xref: /dragonfly/contrib/gcc-4.7/gcc/rtl.def (revision 9348a738)
1/* This file contains the definitions and documentation for the
2   Register Transfer Expressions (rtx's) that make up the
3   Register Transfer Language (rtl) used in the Back End of the GNU compiler.
4   Copyright (C) 1987, 1988, 1992, 1994, 1995, 1997, 1998, 1999, 2000, 2004,
5   2005, 2006, 2007, 2008, 2009, 2010, 2011
6   Free Software Foundation, Inc.
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 3, 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 COPYING3.  If not see
22<http://www.gnu.org/licenses/>.  */
23
24
25/* Expression definitions and descriptions for all targets are in this file.
26   Some will not be used for some targets.
27
28   The fields in the cpp macro call "DEF_RTL_EXPR()"
29   are used to create declarations in the C source of the compiler.
30
31   The fields are:
32
33   1.  The internal name of the rtx used in the C source.
34   It is a tag in the enumeration "enum rtx_code" defined in "rtl.h".
35   By convention these are in UPPER_CASE.
36
37   2.  The name of the rtx in the external ASCII format read by
38   read_rtx(), and printed by print_rtx().
39   These names are stored in rtx_name[].
40   By convention these are the internal (field 1) names in lower_case.
41
42   3.  The print format, and type of each rtx->u.fld[] (field) in this rtx.
43   These formats are stored in rtx_format[].
44   The meaning of the formats is documented in front of this array in rtl.c
45
46   4.  The class of the rtx.  These are stored in rtx_class and are accessed
47   via the GET_RTX_CLASS macro.  They are defined as follows:
48
49     RTX_CONST_OBJ
50         an rtx code that can be used to represent a constant object
51         (e.g, CONST_INT)
52     RTX_OBJ
53         an rtx code that can be used to represent an object (e.g, REG, MEM)
54     RTX_COMPARE
55         an rtx code for a comparison (e.g, LT, GT)
56     RTX_COMM_COMPARE
57         an rtx code for a commutative comparison (e.g, EQ, NE, ORDERED)
58     RTX_UNARY
59         an rtx code for a unary arithmetic expression (e.g, NEG, NOT)
60     RTX_COMM_ARITH
61         an rtx code for a commutative binary operation (e.g,, PLUS, MULT)
62     RTX_TERNARY
63         an rtx code for a non-bitfield three input operation (IF_THEN_ELSE)
64     RTX_BIN_ARITH
65         an rtx code for a non-commutative binary operation (e.g., MINUS, DIV)
66     RTX_BITFIELD_OPS
67         an rtx code for a bit-field operation (ZERO_EXTRACT, SIGN_EXTRACT)
68     RTX_INSN
69         an rtx code for a machine insn (INSN, JUMP_INSN, CALL_INSN)
70     RTX_MATCH
71         an rtx code for something that matches in insns (e.g, MATCH_DUP)
72     RTX_AUTOINC
73         an rtx code for autoincrement addressing modes (e.g. POST_DEC)
74     RTX_EXTRA
75         everything else
76
77   All of the expressions that appear only in machine descriptions,
78   not in RTL used by the compiler itself, are at the end of the file.  */
79
80/* Unknown, or no such operation; the enumeration constant should have
81   value zero.  */
82DEF_RTL_EXPR(UNKNOWN, "UnKnown", "*", RTX_EXTRA)
83
84/* Used in the cselib routines to describe a value.  Objects of this
85   kind are only allocated in cselib.c, in an alloc pool instead of in
86   GC memory.  The only operand of a VALUE is a cselib_val_struct.
87   var-tracking requires this to have a distinct integral value from
88   DECL codes in trees.  */
89DEF_RTL_EXPR(VALUE, "value", "0", RTX_OBJ)
90
91/* The RTL generated for a DEBUG_EXPR_DECL.  It links back to the
92   DEBUG_EXPR_DECL in the first operand.  */
93DEF_RTL_EXPR(DEBUG_EXPR, "debug_expr", "0", RTX_OBJ)
94
95/* ---------------------------------------------------------------------
96   Expressions used in constructing lists.
97   --------------------------------------------------------------------- */
98
99/* a linked list of expressions */
100DEF_RTL_EXPR(EXPR_LIST, "expr_list", "ee", RTX_EXTRA)
101
102/* a linked list of instructions.
103   The insns are represented in print by their uids.  */
104DEF_RTL_EXPR(INSN_LIST, "insn_list", "ue", RTX_EXTRA)
105
106/* SEQUENCE appears in the result of a `gen_...' function
107   for a DEFINE_EXPAND that wants to make several insns.
108   Its elements are the bodies of the insns that should be made.
109   `emit_insn' takes the SEQUENCE apart and makes separate insns.  */
110DEF_RTL_EXPR(SEQUENCE, "sequence", "E", RTX_EXTRA)
111
112/* Refers to the address of its argument.  This is only used in alias.c.  */
113DEF_RTL_EXPR(ADDRESS, "address", "e", RTX_MATCH)
114
115/* ----------------------------------------------------------------------
116   Expression types used for things in the instruction chain.
117
118   All formats must start with "iuu" to handle the chain.
119   Each insn expression holds an rtl instruction and its semantics
120   during back-end processing.
121   See macros's in "rtl.h" for the meaning of each rtx->u.fld[].
122
123   ---------------------------------------------------------------------- */
124
125/* An annotation for variable assignment tracking.  */
126DEF_RTL_EXPR(DEBUG_INSN, "debug_insn", "iuuBeiie", RTX_INSN)
127
128/* An instruction that cannot jump.  */
129DEF_RTL_EXPR(INSN, "insn", "iuuBeiie", RTX_INSN)
130
131/* An instruction that can possibly jump.
132   Fields ( rtx->u.fld[] ) have exact same meaning as INSN's.  */
133DEF_RTL_EXPR(JUMP_INSN, "jump_insn", "iuuBeiie0", RTX_INSN)
134
135/* An instruction that can possibly call a subroutine
136   but which will not change which instruction comes next
137   in the current function.
138   Field ( rtx->u.fld[8] ) is CALL_INSN_FUNCTION_USAGE.
139   All other fields ( rtx->u.fld[] ) have exact same meaning as INSN's.  */
140DEF_RTL_EXPR(CALL_INSN, "call_insn", "iuuBeiiee", RTX_INSN)
141
142/* A marker that indicates that control will not flow through.  */
143DEF_RTL_EXPR(BARRIER, "barrier", "iuu00000", RTX_EXTRA)
144
145/* Holds a label that is followed by instructions.
146   Operand:
147   4: is used in jump.c for the use-count of the label.
148   5: is used in the sh backend.
149   6: is a number that is unique in the entire compilation.
150   7: is the user-given name of the label, if any.  */
151DEF_RTL_EXPR(CODE_LABEL, "code_label", "iuuB00is", RTX_EXTRA)
152
153/* Say where in the code a source line starts, for symbol table's sake.
154   Operand:
155   4: note-specific data
156   5: enum insn_note
157   6: unique number if insn_note == note_insn_deleted_label.  */
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", "si", RTX_EXTRA)
183
184/* An assembler instruction with operands.
185   1st operand is the instruction template.
186   2nd operand is the constraint for the output.
187   3rd operand is the number of the output this expression refers to.
188     When an insn stores more than one value, a separate ASM_OPERANDS
189     is made for each output; this integer distinguishes them.
190   4th is a vector of values of input operands.
191   5th is a vector of modes and constraints for the input operands.
192     Each element is an ASM_INPUT containing a constraint string
193     and whose mode indicates the mode of the input operand.
194   6th is a vector of labels that may be branched to by the asm.
195   7th is the source line number.  */
196DEF_RTL_EXPR(ASM_OPERANDS, "asm_operands", "ssiEEEi", RTX_EXTRA)
197
198/* A machine-specific operation.
199   1st operand is a vector of operands being used by the operation so that
200     any needed reloads can be done.
201   2nd operand is a unique value saying which of a number of machine-specific
202     operations is to be performed.
203   (Note that the vector must be the first operand because of the way that
204   genrecog.c record positions within an insn.)
205
206   UNSPEC can occur all by itself in a PATTERN, as a component of a PARALLEL,
207   or inside an expression.
208   UNSPEC by itself or as a component of a PARALLEL
209   is currently considered not deletable.
210
211   FIXME: Replace all uses of UNSPEC that appears by itself or as a component
212   of a PARALLEL with USE.
213   */
214DEF_RTL_EXPR(UNSPEC, "unspec", "Ei", RTX_EXTRA)
215
216/* Similar, but a volatile operation and one which may trap.  */
217DEF_RTL_EXPR(UNSPEC_VOLATILE, "unspec_volatile", "Ei", RTX_EXTRA)
218
219/* Vector of addresses, stored as full words.  */
220/* Each element is a LABEL_REF to a CODE_LABEL whose address we want.  */
221DEF_RTL_EXPR(ADDR_VEC, "addr_vec", "E", RTX_EXTRA)
222
223/* Vector of address differences X0 - BASE, X1 - BASE, ...
224   First operand is BASE; the vector contains the X's.
225   The machine mode of this rtx says how much space to leave
226   for each difference and is adjusted by branch shortening if
227   CASE_VECTOR_SHORTEN_MODE is defined.
228   The third and fourth operands store the target labels with the
229   minimum and maximum addresses respectively.
230   The fifth operand stores flags for use by branch shortening.
231  Set at the start of shorten_branches:
232   min_align: the minimum alignment for any of the target labels.
233   base_after_vec: true iff BASE is after the ADDR_DIFF_VEC.
234   min_after_vec: true iff minimum addr target label is after the ADDR_DIFF_VEC.
235   max_after_vec: true iff maximum addr target label is after the ADDR_DIFF_VEC.
236   min_after_base: true iff minimum address target label is after BASE.
237   max_after_base: true iff maximum address target label is after BASE.
238  Set by the actual branch shortening process:
239   offset_unsigned: true iff offsets have to be treated as unsigned.
240   scale: scaling that is necessary to make offsets fit into the mode.
241
242   The third, fourth and fifth operands are only valid when
243   CASE_VECTOR_SHORTEN_MODE is defined, and only in an optimizing
244   compilations.  */
245
246DEF_RTL_EXPR(ADDR_DIFF_VEC, "addr_diff_vec", "eEee0", RTX_EXTRA)
247
248/* Memory prefetch, with attributes supported on some targets.
249   Operand 1 is the address of the memory to fetch.
250   Operand 2 is 1 for a write access, 0 otherwise.
251   Operand 3 is the level of temporal locality; 0 means there is no
252   temporal locality and 1, 2, and 3 are for increasing levels of temporal
253   locality.
254
255   The attributes specified by operands 2 and 3 are ignored for targets
256   whose prefetch instructions do not support them.  */
257DEF_RTL_EXPR(PREFETCH, "prefetch", "eee", RTX_EXTRA)
258
259/* ----------------------------------------------------------------------
260   At the top level of an instruction (perhaps under PARALLEL).
261   ---------------------------------------------------------------------- */
262
263/* Assignment.
264   Operand 1 is the location (REG, MEM, PC, CC0 or whatever) assigned to.
265   Operand 2 is the value stored there.
266   ALL assignment must use SET.
267   Instructions that do multiple assignments must use multiple SET,
268   under PARALLEL.  */
269DEF_RTL_EXPR(SET, "set", "ee", RTX_EXTRA)
270
271/* Indicate something is used in a way that we don't want to explain.
272   For example, subroutine calls will use the register
273   in which the static chain is passed.
274
275   USE can not appear as an operand of other rtx except for PARALLEL.
276   USE is not deletable, as it indicates that the operand
277   is used in some unknown way.  */
278DEF_RTL_EXPR(USE, "use", "e", RTX_EXTRA)
279
280/* Indicate something is clobbered in a way that we don't want to explain.
281   For example, subroutine calls will clobber some physical registers
282   (the ones that are by convention not saved).
283
284   CLOBBER can not appear as an operand of other rtx except for PARALLEL.
285   CLOBBER of a hard register appearing by itself (not within PARALLEL)
286   is considered undeletable before reload.  */
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/* Like RETURN, but truly represents only a function return, while
300   RETURN may represent an insn that also performs other functions
301   of the function epilogue.  Like RETURN, this may also occur in
302   conditional jumps.  */
303DEF_RTL_EXPR(SIMPLE_RETURN, "simple_return", "", RTX_EXTRA)
304
305/* Special for EH return from subroutine.  */
306
307DEF_RTL_EXPR(EH_RETURN, "eh_return", "", RTX_EXTRA)
308
309/* Conditional trap.
310   Operand 1 is the condition.
311   Operand 2 is the trap code.
312   For an unconditional trap, make the condition (const_int 1).  */
313DEF_RTL_EXPR(TRAP_IF, "trap_if", "ee", RTX_EXTRA)
314
315/* ----------------------------------------------------------------------
316   Primitive values for use in expressions.
317   ---------------------------------------------------------------------- */
318
319/* numeric integer constant */
320DEF_RTL_EXPR(CONST_INT, "const_int", "w", RTX_CONST_OBJ)
321
322/* fixed-point constant */
323DEF_RTL_EXPR(CONST_FIXED, "const_fixed", "www", RTX_CONST_OBJ)
324
325/* numeric floating point constant.
326   Operands hold the value.  They are all 'w' and there may be from 2 to 6;
327   see real.h.  */
328DEF_RTL_EXPR(CONST_DOUBLE, "const_double", CONST_DOUBLE_FORMAT, RTX_CONST_OBJ)
329
330/* Describes a vector constant.  */
331DEF_RTL_EXPR(CONST_VECTOR, "const_vector", "E", RTX_CONST_OBJ)
332
333/* String constant.  Used for attributes in machine descriptions and
334   for special cases in DWARF2 debug output.  NOT used for source-
335   language string constants.  */
336DEF_RTL_EXPR(CONST_STRING, "const_string", "s", RTX_OBJ)
337
338/* This is used to encapsulate an expression whose value is constant
339   (such as the sum of a SYMBOL_REF and a CONST_INT) so that it will be
340   recognized as a constant operand rather than by arithmetic instructions.  */
341
342DEF_RTL_EXPR(CONST, "const", "e", RTX_CONST_OBJ)
343
344/* program counter.  Ordinary jumps are represented
345   by a SET whose first operand is (PC).  */
346DEF_RTL_EXPR(PC, "pc", "", RTX_OBJ)
347
348/* A register.  The "operand" is the register number, accessed with
349   the REGNO macro.  If this number is less than FIRST_PSEUDO_REGISTER
350   than a hardware register is being referred to.  The second operand
351   holds the original register number - this will be different for a
352   pseudo register that got turned into a hard register.  The third
353   operand points to a reg_attrs structure.
354   This rtx needs to have as many (or more) fields as a MEM, since we
355   can change REG rtx's into MEMs during reload.  */
356DEF_RTL_EXPR(REG, "reg", "i00", RTX_OBJ)
357
358/* A scratch register.  This represents a register used only within a
359   single insn.  It will be turned into a REG during register allocation
360   or reload unless the constraint indicates that the register won't be
361   needed, in which case it can remain a SCRATCH.  This code is
362   marked as having one operand so it can be turned into a REG.  */
363DEF_RTL_EXPR(SCRATCH, "scratch", "0", RTX_OBJ)
364
365/* A reference to a part of another value.  The first operand is the
366   complete value and the second is the byte offset of the selected part.   */
367DEF_RTL_EXPR(SUBREG, "subreg", "ei", RTX_EXTRA)
368
369/* This one-argument rtx is used for move instructions
370   that are guaranteed to alter only the low part of a destination.
371   Thus, (SET (SUBREG:HI (REG...)) (MEM:HI ...))
372   has an unspecified effect on the high part of REG,
373   but (SET (STRICT_LOW_PART (SUBREG:HI (REG...))) (MEM:HI ...))
374   is guaranteed to alter only the bits of REG that are in HImode.
375
376   The actual instruction used is probably the same in both cases,
377   but the register constraints may be tighter when STRICT_LOW_PART
378   is in use.  */
379
380DEF_RTL_EXPR(STRICT_LOW_PART, "strict_low_part", "e", RTX_EXTRA)
381
382/* (CONCAT a b) represents the virtual concatenation of a and b
383   to make a value that has as many bits as a and b put together.
384   This is used for complex values.  Normally it appears only
385   in DECL_RTLs and during RTL generation, but not in the insn chain.  */
386DEF_RTL_EXPR(CONCAT, "concat", "ee", RTX_OBJ)
387
388/* (CONCATN [a1 a2 ... an]) represents the virtual concatenation of
389   all An to make a value.  This is an extension of CONCAT to larger
390   number of components.  Like CONCAT, it should not appear in the
391   insn chain.  Every element of the CONCATN is the same size.  */
392DEF_RTL_EXPR(CONCATN, "concatn", "E", RTX_OBJ)
393
394/* A memory location; operand is the address.  The second operand is the
395   alias set to which this MEM belongs.  We use `0' instead of `w' for this
396   field so that the field need not be specified in machine descriptions.  */
397DEF_RTL_EXPR(MEM, "mem", "e0", RTX_OBJ)
398
399/* Reference to an assembler label in the code for this function.
400   The operand is a CODE_LABEL found in the insn chain.  */
401DEF_RTL_EXPR(LABEL_REF, "label_ref", "u", RTX_CONST_OBJ)
402
403/* Reference to a named label:
404   Operand 0: label name
405   Operand 1: flags (see SYMBOL_FLAG_* in rtl.h)
406   Operand 2: tree from which this symbol is derived, or null.
407   This is either a DECL node, or some kind of constant.  */
408DEF_RTL_EXPR(SYMBOL_REF, "symbol_ref", "s00", RTX_CONST_OBJ)
409
410/* The condition code register is represented, in our imagination,
411   as a register holding a value that can be compared to zero.
412   In fact, the machine has already compared them and recorded the
413   results; but instructions that look at the condition code
414   pretend to be looking at the entire value and comparing it.  */
415DEF_RTL_EXPR(CC0, "cc0", "", RTX_OBJ)
416
417/* ----------------------------------------------------------------------
418   Expressions for operators in an rtl pattern
419   ---------------------------------------------------------------------- */
420
421/* if_then_else.  This is used in representing ordinary
422   conditional jump instructions.
423     Operand:
424     0:  condition
425     1:  then expr
426     2:  else expr */
427DEF_RTL_EXPR(IF_THEN_ELSE, "if_then_else", "eee", RTX_TERNARY)
428
429/* Comparison, produces a condition code result.  */
430DEF_RTL_EXPR(COMPARE, "compare", "ee", RTX_BIN_ARITH)
431
432/* plus */
433DEF_RTL_EXPR(PLUS, "plus", "ee", RTX_COMM_ARITH)
434
435/* Operand 0 minus operand 1.  */
436DEF_RTL_EXPR(MINUS, "minus", "ee", RTX_BIN_ARITH)
437
438/* Minus operand 0.  */
439DEF_RTL_EXPR(NEG, "neg", "e", RTX_UNARY)
440
441DEF_RTL_EXPR(MULT, "mult", "ee", RTX_COMM_ARITH)
442
443/* Multiplication with signed saturation */
444DEF_RTL_EXPR(SS_MULT, "ss_mult", "ee", RTX_COMM_ARITH)
445/* Multiplication with unsigned saturation */
446DEF_RTL_EXPR(US_MULT, "us_mult", "ee", RTX_COMM_ARITH)
447
448/* Operand 0 divided by operand 1.  */
449DEF_RTL_EXPR(DIV, "div", "ee", RTX_BIN_ARITH)
450/* Division with signed saturation */
451DEF_RTL_EXPR(SS_DIV, "ss_div", "ee", RTX_BIN_ARITH)
452/* Division with unsigned saturation */
453DEF_RTL_EXPR(US_DIV, "us_div", "ee", RTX_BIN_ARITH)
454
455/* Remainder of operand 0 divided by operand 1.  */
456DEF_RTL_EXPR(MOD, "mod", "ee", RTX_BIN_ARITH)
457
458/* Unsigned divide and remainder.  */
459DEF_RTL_EXPR(UDIV, "udiv", "ee", RTX_BIN_ARITH)
460DEF_RTL_EXPR(UMOD, "umod", "ee", RTX_BIN_ARITH)
461
462/* Bitwise operations.  */
463DEF_RTL_EXPR(AND, "and", "ee", RTX_COMM_ARITH)
464DEF_RTL_EXPR(IOR, "ior", "ee", RTX_COMM_ARITH)
465DEF_RTL_EXPR(XOR, "xor", "ee", RTX_COMM_ARITH)
466DEF_RTL_EXPR(NOT, "not", "e", RTX_UNARY)
467
468/* Operand:
469     0:  value to be shifted.
470     1:  number of bits.  */
471DEF_RTL_EXPR(ASHIFT, "ashift", "ee", RTX_BIN_ARITH) /* shift left */
472DEF_RTL_EXPR(ROTATE, "rotate", "ee", RTX_BIN_ARITH) /* rotate left */
473DEF_RTL_EXPR(ASHIFTRT, "ashiftrt", "ee", RTX_BIN_ARITH) /* arithmetic shift right */
474DEF_RTL_EXPR(LSHIFTRT, "lshiftrt", "ee", RTX_BIN_ARITH) /* logical shift right */
475DEF_RTL_EXPR(ROTATERT, "rotatert", "ee", RTX_BIN_ARITH) /* rotate right */
476
477/* Minimum and maximum values of two operands.  We need both signed and
478   unsigned forms.  (We cannot use MIN for SMIN because it conflicts
479   with a macro of the same name.)   The signed variants should be used
480   with floating point.  Further, if both operands are zeros, or if either
481   operand is NaN, then it is unspecified which of the two operands is
482   returned as the result.  */
483
484DEF_RTL_EXPR(SMIN, "smin", "ee", RTX_COMM_ARITH)
485DEF_RTL_EXPR(SMAX, "smax", "ee", RTX_COMM_ARITH)
486DEF_RTL_EXPR(UMIN, "umin", "ee", RTX_COMM_ARITH)
487DEF_RTL_EXPR(UMAX, "umax", "ee", RTX_COMM_ARITH)
488
489/* These unary operations are used to represent incrementation
490   and decrementation as they occur in memory addresses.
491   The amount of increment or decrement are not represented
492   because they can be understood from the machine-mode of the
493   containing MEM.  These operations exist in only two cases:
494   1. pushes onto the stack.
495   2. created automatically by the auto-inc-dec pass.  */
496DEF_RTL_EXPR(PRE_DEC, "pre_dec", "e", RTX_AUTOINC)
497DEF_RTL_EXPR(PRE_INC, "pre_inc", "e", RTX_AUTOINC)
498DEF_RTL_EXPR(POST_DEC, "post_dec", "e", RTX_AUTOINC)
499DEF_RTL_EXPR(POST_INC, "post_inc", "e", RTX_AUTOINC)
500
501/* These binary operations are used to represent generic address
502   side-effects in memory addresses, except for simple incrementation
503   or decrementation which use the above operations.  They are
504   created automatically by the life_analysis pass in flow.c.
505   The first operand is a REG which is used as the address.
506   The second operand is an expression that is assigned to the
507   register, either before (PRE_MODIFY) or after (POST_MODIFY)
508   evaluating the address.
509   Currently, the compiler can only handle second operands of the
510   form (plus (reg) (reg)) and (plus (reg) (const_int)), where
511   the first operand of the PLUS has to be the same register as
512   the first operand of the *_MODIFY.  */
513DEF_RTL_EXPR(PRE_MODIFY, "pre_modify", "ee", RTX_AUTOINC)
514DEF_RTL_EXPR(POST_MODIFY, "post_modify", "ee", RTX_AUTOINC)
515
516/* Comparison operations.  The ordered comparisons exist in two
517   flavors, signed and unsigned.  */
518DEF_RTL_EXPR(NE, "ne", "ee", RTX_COMM_COMPARE)
519DEF_RTL_EXPR(EQ, "eq", "ee", RTX_COMM_COMPARE)
520DEF_RTL_EXPR(GE, "ge", "ee", RTX_COMPARE)
521DEF_RTL_EXPR(GT, "gt", "ee", RTX_COMPARE)
522DEF_RTL_EXPR(LE, "le", "ee", RTX_COMPARE)
523DEF_RTL_EXPR(LT, "lt", "ee", RTX_COMPARE)
524DEF_RTL_EXPR(GEU, "geu", "ee", RTX_COMPARE)
525DEF_RTL_EXPR(GTU, "gtu", "ee", RTX_COMPARE)
526DEF_RTL_EXPR(LEU, "leu", "ee", RTX_COMPARE)
527DEF_RTL_EXPR(LTU, "ltu", "ee", RTX_COMPARE)
528
529/* Additional floating point unordered comparison flavors.  */
530DEF_RTL_EXPR(UNORDERED, "unordered", "ee", RTX_COMM_COMPARE)
531DEF_RTL_EXPR(ORDERED, "ordered", "ee", RTX_COMM_COMPARE)
532
533/* These are equivalent to unordered or ...  */
534DEF_RTL_EXPR(UNEQ, "uneq", "ee", RTX_COMM_COMPARE)
535DEF_RTL_EXPR(UNGE, "unge", "ee", RTX_COMPARE)
536DEF_RTL_EXPR(UNGT, "ungt", "ee", RTX_COMPARE)
537DEF_RTL_EXPR(UNLE, "unle", "ee", RTX_COMPARE)
538DEF_RTL_EXPR(UNLT, "unlt", "ee", RTX_COMPARE)
539
540/* This is an ordered NE, ie !UNEQ, ie false for NaN.  */
541DEF_RTL_EXPR(LTGT, "ltgt", "ee", RTX_COMM_COMPARE)
542
543/* Represents the result of sign-extending the sole operand.
544   The machine modes of the operand and of the SIGN_EXTEND expression
545   determine how much sign-extension is going on.  */
546DEF_RTL_EXPR(SIGN_EXTEND, "sign_extend", "e", RTX_UNARY)
547
548/* Similar for zero-extension (such as unsigned short to int).  */
549DEF_RTL_EXPR(ZERO_EXTEND, "zero_extend", "e", RTX_UNARY)
550
551/* Similar but here the operand has a wider mode.  */
552DEF_RTL_EXPR(TRUNCATE, "truncate", "e", RTX_UNARY)
553
554/* Similar for extending floating-point values (such as SFmode to DFmode).  */
555DEF_RTL_EXPR(FLOAT_EXTEND, "float_extend", "e", RTX_UNARY)
556DEF_RTL_EXPR(FLOAT_TRUNCATE, "float_truncate", "e", RTX_UNARY)
557
558/* Conversion of fixed point operand to floating point value.  */
559DEF_RTL_EXPR(FLOAT, "float", "e", RTX_UNARY)
560
561/* With fixed-point machine mode:
562   Conversion of floating point operand to fixed point value.
563   Value is defined only when the operand's value is an integer.
564   With floating-point machine mode (and operand with same mode):
565   Operand is rounded toward zero to produce an integer value
566   represented in floating point.  */
567DEF_RTL_EXPR(FIX, "fix", "e", RTX_UNARY)
568
569/* Conversion of unsigned fixed point operand to floating point value.  */
570DEF_RTL_EXPR(UNSIGNED_FLOAT, "unsigned_float", "e", RTX_UNARY)
571
572/* With fixed-point machine mode:
573   Conversion of floating point operand to *unsigned* fixed point value.
574   Value is defined only when the operand's value is an integer.  */
575DEF_RTL_EXPR(UNSIGNED_FIX, "unsigned_fix", "e", RTX_UNARY)
576
577/* Conversions involving fractional fixed-point types without saturation,
578   including:
579     fractional to fractional (of different precision),
580     signed integer to fractional,
581     fractional to signed integer,
582     floating point to fractional,
583     fractional to floating point.
584   NOTE: fractional can be either signed or unsigned for conversions.  */
585DEF_RTL_EXPR(FRACT_CONVERT, "fract_convert", "e", RTX_UNARY)
586
587/* Conversions involving fractional fixed-point types and unsigned integer
588   without saturation, including:
589     unsigned integer to fractional,
590     fractional to unsigned integer.
591   NOTE: fractional can be either signed or unsigned for conversions.  */
592DEF_RTL_EXPR(UNSIGNED_FRACT_CONVERT, "unsigned_fract_convert", "e", RTX_UNARY)
593
594/* Conversions involving fractional fixed-point types with saturation,
595   including:
596     fractional to fractional (of different precision),
597     signed integer to fractional,
598     floating point to fractional.
599   NOTE: fractional can be either signed or unsigned for conversions.  */
600DEF_RTL_EXPR(SAT_FRACT, "sat_fract", "e", RTX_UNARY)
601
602/* Conversions involving fractional fixed-point types and unsigned integer
603   with saturation, including:
604     unsigned integer to fractional.
605   NOTE: fractional can be either signed or unsigned for conversions.  */
606DEF_RTL_EXPR(UNSIGNED_SAT_FRACT, "unsigned_sat_fract", "e", RTX_UNARY)
607
608/* Absolute value */
609DEF_RTL_EXPR(ABS, "abs", "e", RTX_UNARY)
610
611/* Square root */
612DEF_RTL_EXPR(SQRT, "sqrt", "e", RTX_UNARY)
613
614/* Swap bytes.  */
615DEF_RTL_EXPR(BSWAP, "bswap", "e", RTX_UNARY)
616
617/* Find first bit that is set.
618   Value is 1 + number of trailing zeros in the arg.,
619   or 0 if arg is 0.  */
620DEF_RTL_EXPR(FFS, "ffs", "e", RTX_UNARY)
621
622/* Count number of leading redundant sign bits (number of leading
623   sign bits minus one).  */
624DEF_RTL_EXPR(CLRSB, "clrsb", "e", RTX_UNARY)
625
626/* Count leading zeros.  */
627DEF_RTL_EXPR(CLZ, "clz", "e", RTX_UNARY)
628
629/* Count trailing zeros.  */
630DEF_RTL_EXPR(CTZ, "ctz", "e", RTX_UNARY)
631
632/* Population count (number of 1 bits).  */
633DEF_RTL_EXPR(POPCOUNT, "popcount", "e", RTX_UNARY)
634
635/* Population parity (number of 1 bits modulo 2).  */
636DEF_RTL_EXPR(PARITY, "parity", "e", RTX_UNARY)
637
638/* Reference to a signed bit-field of specified size and position.
639   Operand 0 is the memory unit (usually SImode or QImode) which
640   contains the field's first bit.  Operand 1 is the width, in bits.
641   Operand 2 is the number of bits in the memory unit before the
642   first bit of this field.
643   If BITS_BIG_ENDIAN is defined, the first bit is the msb and
644   operand 2 counts from the msb of the memory unit.
645   Otherwise, the first bit is the lsb and operand 2 counts from
646   the lsb of the memory unit.
647   This kind of expression can not appear as an lvalue in RTL.  */
648DEF_RTL_EXPR(SIGN_EXTRACT, "sign_extract", "eee", RTX_BITFIELD_OPS)
649
650/* Similar for unsigned bit-field.
651   But note!  This kind of expression _can_ appear as an lvalue.  */
652DEF_RTL_EXPR(ZERO_EXTRACT, "zero_extract", "eee", RTX_BITFIELD_OPS)
653
654/* For RISC machines.  These save memory when splitting insns.  */
655
656/* HIGH are the high-order bits of a constant expression.  */
657DEF_RTL_EXPR(HIGH, "high", "e", RTX_CONST_OBJ)
658
659/* LO_SUM is the sum of a register and the low-order bits
660   of a constant expression.  */
661DEF_RTL_EXPR(LO_SUM, "lo_sum", "ee", RTX_OBJ)
662
663/* Describes a merge operation between two vector values.
664   Operands 0 and 1 are the vectors to be merged, operand 2 is a bitmask
665   that specifies where the parts of the result are taken from.  Set bits
666   indicate operand 0, clear bits indicate operand 1.  The parts are defined
667   by the mode of the vectors.  */
668DEF_RTL_EXPR(VEC_MERGE, "vec_merge", "eee", RTX_TERNARY)
669
670/* Describes an operation that selects parts of a vector.
671   Operands 0 is the source vector, operand 1 is a PARALLEL that contains
672   a CONST_INT for each of the subparts of the result vector, giving the
673   number of the source subpart that should be stored into it.  */
674DEF_RTL_EXPR(VEC_SELECT, "vec_select", "ee", RTX_BIN_ARITH)
675
676/* Describes a vector concat operation.  Operands 0 and 1 are the source
677   vectors, the result is a vector that is as long as operands 0 and 1
678   combined and is the concatenation of the two source vectors.  */
679DEF_RTL_EXPR(VEC_CONCAT, "vec_concat", "ee", RTX_BIN_ARITH)
680
681/* Describes an operation that converts a small vector into a larger one by
682   duplicating the input values.  The output vector mode must have the same
683   submodes as the input vector mode, and the number of output parts must be
684   an integer multiple of the number of input parts.  */
685DEF_RTL_EXPR(VEC_DUPLICATE, "vec_duplicate", "e", RTX_UNARY)
686
687/* Addition with signed saturation */
688DEF_RTL_EXPR(SS_PLUS, "ss_plus", "ee", RTX_COMM_ARITH)
689
690/* Addition with unsigned saturation */
691DEF_RTL_EXPR(US_PLUS, "us_plus", "ee", RTX_COMM_ARITH)
692
693/* Operand 0 minus operand 1, with signed saturation.  */
694DEF_RTL_EXPR(SS_MINUS, "ss_minus", "ee", RTX_BIN_ARITH)
695
696/* Negation with signed saturation.  */
697DEF_RTL_EXPR(SS_NEG, "ss_neg", "e", RTX_UNARY)
698/* Negation with unsigned saturation.  */
699DEF_RTL_EXPR(US_NEG, "us_neg", "e", RTX_UNARY)
700
701/* Absolute value with signed saturation.  */
702DEF_RTL_EXPR(SS_ABS, "ss_abs", "e", RTX_UNARY)
703
704/* Shift left with signed saturation.  */
705DEF_RTL_EXPR(SS_ASHIFT, "ss_ashift", "ee", RTX_BIN_ARITH)
706
707/* Shift left with unsigned saturation.  */
708DEF_RTL_EXPR(US_ASHIFT, "us_ashift", "ee", RTX_BIN_ARITH)
709
710/* Operand 0 minus operand 1, with unsigned saturation.  */
711DEF_RTL_EXPR(US_MINUS, "us_minus", "ee", RTX_BIN_ARITH)
712
713/* Signed saturating truncate.  */
714DEF_RTL_EXPR(SS_TRUNCATE, "ss_truncate", "e", RTX_UNARY)
715
716/* Unsigned saturating truncate.  */
717DEF_RTL_EXPR(US_TRUNCATE, "us_truncate", "e", RTX_UNARY)
718
719/* Floating point multiply/add combined instruction.  */
720DEF_RTL_EXPR(FMA, "fma", "eee", RTX_TERNARY)
721
722/* Information about the variable and its location.  */
723/* Changed 'te' to 'tei'; the 'i' field is for recording
724   initialization status of variables.  */
725DEF_RTL_EXPR(VAR_LOCATION, "var_location", "tei", RTX_EXTRA)
726
727/* Used in VAR_LOCATION for a pointer to a decl that is no longer
728   addressable.  */
729DEF_RTL_EXPR(DEBUG_IMPLICIT_PTR, "debug_implicit_ptr", "t", RTX_OBJ)
730
731/* Represents value that argument had on function entry.  The
732   single argument is the DECL_INCOMING_RTL of the corresponding
733   parameter.  */
734DEF_RTL_EXPR(ENTRY_VALUE, "entry_value", "0", RTX_OBJ)
735
736/* Used in VAR_LOCATION for a reference to a parameter that has
737   been optimized away completely.  */
738DEF_RTL_EXPR(DEBUG_PARAMETER_REF, "debug_parameter_ref", "t", RTX_OBJ)
739
740/* All expressions from this point forward appear only in machine
741   descriptions.  */
742#ifdef GENERATOR_FILE
743
744/* Pattern-matching operators:  */
745
746/* Use the function named by the second arg (the string)
747   as a predicate; if matched, store the structure that was matched
748   in the operand table at index specified by the first arg (the integer).
749   If the second arg is the null string, the structure is just stored.
750
751   A third string argument indicates to the register allocator restrictions
752   on where the operand can be allocated.
753
754   If the target needs no restriction on any instruction this field should
755   be the null string.
756
757   The string is prepended by:
758   '=' to indicate the operand is only written to.
759   '+' to indicate the operand is both read and written to.
760
761   Each character in the string represents an allocable class for an operand.
762   'g' indicates the operand can be any valid class.
763   'i' indicates the operand can be immediate (in the instruction) data.
764   'r' indicates the operand can be in a register.
765   'm' indicates the operand can be in memory.
766   'o' a subset of the 'm' class.  Those memory addressing modes that
767       can be offset at compile time (have a constant added to them).
768
769   Other characters indicate target dependent operand classes and
770   are described in each target's machine description.
771
772   For instructions with more than one operand, sets of classes can be
773   separated by a comma to indicate the appropriate multi-operand constraints.
774   There must be a 1 to 1 correspondence between these sets of classes in
775   all operands for an instruction.
776   */
777DEF_RTL_EXPR(MATCH_OPERAND, "match_operand", "iss", RTX_MATCH)
778
779/* Match a SCRATCH or a register.  When used to generate rtl, a
780   SCRATCH is generated.  As for MATCH_OPERAND, the mode specifies
781   the desired mode and the first argument is the operand number.
782   The second argument is the constraint.  */
783DEF_RTL_EXPR(MATCH_SCRATCH, "match_scratch", "is", RTX_MATCH)
784
785/* Apply a predicate, AND match recursively the operands of the rtx.
786   Operand 0 is the operand-number, as in match_operand.
787   Operand 1 is a predicate to apply (as a string, a function name).
788   Operand 2 is a vector of expressions, each of which must match
789   one subexpression of the rtx this construct is matching.  */
790DEF_RTL_EXPR(MATCH_OPERATOR, "match_operator", "isE", RTX_MATCH)
791
792/* Match a PARALLEL of arbitrary length.  The predicate is applied
793   to the PARALLEL and the initial expressions in the PARALLEL are matched.
794   Operand 0 is the operand-number, as in match_operand.
795   Operand 1 is a predicate to apply to the PARALLEL.
796   Operand 2 is a vector of expressions, each of which must match the
797   corresponding element in the PARALLEL.  */
798DEF_RTL_EXPR(MATCH_PARALLEL, "match_parallel", "isE", RTX_MATCH)
799
800/* Match only something equal to what is stored in the operand table
801   at the index specified by the argument.  Use with MATCH_OPERAND.  */
802DEF_RTL_EXPR(MATCH_DUP, "match_dup", "i", RTX_MATCH)
803
804/* Match only something equal to what is stored in the operand table
805   at the index specified by the argument.  Use with MATCH_OPERATOR.  */
806DEF_RTL_EXPR(MATCH_OP_DUP, "match_op_dup", "iE", RTX_MATCH)
807
808/* Match only something equal to what is stored in the operand table
809   at the index specified by the argument.  Use with MATCH_PARALLEL.  */
810DEF_RTL_EXPR(MATCH_PAR_DUP, "match_par_dup", "iE", RTX_MATCH)
811
812/* Appears only in define_predicate/define_special_predicate
813   expressions.  Evaluates true only if the operand has an RTX code
814   from the set given by the argument (a comma-separated list).  If the
815   second argument is present and nonempty, it is a sequence of digits
816   and/or letters which indicates the subexpression to test, using the
817   same syntax as genextract/genrecog's location strings: 0-9 for
818   XEXP (op, n), a-z for XVECEXP (op, 0, n); each character applies to
819   the result of the one before it.  */
820DEF_RTL_EXPR(MATCH_CODE, "match_code", "ss", RTX_MATCH)
821
822/* Used to inject a C conditional expression into an .md file.  It can
823   appear in a predicate definition or an attribute expression.  */
824DEF_RTL_EXPR(MATCH_TEST, "match_test", "s", RTX_MATCH)
825
826/* Insn (and related) definitions.  */
827
828/* Definition of the pattern for one kind of instruction.
829   Operand:
830   0: names this instruction.
831      If the name is the null string, the instruction is in the
832      machine description just to be recognized, and will never be emitted by
833      the tree to rtl expander.
834   1: is the pattern.
835   2: is a string which is a C expression
836      giving an additional condition for recognizing this pattern.
837      A null string means no extra condition.
838   3: is the action to execute if this pattern is matched.
839      If this assembler code template starts with a * then it is a fragment of
840      C code to run to decide on a template to use.  Otherwise, it is the
841      template to use.
842   4: optionally, a vector of attributes for this insn.
843     */
844DEF_RTL_EXPR(DEFINE_INSN, "define_insn", "sEsTV", RTX_EXTRA)
845
846/* Definition of a peephole optimization.
847   1st operand: vector of insn patterns to match
848   2nd operand: C expression that must be true
849   3rd operand: template or C code to produce assembler output.
850   4: optionally, a vector of attributes for this insn.
851
852   This form is deprecated; use define_peephole2 instead.  */
853DEF_RTL_EXPR(DEFINE_PEEPHOLE, "define_peephole", "EsTV", RTX_EXTRA)
854
855/* Definition of a split operation.
856   1st operand: insn pattern to match
857   2nd operand: C expression that must be true
858   3rd operand: vector of insn patterns to place into a SEQUENCE
859   4th operand: optionally, some C code to execute before generating the
860	insns.  This might, for example, create some RTX's and store them in
861	elements of `recog_data.operand' for use by the vector of
862	insn-patterns.
863	(`operands' is an alias here for `recog_data.operand').  */
864DEF_RTL_EXPR(DEFINE_SPLIT, "define_split", "EsES", RTX_EXTRA)
865
866/* Definition of an insn and associated split.
867   This is the concatenation, with a few modifications, of a define_insn
868   and a define_split which share the same pattern.
869   Operand:
870   0: names this instruction.
871      If the name is the null string, the instruction is in the
872      machine description just to be recognized, and will never be emitted by
873      the tree to rtl expander.
874   1: is the pattern.
875   2: is a string which is a C expression
876      giving an additional condition for recognizing this pattern.
877      A null string means no extra condition.
878   3: is the action to execute if this pattern is matched.
879      If this assembler code template starts with a * then it is a fragment of
880      C code to run to decide on a template to use.  Otherwise, it is the
881      template to use.
882   4: C expression that must be true for split.  This may start with "&&"
883      in which case the split condition is the logical and of the insn
884      condition and what follows the "&&" of this operand.
885   5: vector of insn patterns to place into a SEQUENCE
886   6: optionally, some C code to execute before generating the
887	insns.  This might, for example, create some RTX's and store them in
888	elements of `recog_data.operand' for use by the vector of
889	insn-patterns.
890	(`operands' is an alias here for `recog_data.operand').
891   7: optionally, a vector of attributes for this insn.  */
892DEF_RTL_EXPR(DEFINE_INSN_AND_SPLIT, "define_insn_and_split", "sEsTsESV", RTX_EXTRA)
893
894/* Definition of an RTL peephole operation.
895   Follows the same arguments as define_split.  */
896DEF_RTL_EXPR(DEFINE_PEEPHOLE2, "define_peephole2", "EsES", RTX_EXTRA)
897
898/* Define how to generate multiple insns for a standard insn name.
899   1st operand: the insn name.
900   2nd operand: vector of insn-patterns.
901	Use match_operand to substitute an element of `recog_data.operand'.
902   3rd operand: C expression that must be true for this to be available.
903	This may not test any operands.
904   4th operand: Extra C code to execute before generating the insns.
905	This might, for example, create some RTX's and store them in
906	elements of `recog_data.operand' for use by the vector of
907	insn-patterns.
908	(`operands' is an alias here for `recog_data.operand').  */
909DEF_RTL_EXPR(DEFINE_EXPAND, "define_expand", "sEss", RTX_EXTRA)
910
911/* Define a requirement for delay slots.
912   1st operand: Condition involving insn attributes that, if true,
913	        indicates that the insn requires the number of delay slots
914		shown.
915   2nd operand: Vector whose length is the three times the number of delay
916		slots required.
917	        Each entry gives three conditions, each involving attributes.
918		The first must be true for an insn to occupy that delay slot
919		location.  The second is true for all insns that can be
920		annulled if the branch is true and the third is true for all
921		insns that can be annulled if the branch is false.
922
923   Multiple DEFINE_DELAYs may be present.  They indicate differing
924   requirements for delay slots.  */
925DEF_RTL_EXPR(DEFINE_DELAY, "define_delay", "eE", RTX_EXTRA)
926
927/* Define attribute computation for `asm' instructions.  */
928DEF_RTL_EXPR(DEFINE_ASM_ATTRIBUTES, "define_asm_attributes", "V", RTX_EXTRA)
929
930/* Definition of a conditional execution meta operation.  Automatically
931   generates new instances of DEFINE_INSN, selected by having attribute
932   "predicable" true.  The new pattern will contain a COND_EXEC and the
933   predicate at top-level.
934
935   Operand:
936   0: The predicate pattern.  The top-level form should match a
937      relational operator.  Operands should have only one alternative.
938   1: A C expression giving an additional condition for recognizing
939      the generated pattern.
940   2: A template or C code to produce assembler output.  */
941DEF_RTL_EXPR(DEFINE_COND_EXEC, "define_cond_exec", "Ess", RTX_EXTRA)
942
943/* Definition of an operand predicate.  The difference between
944   DEFINE_PREDICATE and DEFINE_SPECIAL_PREDICATE is that genrecog will
945   not warn about a match_operand with no mode if it has a predicate
946   defined with DEFINE_SPECIAL_PREDICATE.
947
948   Operand:
949   0: The name of the predicate.
950   1: A boolean expression which computes whether or not the predicate
951      matches.  This expression can use IOR, AND, NOT, MATCH_OPERAND,
952      MATCH_CODE, and MATCH_TEST.  It must be specific enough that genrecog
953      can calculate the set of RTX codes that can possibly match.
954   2: A C function body which must return true for the predicate to match.
955      Optional.  Use this when the test is too complicated to fit into a
956      match_test expression.  */
957DEF_RTL_EXPR(DEFINE_PREDICATE, "define_predicate", "ses", RTX_EXTRA)
958DEF_RTL_EXPR(DEFINE_SPECIAL_PREDICATE, "define_special_predicate", "ses", RTX_EXTRA)
959
960/* Definition of a register operand constraint.  This simply maps the
961   constraint string to a register class.
962
963   Operand:
964   0: The name of the constraint (often, but not always, a single letter).
965   1: A C expression which evaluates to the appropriate register class for
966      this constraint.  If this is not just a constant, it should look only
967      at -m switches and the like.
968   2: A docstring for this constraint, in Texinfo syntax; not currently
969      used, in future will be incorporated into the manual's list of
970      machine-specific operand constraints.  */
971DEF_RTL_EXPR(DEFINE_REGISTER_CONSTRAINT, "define_register_constraint", "sss", RTX_EXTRA)
972
973/* Definition of a non-register operand constraint.  These look at the
974   operand and decide whether it fits the constraint.
975
976   DEFINE_CONSTRAINT gets no special treatment if it fails to match.
977   It is appropriate for constant-only constraints, and most others.
978
979   DEFINE_MEMORY_CONSTRAINT tells reload that this constraint can be made
980   to match, if it doesn't already, by converting the operand to the form
981   (mem (reg X)) where X is a base register.  It is suitable for constraints
982   that describe a subset of all memory references.
983
984   DEFINE_ADDRESS_CONSTRAINT tells reload that this constraint can be made
985   to match, if it doesn't already, by converting the operand to the form
986   (reg X) where X is a base register.  It is suitable for constraints that
987   describe a subset of all address references.
988
989   When in doubt, use plain DEFINE_CONSTRAINT.
990
991   Operand:
992   0: The name of the constraint (often, but not always, a single letter).
993   1: A docstring for this constraint, in Texinfo syntax; not currently
994      used, in future will be incorporated into the manual's list of
995      machine-specific operand constraints.
996   2: A boolean expression which computes whether or not the constraint
997      matches.  It should follow the same rules as a define_predicate
998      expression, including the bit about specifying the set of RTX codes
999      that could possibly match.  MATCH_TEST subexpressions may make use of
1000      these variables:
1001        `op'    - the RTL object defining the operand.
1002        `mode'  - the mode of `op'.
1003	`ival'  - INTVAL(op), if op is a CONST_INT.
1004        `hval'  - CONST_DOUBLE_HIGH(op), if op is an integer CONST_DOUBLE.
1005        `lval'  - CONST_DOUBLE_LOW(op), if op is an integer CONST_DOUBLE.
1006        `rval'  - CONST_DOUBLE_REAL_VALUE(op), if op is a floating-point
1007                  CONST_DOUBLE.
1008      Do not use ival/hval/lval/rval if op is not the appropriate kind of
1009      RTL object.  */
1010DEF_RTL_EXPR(DEFINE_CONSTRAINT, "define_constraint", "sse", RTX_EXTRA)
1011DEF_RTL_EXPR(DEFINE_MEMORY_CONSTRAINT, "define_memory_constraint", "sse", RTX_EXTRA)
1012DEF_RTL_EXPR(DEFINE_ADDRESS_CONSTRAINT, "define_address_constraint", "sse", RTX_EXTRA)
1013
1014
1015/* Constructions for CPU pipeline description described by NDFAs.  */
1016
1017/* (define_cpu_unit string [string]) describes cpu functional
1018   units (separated by comma).
1019
1020   1st operand: Names of cpu functional units.
1021   2nd operand: Name of automaton (see comments for DEFINE_AUTOMATON).
1022
1023   All define_reservations, define_cpu_units, and
1024   define_query_cpu_units should have unique names which may not be
1025   "nothing".  */
1026DEF_RTL_EXPR(DEFINE_CPU_UNIT, "define_cpu_unit", "sS", RTX_EXTRA)
1027
1028/* (define_query_cpu_unit string [string]) describes cpu functional
1029   units analogously to define_cpu_unit.  The reservation of such
1030   units can be queried for automaton state.  */
1031DEF_RTL_EXPR(DEFINE_QUERY_CPU_UNIT, "define_query_cpu_unit", "sS", RTX_EXTRA)
1032
1033/* (exclusion_set string string) means that each CPU functional unit
1034   in the first string can not be reserved simultaneously with any
1035   unit whose name is in the second string and vise versa.  CPU units
1036   in the string are separated by commas.  For example, it is useful
1037   for description CPU with fully pipelined floating point functional
1038   unit which can execute simultaneously only single floating point
1039   insns or only double floating point insns.  All CPU functional
1040   units in a set should belong to the same automaton.  */
1041DEF_RTL_EXPR(EXCLUSION_SET, "exclusion_set", "ss", RTX_EXTRA)
1042
1043/* (presence_set string string) means that each CPU functional unit in
1044   the first string can not be reserved unless at least one of pattern
1045   of units whose names are in the second string is reserved.  This is
1046   an asymmetric relation.  CPU units or unit patterns in the strings
1047   are separated by commas.  Pattern is one unit name or unit names
1048   separated by white-spaces.
1049
1050   For example, it is useful for description that slot1 is reserved
1051   after slot0 reservation for a VLIW processor.  We could describe it
1052   by the following construction
1053
1054      (presence_set "slot1" "slot0")
1055
1056   Or slot1 is reserved only after slot0 and unit b0 reservation.  In
1057   this case we could write
1058
1059      (presence_set "slot1" "slot0 b0")
1060
1061   All CPU functional units in a set should belong to the same
1062   automaton.  */
1063DEF_RTL_EXPR(PRESENCE_SET, "presence_set", "ss", RTX_EXTRA)
1064
1065/* (final_presence_set string string) is analogous to `presence_set'.
1066   The difference between them is when checking is done.  When an
1067   instruction is issued in given automaton state reflecting all
1068   current and planned unit reservations, the automaton state is
1069   changed.  The first state is a source state, the second one is a
1070   result state.  Checking for `presence_set' is done on the source
1071   state reservation, checking for `final_presence_set' is done on the
1072   result reservation.  This construction is useful to describe a
1073   reservation which is actually two subsequent reservations.  For
1074   example, if we use
1075
1076      (presence_set "slot1" "slot0")
1077
1078   the following insn will be never issued (because slot1 requires
1079   slot0 which is absent in the source state).
1080
1081      (define_reservation "insn_and_nop" "slot0 + slot1")
1082
1083   but it can be issued if we use analogous `final_presence_set'.  */
1084DEF_RTL_EXPR(FINAL_PRESENCE_SET, "final_presence_set", "ss", RTX_EXTRA)
1085
1086/* (absence_set string string) means that each CPU functional unit in
1087   the first string can be reserved only if each pattern of units
1088   whose names are in the second string is not reserved.  This is an
1089   asymmetric relation (actually exclusion set is analogous to this
1090   one but it is symmetric).  CPU units or unit patterns in the string
1091   are separated by commas.  Pattern is one unit name or unit names
1092   separated by white-spaces.
1093
1094   For example, it is useful for description that slot0 can not be
1095   reserved after slot1 or slot2 reservation for a VLIW processor.  We
1096   could describe it by the following construction
1097
1098      (absence_set "slot2" "slot0, slot1")
1099
1100   Or slot2 can not be reserved if slot0 and unit b0 are reserved or
1101   slot1 and unit b1 are reserved .  In this case we could write
1102
1103      (absence_set "slot2" "slot0 b0, slot1 b1")
1104
1105   All CPU functional units in a set should to belong the same
1106   automaton.  */
1107DEF_RTL_EXPR(ABSENCE_SET, "absence_set", "ss", RTX_EXTRA)
1108
1109/* (final_absence_set string string) is analogous to `absence_set' but
1110   checking is done on the result (state) reservation.  See comments
1111   for `final_presence_set'.  */
1112DEF_RTL_EXPR(FINAL_ABSENCE_SET, "final_absence_set", "ss", RTX_EXTRA)
1113
1114/* (define_bypass number out_insn_names in_insn_names) names bypass
1115   with given latency (the first number) from insns given by the first
1116   string (see define_insn_reservation) into insns given by the second
1117   string.  Insn names in the strings are separated by commas.  The
1118   third operand is optional name of function which is additional
1119   guard for the bypass.  The function will get the two insns as
1120   parameters.  If the function returns zero the bypass will be
1121   ignored for this case.  Additional guard is necessary to recognize
1122   complicated bypasses, e.g. when consumer is load address.  If there
1123   are more one bypass with the same output and input insns, the
1124   chosen bypass is the first bypass with a guard in description whose
1125   guard function returns nonzero.  If there is no such bypass, then
1126   bypass without the guard function is chosen.  */
1127DEF_RTL_EXPR(DEFINE_BYPASS, "define_bypass", "issS", RTX_EXTRA)
1128
1129/* (define_automaton string) describes names of automata generated and
1130   used for pipeline hazards recognition.  The names are separated by
1131   comma.  Actually it is possibly to generate the single automaton
1132   but unfortunately it can be very large.  If we use more one
1133   automata, the summary size of the automata usually is less than the
1134   single one.  The automaton name is used in define_cpu_unit and
1135   define_query_cpu_unit.  All automata should have unique names.  */
1136DEF_RTL_EXPR(DEFINE_AUTOMATON, "define_automaton", "s", RTX_EXTRA)
1137
1138/* (automata_option string) describes option for generation of
1139   automata.  Currently there are the following options:
1140
1141   o "no-minimization" which makes no minimization of automata.  This
1142     is only worth to do when we are debugging the description and
1143     need to look more accurately at reservations of states.
1144
1145   o "time" which means printing additional time statistics about
1146      generation of automata.
1147
1148   o "v" which means generation of file describing the result
1149     automata.  The file has suffix `.dfa' and can be used for the
1150     description verification and debugging.
1151
1152   o "w" which means generation of warning instead of error for
1153     non-critical errors.
1154
1155   o "ndfa" which makes nondeterministic finite state automata.
1156
1157   o "progress" which means output of a progress bar showing how many
1158     states were generated so far for automaton being processed.  */
1159DEF_RTL_EXPR(AUTOMATA_OPTION, "automata_option", "s", RTX_EXTRA)
1160
1161/* (define_reservation string string) names reservation (the first
1162   string) of cpu functional units (the 2nd string).  Sometimes unit
1163   reservations for different insns contain common parts.  In such
1164   case, you can describe common part and use its name (the 1st
1165   parameter) in regular expression in define_insn_reservation.  All
1166   define_reservations, define_cpu_units, and define_query_cpu_units
1167   should have unique names which may not be "nothing".  */
1168DEF_RTL_EXPR(DEFINE_RESERVATION, "define_reservation", "ss", RTX_EXTRA)
1169
1170/* (define_insn_reservation name default_latency condition regexpr)
1171   describes reservation of cpu functional units (the 3nd operand) for
1172   instruction which is selected by the condition (the 2nd parameter).
1173   The first parameter is used for output of debugging information.
1174   The reservations are described by a regular expression according
1175   the following syntax:
1176
1177       regexp = regexp "," oneof
1178              | oneof
1179
1180       oneof = oneof "|" allof
1181             | allof
1182
1183       allof = allof "+" repeat
1184             | repeat
1185
1186       repeat = element "*" number
1187              | element
1188
1189       element = cpu_function_unit_name
1190               | reservation_name
1191               | result_name
1192               | "nothing"
1193               | "(" regexp ")"
1194
1195       1. "," is used for describing start of the next cycle in
1196       reservation.
1197
1198       2. "|" is used for describing the reservation described by the
1199       first regular expression *or* the reservation described by the
1200       second regular expression *or* etc.
1201
1202       3. "+" is used for describing the reservation described by the
1203       first regular expression *and* the reservation described by the
1204       second regular expression *and* etc.
1205
1206       4. "*" is used for convenience and simply means sequence in
1207       which the regular expression are repeated NUMBER times with
1208       cycle advancing (see ",").
1209
1210       5. cpu functional unit name which means its reservation.
1211
1212       6. reservation name -- see define_reservation.
1213
1214       7. string "nothing" means no units reservation.  */
1215
1216DEF_RTL_EXPR(DEFINE_INSN_RESERVATION, "define_insn_reservation", "sies", RTX_EXTRA)
1217
1218/* Expressions used for insn attributes.  */
1219
1220/* Definition of an insn attribute.
1221   1st operand: name of the attribute
1222   2nd operand: comma-separated list of possible attribute values
1223   3rd operand: expression for the default value of the attribute.  */
1224DEF_RTL_EXPR(DEFINE_ATTR, "define_attr", "sse", RTX_EXTRA)
1225
1226/* Definition of an insn attribute that uses an existing enumerated type.
1227   1st operand: name of the attribute
1228   2nd operand: the name of the enumerated type
1229   3rd operand: expression for the default value of the attribute.  */
1230DEF_RTL_EXPR(DEFINE_ENUM_ATTR, "define_enum_attr", "sse", RTX_EXTRA)
1231
1232/* Marker for the name of an attribute.  */
1233DEF_RTL_EXPR(ATTR, "attr", "s", RTX_EXTRA)
1234
1235/* For use in the last (optional) operand of DEFINE_INSN or DEFINE_PEEPHOLE and
1236   in DEFINE_ASM_INSN to specify an attribute to assign to insns matching that
1237   pattern.
1238
1239   (set_attr "name" "value") is equivalent to
1240   (set (attr "name") (const_string "value"))  */
1241DEF_RTL_EXPR(SET_ATTR, "set_attr", "ss", RTX_EXTRA)
1242
1243/* In the last operand of DEFINE_INSN and DEFINE_PEEPHOLE, this can be used to
1244   specify that attribute values are to be assigned according to the
1245   alternative matched.
1246
1247   The following three expressions are equivalent:
1248
1249   (set (attr "att") (cond [(eq_attrq "alternative" "1") (const_string "a1")
1250			    (eq_attrq "alternative" "2") (const_string "a2")]
1251			   (const_string "a3")))
1252   (set_attr_alternative "att" [(const_string "a1") (const_string "a2")
1253				 (const_string "a3")])
1254   (set_attr "att" "a1,a2,a3")
1255 */
1256DEF_RTL_EXPR(SET_ATTR_ALTERNATIVE, "set_attr_alternative", "sE", RTX_EXTRA)
1257
1258/* A conditional expression true if the value of the specified attribute of
1259   the current insn equals the specified value.  The first operand is the
1260   attribute name and the second is the comparison value.  */
1261DEF_RTL_EXPR(EQ_ATTR, "eq_attr", "ss", RTX_EXTRA)
1262
1263/* A special case of the above representing a set of alternatives.  The first
1264   operand is bitmap of the set, the second one is the default value.  */
1265DEF_RTL_EXPR(EQ_ATTR_ALT, "eq_attr_alt", "ii", RTX_EXTRA)
1266
1267/* A conditional expression which is true if the specified flag is
1268   true for the insn being scheduled in reorg.
1269
1270   genattr.c defines the following flags which can be tested by
1271   (attr_flag "foo") expressions in eligible_for_delay.
1272
1273   forward, backward, very_likely, likely, very_unlikely, and unlikely.  */
1274
1275DEF_RTL_EXPR (ATTR_FLAG, "attr_flag", "s", RTX_EXTRA)
1276
1277/* General conditional. The first operand is a vector composed of pairs of
1278   expressions.  The first element of each pair is evaluated, in turn.
1279   The value of the conditional is the second expression of the first pair
1280   whose first expression evaluates nonzero.  If none of the expressions is
1281   true, the second operand will be used as the value of the conditional.  */
1282DEF_RTL_EXPR(COND, "cond", "Ee", RTX_EXTRA)
1283
1284#endif /* GENERATOR_FILE */
1285
1286/*
1287Local variables:
1288mode:c
1289End:
1290*/
1291