DEF_RTL_EXPR(GTU, "gtu", "ee", RTX_COMPARE)
513DEF_RTL_EXPR(LEU, "leu", "ee", RTX_COMPARE)
514DEF_RTL_EXPR(LTU, "ltu", "ee", RTX_COMPARE)
515
516/* Additional floating point unordered comparison flavors.  */
517DEF_RTL_EXPR(UNORDERED, "unordered", "ee", RTX_COMM_COMPARE)
518DEF_RTL_EXPR(ORDERED, "ordered", "ee", RTX_COMM_COMPARE)
519
520/* These are equivalent to unordered or ...  */
521DEF_RTL_EXPR(UNEQ, "uneq", "ee", RTX_COMM_COMPARE)
522DEF_RTL_EXPR(UNGE, "unge", "ee", RTX_COMPARE)
523DEF_RTL_EXPR(UNGT, "ungt", "ee", RTX_COMPARE)
524DEF_RTL_EXPR(UNLE, "unle", "ee", RTX_COMPARE)
525DEF_RTL_EXPR(UNLT, "unlt", "ee", RTX_COMPARE)
526
527/* This is an ordered NE, ie !UNEQ, ie false for NaN.  */
528DEF_RTL_EXPR(LTGT, "ltgt", "ee", RTX_COMM_COMPARE)
529
530/* Represents the result of sign-extending the sole operand.
531   The machine modes of the operand and of the SIGN_EXTEND expression
532   determine how much sign-extension is going on.  */
533DEF_RTL_EXPR(SIGN_EXTEND, "sign_extend", "e", RTX_UNARY)
534
535/* Similar for zero-extension (such as unsigned short to int).  */
536DEF_RTL_EXPR(ZERO_EXTEND, "zero_extend", "e", RTX_UNARY)
537
538/* Similar but here the operand has a wider mode.  */
539DEF_RTL_EXPR(TRUNCATE, "truncate", "e", RTX_UNARY)
540
541/* Similar for extending floating-point values (such as SFmode to DFmode).  */
542DEF_RTL_EXPR(FLOAT_EXTEND, "float_extend", "e", RTX_UNARY)
543DEF_RTL_EXPR(FLOAT_TRUNCATE, "float_truncate", "e", RTX_UNARY)
544
545/* Conversion of fixed point operand to floating point value.  */
546DEF_RTL_EXPR(FLOAT, "float", "e", RTX_UNARY)
547
548/* With fixed-point machine mode:
549   Conversion of floating point operand to fixed point value.
550   Value is defined only when the operand's value is an integer.
551   With floating-point machine mode (and operand with same mode):
552   Operand is rounded toward zero to produce an integer value
553   represented in floating point.  */
554DEF_RTL_EXPR(FIX, "fix", "e", RTX_UNARY)
555
556/* Conversion of unsigned fixed point operand to floating point value.  */
557DEF_RTL_EXPR(UNSIGNED_FLOAT, "unsigned_float", "e", RTX_UNARY)
558
559/* With fixed-point machine mode:
560   Conversion of floating point operand to *unsigned* fixed point value.
561   Value is defined only when the operand's value is an integer.  */
562DEF_RTL_EXPR(UNSIGNED_FIX, "unsigned_fix", "e", RTX_UNARY)
563
564/* Absolute value */
565DEF_RTL_EXPR(ABS, "abs", "e", RTX_UNARY)
566
567/* Square root */
568DEF_RTL_EXPR(SQRT, "sqrt", "e", RTX_UNARY)
569
570/* Swap bytes.  */
571DEF_RTL_EXPR(BSWAP, "bswap", "e", RTX_UNARY)
572
573/* Find first bit that is set.
574   Value is 1 + number of trailing zeros in the arg.,
575   or 0 if arg is 0.  */
576DEF_RTL_EXPR(FFS, "ffs", "e", RTX_UNARY)
577
578/* Count leading zeros.  */
579DEF_RTL_EXPR(CLZ, "clz", "e", RTX_UNARY)
580
581/* Count trailing zeros.  */
582DEF_RTL_EXPR(CTZ, "ctz", "e", RTX_UNARY)
583
584/* Population count (number of 1 bits).  */
585DEF_RTL_EXPR(POPCOUNT, "popcount", "e", RTX_UNARY)
586
587/* Population parity (number of 1 bits modulo 2).  */
588DEF_RTL_EXPR(PARITY, "parity", "e", RTX_UNARY)
589
590/* Reference to a signed bit-field of specified size and position.
591   Operand 0 is the memory unit (usually SImode or QImode) which
592   contains the field's first bit.  Operand 1 is the width, in bits.
593   Operand 2 is the number of bits in the memory unit before the
594   first bit of this field.
595   If BITS_BIG_ENDIAN is defined, the first bit is the msb and
596   operand 2 counts from the msb of the memory unit.
597   Otherwise, the first bit is the lsb and operand 2 counts from
598   the lsb of the memory unit.
599   This kind of expression can not appear as an lvalue in RTL.  */
600DEF_RTL_EXPR(SIGN_EXTRACT, "sign_extract", "eee", RTX_BITFIELD_OPS)
601
602/* Similar for unsigned bit-field.
603   But note!  This kind of expression _can_ appear as an lvalue.  */
604DEF_RTL_EXPR(ZERO_EXTRACT, "zero_extract", "eee", RTX_BITFIELD_OPS)
605
606/* For RISC machines.  These save memory when splitting insns.  */
607
608/* HIGH are the high-order bits of a constant expression.  */
609DEF_RTL_EXPR(HIGH, "high", "e", RTX_CONST_OBJ)
610
611/* LO_SUM is the sum of a register and the low-order bits
612   of a constant expression.  */
613DEF_RTL_EXPR(LO_SUM, "lo_sum", "ee", RTX_OBJ)
614
615/* Describes a merge operation between two vector values.
616   Operands 0 and 1 are the vectors to be merged, operand 2 is a bitmask
617   that specifies where the parts of the result are taken from.  Set bits
618   indicate operand 0, clear bits indicate operand 1.  The parts are defined
619   by the mode of the vectors.  */
620DEF_RTL_EXPR(VEC_MERGE, "vec_merge", "eee", RTX_TERNARY)
621
622/* Describes an operation that selects parts of a vector.
623   Operands 0 is the source vector, operand 1 is a PARALLEL that contains
624   a CONST_INT for each of the subparts of the result vector, giving the
625   number of the source subpart that should be stored into it.  */
626DEF_RTL_EXPR(VEC_SELECT, "vec_select", "ee", RTX_BIN_ARITH)
627
628/* Describes a vector concat operation.  Operands 0 and 1 are the source
629   vectors, the result is a vector that is as long as operands 0 and 1
630   combined and is the concatenation of the two source vectors.  */
631DEF_RTL_EXPR(VEC_CONCAT, "vec_concat", "ee", RTX_BIN_ARITH)
632
633/* Describes an operation that converts a small vector into a larger one by
634   duplicating the input values.  The output vector mode must have the same
635   submodes as the input vector mode, and the number of output parts must be
636   an integer multiple of the number of input parts.  */
637DEF_RTL_EXPR(VEC_DUPLICATE, "vec_duplicate", "e", RTX_UNARY)
638     
639/* Addition with signed saturation */
640DEF_RTL_EXPR(SS_PLUS, "ss_plus", "ee", RTX_COMM_ARITH)
641
642/* Addition with unsigned saturation */
643DEF_RTL_EXPR(US_PLUS, "us_plus", "ee", RTX_COMM_ARITH)
644
645/* Operand 0 minus operand 1, with signed saturation.  */
646DEF_RTL_EXPR(SS_MINUS, "ss_minus", "ee", RTX_BIN_ARITH)
647
648/* Negation with signed saturation.  */
649DEF_RTL_EXPR(SS_NEG, "ss_neg", "e", RTX_UNARY)
650
651/* Shift left with signed saturation.  */
652DEF_RTL_EXPR(SS_ASHIFT, "ss_ashift", "ee", RTX_BIN_ARITH)
653
654/* Operand 0 minus operand 1, with unsigned saturation.  */
655DEF_RTL_EXPR(US_MINUS, "us_minus", "ee", RTX_BIN_ARITH)
656
657/* Signed saturating truncate.  */
658DEF_RTL_EXPR(SS_TRUNCATE, "ss_truncate", "e", RTX_UNARY)
659
660/* Unsigned saturating truncate.  */
661DEF_RTL_EXPR(US_TRUNCATE, "us_truncate", "e", RTX_UNARY)
662
663/* Information about the variable and its location.  */
664DEF_RTL_EXPR(VAR_LOCATION, "var_location", "te", RTX_EXTRA)
665
666/* All expressions from this point forward appear only in machine
667   descriptions.  */
668#ifdef GENERATOR_FILE
669
670/* Include a secondary machine-description file at this point.  */
671DEF_RTL_EXPR(INCLUDE, "include", "s", RTX_EXTRA)
672
673/* Pattern-matching operators:  */
674
675/* Use the function named by the second arg (the string)
676   as a predicate; if matched, store the structure that was matched
677   in the operand table at index specified by the first arg (the integer).
678   If the second arg is the null string, the structure is just stored.
679
680   A third string argument indicates to the register allocator restrictions
681   on where the operand can be allocated.
682
683   If the target needs no restriction on any instruction this field should
684   be the null string.
685
686   The string is prepended by:
687   '=' to indicate the operand is only written to.
688   '+' to indicate the operand is both read and written to.
689
690   Each character in the string represents an allocable class for an operand.
691   'g' indicates the operand can be any valid class.
692   'i' indicates the operand can be immediate (in the instruction) data.
693   'r' indicates the operand can be in a register.
694   'm' indicates the operand can be in memory.
695   'o' a subset of the 'm' class.  Those memory addressing modes that
696       can be offset at compile time (have a constant added to them).
697
698   Other characters indicate target dependent operand classes and
699   are described in each target's machine description.
700
701   For instructions with more than one operand, sets of classes can be
702   separated by a comma to indicate the appropriate multi-operand constraints.
703   There must be a 1 to 1 correspondence between these sets of classes in
704   all operands for an instruction.
705   */
706DEF_RTL_EXPR(MATCH_OPERAND, "match_operand", "iss", RTX_MATCH)
707
708/* Match a SCRATCH or a register.  When used to generate rtl, a
709   SCRATCH is generated.  As for MATCH_OPERAND, the mode specifies
710   the desired mode and the first argument is the operand number.
711   The second argument is the constraint.  */
712DEF_RTL_EXPR(MATCH_SCRATCH, "match_scratch", "is", RTX_MATCH)
713
714/* Apply a predicate, AND match recursively the operands of the rtx.
715   Operand 0 is the operand-number, as in match_operand.
716   Operand 1 is a predicate to apply (as a string, a function name).
717   Operand 2 is a vector of expressions, each of which must match
718   one subexpression of the rtx this construct is matching.  */
719DEF_RTL_EXPR(MATCH_OPERATOR, "match_operator", "isE", RTX_MATCH)
720
721/* Match a PARALLEL of arbitrary length.  The predicate is applied
722   to the PARALLEL and the initial expressions in the PARALLEL are matched.
723   Operand 0 is the operand-number, as in match_operand.
724   Operand 1 is a predicate to apply to the PARALLEL.
725   Operand 2 is a vector of expressions, each of which must match the 
726   corresponding element in the PARALLEL.  */
727DEF_RTL_EXPR(MATCH_PARALLEL, "match_parallel", "isE", RTX_MATCH)
728
729/* Match only something equal to what is stored in the operand table
730   at the index specified by the argument.  Use with MATCH_OPERAND.  */
731DEF_RTL_EXPR(MATCH_DUP, "match_dup", "i", RTX_MATCH)
732
733/* Match only something equal to what is stored in the operand table
734   at the index specified by the argument.  Use with MATCH_OPERATOR.  */
735DEF_RTL_EXPR(MATCH_OP_DUP, "match_op_dup", "iE", RTX_MATCH)
736
737/* Match only something equal to what is stored in the operand table
738   at the index specified by the argument.  Use with MATCH_PARALLEL.  */
739DEF_RTL_EXPR(MATCH_PAR_DUP, "match_par_dup", "iE", RTX_MATCH)
740
741/* Appears only in define_predicate/define_special_predicate
742   expressions.  Evaluates true only if the operand has an RTX code
743   from the set given by the argument (a comma-separated list).  If the
744   second argument is present and nonempty, it is a sequence of digits
745   and/or letters which indicates the subexpression to test, using the
746   same syntax as genextract/genrecog's location strings: 0-9 for
747   XEXP (op, n), a-z for XVECEXP (op, 0, n); each character applies to
748   the result of the one before it.  */
749DEF_RTL_EXPR(MATCH_CODE, "match_code", "ss", RTX_MATCH)
750
751/* Appears only in define_predicate/define_special_predicate
752    expressions.  The argument is a C expression to be injected at this
753    point in the predicate formula.  */
754DEF_RTL_EXPR(MATCH_TEST, "match_test", "s", RTX_MATCH)
755
756/* Insn (and related) definitions.  */
757
758/* Definition of the pattern for one kind of instruction.
759   Operand:
760   0: names this instruction.
761      If the name is the null string, the instruction is in the
762      machine description just to be recognized, and will never be emitted by
763      the tree to rtl expander.
764   1: is the pattern.
765   2: is a string which is a C expression
766      giving an additional condition for recognizing this pattern.
767      A null string means no extra condition.
768   3: is the action to execute if this pattern is matched.
769      If this assembler code template starts with a * then it is a fragment of
770      C code to run to decide on a template to use.  Otherwise, it is the
771      template to use.
772   4: optionally, a vector of attributes for this insn.
773     */
774DEF_RTL_EXPR(DEFINE_INSN, "define_insn", "sEsTV", RTX_EXTRA)
775
776/* Definition of a peephole optimization.
777   1st operand: vector of insn patterns to match
778   2nd operand: C expression that must be true
779   3rd operand: template or C code to produce assembler output.
780   4: optionally, a vector of attributes for this insn.
781
782   This form is deprecated; use define_peephole2 instead.  */
783DEF_RTL_EXPR(DEFINE_PEEPHOLE, "define_peephole", "EsTV", RTX_EXTRA)
784
785/* Definition of a split operation.
786   1st operand: insn pattern to match
787   2nd operand: C expression that must be true
788   3rd operand: vector of insn patterns to place into a SEQUENCE
789   4th operand: optionally, some C code to execute before generating the
790	insns.  This might, for example, create some RTX's and store them in
791	elements of `recog_data.operand' for use by the vector of
792	insn-patterns.
793	(`operands' is an alias here for `recog_data.operand').  */
794DEF_RTL_EXPR(DEFINE_SPLIT, "define_split", "EsES", RTX_EXTRA)
795
796/* Definition of an insn and associated split.
797   This is the concatenation, with a few modifications, of a define_insn
798   and a define_split which share the same pattern.
799   Operand:
800   0: names this instruction.
801      If the name is the null string, the instruction is in the
802      machine description just to be recognized, and will never be emitted by
803      the tree to rtl expander.
804   1: is the pattern.
805   2: is a string which is a C expression
806      giving an additional condition for recognizing this pattern.
807      A null string means no extra condition.
808   3: is the action to execute if this pattern is matched.
809      If this assembler code template starts with a * then it is a fragment of
810      C code to run to decide on a template to use.  Otherwise, it is the
811      template to use.
812   4: C expression that must be true for split.  This may start with "&&"
813      in which case the split condition is the logical and of the insn 
814      condition and what follows the "&&" of this operand.
815   5: vector of insn patterns to place into a SEQUENCE
816   6: optionally, some C code to execute before generating the
817	insns.  This might, for example, create some RTX's and store them in
818	elements of `recog_data.operand' for use by the vector of
819	insn-patterns.
820	(`operands' is an alias here for `recog_data.operand').  
821   7: optionally, a vector of attributes for this insn.  */
822DEF_RTL_EXPR(DEFINE_INSN_AND_SPLIT, "define_insn_and_split", "sEsTsESV", RTX_EXTRA)
823
824/* Definition of an RTL peephole operation.
825   Follows the same arguments as define_split.  */
826DEF_RTL_EXPR(DEFINE_PEEPHOLE2, "define_peephole2", "EsES", RTX_EXTRA)
827
828/* Define how to generate multiple insns for a standard insn name.
829   1st operand: the insn name.
830   2nd operand: vector of insn-patterns.
831	Use match_operand to substitute an element of `recog_data.operand'.
832   3rd operand: C expression that must be true for this to be available.
833	This may not test any operands.
834   4th operand: Extra C code to execute before generating the insns.
835	This might, for example, create some RTX's and store them in
836	elements of `recog_data.operand' for use by the vector of
837	insn-patterns.
838	(`operands' is an alias here for `recog_data.operand').  */
839DEF_RTL_EXPR(DEFINE_EXPAND, "define_expand", "sEss", RTX_EXTRA)
840   
841/* Define a requirement for delay slots.
842   1st operand: Condition involving insn attributes that, if true,
843	        indicates that the insn requires the number of delay slots
844		shown.
845   2nd operand: Vector whose length is the three times the number of delay
846		slots required.
847	        Each entry gives three conditions, each involving attributes.
848		The first must be true for an insn to occupy that delay slot
849		location.  The second is true for all insns that can be
850		annulled if the branch is true and the third is true for all
851		insns that can be annulled if the branch is false. 
852
853   Multiple DEFINE_DELAYs may be present.  They indicate differing
854   requirements for delay slots.  */
855DEF_RTL_EXPR(DEFINE_DELAY, "define_delay", "eE", RTX_EXTRA)
856
857/* Define attribute computation for `asm' instructions.  */
858DEF_RTL_EXPR(DEFINE_ASM_ATTRIBUTES, "define_asm_attributes", "V", RTX_EXTRA)
859
860/* Definition of a conditional execution meta operation.  Automatically
861   generates new instances of DEFINE_INSN, selected by having attribute
862   "predicable" true.  The new pattern will contain a COND_EXEC and the
863   predicate at top-level.
864
865   Operand:
866   0: The predicate pattern.  The top-level form should match a
867      relational operator.  Operands should have only one alternative.
868   1: A C expression giving an additional condition for recognizing
869      the generated pattern.
870   2: A template or C code to produce assembler output.  */
871DEF_RTL_EXPR(DEFINE_COND_EXEC, "define_cond_exec", "Ess", RTX_EXTRA)
872
873/* Definition of an operand predicate.  The difference between
874   DEFINE_PREDICATE and DEFINE_SPECIAL_PREDICATE is that genrecog will
875   not warn about a match_operand with no mode if it has a predicate
876   defined with DEFINE_SPECIAL_PREDICATE.
877
878   Operand:
879   0: The name of the predicate.
880   1: A boolean expression which computes whether or not the predicate
881      matches.  This expression can use IOR, AND, NOT, MATCH_OPERAND,
882      MATCH_CODE, and MATCH_TEST.  It must be specific enough that genrecog
883      can calculate the set of RTX codes that can possibly match.
884   2: A C function body which must return true for the predicate to match.
885      Optional.  Use this when the test is too complicated to fit into a
886      match_test expression.  */
887DEF_RTL_EXPR(DEFINE_PREDICATE, "define_predicate", "ses", RTX_EXTRA)
888DEF_RTL_EXPR(DEFINE_SPECIAL_PREDICATE, "define_special_predicate", "ses", RTX_EXTRA)
889
890/* Definition of a register operand constraint.  This simply maps the
891   constraint string to a register class.
892
893   Operand:
894   0: The name of the constraint (often, but not always, a single letter).
895   1: A C expression which evaluates to the appropriate register class for
896      this constraint.  If this is not just a constant, it should look only
897      at -m switches and the like.
898   2: A docstring for this constraint, in Texinfo syntax; not currently
899      used, in future will be incorporated into the manual's list of
900      machine-specific operand constraints.  */
901DEF_RTL_EXPR(DEFINE_REGISTER_CONSTRAINT, "define_register_constraint", "sss", RTX_EXTRA)
902
903/* Definition of a non-register operand constraint.  These look at the
904   operand and decide whether it fits the constraint.
905
906   DEFINE_CONSTRAINT gets no special treatment if it fails to match.
907   It is appropriate for constant-only constraints, and most others.
908
909   DEFINE_MEMORY_CONSTRAINT tells reload that this constraint can be made
910   to match, if it doesn't already, by converting the operand to the form
911   (mem (reg X)) where X is a base register.  It is suitable for constraints
912   that describe a subset of all memory references.
913
914   DEFINE_ADDRESS_CONSTRAINT tells reload that this constraint can be made
915   to match, if it doesn't already, by converting the operand to the form
916   (reg X) where X is a base register.  It is suitable for constraints that
917   describe a subset of all address references.
918
919   When in doubt, use plain DEFINE_CONSTRAINT.  
920
921   Operand:
922   0: The name of the constraint (often, but not always, a single letter).
923   1: A docstring for this constraint, in Texinfo syntax; not currently
924      used, in future will be incorporated into the manual's list of
925      machine-specific operand constraints.
926   2: A boolean expression which computes whether or not the constraint
927      matches.  It should follow the same rules as a define_predicate
928      expression, including the bit about specifying the set of RTX codes
929      that could possibly match.  MATCH_TEST subexpressions may make use of
930      these variables:
931        `op'    - the RTL object defining the operand.
932        `mode'  - the mode of `op'.
933	`ival'  - INTVAL(op), if op is a CONST_INT.
934        `hval'  - CONST_DOUBLE_HIGH(op), if op is an integer CONST_DOUBLE.
935        `lval'  - CONST_DOUBLE_LOW(op), if op is an integer CONST_DOUBLE.
936        `rval'  - CONST_DOUBLE_REAL_VALUE(op), if op is a floating-point
937                  CONST_DOUBLE.
938      Do not use ival/hval/lval/rval if op is not the appropriate kind of
939      RTL object.  */
940DEF_RTL_EXPR(DEFINE_CONSTRAINT, "define_constraint", "sse", RTX_EXTRA)
941DEF_RTL_EXPR(DEFINE_MEMORY_CONSTRAINT, "define_memory_constraint", "sse", RTX_EXTRA)
942DEF_RTL_EXPR(DEFINE_ADDRESS_CONSTRAINT, "define_address_constraint", "sse", RTX_EXTRA)
943   
944
945/* Constructions for CPU pipeline description described by NDFAs.  */
946
947/* (define_cpu_unit string [string]) describes cpu functional
948   units (separated by comma).
949
950   1st operand: Names of cpu functional units.
951   2nd operand: Name of automaton (see comments for DEFINE_AUTOMATON).
952
953   All define_reservations, define_cpu_units, and
954   define_query_cpu_units should have unique names which may not be
955   "nothing".  */
956DEF_RTL_EXPR(DEFINE_CPU_UNIT, "define_cpu_unit", "sS", RTX_EXTRA)
957
958/* (define_query_cpu_unit string [string]) describes cpu functional
959   units analogously to define_cpu_unit.  The reservation of such
960   units can be queried for automaton state.  */
961DEF_RTL_EXPR(DEFINE_QUERY_CPU_UNIT, "define_query_cpu_unit", "sS", RTX_EXTRA)
962
963/* (exclusion_set string string) means that each CPU functional unit
964   in the first string can not be reserved simultaneously with any
965   unit whose name is in the second string and vise versa.  CPU units
966   in the string are separated by commas.  For example, it is useful
967   for description CPU with fully pipelined floating point functional
968   unit which can execute simultaneously only single floating point
969   insns or only double floating point insns.  All CPU functional
970   units in a set should belong to the same automaton.  */
971DEF_RTL_EXPR(EXCLUSION_SET, "exclusion_set", "ss", RTX_EXTRA)
972
973/* (presence_set string string) means that each CPU functional unit in
974   the first string can not be reserved unless at least one of pattern
975   of units whose names are in the second string is reserved.  This is
976   an asymmetric relation.  CPU units or unit patterns in the strings
977   are separated by commas.  Pattern is one unit name or unit names
978   separated by white-spaces.
979 
980   For example, it is useful for description that slot1 is reserved
981   after slot0 reservation for a VLIW processor.  We could describe it
982   by the following construction
983
984      (presence_set "slot1" "slot0")
985
986   Or slot1 is reserved only after slot0 and unit b0 reservation.  In
987   this case we could write
988
989      (presence_set "slot1" "slot0 b0")
990
991   All CPU functional units in a set should belong to the same
992   automaton.  */
993DEF_RTL_EXPR(PRESENCE_SET, "presence_set", "ss", RTX_EXTRA)
994
995/* (final_presence_set string string) is analogous to `presence_set'.
996   The difference between them is when checking is done.  When an
997   instruction is issued in given automaton state reflecting all
998   current and planned unit reservations, the automaton state is
999   changed.  The first state is a source state, the second one is a
1000   result state.  Checking for `presence_set' is done on the source
1001   state reservation, checking for `final_presence_set' is done on the
1002   result reservation.  This construction is useful to describe a
1003   reservation which is actually two subsequent reservations.  For
1004   example, if we use 
1005
1006      (presence_set "slot1" "slot0")
1007
1008   the following insn will be never issued (because slot1 requires
1009   slot0 which is absent in the source state).
1010
1011      (define_reservation "insn_and_nop" "slot0 + slot1")
1012
1013   but it can be issued if we use analogous `final_presence_set'.  */
1014DEF_RTL_EXPR(FINAL_PRESENCE_SET, "final_presence_set", "ss", RTX_EXTRA)
1015
1016/* (absence_set string string) means that each CPU functional unit in
1017   the first string can be reserved only if each pattern of units
1018   whose names are in the second string is not reserved.  This is an
1019   asymmetric relation (actually exclusion set is analogous to this
1020   one but it is symmetric).  CPU units or unit patterns in the string
1021   are separated by commas.  Pattern is one unit name or unit names
1022   separated by white-spaces.
1023
1024   For example, it is useful for description that slot0 can not be
1025   reserved after slot1 or slot2 reservation for a VLIW processor.  We
1026   could describe it by the following construction
1027
1028      (absence_set "slot2" "slot0, slot1")
1029
1030   Or slot2 can not be reserved if slot0 and unit b0 are reserved or
1031   slot1 and unit b1 are reserved .  In this case we could write
1032
1033      (absence_set "slot2" "slot0 b0, slot1 b1")
1034
1035   All CPU functional units in a set should to belong the same
1036   automaton.  */
1037DEF_RTL_EXPR(ABSENCE_SET, "absence_set", "ss", RTX_EXTRA)
1038
1039/* (final_absence_set string string) is analogous to `absence_set' but
1040   checking is done on the result (state) reservation.  See comments
1041   for `final_presence_set'.  */
1042DEF_RTL_EXPR(FINAL_ABSENCE_SET, "final_absence_set", "ss", RTX_EXTRA)
1043
1044/* (define_bypass number out_insn_names in_insn_names) names bypass
1045   with given latency (the first number) from insns given by the first
1046   string (see define_insn_reservation) into insns given by the second
1047   string.  Insn names in the strings are separated by commas.  The
1048   third operand is optional name of function which is additional
1049   guard for the bypass.  The function will get the two insns as
1050   parameters.  If the function returns zero the bypass will be
1051   ignored for this case.  Additional guard is necessary to recognize
1052   complicated bypasses, e.g. when consumer is load address.  */
1053DEF_RTL_EXPR(DEFINE_BYPASS, "define_bypass", "issS", RTX_EXTRA)
1054
1055/* (define_automaton string) describes names of automata generated and
1056   used for pipeline hazards recognition.  The names are separated by
1057   comma.  Actually it is possibly to generate the single automaton
1058   but unfortunately it can be very large.  If we use more one
1059   automata, the summary size of the automata usually is less than the
1060   single one.  The automaton name is used in define_cpu_unit and
1061   define_query_cpu_unit.  All automata should have unique names.  */
1062DEF_RTL_EXPR(DEFINE_AUTOMATON, "define_automaton", "s", RTX_EXTRA)
1063
1064/* (automata_option string) describes option for generation of
1065   automata.  Currently there are the following options:
1066
1067   o "no-minimization" which makes no minimization of automata.  This
1068     is only worth to do when we are debugging the description and
1069     need to look more accurately at reservations of states.
1070
1071   o "time" which means printing additional time statistics about
1072      generation of automata.
1073  
1074   o "v" which means generation of file describing the result
1075     automata.  The file has suffix `.dfa' and can be used for the
1076     description verification and debugging.
1077
1078   o "w" which means generation of warning instead of error for
1079     non-critical errors.
1080
1081   o "ndfa" which makes nondeterministic finite state automata.
1082
1083   o "progress" which means output of a progress bar showing how many
1084     states were generated so far for automaton being processed.  */
1085DEF_RTL_EXPR(AUTOMATA_OPTION, "automata_option", "s", RTX_EXTRA)
1086
1087/* (define_reservation string string) names reservation (the first
1088   string) of cpu functional units (the 2nd string).  Sometimes unit
1089   reservations for different insns contain common parts.  In such
1090   case, you can describe common part and use its name (the 1st
1091   parameter) in regular expression in define_insn_reservation.  All
1092   define_reservations, define_cpu_units, and define_query_cpu_units
1093   should have unique names which may not be "nothing".  */
1094DEF_RTL_EXPR(DEFINE_RESERVATION, "define_reservation", "ss", RTX_EXTRA)
1095
1096/* (define_insn_reservation name default_latency condition regexpr)
1097   describes reservation of cpu functional units (the 3nd operand) for
1098   instruction which is selected by the condition (the 2nd parameter).
1099   The first parameter is used for output of debugging information.
1100   The reservations are described by a regular expression according
1101   the following syntax:
1102
1103       regexp = regexp "," oneof
1104              | oneof
1105
1106       oneof = oneof "|" allof
1107             | allof
1108
1109       allof = allof "+" repeat
1110             | repeat
1111 
1112       repeat = element "*" number
1113              | element
1114
1115       element = cpu_function_unit_name
1116               | reservation_name
1117               | result_name
1118               | "nothing"
1119               | "(" regexp ")"
1120
1121       1. "," is used for describing start of the next cycle in
1122       reservation.
1123
1124       2. "|" is used for describing the reservation described by the
1125       first regular expression *or* the reservation described by the
1126       second regular expression *or* etc.
1127
1128       3. "+" is used for describing the reservation described by the
1129       first regular expression *and* the reservation described by the
1130       second regular expression *and* etc.
1131
1132       4. "*" is used for convenience and simply means sequence in
1133       which the regular expression are repeated NUMBER times with
1134       cycle advancing (see ",").
1135
1136       5. cpu functional unit name which means its reservation.
1137
1138       6. reservation name -- see define_reservation.
1139
1140       7. string "nothing" means no units reservation.  */
1141
1142DEF_RTL_EXPR(DEFINE_INSN_RESERVATION, "define_insn_reservation", "sies", RTX_EXTRA)
1143
1144/* Expressions used for insn attributes.  */
1145
1146/* Definition of an insn attribute.
1147   1st operand: name of the attribute
1148   2nd operand: comma-separated list of possible attribute values
1149   3rd operand: expression for the default value of the attribute.  */
1150DEF_RTL_EXPR(DEFINE_ATTR, "define_attr", "sse", RTX_EXTRA)
1151
1152/* Marker for the name of an attribute.  */
1153DEF_RTL_EXPR(ATTR, "attr", "s", RTX_EXTRA)
1154
1155/* For use in the last (optional) operand of DEFINE_INSN or DEFINE_PEEPHOLE and
1156   in DEFINE_ASM_INSN to specify an attribute to assign to insns matching that
1157   pattern.
1158
1159   (set_attr "name" "value") is equivalent to
1160   (set (attr "name") (const_string "value"))  */
1161DEF_RTL_EXPR(SET_ATTR, "set_attr", "ss", RTX_EXTRA)
1162
1163/* In the last operand of DEFINE_INSN and DEFINE_PEEPHOLE, this can be used to
1164   specify that attribute values are to be assigned according to the
1165   alternative matched.
1166
1167   The following three expressions are equivalent:
1168
1169   (set (attr "att") (cond [(eq_attrq "alternative" "1") (const_string "a1")
1170			    (eq_attrq "alternative" "2") (const_string "a2")]
1171			   (const_string "a3")))
1172   (set_attr_alternative "att" [(const_string "a1") (const_string "a2")
1173				 (const_string "a3")])
1174   (set_attr "att" "a1,a2,a3")
1175 */
1176DEF_RTL_EXPR(SET_ATTR_ALTERNATIVE, "set_attr_alternative", "sE", RTX_EXTRA)
1177
1178/* A conditional expression true if the value of the specified attribute of
1179   the current insn equals the specified value.  The first operand is the
1180   attribute name and the second is the comparison value.  */
1181DEF_RTL_EXPR(EQ_ATTR, "eq_attr", "ss", RTX_EXTRA)
1182
1183/* A special case of the above representing a set of alternatives.  The first
1184   operand is bitmap of the set, the second one is the default value.  */
1185DEF_RTL_EXPR(EQ_ATTR_ALT, "eq_attr_alt", "ii", RTX_EXTRA)
1186
1187/* A conditional expression which is true if the specified flag is
1188   true for the insn being scheduled in reorg.
1189
1190   genattr.c defines the following flags which can be tested by
1191   (attr_flag "foo") expressions in eligible_for_delay.
1192
1193   forward, backward, very_likely, likely, very_unlikely, and unlikely.  */
1194
1195DEF_RTL_EXPR (ATTR_FLAG, "attr_flag", "s", RTX_EXTRA)
1196
1197/* General conditional. The first operand is a vector composed of pairs of
1198   expressions.  The first element of each pair is evaluated, in turn.
1199   The value of the conditional is the second expression of the first pair
1200   whose first expression evaluates nonzero.  If none of the expressions is
1201   true, the second operand will be used as the value of the conditional.  */
1202DEF_RTL_EXPR(COND, "cond", "Ee", RTX_EXTRA)
1203
1204#endif /* GENERATOR_FILE */
1205
1206/*
1207Local variables:
1208mode:c
1209End:
1210*/
1211