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) 1987-2015 Free Software Foundation, Inc.
5
6This file is part of GCC.
7
8GCC is free software; you can redistribute it and/or modify it under
9the terms of the GNU General Public License as published by the Free
10Software Foundation; either version 3, or (at your option) any later
11version.
12
13GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14WARRANTY; without even the implied warranty of MERCHANTABILITY or
15FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
16for more details.
17
18You should have received a copy of the GNU General Public License
19along with GCC; see the file COPYING3.  If not see
20<http://www.gnu.org/licenses/>.  */
21
22
23/* Expression definitions and descriptions for all targets are in this file.
24   Some will not be used for some targets.
25
26   The fields in the cpp macro call "DEF_RTL_EXPR()"
27   are used to create declarations in the C source of the compiler.
28
29   The fields are:
30
31   1.  The internal name of the rtx used in the C source.
32   It is a tag in the enumeration "enum rtx_code" defined in "rtl.h".
33   By convention these are in UPPER_CASE.
34
35   2.  The name of the rtx in the external ASCII format read by
36   read_rtx(), and printed by print_rtx().
37   These names are stored in rtx_name[].
38   By convention these are the internal (field 1) names in lower_case.
39
40   3.  The print format, and type of each rtx->u.fld[] (field) in this rtx.
41   These formats are stored in rtx_format[].
42   The meaning of the formats is documented in front of this array in rtl.c
43
44   4.  The class of the rtx.  These are stored in rtx_class and are accessed
45   via the GET_RTX_CLASS macro.  They are defined as follows:
46
47     RTX_CONST_OBJ
48         an rtx code that can be used to represent a constant object
49         (e.g, CONST_INT)
50     RTX_OBJ
51         an rtx code that can be used to represent an object (e.g, REG, MEM)
52     RTX_COMPARE
53         an rtx code for a comparison (e.g, LT, GT)
54     RTX_COMM_COMPARE
55         an rtx code for a commutative comparison (e.g, EQ, NE, ORDERED)
56     RTX_UNARY
57         an rtx code for a unary arithmetic expression (e.g, NEG, NOT)
58     RTX_COMM_ARITH
59         an rtx code for a commutative binary operation (e.g,, PLUS, MULT)
60     RTX_TERNARY
61         an rtx code for a non-bitfield three input operation (IF_THEN_ELSE)
62     RTX_BIN_ARITH
63         an rtx code for a non-commutative binary operation (e.g., MINUS, DIV)
64     RTX_BITFIELD_OPS
65         an rtx code for a bit-field operation (ZERO_EXTRACT, SIGN_EXTRACT)
66     RTX_INSN
67         an rtx code for a machine insn (INSN, JUMP_INSN, CALL_INSN) or
68	 data that will be output as assembly pseudo-ops (DEBUG_INSN)
69     RTX_MATCH
70         an rtx code for something that matches in insns (e.g, MATCH_DUP)
71     RTX_AUTOINC
72         an rtx code for autoincrement addressing modes (e.g. POST_DEC)
73     RTX_EXTRA
74         everything else
75
76   All of the expressions that appear only in machine descriptions,
77   not in RTL used by the compiler itself, are at the end of the file.  */
78
79/* Unknown, or no such operation; the enumeration constant should have
80   value zero.  */
81DEF_RTL_EXPR(UNKNOWN, "UnKnown", "*", RTX_EXTRA)
82
83/* Used in the cselib routines to describe a value.  Objects of this
84   kind are only allocated in cselib.c, in an alloc pool instead of in
85   GC memory.  The only operand of a VALUE is a cselib_val.
86   var-tracking requires this to have a distinct integral value from
87   DECL codes in trees.  */
88DEF_RTL_EXPR(VALUE, "value", "0", RTX_OBJ)
89
90/* The RTL generated for a DEBUG_EXPR_DECL.  It links back to the
91   DEBUG_EXPR_DECL in the first operand.  */
92DEF_RTL_EXPR(DEBUG_EXPR, "debug_expr", "0", RTX_OBJ)
93
94/* ---------------------------------------------------------------------
95   Expressions used in constructing lists.
96   --------------------------------------------------------------------- */
97
98/* A linked list of expressions.  */
99DEF_RTL_EXPR(EXPR_LIST, "expr_list", "ee", RTX_EXTRA)
100
101/* A linked list of instructions.
102   The insns are represented in print by their uids.  */
103DEF_RTL_EXPR(INSN_LIST, "insn_list", "ue", RTX_EXTRA)
104
105/* A linked list of integers.  */
106DEF_RTL_EXPR(INT_LIST, "int_list", "ie", RTX_EXTRA)
107
108/* SEQUENCE is used in late passes of the compiler to group insns for
109   one reason or another.
110
111   For example, after delay slot filling, branch instructions with filled
112   delay slots are represented as a SEQUENCE of length 1 + n_delay_slots,
113   with the branch instruction in XEXPVEC(seq, 0, 0) and the instructions
114   occupying the delay slots in the remaining XEXPVEC slots.
115
116   Another place where a SEQUENCE may appear, is in REG_FRAME_RELATED_EXPR
117   notes, to express complex operations that are not obvious from the insn
118   to which the REG_FRAME_RELATED_EXPR note is attached.  In this usage of
119   SEQUENCE, the sequence vector slots do not hold real instructions but
120   only pseudo-instructions that can be translated to DWARF CFA expressions.
121
122   Some back ends also use SEQUENCE to group insns in bundles.
123
124   Much of the compiler infrastructure is not prepared to handle SEQUENCE
125   objects.  Only passes after pass_free_cfg are expected to handle them.  */
126DEF_RTL_EXPR(SEQUENCE, "sequence", "E", RTX_EXTRA)
127
128/* Represents a non-global base address.  This is only used in alias.c.  */
129DEF_RTL_EXPR(ADDRESS, "address", "i", RTX_EXTRA)
130
131/* ----------------------------------------------------------------------
132   Expression types used for things in the instruction chain.
133
134   All formats must start with "iuu" to handle the chain.
135   Each insn expression holds an rtl instruction and its semantics
136   during back-end processing.
137   See macros's in "rtl.h" for the meaning of each rtx->u.fld[].
138
139   ---------------------------------------------------------------------- */
140
141/* An annotation for variable assignment tracking.  */
142DEF_RTL_EXPR(DEBUG_INSN, "debug_insn", "uuBeiie", RTX_INSN)
143
144/* An instruction that cannot jump.  */
145DEF_RTL_EXPR(INSN, "insn", "uuBeiie", RTX_INSN)
146
147/* An instruction that can possibly jump.
148   Fields ( rtx->u.fld[] ) have exact same meaning as INSN's.  */
149DEF_RTL_EXPR(JUMP_INSN, "jump_insn", "uuBeiie0", RTX_INSN)
150
151/* An instruction that can possibly call a subroutine
152   but which will not change which instruction comes next
153   in the current function.
154   Field ( rtx->u.fld[8] ) is CALL_INSN_FUNCTION_USAGE.
155   All other fields ( rtx->u.fld[] ) have exact same meaning as INSN's.  */
156DEF_RTL_EXPR(CALL_INSN, "call_insn", "uuBeiiee", RTX_INSN)
157
158/* Placeholder for tablejump JUMP_INSNs.  The pattern of this kind
159   of rtx is always either an ADDR_VEC or an ADDR_DIFF_VEC.  These
160   placeholders do not appear as real instructions inside a basic
161   block, but are considered active_insn_p instructions for historical
162   reasons, when jump table data was represented with JUMP_INSNs.  */
163DEF_RTL_EXPR(JUMP_TABLE_DATA, "jump_table_data", "uuBe0000", RTX_INSN)
164
165/* A marker that indicates that control will not flow through.  */
166DEF_RTL_EXPR(BARRIER, "barrier", "uu00000", RTX_EXTRA)
167
168/* Holds a label that is followed by instructions.
169   Operand:
170   3: is used in jump.c for the use-count of the label.
171   4: is used in the sh backend.
172   5: is a number that is unique in the entire compilation.
173   6: is the user-given name of the label, if any.  */
174DEF_RTL_EXPR(CODE_LABEL, "code_label", "uuB00is", RTX_EXTRA)
175
176/* Say where in the code a source line starts, for symbol table's sake.
177   Operand:
178   3: note-specific data
179   4: enum insn_note
180   5: unique number if insn_note == note_insn_deleted_label.  */
181DEF_RTL_EXPR(NOTE, "note", "uuB0ni", RTX_EXTRA)
182
183/* ----------------------------------------------------------------------
184   Top level constituents of INSN, JUMP_INSN and CALL_INSN.
185   ---------------------------------------------------------------------- */
186
187/* Conditionally execute code.
188   Operand 0 is the condition that if true, the code is executed.
189   Operand 1 is the code to be executed (typically a SET).
190
191   Semantics are that there are no side effects if the condition
192   is false.  This pattern is created automatically by the if_convert
193   pass run after reload or by target-specific splitters.  */
194DEF_RTL_EXPR(COND_EXEC, "cond_exec", "ee", RTX_EXTRA)
195
196/* Several operations to be done in parallel (perhaps under COND_EXEC).  */
197DEF_RTL_EXPR(PARALLEL, "parallel", "E", RTX_EXTRA)
198
199/* A string that is passed through to the assembler as input.
200     One can obviously pass comments through by using the
201     assembler comment syntax.
202     These occur in an insn all by themselves as the PATTERN.
203     They also appear inside an ASM_OPERANDS
204     as a convenient way to hold a string.  */
205DEF_RTL_EXPR(ASM_INPUT, "asm_input", "si", RTX_EXTRA)
206
207/* An assembler instruction with operands.
208   1st operand is the instruction template.
209   2nd operand is the constraint for the output.
210   3rd operand is the number of the output this expression refers to.
211     When an insn stores more than one value, a separate ASM_OPERANDS
212     is made for each output; this integer distinguishes them.
213   4th is a vector of values of input operands.
214   5th is a vector of modes and constraints for the input operands.
215     Each element is an ASM_INPUT containing a constraint string
216     and whose mode indicates the mode of the input operand.
217   6th is a vector of labels that may be branched to by the asm.
218   7th is the source line number.  */
219DEF_RTL_EXPR(ASM_OPERANDS, "asm_operands", "ssiEEEi", RTX_EXTRA)
220
221/* A machine-specific operation.
222   1st operand is a vector of operands being used by the operation so that
223     any needed reloads can be done.
224   2nd operand is a unique value saying which of a number of machine-specific
225     operations is to be performed.
226   (Note that the vector must be the first operand because of the way that
227   genrecog.c record positions within an insn.)
228
229   UNSPEC can occur all by itself in a PATTERN, as a component of a PARALLEL,
230   or inside an expression.
231   UNSPEC by itself or as a component of a PARALLEL
232   is currently considered not deletable.
233
234   FIXME: Replace all uses of UNSPEC that appears by itself or as a component
235   of a PARALLEL with USE.
236   */
237DEF_RTL_EXPR(UNSPEC, "unspec", "Ei", RTX_EXTRA)
238
239/* Similar, but a volatile operation and one which may trap.  */
240DEF_RTL_EXPR(UNSPEC_VOLATILE, "unspec_volatile", "Ei", RTX_EXTRA)
241
242/* ----------------------------------------------------------------------
243   Table jump addresses.
244   ---------------------------------------------------------------------- */
245
246/* Vector of addresses, stored as full words.
247   Each element is a LABEL_REF to a CODE_LABEL whose address we want.  */
248DEF_RTL_EXPR(ADDR_VEC, "addr_vec", "E", RTX_EXTRA)
249
250/* Vector of address differences X0 - BASE, X1 - BASE, ...
251   First operand is BASE; the vector contains the X's.
252   The machine mode of this rtx says how much space to leave
253   for each difference and is adjusted by branch shortening if
254   CASE_VECTOR_SHORTEN_MODE is defined.
255   The third and fourth operands store the target labels with the
256   minimum and maximum addresses respectively.
257   The fifth operand stores flags for use by branch shortening.
258  Set at the start of shorten_branches:
259   min_align: the minimum alignment for any of the target labels.
260   base_after_vec: true iff BASE is after the ADDR_DIFF_VEC.
261   min_after_vec: true iff minimum addr target label is after the ADDR_DIFF_VEC.
262   max_after_vec: true iff maximum addr target label is after the ADDR_DIFF_VEC.
263   min_after_base: true iff minimum address target label is after BASE.
264   max_after_base: true iff maximum address target label is after BASE.
265  Set by the actual branch shortening process:
266   offset_unsigned: true iff offsets have to be treated as unsigned.
267   scale: scaling that is necessary to make offsets fit into the mode.
268
269   The third, fourth and fifth operands are only valid when
270   CASE_VECTOR_SHORTEN_MODE is defined, and only in an optimizing
271   compilation.  */
272DEF_RTL_EXPR(ADDR_DIFF_VEC, "addr_diff_vec", "eEee0", RTX_EXTRA)
273
274/* Memory prefetch, with attributes supported on some targets.
275   Operand 1 is the address of the memory to fetch.
276   Operand 2 is 1 for a write access, 0 otherwise.
277   Operand 3 is the level of temporal locality; 0 means there is no
278   temporal locality and 1, 2, and 3 are for increasing levels of temporal
279   locality.
280
281   The attributes specified by operands 2 and 3 are ignored for targets
282   whose prefetch instructions do not support them.  */
283DEF_RTL_EXPR(PREFETCH, "prefetch", "eee", RTX_EXTRA)
284
285/* ----------------------------------------------------------------------
286   At the top level of an instruction (perhaps under PARALLEL).
287   ---------------------------------------------------------------------- */
288
289/* Assignment.
290   Operand 1 is the location (REG, MEM, PC, CC0 or whatever) assigned to.
291   Operand 2 is the value stored there.
292   ALL assignment must use SET.
293   Instructions that do multiple assignments must use multiple SET,
294   under PARALLEL.  */
295DEF_RTL_EXPR(SET, "set", "ee", RTX_EXTRA)
296
297/* Indicate something is used in a way that we don't want to explain.
298   For example, subroutine calls will use the register
299   in which the static chain is passed.
300
301   USE can not appear as an operand of other rtx except for PARALLEL.
302   USE is not deletable, as it indicates that the operand
303   is used in some unknown way.  */
304DEF_RTL_EXPR(USE, "use", "e", RTX_EXTRA)
305
306/* Indicate something is clobbered in a way that we don't want to explain.
307   For example, subroutine calls will clobber some physical registers
308   (the ones that are by convention not saved).
309
310   CLOBBER can not appear as an operand of other rtx except for PARALLEL.
311   CLOBBER of a hard register appearing by itself (not within PARALLEL)
312   is considered undeletable before reload.  */
313DEF_RTL_EXPR(CLOBBER, "clobber", "e", RTX_EXTRA)
314
315/* Call a subroutine.
316   Operand 1 is the address to call.
317   Operand 2 is the number of arguments.  */
318
319DEF_RTL_EXPR(CALL, "call", "ee", RTX_EXTRA)
320
321/* Return from a subroutine.  */
322
323DEF_RTL_EXPR(RETURN, "return", "", RTX_EXTRA)
324
325/* Like RETURN, but truly represents only a function return, while
326   RETURN may represent an insn that also performs other functions
327   of the function epilogue.  Like RETURN, this may also occur in
328   conditional jumps.  */
329DEF_RTL_EXPR(SIMPLE_RETURN, "simple_return", "", RTX_EXTRA)
330
331/* Special for EH return from subroutine.  */
332
333DEF_RTL_EXPR(EH_RETURN, "eh_return", "", RTX_EXTRA)
334
335/* Conditional trap.
336   Operand 1 is the condition.
337   Operand 2 is the trap code.
338   For an unconditional trap, make the condition (const_int 1).  */
339DEF_RTL_EXPR(TRAP_IF, "trap_if", "ee", RTX_EXTRA)
340
341/* ----------------------------------------------------------------------
342   Primitive values for use in expressions.
343   ---------------------------------------------------------------------- */
344
345/* numeric integer constant */
346DEF_RTL_EXPR(CONST_INT, "const_int", "w", RTX_CONST_OBJ)
347
348/* numeric integer constant */
349DEF_RTL_EXPR(CONST_WIDE_INT, "const_wide_int", "", RTX_CONST_OBJ)
350
351/* fixed-point constant */
352DEF_RTL_EXPR(CONST_FIXED, "const_fixed", "www", RTX_CONST_OBJ)
353
354/* numeric floating point or integer constant.  If the mode is
355   VOIDmode it is an int otherwise it has a floating point mode and a
356   floating point value.  Operands hold the value.  They are all 'w'
357   and there may be from 2 to 6; see real.h.  */
358DEF_RTL_EXPR(CONST_DOUBLE, "const_double", CONST_DOUBLE_FORMAT, RTX_CONST_OBJ)
359
360/* Describes a vector constant.  */
361DEF_RTL_EXPR(CONST_VECTOR, "const_vector", "E", RTX_CONST_OBJ)
362
363/* String constant.  Used for attributes in machine descriptions and
364   for special cases in DWARF2 debug output.  NOT used for source-
365   language string constants.  */
366DEF_RTL_EXPR(CONST_STRING, "const_string", "s", RTX_OBJ)
367
368/* This is used to encapsulate an expression whose value is constant
369   (such as the sum of a SYMBOL_REF and a CONST_INT) so that it will be
370   recognized as a constant operand rather than by arithmetic instructions.  */
371
372DEF_RTL_EXPR(CONST, "const", "e", RTX_CONST_OBJ)
373
374/* program counter.  Ordinary jumps are represented
375   by a SET whose first operand is (PC).  */
376DEF_RTL_EXPR(PC, "pc", "", RTX_OBJ)
377
378/* A register.  The "operand" is the register number, accessed with
379   the REGNO macro.  If this number is less than FIRST_PSEUDO_REGISTER
380   than a hardware register is being referred to.  The second operand
381   points to a reg_attrs structure.
382   This rtx needs to have as many (or more) fields as a MEM, since we
383   can change REG rtx's into MEMs during reload.  */
384DEF_RTL_EXPR(REG, "reg", "i0", RTX_OBJ)
385
386/* A scratch register.  This represents a register used only within a
387   single insn.  It will be replaced by a REG during register allocation
388   or reload unless the constraint indicates that the register won't be
389   needed, in which case it can remain a SCRATCH.  */
390DEF_RTL_EXPR(SCRATCH, "scratch", "", RTX_OBJ)
391
392/* A reference to a part of another value.  The first operand is the
393   complete value and the second is the byte offset of the selected part.   */
394DEF_RTL_EXPR(SUBREG, "subreg", "ei", RTX_EXTRA)
395
396/* This one-argument rtx is used for move instructions
397   that are guaranteed to alter only the low part of a destination.
398   Thus, (SET (SUBREG:HI (REG...)) (MEM:HI ...))
399   has an unspecified effect on the high part of REG,
400   but (SET (STRICT_LOW_PART (SUBREG:HI (REG...))) (MEM:HI ...))
401   is guaranteed to alter only the bits of REG that are in HImode.
402
403   The actual instruction used is probably the same in both cases,
404   but the register constraints may be tighter when STRICT_LOW_PART
405   is in use.  */
406
407DEF_RTL_EXPR(STRICT_LOW_PART, "strict_low_part", "e", RTX_EXTRA)
408
409/* (CONCAT a b) represents the virtual concatenation of a and b
410   to make a value that has as many bits as a and b put together.
411   This is used for complex values.  Normally it appears only
412   in DECL_RTLs and during RTL generation, but not in the insn chain.  */
413DEF_RTL_EXPR(CONCAT, "concat", "ee", RTX_OBJ)
414
415/* (CONCATN [a1 a2 ... an]) represents the virtual concatenation of
416   all An to make a value.  This is an extension of CONCAT to larger
417   number of components.  Like CONCAT, it should not appear in the
418   insn chain.  Every element of the CONCATN is the same size.  */
419DEF_RTL_EXPR(CONCATN, "concatn", "E", RTX_OBJ)
420
421/* A memory location; operand is the address.  The second operand is the
422   alias set to which this MEM belongs.  We use `0' instead of `w' for this
423   field so that the field need not be specified in machine descriptions.  */
424DEF_RTL_EXPR(MEM, "mem", "e0", RTX_OBJ)
425
426/* Reference to an assembler label in the code for this function.
427   The operand is a CODE_LABEL found in the insn chain.  */
428DEF_RTL_EXPR(LABEL_REF, "label_ref", "u", RTX_CONST_OBJ)
429
430/* Reference to a named label:
431   Operand 0: label name
432   Operand 1: tree from which this symbol is derived, or null.
433   This is either a DECL node, or some kind of constant.  */
434DEF_RTL_EXPR(SYMBOL_REF, "symbol_ref", "s0", RTX_CONST_OBJ)
435
436/* The condition code register is represented, in our imagination,
437   as a register holding a value that can be compared to zero.
438   In fact, the machine has already compared them and recorded the
439   results; but instructions that look at the condition code
440   pretend to be looking at the entire value and comparing it.  */
441DEF_RTL_EXPR(CC0, "cc0", "", RTX_OBJ)
442
443/* ----------------------------------------------------------------------
444   Expressions for operators in an rtl pattern
445   ---------------------------------------------------------------------- */
446
447/* if_then_else.  This is used in representing ordinary
448   conditional jump instructions.
449     Operand:
450     0:  condition
451     1:  then expr
452     2:  else expr */
453DEF_RTL_EXPR(IF_THEN_ELSE, "if_then_else", "eee", RTX_TERNARY)
454
455/* Comparison, produces a condition code result.  */
456DEF_RTL_EXPR(COMPARE, "compare", "ee", RTX_BIN_ARITH)
457
458/* plus */
459DEF_RTL_EXPR(PLUS, "plus", "ee", RTX_COMM_ARITH)
460
461/* Operand 0 minus operand 1.  */
462DEF_RTL_EXPR(MINUS, "minus", "ee", RTX_BIN_ARITH)
463
464/* Minus operand 0.  */
465DEF_RTL_EXPR(NEG, "neg", "e", RTX_UNARY)
466
467DEF_RTL_EXPR(MULT, "mult", "ee", RTX_COMM_ARITH)
468
469/* Multiplication with signed saturation */
470DEF_RTL_EXPR(SS_MULT, "ss_mult", "ee", RTX_COMM_ARITH)
471/* Multiplication with unsigned saturation */
472DEF_RTL_EXPR(US_MULT, "us_mult", "ee", RTX_COMM_ARITH)
473
474/* Operand 0 divided by operand 1.  */
475DEF_RTL_EXPR(DIV, "div", "ee", RTX_BIN_ARITH)
476/* Division with signed saturation */
477DEF_RTL_EXPR(SS_DIV, "ss_div", "ee", RTX_BIN_ARITH)
478/* Division with unsigned saturation */
479DEF_RTL_EXPR(US_DIV, "us_div", "ee", RTX_BIN_ARITH)
480
481/* Remainder of operand 0 divided by operand 1.  */
482DEF_RTL_EXPR(MOD, "mod", "ee", RTX_BIN_ARITH)
483
484/* Unsigned divide and remainder.  */
485DEF_RTL_EXPR(UDIV, "udiv", "ee", RTX_BIN_ARITH)
486DEF_RTL_EXPR(UMOD, "umod", "ee", RTX_BIN_ARITH)
487
488/* Bitwise operations.  */
489DEF_RTL_EXPR(AND, "and", "ee", RTX_COMM_ARITH)
490DEF_RTL_EXPR(IOR, "ior", "ee", RTX_COMM_ARITH)
491DEF_RTL_EXPR(XOR, "xor", "ee", RTX_COMM_ARITH)
492DEF_RTL_EXPR(NOT, "not", "e", RTX_UNARY)
493
494/* Operand:
495     0:  value to be shifted.
496     1:  number of bits.  */
497DEF_RTL_EXPR(ASHIFT, "ashift", "ee", RTX_BIN_ARITH) /* shift left */
498DEF_RTL_EXPR(ROTATE, "rotate", "ee", RTX_BIN_ARITH) /* rotate left */
499DEF_RTL_EXPR(ASHIFTRT, "ashiftrt", "ee", RTX_BIN_ARITH) /* arithmetic shift right */
500DEF_RTL_EXPR(LSHIFTRT, "lshiftrt", "ee", RTX_BIN_ARITH) /* logical shift right */
501DEF_RTL_EXPR(ROTATERT, "rotatert", "ee", RTX_BIN_ARITH) /* rotate right */
502
503/* Minimum and maximum values of two operands.  We need both signed and
504   unsigned forms.  (We cannot use MIN for SMIN because it conflicts
505   with a macro of the same name.)   The signed variants should be used
506   with floating point.  Further, if both operands are zeros, or if either
507   operand is NaN, then it is unspecified which of the two operands is
508   returned as the result.  */
509
510DEF_RTL_EXPR(SMIN, "smin", "ee", RTX_COMM_ARITH)
511DEF_RTL_EXPR(SMAX, "smax", "ee", RTX_COMM_ARITH)
512DEF_RTL_EXPR(UMIN, "umin", "ee", RTX_COMM_ARITH)
513DEF_RTL_EXPR(UMAX, "umax", "ee", RTX_COMM_ARITH)
514
515/* These unary operations are used to represent incrementation
516   and decrementation as they occur in memory addresses.
517   The amount of increment or decrement are not represented
518   because they can be understood from the machine-mode of the
519   containing MEM.  These operations exist in only two cases:
520   1. pushes onto the stack.
521   2. created automatically by the auto-inc-dec pass.  */
522DEF_RTL_EXPR(PRE_DEC, "pre_dec", "e", RTX_AUTOINC)
523DEF_RTL_EXPR(PRE_INC, "pre_inc", "e", RTX_AUTOINC)
524DEF_RTL_EXPR(POST_DEC, "post_dec", "e", RTX_AUTOINC)
525DEF_RTL_EXPR(POST_INC, "post_inc", "e", RTX_AUTOINC)
526
527/* These binary operations are used to represent generic address
528   side-effects in memory addresses, except for simple incrementation
529   or decrementation which use the above operations.  They are
530   created automatically by the life_analysis pass in flow.c.
531   The first operand is a REG which is used as the address.
532   The second operand is an expression that is assigned to the
533   register, either before (PRE_MODIFY) or after (POST_MODIFY)
534   evaluating the address.
535   Currently, the compiler can only handle second operands of the
536   form (plus (reg) (reg)) and (plus (reg) (const_int)), where
537   the first operand of the PLUS has to be the same register as
538   the first operand of the *_MODIFY.  */
539DEF_RTL_EXPR(PRE_MODIFY, "pre_modify", "ee", RTX_AUTOINC)
540DEF_RTL_EXPR(POST_MODIFY, "post_modify", "ee", RTX_AUTOINC)
541
542/* Comparison operations.  The ordered comparisons exist in two
543   flavors, signed and unsigned.  */
544DEF_RTL_EXPR(NE, "ne", "ee", RTX_COMM_COMPARE)
545DEF_RTL_EXPR(EQ, "eq", "ee", RTX_COMM_COMPARE)
546DEF_RTL_EXPR(GE, "ge", "ee", RTX_COMPARE)
547DEF_RTL_EXPR(GT, "gt", "ee", RTX_COMPARE)
548DEF_RTL_EXPR(LE, "le", "ee", RTX_COMPARE)
549DEF_RTL_EXPR(LT, "lt", "ee", RTX_COMPARE)
550DEF_RTL_EXPR(GEU, "geu", "ee", RTX_COMPARE)
551DEF_RTL_EXPR(GTU, "gtu", "ee", RTX_COMPARE)
552DEF_RTL_EXPR(LEU, "leu", "ee", RTX_COMPARE)
553DEF_RTL_EXPR(LTU, "ltu", "ee", RTX_COMPARE)
554
555/* Additional floating point unordered comparison flavors.  */
556DEF_RTL_EXPR(UNORDERED, "unordered", "ee", RTX_COMM_COMPARE)
557DEF_RTL_EXPR(ORDERED, "ordered", "ee", RTX_COMM_COMPARE)
558
559/* These are equivalent to unordered or ...  */
560DEF_RTL_EXPR(UNEQ, "uneq", "ee", RTX_COMM_COMPARE)
561DEF_RTL_EXPR(UNGE, "unge", "ee", RTX_COMPARE)
562DEF_RTL_EXPR(UNGT, "ungt", "ee", RTX_COMPARE)
563DEF_RTL_EXPR(UNLE, "unle", "ee", RTX_COMPARE)
564DEF_RTL_EXPR(UNLT, "unlt", "ee", RTX_COMPARE)
565
566/* This is an ordered NE, ie !UNEQ, ie false for NaN.  */
567DEF_RTL_EXPR(LTGT, "ltgt", "ee", RTX_COMM_COMPARE)
568
569/* Represents the result of sign-extending the sole operand.
570   The machine modes of the operand and of the SIGN_EXTEND expression
571   determine how much sign-extension is going on.  */
572DEF_RTL_EXPR(SIGN_EXTEND, "sign_extend", "e", RTX_UNARY)
573
574/* Similar for zero-extension (such as unsigned short to int).  */
575DEF_RTL_EXPR(ZERO_EXTEND, "zero_extend", "e", RTX_UNARY)
576
577/* Similar but here the operand has a wider mode.  */
578DEF_RTL_EXPR(TRUNCATE, "truncate", "e", RTX_UNARY)
579
580/* Similar for extending floating-point values (such as SFmode to DFmode).  */
581DEF_RTL_EXPR(FLOAT_EXTEND, "float_extend", "e", RTX_UNARY)
582DEF_RTL_EXPR(FLOAT_TRUNCATE, "float_truncate", "e", RTX_UNARY)
583
584/* Conversion of fixed point operand to floating point value.  */
585DEF_RTL_EXPR(FLOAT, "float", "e", RTX_UNARY)
586
587/* With fixed-point machine mode:
588   Conversion of floating point operand to fixed point value.
589   Value is defined only when the operand's value is an integer.
590   With floating-point machine mode (and operand with same mode):
591   Operand is rounded toward zero to produce an integer value
592   represented in floating point.  */
593DEF_RTL_EXPR(FIX, "fix", "e", RTX_UNARY)
594
595/* Conversion of unsigned fixed point operand to floating point value.  */
596DEF_RTL_EXPR(UNSIGNED_FLOAT, "unsigned_float", "e", RTX_UNARY)
597
598/* With fixed-point machine mode:
599   Conversion of floating point operand to *unsigned* fixed point value.
600   Value is defined only when the operand's value is an integer.  */
601DEF_RTL_EXPR(UNSIGNED_FIX, "unsigned_fix", "e", RTX_UNARY)
602
603/* Conversions involving fractional fixed-point types without saturation,
604   including:
605     fractional to fractional (of different precision),
606     signed integer to fractional,
607     fractional to signed integer,
608     floating point to fractional,
609     fractional to floating point.
610   NOTE: fractional can be either signed or unsigned for conversions.  */
611DEF_RTL_EXPR(FRACT_CONVERT, "fract_convert", "e", RTX_UNARY)
612
613/* Conversions involving fractional fixed-point types and unsigned integer
614   without saturation, including:
615     unsigned integer to fractional,
616     fractional to unsigned integer.
617   NOTE: fractional can be either signed or unsigned for conversions.  */
618DEF_RTL_EXPR(UNSIGNED_FRACT_CONVERT, "unsigned_fract_convert", "e", RTX_UNARY)
619
620/* Conversions involving fractional fixed-point types with saturation,
621   including:
622     fractional to fractional (of different precision),
623     signed integer to fractional,
624     floating point to fractional.
625   NOTE: fractional can be either signed or unsigned for conversions.  */
626DEF_RTL_EXPR(SAT_FRACT, "sat_fract", "e", RTX_UNARY)
627
628/* Conversions involving fractional fixed-point types and unsigned integer
629   with saturation, including:
630     unsigned integer to fractional.
631   NOTE: fractional can be either signed or unsigned for conversions.  */
632DEF_RTL_EXPR(UNSIGNED_SAT_FRACT, "unsigned_sat_fract", "e", RTX_UNARY)
633
634/* Absolute value */
635DEF_RTL_EXPR(ABS, "abs", "e", RTX_UNARY)
636
637/* Square root */
638DEF_RTL_EXPR(SQRT, "sqrt", "e", RTX_UNARY)
639
640/* Swap bytes.  */
641DEF_RTL_EXPR(BSWAP, "bswap", "e", RTX_UNARY)
642
643/* Find first bit that is set.
644   Value is 1 + number of trailing zeros in the arg.,
645   or 0 if arg is 0.  */
646DEF_RTL_EXPR(FFS, "ffs", "e", RTX_UNARY)
647
648/* Count number of leading redundant sign bits (number of leading
649   sign bits minus one).  */
650DEF_RTL_EXPR(CLRSB, "clrsb", "e", RTX_UNARY)
651
652/* Count leading zeros.  */
653DEF_RTL_EXPR(CLZ, "clz", "e", RTX_UNARY)
654
655/* Count trailing zeros.  */
656DEF_RTL_EXPR(CTZ, "ctz", "e", RTX_UNARY)
657
658/* Population count (number of 1 bits).  */
659DEF_RTL_EXPR(POPCOUNT, "popcount", "e", RTX_UNARY)
660
661/* Population parity (number of 1 bits modulo 2).  */
662DEF_RTL_EXPR(PARITY, "parity", "e", RTX_UNARY)
663
664/* Reference to a signed bit-field of specified size and position.
665   Operand 0 is the memory unit (usually SImode or QImode) which
666   contains the field's first bit.  Operand 1 is the width, in bits.
667   Operand 2 is the number of bits in the memory unit before the
668   first bit of this field.
669   If BITS_BIG_ENDIAN is defined, the first bit is the msb and
670   operand 2 counts from the msb of the memory unit.
671   Otherwise, the first bit is the lsb and operand 2 counts from
672   the lsb of the memory unit.
673   This kind of expression can not appear as an lvalue in RTL.  */
674DEF_RTL_EXPR(SIGN_EXTRACT, "sign_extract", "eee", RTX_BITFIELD_OPS)
675
676/* Similar for unsigned bit-field.
677   But note!  This kind of expression _can_ appear as an lvalue.  */
678DEF_RTL_EXPR(ZERO_EXTRACT, "zero_extract", "eee", RTX_BITFIELD_OPS)
679
680/* For RISC machines.  These save memory when splitting insns.  */
681
682/* HIGH are the high-order bits of a constant expression.  */
683DEF_RTL_EXPR(HIGH, "high", "e", RTX_CONST_OBJ)
684
685/* LO_SUM is the sum of a register and the low-order bits
686   of a constant expression.  */
687DEF_RTL_EXPR(LO_SUM, "lo_sum", "ee", RTX_OBJ)
688
689/* Describes a merge operation between two vector values.
690   Operands 0 and 1 are the vectors to be merged, operand 2 is a bitmask
691   that specifies where the parts of the result are taken from.  Set bits
692   indicate operand 0, clear bits indicate operand 1.  The parts are defined
693   by the mode of the vectors.  */
694DEF_RTL_EXPR(VEC_MERGE, "vec_merge", "eee", RTX_TERNARY)
695
696/* Describes an operation that selects parts of a vector.
697   Operands 0 is the source vector, operand 1 is a PARALLEL that contains
698   a CONST_INT for each of the subparts of the result vector, giving the
699   number of the source subpart that should be stored into it.  */
700DEF_RTL_EXPR(VEC_SELECT, "vec_select", "ee", RTX_BIN_ARITH)
701
702/* Describes a vector concat operation.  Operands 0 and 1 are the source
703   vectors, the result is a vector that is as long as operands 0 and 1
704   combined and is the concatenation of the two source vectors.  */
705DEF_RTL_EXPR(VEC_CONCAT, "vec_concat", "ee", RTX_BIN_ARITH)
706
707/* Describes an operation that converts a small vector into a larger one by
708   duplicating the input values.  The output vector mode must have the same
709   submodes as the input vector mode, and the number of output parts must be
710   an integer multiple of the number of input parts.  */
711DEF_RTL_EXPR(VEC_DUPLICATE, "vec_duplicate", "e", RTX_UNARY)
712
713/* Addition with signed saturation */
714DEF_RTL_EXPR(SS_PLUS, "ss_plus", "ee", RTX_COMM_ARITH)
715
716/* Addition with unsigned saturation */
717DEF_RTL_EXPR(US_PLUS, "us_plus", "ee", RTX_COMM_ARITH)
718
719/* Operand 0 minus operand 1, with signed saturation.  */
720DEF_RTL_EXPR(SS_MINUS, "ss_minus", "ee", RTX_BIN_ARITH)
721
722/* Negation with signed saturation.  */
723DEF_RTL_EXPR(SS_NEG, "ss_neg", "e", RTX_UNARY)
724/* Negation with unsigned saturation.  */
725DEF_RTL_EXPR(US_NEG, "us_neg", "e", RTX_UNARY)
726
727/* Absolute value with signed saturation.  */
728DEF_RTL_EXPR(SS_ABS, "ss_abs", "e", RTX_UNARY)
729
730/* Shift left with signed saturation.  */
731DEF_RTL_EXPR(SS_ASHIFT, "ss_ashift", "ee", RTX_BIN_ARITH)
732
733/* Shift left with unsigned saturation.  */
734DEF_RTL_EXPR(US_ASHIFT, "us_ashift", "ee", RTX_BIN_ARITH)
735
736/* Operand 0 minus operand 1, with unsigned saturation.  */
737DEF_RTL_EXPR(US_MINUS, "us_minus", "ee", RTX_BIN_ARITH)
738
739/* Signed saturating truncate.  */
740DEF_RTL_EXPR(SS_TRUNCATE, "ss_truncate", "e", RTX_UNARY)
741
742/* Unsigned saturating truncate.  */
743DEF_RTL_EXPR(US_TRUNCATE, "us_truncate", "e", RTX_UNARY)
744
745/* Floating point multiply/add combined instruction.  */
746DEF_RTL_EXPR(FMA, "fma", "eee", RTX_TERNARY)
747
748/* Information about the variable and its location.  */
749DEF_RTL_EXPR(VAR_LOCATION, "var_location", "te", RTX_EXTRA)
750
751/* Used in VAR_LOCATION for a pointer to a decl that is no longer
752   addressable.  */
753DEF_RTL_EXPR(DEBUG_IMPLICIT_PTR, "debug_implicit_ptr", "t", RTX_OBJ)
754
755/* Represents value that argument had on function entry.  The
756   single argument is the DECL_INCOMING_RTL of the corresponding
757   parameter.  */
758DEF_RTL_EXPR(ENTRY_VALUE, "entry_value", "0", RTX_OBJ)
759
760/* Used in VAR_LOCATION for a reference to a parameter that has
761   been optimized away completely.  */
762DEF_RTL_EXPR(DEBUG_PARAMETER_REF, "debug_parameter_ref", "t", RTX_OBJ)
763
764/* All expressions from this point forward appear only in machine
765   descriptions.  */
766#ifdef GENERATOR_FILE
767
768/* Pattern-matching operators:  */
769
770/* Use the function named by the second arg (the string)
771   as a predicate; if matched, store the structure that was matched
772   in the operand table at index specified by the first arg (the integer).
773   If the second arg is the null string, the structure is just stored.
774
775   A third string argument indicates to the register allocator restrictions
776   on where the operand can be allocated.
777
778   If the target needs no restriction on any instruction this field should
779   be the null string.
780
781   The string is prepended by:
782   '=' to indicate the operand is only written to.
783   '+' to indicate the operand is both read and written to.
784
785   Each character in the string represents an allocable class for an operand.
786   'g' indicates the operand can be any valid class.
787   'i' indicates the operand can be immediate (in the instruction) data.
788   'r' indicates the operand can be in a register.
789   'm' indicates the operand can be in memory.
790   'o' a subset of the 'm' class.  Those memory addressing modes that
791       can be offset at compile time (have a constant added to them).
792
793   Other characters indicate target dependent operand classes and
794   are described in each target's machine description.
795
796   For instructions with more than one operand, sets of classes can be
797   separated by a comma to indicate the appropriate multi-operand constraints.
798   There must be a 1 to 1 correspondence between these sets of classes in
799   all operands for an instruction.
800   */
801DEF_RTL_EXPR(MATCH_OPERAND, "match_operand", "iss", RTX_MATCH)
802
803/* Match a SCRATCH or a register.  When used to generate rtl, a
804   SCRATCH is generated.  As for MATCH_OPERAND, the mode specifies
805   the desired mode and the first argument is the operand number.
806   The second argument is the constraint.  */
807DEF_RTL_EXPR(MATCH_SCRATCH, "match_scratch", "is", RTX_MATCH)
808
809/* Apply a predicate, AND match recursively the operands of the rtx.
810   Operand 0 is the operand-number, as in match_operand.
811   Operand 1 is a predicate to apply (as a string, a function name).
812   Operand 2 is a vector of expressions, each of which must match
813   one subexpression of the rtx this construct is matching.  */
814DEF_RTL_EXPR(MATCH_OPERATOR, "match_operator", "isE", RTX_MATCH)
815
816/* Match a PARALLEL of arbitrary length.  The predicate is applied
817   to the PARALLEL and the initial expressions in the PARALLEL are matched.
818   Operand 0 is the operand-number, as in match_operand.
819   Operand 1 is a predicate to apply to the PARALLEL.
820   Operand 2 is a vector of expressions, each of which must match the
821   corresponding element in the PARALLEL.  */
822DEF_RTL_EXPR(MATCH_PARALLEL, "match_parallel", "isE", RTX_MATCH)
823
824/* Match only something equal to what is stored in the operand table
825   at the index specified by the argument.  Use with MATCH_OPERAND.  */
826DEF_RTL_EXPR(MATCH_DUP, "match_dup", "i", RTX_MATCH)
827
828/* Match only something equal to what is stored in the operand table
829   at the index specified by the argument.  Use with MATCH_OPERATOR.  */
830DEF_RTL_EXPR(MATCH_OP_DUP, "match_op_dup", "iE", RTX_MATCH)
831
832/* Match only something equal to what is stored in the operand table
833   at the index specified by the argument.  Use with MATCH_PARALLEL.  */
834DEF_RTL_EXPR(MATCH_PAR_DUP, "match_par_dup", "iE", RTX_MATCH)
835
836/* Appears only in define_predicate/define_special_predicate
837   expressions.  Evaluates true only if the operand has an RTX code
838   from the set given by the argument (a comma-separated list).  If the
839   second argument is present and nonempty, it is a sequence of digits
840   and/or letters which indicates the subexpression to test, using the
841   same syntax as genextract/genrecog's location strings: 0-9 for
842   XEXP (op, n), a-z for XVECEXP (op, 0, n); each character applies to
843   the result of the one before it.  */
844DEF_RTL_EXPR(MATCH_CODE, "match_code", "ss", RTX_MATCH)
845
846/* Used to inject a C conditional expression into an .md file.  It can
847   appear in a predicate definition or an attribute expression.  */
848DEF_RTL_EXPR(MATCH_TEST, "match_test", "s", RTX_MATCH)
849
850/* Insn (and related) definitions.  */
851
852/* Definition of the pattern for one kind of instruction.
853   Operand:
854   0: names this instruction.
855      If the name is the null string, the instruction is in the
856      machine description just to be recognized, and will never be emitted by
857      the tree to rtl expander.
858   1: is the pattern.
859   2: is a string which is a C expression
860      giving an additional condition for recognizing this pattern.
861      A null string means no extra condition.
862   3: is the action to execute if this pattern is matched.
863      If this assembler code template starts with a * then it is a fragment of
864      C code to run to decide on a template to use.  Otherwise, it is the
865      template to use.
866   4: optionally, a vector of attributes for this insn.
867     */
868DEF_RTL_EXPR(DEFINE_INSN, "define_insn", "sEsTV", RTX_EXTRA)
869
870/* Definition of a peephole optimization.
871   1st operand: vector of insn patterns to match
872   2nd operand: C expression that must be true
873   3rd operand: template or C code to produce assembler output.
874   4: optionally, a vector of attributes for this insn.
875
876   This form is deprecated; use define_peephole2 instead.  */
877DEF_RTL_EXPR(DEFINE_PEEPHOLE, "define_peephole", "EsTV", RTX_EXTRA)
878
879/* Definition of a split operation.
880   1st operand: insn pattern to match
881   2nd operand: C expression that must be true
882   3rd operand: vector of insn patterns to place into a SEQUENCE
883   4th operand: optionally, some C code to execute before generating the
884	insns.  This might, for example, create some RTX's and store them in
885	elements of `recog_data.operand' for use by the vector of
886	insn-patterns.
887	(`operands' is an alias here for `recog_data.operand').  */
888DEF_RTL_EXPR(DEFINE_SPLIT, "define_split", "EsES", RTX_EXTRA)
889
890/* Definition of an insn and associated split.
891   This is the concatenation, with a few modifications, of a define_insn
892   and a define_split which share the same pattern.
893   Operand:
894   0: names this instruction.
895      If the name is the null string, the instruction is in the
896      machine description just to be recognized, and will never be emitted by
897      the tree to rtl expander.
898   1: is the pattern.
899   2: is a string which is a C expression
900      giving an additional condition for recognizing this pattern.
901      A null string means no extra condition.
902   3: is the action to execute if this pattern is matched.
903      If this assembler code template starts with a * then it is a fragment of
904      C code to run to decide on a template to use.  Otherwise, it is the
905      template to use.
906   4: C expression that must be true for split.  This may start with "&&"
907      in which case the split condition is the logical and of the insn
908      condition and what follows the "&&" of this operand.
909   5: vector of insn patterns to place into a SEQUENCE
910   6: optionally, some C code to execute before generating the
911	insns.  This might, for example, create some RTX's and store them in
912	elements of `recog_data.operand' for use by the vector of
913	insn-patterns.
914	(`operands' is an alias here for `recog_data.operand').
915   7: optionally, a vector of attributes for this insn.  */
916DEF_RTL_EXPR(DEFINE_INSN_AND_SPLIT, "define_insn_and_split", "sEsTsESV", RTX_EXTRA)
917
918/* Definition of an RTL peephole operation.
919   Follows the same arguments as define_split.  */
920DEF_RTL_EXPR(DEFINE_PEEPHOLE2, "define_peephole2", "EsES", RTX_EXTRA)
921
922/* Define how to generate multiple insns for a standard insn name.
923   1st operand: the insn name.
924   2nd operand: vector of insn-patterns.
925	Use match_operand to substitute an element of `recog_data.operand'.
926   3rd operand: C expression that must be true for this to be available.
927	This may not test any operands.
928   4th operand: Extra C code to execute before generating the insns.
929	This might, for example, create some RTX's and store them in
930	elements of `recog_data.operand' for use by the vector of
931	insn-patterns.
932	(`operands' is an alias here for `recog_data.operand').
933   5th: optionally, a vector of attributes for this expand.  */
934DEF_RTL_EXPR(DEFINE_EXPAND, "define_expand", "sEssV", RTX_EXTRA)
935
936/* Define a requirement for delay slots.
937   1st operand: Condition involving insn attributes that, if true,
938	        indicates that the insn requires the number of delay slots
939		shown.
940   2nd operand: Vector whose length is the three times the number of delay
941		slots required.
942	        Each entry gives three conditions, each involving attributes.
943		The first must be true for an insn to occupy that delay slot
944		location.  The second is true for all insns that can be
945		annulled if the branch is true and the third is true for all
946		insns that can be annulled if the branch is false.
947
948   Multiple DEFINE_DELAYs may be present.  They indicate differing
949   requirements for delay slots.  */
950DEF_RTL_EXPR(DEFINE_DELAY, "define_delay", "eE", RTX_EXTRA)
951
952/* Define attribute computation for `asm' instructions.  */
953DEF_RTL_EXPR(DEFINE_ASM_ATTRIBUTES, "define_asm_attributes", "V", RTX_EXTRA)
954
955/* Definition of a conditional execution meta operation.  Automatically
956   generates new instances of DEFINE_INSN, selected by having attribute
957   "predicable" true.  The new pattern will contain a COND_EXEC and the
958   predicate at top-level.
959
960   Operand:
961   0: The predicate pattern.  The top-level form should match a
962      relational operator.  Operands should have only one alternative.
963   1: A C expression giving an additional condition for recognizing
964      the generated pattern.
965   2: A template or C code to produce assembler output.
966   3: A vector of attributes to append to the resulting cond_exec insn.  */
967DEF_RTL_EXPR(DEFINE_COND_EXEC, "define_cond_exec", "EssV", RTX_EXTRA)
968
969/* Definition of an operand predicate.  The difference between
970   DEFINE_PREDICATE and DEFINE_SPECIAL_PREDICATE is that genrecog will
971   not warn about a match_operand with no mode if it has a predicate
972   defined with DEFINE_SPECIAL_PREDICATE.
973
974   Operand:
975   0: The name of the predicate.
976   1: A boolean expression which computes whether or not the predicate
977      matches.  This expression can use IOR, AND, NOT, MATCH_OPERAND,
978      MATCH_CODE, and MATCH_TEST.  It must be specific enough that genrecog
979      can calculate the set of RTX codes that can possibly match.
980   2: A C function body which must return true for the predicate to match.
981      Optional.  Use this when the test is too complicated to fit into a
982      match_test expression.  */
983DEF_RTL_EXPR(DEFINE_PREDICATE, "define_predicate", "ses", RTX_EXTRA)
984DEF_RTL_EXPR(DEFINE_SPECIAL_PREDICATE, "define_special_predicate", "ses", RTX_EXTRA)
985
986/* Definition of a register operand constraint.  This simply maps the
987   constraint string to a register class.
988
989   Operand:
990   0: The name of the constraint (often, but not always, a single letter).
991   1: A C expression which evaluates to the appropriate register class for
992      this constraint.  If this is not just a constant, it should look only
993      at -m switches and the like.
994   2: A docstring for this constraint, in Texinfo syntax; not currently
995      used, in future will be incorporated into the manual's list of
996      machine-specific operand constraints.  */
997DEF_RTL_EXPR(DEFINE_REGISTER_CONSTRAINT, "define_register_constraint", "sss", RTX_EXTRA)
998
999/* Definition of a non-register operand constraint.  These look at the
1000   operand and decide whether it fits the constraint.
1001
1002   DEFINE_CONSTRAINT gets no special treatment if it fails to match.
1003   It is appropriate for constant-only constraints, and most others.
1004
1005   DEFINE_MEMORY_CONSTRAINT tells reload that this constraint can be made
1006   to match, if it doesn't already, by converting the operand to the form
1007   (mem (reg X)) where X is a base register.  It is suitable for constraints
1008   that describe a subset of all memory references.
1009
1010   DEFINE_ADDRESS_CONSTRAINT tells reload that this constraint can be made
1011   to match, if it doesn't already, by converting the operand to the form
1012   (reg X) where X is a base register.  It is suitable for constraints that
1013   describe a subset of all address references.
1014
1015   When in doubt, use plain DEFINE_CONSTRAINT.
1016
1017   Operand:
1018   0: The name of the constraint (often, but not always, a single letter).
1019   1: A docstring for this constraint, in Texinfo syntax; not currently
1020      used, in future will be incorporated into the manual's list of
1021      machine-specific operand constraints.
1022   2: A boolean expression which computes whether or not the constraint
1023      matches.  It should follow the same rules as a define_predicate
1024      expression, including the bit about specifying the set of RTX codes
1025      that could possibly match.  MATCH_TEST subexpressions may make use of
1026      these variables:
1027        `op'    - the RTL object defining the operand.
1028        `mode'  - the mode of `op'.
1029	`ival'  - INTVAL(op), if op is a CONST_INT.
1030        `hval'  - CONST_DOUBLE_HIGH(op), if op is an integer CONST_DOUBLE.
1031        `lval'  - CONST_DOUBLE_LOW(op), if op is an integer CONST_DOUBLE.
1032        `rval'  - CONST_DOUBLE_REAL_VALUE(op), if op is a floating-point
1033                  CONST_DOUBLE.
1034      Do not use ival/hval/lval/rval if op is not the appropriate kind of
1035      RTL object.  */
1036DEF_RTL_EXPR(DEFINE_CONSTRAINT, "define_constraint", "sse", RTX_EXTRA)
1037DEF_RTL_EXPR(DEFINE_MEMORY_CONSTRAINT, "define_memory_constraint", "sse", RTX_EXTRA)
1038DEF_RTL_EXPR(DEFINE_ADDRESS_CONSTRAINT, "define_address_constraint", "sse", RTX_EXTRA)
1039
1040
1041/* Constructions for CPU pipeline description described by NDFAs.  */
1042
1043/* (define_cpu_unit string [string]) describes cpu functional
1044   units (separated by comma).
1045
1046   1st operand: Names of cpu functional units.
1047   2nd operand: Name of automaton (see comments for DEFINE_AUTOMATON).
1048
1049   All define_reservations, define_cpu_units, and
1050   define_query_cpu_units should have unique names which may not be
1051   "nothing".  */
1052DEF_RTL_EXPR(DEFINE_CPU_UNIT, "define_cpu_unit", "sS", RTX_EXTRA)
1053
1054/* (define_query_cpu_unit string [string]) describes cpu functional
1055   units analogously to define_cpu_unit.  The reservation of such
1056   units can be queried for automaton state.  */
1057DEF_RTL_EXPR(DEFINE_QUERY_CPU_UNIT, "define_query_cpu_unit", "sS", RTX_EXTRA)
1058
1059/* (exclusion_set string string) means that each CPU functional unit
1060   in the first string can not be reserved simultaneously with any
1061   unit whose name is in the second string and vise versa.  CPU units
1062   in the string are separated by commas.  For example, it is useful
1063   for description CPU with fully pipelined floating point functional
1064   unit which can execute simultaneously only single floating point
1065   insns or only double floating point insns.  All CPU functional
1066   units in a set should belong to the same automaton.  */
1067DEF_RTL_EXPR(EXCLUSION_SET, "exclusion_set", "ss", RTX_EXTRA)
1068
1069/* (presence_set string string) means that each CPU functional unit in
1070   the first string can not be reserved unless at least one of pattern
1071   of units whose names are in the second string is reserved.  This is
1072   an asymmetric relation.  CPU units or unit patterns in the strings
1073   are separated by commas.  Pattern is one unit name or unit names
1074   separated by white-spaces.
1075
1076   For example, it is useful for description that slot1 is reserved
1077   after slot0 reservation for a VLIW processor.  We could describe it
1078   by the following construction
1079
1080      (presence_set "slot1" "slot0")
1081
1082   Or slot1 is reserved only after slot0 and unit b0 reservation.  In
1083   this case we could write
1084
1085      (presence_set "slot1" "slot0 b0")
1086
1087   All CPU functional units in a set should belong to the same
1088   automaton.  */
1089DEF_RTL_EXPR(PRESENCE_SET, "presence_set", "ss", RTX_EXTRA)
1090
1091/* (final_presence_set string string) is analogous to `presence_set'.
1092   The difference between them is when checking is done.  When an
1093   instruction is issued in given automaton state reflecting all
1094   current and planned unit reservations, the automaton state is
1095   changed.  The first state is a source state, the second one is a
1096   result state.  Checking for `presence_set' is done on the source
1097   state reservation, checking for `final_presence_set' is done on the
1098   result reservation.  This construction is useful to describe a
1099   reservation which is actually two subsequent reservations.  For
1100   example, if we use
1101
1102      (presence_set "slot1" "slot0")
1103
1104   the following insn will be never issued (because slot1 requires
1105   slot0 which is absent in the source state).
1106
1107      (define_reservation "insn_and_nop" "slot0 + slot1")
1108
1109   but it can be issued if we use analogous `final_presence_set'.  */
1110DEF_RTL_EXPR(FINAL_PRESENCE_SET, "final_presence_set", "ss", RTX_EXTRA)
1111
1112/* (absence_set string string) means that each CPU functional unit in
1113   the first string can be reserved only if each pattern of units
1114   whose names are in the second string is not reserved.  This is an
1115   asymmetric relation (actually exclusion set is analogous to this
1116   one but it is symmetric).  CPU units or unit patterns in the string
1117   are separated by commas.  Pattern is one unit name or unit names
1118   separated by white-spaces.
1119
1120   For example, it is useful for description that slot0 can not be
1121   reserved after slot1 or slot2 reservation for a VLIW processor.  We
1122   could describe it by the following construction
1123
1124      (absence_set "slot2" "slot0, slot1")
1125
1126   Or slot2 can not be reserved if slot0 and unit b0 are reserved or
1127   slot1 and unit b1 are reserved .  In this case we could write
1128
1129      (absence_set "slot2" "slot0 b0, slot1 b1")
1130
1131   All CPU functional units in a set should to belong the same
1132   automaton.  */
1133DEF_RTL_EXPR(ABSENCE_SET, "absence_set", "ss", RTX_EXTRA)
1134
1135/* (final_absence_set string string) is analogous to `absence_set' but
1136   checking is done on the result (state) reservation.  See comments
1137   for `final_presence_set'.  */
1138DEF_RTL_EXPR(FINAL_ABSENCE_SET, "final_absence_set", "ss", RTX_EXTRA)
1139
1140/* (define_bypass number out_insn_names in_insn_names) names bypass
1141   with given latency (the first number) from insns given by the first
1142   string (see define_insn_reservation) into insns given by the second
1143   string.  Insn names in the strings are separated by commas.  The
1144   third operand is optional name of function which is additional
1145   guard for the bypass.  The function will get the two insns as
1146   parameters.  If the function returns zero the bypass will be
1147   ignored for this case.  Additional guard is necessary to recognize
1148   complicated bypasses, e.g. when consumer is load address.  If there
1149   are more one bypass with the same output and input insns, the
1150   chosen bypass is the first bypass with a guard in description whose
1151   guard function returns nonzero.  If there is no such bypass, then
1152   bypass without the guard function is chosen.  */
1153DEF_RTL_EXPR(DEFINE_BYPASS, "define_bypass", "issS", RTX_EXTRA)
1154
1155/* (define_automaton string) describes names of automata generated and
1156   used for pipeline hazards recognition.  The names are separated by
1157   comma.  Actually it is possibly to generate the single automaton
1158   but unfortunately it can be very large.  If we use more one
1159   automata, the summary size of the automata usually is less than the
1160   single one.  The automaton name is used in define_cpu_unit and
1161   define_query_cpu_unit.  All automata should have unique names.  */
1162DEF_RTL_EXPR(DEFINE_AUTOMATON, "define_automaton", "s", RTX_EXTRA)
1163
1164/* (automata_option string) describes option for generation of
1165   automata.  Currently there are the following options:
1166
1167   o "no-minimization" which makes no minimization of automata.  This
1168     is only worth to do when we are debugging the description and
1169     need to look more accurately at reservations of states.
1170
1171   o "time" which means printing additional time statistics about
1172      generation of automata.
1173
1174   o "v" which means generation of file describing the result
1175     automata.  The file has suffix `.dfa' and can be used for the
1176     description verification and debugging.
1177
1178   o "w" which means generation of warning instead of error for
1179     non-critical errors.
1180
1181   o "ndfa" which makes nondeterministic finite state automata.
1182
1183   o "progress" which means output of a progress bar showing how many
1184     states were generated so far for automaton being processed.  */
1185DEF_RTL_EXPR(AUTOMATA_OPTION, "automata_option", "s", RTX_EXTRA)
1186
1187/* (define_reservation string string) names reservation (the first
1188   string) of cpu functional units (the 2nd string).  Sometimes unit
1189   reservations for different insns contain common parts.  In such
1190   case, you can describe common part and use its name (the 1st
1191   parameter) in regular expression in define_insn_reservation.  All
1192   define_reservations, define_cpu_units, and define_query_cpu_units
1193   should have unique names which may not be "nothing".  */
1194DEF_RTL_EXPR(DEFINE_RESERVATION, "define_reservation", "ss", RTX_EXTRA)
1195
1196/* (define_insn_reservation name default_latency condition regexpr)
1197   describes reservation of cpu functional units (the 3nd operand) for
1198   instruction which is selected by the condition (the 2nd parameter).
1199   The first parameter is used for output of debugging information.
1200   The reservations are described by a regular expression according
1201   the following syntax:
1202
1203       regexp = regexp "," oneof
1204              | oneof
1205
1206       oneof = oneof "|" allof
1207             | allof
1208
1209       allof = allof "+" repeat
1210             | repeat
1211
1212       repeat = element "*" number
1213              | element
1214
1215       element = cpu_function_unit_name
1216               | reservation_name
1217               | result_name
1218               | "nothing"
1219               | "(" regexp ")"
1220
1221       1. "," is used for describing start of the next cycle in
1222       reservation.
1223
1224       2. "|" is used for describing the reservation described by the
1225       first regular expression *or* the reservation described by the
1226       second regular expression *or* etc.
1227
1228       3. "+" is used for describing the reservation described by the
1229       first regular expression *and* the reservation described by the
1230       second regular expression *and* etc.
1231
1232       4. "*" is used for convenience and simply means sequence in
1233       which the regular expression are repeated NUMBER times with
1234       cycle advancing (see ",").
1235
1236       5. cpu functional unit name which means its reservation.
1237
1238       6. reservation name -- see define_reservation.
1239
1240       7. string "nothing" means no units reservation.  */
1241
1242DEF_RTL_EXPR(DEFINE_INSN_RESERVATION, "define_insn_reservation", "sies", RTX_EXTRA)
1243
1244/* Expressions used for insn attributes.  */
1245
1246/* Definition of an insn attribute.
1247   1st operand: name of the attribute
1248   2nd operand: comma-separated list of possible attribute values
1249   3rd operand: expression for the default value of the attribute.  */
1250DEF_RTL_EXPR(DEFINE_ATTR, "define_attr", "sse", RTX_EXTRA)
1251
1252/* Definition of an insn attribute that uses an existing enumerated type.
1253   1st operand: name of the attribute
1254   2nd operand: the name of the enumerated type
1255   3rd operand: expression for the default value of the attribute.  */
1256DEF_RTL_EXPR(DEFINE_ENUM_ATTR, "define_enum_attr", "sse", RTX_EXTRA)
1257
1258/* Marker for the name of an attribute.  */
1259DEF_RTL_EXPR(ATTR, "attr", "s", RTX_EXTRA)
1260
1261/* For use in the last (optional) operand of DEFINE_INSN or DEFINE_PEEPHOLE and
1262   in DEFINE_ASM_INSN to specify an attribute to assign to insns matching that
1263   pattern.
1264
1265   (set_attr "name" "value") is equivalent to
1266   (set (attr "name") (const_string "value"))  */
1267DEF_RTL_EXPR(SET_ATTR, "set_attr", "ss", RTX_EXTRA)
1268
1269/* In the last operand of DEFINE_INSN and DEFINE_PEEPHOLE, this can be used to
1270   specify that attribute values are to be assigned according to the
1271   alternative matched.
1272
1273   The following three expressions are equivalent:
1274
1275   (set (attr "att") (cond [(eq_attrq "alternative" "1") (const_string "a1")
1276			    (eq_attrq "alternative" "2") (const_string "a2")]
1277			   (const_string "a3")))
1278   (set_attr_alternative "att" [(const_string "a1") (const_string "a2")
1279				 (const_string "a3")])
1280   (set_attr "att" "a1,a2,a3")
1281 */
1282DEF_RTL_EXPR(SET_ATTR_ALTERNATIVE, "set_attr_alternative", "sE", RTX_EXTRA)
1283
1284/* A conditional expression true if the value of the specified attribute of
1285   the current insn equals the specified value.  The first operand is the
1286   attribute name and the second is the comparison value.  */
1287DEF_RTL_EXPR(EQ_ATTR, "eq_attr", "ss", RTX_EXTRA)
1288
1289/* A special case of the above representing a set of alternatives.  The first
1290   operand is bitmap of the set, the second one is the default value.  */
1291DEF_RTL_EXPR(EQ_ATTR_ALT, "eq_attr_alt", "ii", RTX_EXTRA)
1292
1293/* A conditional expression which is true if the specified flag is
1294   true for the insn being scheduled in reorg.
1295
1296   genattr.c defines the following flags which can be tested by
1297   (attr_flag "foo") expressions in eligible_for_delay: forward, backward.  */
1298
1299DEF_RTL_EXPR (ATTR_FLAG, "attr_flag", "s", RTX_EXTRA)
1300
1301/* General conditional. The first operand is a vector composed of pairs of
1302   expressions.  The first element of each pair is evaluated, in turn.
1303   The value of the conditional is the second expression of the first pair
1304   whose first expression evaluates nonzero.  If none of the expressions is
1305   true, the second operand will be used as the value of the conditional.  */
1306DEF_RTL_EXPR(COND, "cond", "Ee", RTX_EXTRA)
1307
1308/* Definition of a pattern substitution meta operation on a DEFINE_EXPAND
1309   or a DEFINE_INSN.  Automatically generates new instances of DEFINE_INSNs
1310   that match the substitution pattern.
1311
1312   Operand:
1313   0: The name of the substitition template.
1314   1: Input template to match to see if a substitution is applicable.
1315   2: A C expression giving an additional condition for the generated
1316      new define_expand or define_insn.
1317   3: Output tempalate to generate via substitution.
1318
1319   Within a DEFINE_SUBST template, the meaning of some RTL expressions is
1320   different from their usual interpretation: a MATCH_OPERAND matches any
1321   expression tree with matching machine mode or with VOIDmode.  Likewise,
1322   MATCH_OP_DUP and MATCH_DUP match more liberally in a DEFINE_SUBST than
1323   in other RTL expressions.  MATCH_OPERATOR matches all common operators
1324   but also UNSPEC, UNSPEC_VOLATILE, and MATCH_OPERATORS from the input
1325   DEFINE_EXPAND or DEFINE_INSN.  */
1326DEF_RTL_EXPR(DEFINE_SUBST, "define_subst", "sEsE", RTX_EXTRA)
1327
1328/* Substitution attribute to apply a DEFINE_SUBST to a pattern.
1329
1330   Operand:
1331   0: The name of the subst-attribute.
1332   1: The name of the DEFINE_SUBST to be applied for this attribute.
1333   2: String to substitute for the subst-attribute name in the pattern
1334      name, for the case that the DEFINE_SUBST is not applied (i.e. the
1335      unmodified version of the pattern).
1336   3: String to substitute for the subst-attribute name in the pattern
1337      name, for the case that the DEFINE_SUBST is applied to the patten.
1338      
1339   The use of DEFINE_SUBST and DEFINE_SUBST_ATTR is explained in the
1340   GCC internals manual, under "RTL Templates Transformations".  */
1341DEF_RTL_EXPR(DEFINE_SUBST_ATTR, "define_subst_attr", "ssss", RTX_EXTRA)
1342
1343#endif /* GENERATOR_FILE */
1344
1345/*
1346Local variables:
1347mode:c
1348End:
1349*/
1350