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1 /* Definitions of target machine for GNU compiler for Intel 80386.
2 Copyright (C) 1988, 1992 Free Software Foundation, Inc.
3
4 This file is part of GNU CC.
5
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
9 any later version.
10
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
19
20
21 /* The purpose of this file is to define the characteristics of the i386,
22 independent of assembler syntax or operating system.
23
24 Three other files build on this one to describe a specific assembler syntax:
25 bsd386.h, att386.h, and sun386.h.
26
27 The actual tm.h file for a particular system should include
28 this file, and then the file for the appropriate assembler syntax.
29
30 Many macros that specify assembler syntax are omitted entirely from
31 this file because they really belong in the files for particular
32 assemblers. These include AS1, AS2, AS3, RP, IP, LPREFIX, L_SIZE,
33 PUT_OP_SIZE, USE_STAR, ADDR_BEG, ADDR_END, PRINT_IREG, PRINT_SCALE,
34 PRINT_B_I_S, and many that start with ASM_ or end in ASM_OP. */
35
36 /* Names to predefine in the preprocessor for this target machine. */
37
38 #define I386 1
39
40 /* Stubs for half-pic support if not OSF/1 reference platform. */
41
42 #ifndef HALF_PIC_P
43 #define HALF_PIC_P() 0
44 #define HALF_PIC_NUMBER_PTRS 0
45 #define HALF_PIC_NUMBER_REFS 0
46 #define HALF_PIC_ENCODE(DECL)
47 #define HALF_PIC_DECLARE(NAME)
48 #define HALF_PIC_INIT() error ("half-pic init called on systems that don't support it.")
49 #define HALF_PIC_ADDRESS_P(X) 0
50 #define HALF_PIC_PTR(X) X
51 #define HALF_PIC_FINISH(STREAM)
52 #endif
53
54 /* Run-time compilation parameters selecting different hardware subsets. */
55
56 extern int target_flags;
57
58 /* Macros used in the machine description to test the flags. */
59
60 /* configure can arrage to make this 2, to force a 486. */
61 #ifndef TARGET_CPU_DEFAULT
62 #define TARGET_CPU_DEFAULT 0
63 #endif
64
65 /* Compile 80387 insns for floating point (not library calls). */
66 #define TARGET_80387 (target_flags & 1)
67 /* Compile code for an i486. */
68 #define TARGET_486 (target_flags & 2)
69 /* Compile using ret insn that pops args.
70 This will not work unless you use prototypes at least
71 for all functions that can take varying numbers of args. */
72 #define TARGET_RTD (target_flags & 8)
73 /* Compile passing first two args in regs 0 and 1.
74 This exists only to test compiler features that will
75 be needed for RISC chips. It is not usable
76 and is not intended to be usable on this cpu. */
77 #define TARGET_REGPARM (target_flags & 020)
78
79 /* Put uninitialized locals into bss, not data.
80 Meaningful only on svr3. */
81 #define TARGET_SVR3_SHLIB (target_flags & 040)
82
83 /* Use IEEE floating point comparisons. These handle correctly the cases
84 where the result of a comparison is unordered. Normally SIGFPE is
85 generated in such cases, in which case this isn't needed. */
86 #define TARGET_IEEE_FP (target_flags & 0100)
87
88 /* Functions that return a floating point value may return that value
89 in the 387 FPU or in 386 integer registers. If set, this flag causes
90 the 387 to be used, which is compatible with most calling conventions. */
91 #define TARGET_FLOAT_RETURNS_IN_80387 (target_flags & 0200)
92
93 /* Macro to define tables used to set the flags.
94 This is a list in braces of pairs in braces,
95 each pair being { "NAME", VALUE }
96 where VALUE is the bits to set or minus the bits to clear.
97 An empty string NAME is used to identify the default VALUE. */
98
99 #define TARGET_SWITCHES \
100 { { "80387", 1}, \
101 { "no-80387", -1}, \
102 { "soft-float", -1}, \
103 { "no-soft-float", 1}, \
104 { "486", 2}, \
105 { "no-486", -2}, \
106 { "386", -2}, \
107 { "rtd", 8}, \
108 { "no-rtd", -8}, \
109 { "regparm", 020}, \
110 { "no-regparm", -020}, \
111 { "svr3-shlib", 040}, \
112 { "no-svr3-shlib", -040}, \
113 { "ieee-fp", 0100}, \
114 { "no-ieee-fp", -0100}, \
115 { "fp-ret-in-387", 0200}, \
116 { "no-fp-ret-in-387", -0200}, \
117 SUBTARGET_SWITCHES \
118 { "", TARGET_DEFAULT | TARGET_CPU_DEFAULT}}
119
120 /* This is meant to be redefined in the host dependent files */
121 #define SUBTARGET_SWITCHES
122
123 \f
124 /* target machine storage layout */
125
126 /* Define this if most significant byte of a word is the lowest numbered. */
127 /* That is true on the 80386. */
128
129 #define BITS_BIG_ENDIAN 0
130
131 /* Define this if most significant byte of a word is the lowest numbered. */
132 /* That is not true on the 80386. */
133 #define BYTES_BIG_ENDIAN 0
134
135 /* Define this if most significant word of a multiword number is the lowest
136 numbered. */
137 /* Not true for 80386 */
138 #define WORDS_BIG_ENDIAN 0
139
140 /* number of bits in an addressable storage unit */
141 #define BITS_PER_UNIT 8
142
143 /* Width in bits of a "word", which is the contents of a machine register.
144 Note that this is not necessarily the width of data type `int';
145 if using 16-bit ints on a 80386, this would still be 32.
146 But on a machine with 16-bit registers, this would be 16. */
147 #define BITS_PER_WORD 32
148
149 /* Width of a word, in units (bytes). */
150 #define UNITS_PER_WORD 4
151
152 /* Width in bits of a pointer.
153 See also the macro `Pmode' defined below. */
154 #define POINTER_SIZE 32
155
156 /* Allocation boundary (in *bits*) for storing arguments in argument list. */
157 #define PARM_BOUNDARY 32
158
159 /* Boundary (in *bits*) on which stack pointer should be aligned. */
160 #define STACK_BOUNDARY 32
161
162 /* Allocation boundary (in *bits*) for the code of a function.
163 For i486, we get better performance by aligning to a cache
164 line (i.e. 16 byte) boundary. */
165 #define FUNCTION_BOUNDARY (TARGET_486 ? 128 : 32)
166
167 /* Alignment of field after `int : 0' in a structure. */
168
169 #define EMPTY_FIELD_BOUNDARY 32
170
171 /* Minimum size in bits of the largest boundary to which any
172 and all fundamental data types supported by the hardware
173 might need to be aligned. No data type wants to be aligned
174 rounder than this. The i386 supports 64-bit floating point
175 quantities, but these can be aligned on any 32-bit boundary. */
176 #define BIGGEST_ALIGNMENT 32
177
178 /* Set this non-zero if move instructions will actually fail to work
179 when given unaligned data. */
180 #define STRICT_ALIGNMENT 0
181
182 /* If bit field type is int, don't let it cross an int,
183 and give entire struct the alignment of an int. */
184 /* Required on the 386 since it doesn't have bitfield insns. */
185 #define PCC_BITFIELD_TYPE_MATTERS 1
186
187 /* Align loop starts for optimal branching. */
188 #define ASM_OUTPUT_LOOP_ALIGN(FILE) \
189 ASM_OUTPUT_ALIGN (FILE, 2)
190
191 /* This is how to align an instruction for optimal branching.
192 On i486 we'll get better performance by aligning on a
193 cache line (i.e. 16 byte) boundary. */
194 #define ASM_OUTPUT_ALIGN_CODE(FILE) \
195 ASM_OUTPUT_ALIGN ((FILE), (TARGET_486 ? 4 : 2))
196 \f
197 /* Standard register usage. */
198
199 /* This processor has special stack-like registers. See reg-stack.c
200 for details. */
201
202 #define STACK_REGS
203
204 /* Number of actual hardware registers.
205 The hardware registers are assigned numbers for the compiler
206 from 0 to just below FIRST_PSEUDO_REGISTER.
207 All registers that the compiler knows about must be given numbers,
208 even those that are not normally considered general registers.
209
210 In the 80386 we give the 8 general purpose registers the numbers 0-7.
211 We number the floating point registers 8-15.
212 Note that registers 0-7 can be accessed as a short or int,
213 while only 0-3 may be used with byte `mov' instructions.
214
215 Reg 16 does not correspond to any hardware register, but instead
216 appears in the RTL as an argument pointer prior to reload, and is
217 eliminated during reloading in favor of either the stack or frame
218 pointer. */
219
220 #define FIRST_PSEUDO_REGISTER 17
221
222 /* 1 for registers that have pervasive standard uses
223 and are not available for the register allocator.
224 On the 80386, the stack pointer is such, as is the arg pointer. */
225 #define FIXED_REGISTERS \
226 /*ax,dx,cx,bx,si,di,bp,sp,st,st1,st2,st3,st4,st5,st6,st7,arg*/ \
227 { 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1 }
228
229 /* 1 for registers not available across function calls.
230 These must include the FIXED_REGISTERS and also any
231 registers that can be used without being saved.
232 The latter must include the registers where values are returned
233 and the register where structure-value addresses are passed.
234 Aside from that, you can include as many other registers as you like. */
235
236 #define CALL_USED_REGISTERS \
237 /*ax,dx,cx,bx,si,di,bp,sp,st,st1,st2,st3,st4,st5,st6,st7,arg*/ \
238 { 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 }
239
240 /* Macro to conditionally modify fixed_regs/call_used_regs. */
241 #define CONDITIONAL_REGISTER_USAGE \
242 { \
243 if (flag_pic) \
244 { \
245 fixed_regs[PIC_OFFSET_TABLE_REGNUM] = 1; \
246 call_used_regs[PIC_OFFSET_TABLE_REGNUM] = 1; \
247 } \
248 if (! TARGET_80387 && ! TARGET_FLOAT_RETURNS_IN_80387) \
249 { \
250 int i; \
251 HARD_REG_SET x; \
252 COPY_HARD_REG_SET (x, reg_class_contents[(int)FLOAT_REGS]); \
253 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++ ) \
254 if (TEST_HARD_REG_BIT (x, i)) \
255 fixed_regs[i] = call_used_regs[i] = 1; \
256 } \
257 }
258
259 /* Return number of consecutive hard regs needed starting at reg REGNO
260 to hold something of mode MODE.
261 This is ordinarily the length in words of a value of mode MODE
262 but can be less for certain modes in special long registers.
263
264 Actually there are no two word move instructions for consecutive
265 registers. And only registers 0-3 may have mov byte instructions
266 applied to them.
267 */
268
269 #define HARD_REGNO_NREGS(REGNO, MODE) \
270 (FP_REGNO_P (REGNO) ? 1 \
271 : ((GET_MODE_SIZE (MODE) + UNITS_PER_WORD - 1) / UNITS_PER_WORD))
272
273 /* Value is 1 if hard register REGNO can hold a value of machine-mode MODE.
274 On the 80386, the first 4 cpu registers can hold any mode
275 while the floating point registers may hold only floating point.
276 Make it clear that the fp regs could not hold a 16-byte float. */
277
278 #define HARD_REGNO_MODE_OK(REGNO, MODE) \
279 ((REGNO) < 2 ? 1 \
280 : (REGNO) < 4 ? 1 \
281 : (REGNO) >= 8 ? ((GET_MODE_CLASS (MODE) == MODE_FLOAT \
282 || GET_MODE_CLASS (MODE) == MODE_COMPLEX_FLOAT) \
283 && GET_MODE_UNIT_SIZE (MODE) <= 8) \
284 : (MODE) != QImode)
285
286 /* Value is 1 if it is a good idea to tie two pseudo registers
287 when one has mode MODE1 and one has mode MODE2.
288 If HARD_REGNO_MODE_OK could produce different values for MODE1 and MODE2,
289 for any hard reg, then this must be 0 for correct output. */
290
291 #define MODES_TIEABLE_P(MODE1, MODE2) ((MODE1) == (MODE2))
292
293 /* A C expression returning the cost of moving data from a register of class
294 CLASS1 to one of CLASS2.
295
296 On the i386, copying between floating-point and fixed-point
297 registers is expensive. */
298
299 #define REGISTER_MOVE_COST(CLASS1, CLASS2) \
300 ((((CLASS1) == FLOAT_REGS && (CLASS2) != FLOAT_REGS) \
301 || ((CLASS2) == FLOAT_REGS && (CLASS1) != FLOAT_REGS)) \
302 ? 10 : 2)
303
304 /* Specify the registers used for certain standard purposes.
305 The values of these macros are register numbers. */
306
307 /* on the 386 the pc register is %eip, and is not usable as a general
308 register. The ordinary mov instructions won't work */
309 /* #define PC_REGNUM */
310
311 /* Register to use for pushing function arguments. */
312 #define STACK_POINTER_REGNUM 7
313
314 /* Base register for access to local variables of the function. */
315 #define FRAME_POINTER_REGNUM 6
316
317 /* First floating point reg */
318 #define FIRST_FLOAT_REG 8
319
320 /* First & last stack-like regs */
321 #define FIRST_STACK_REG FIRST_FLOAT_REG
322 #define LAST_STACK_REG (FIRST_FLOAT_REG + 7)
323
324 /* Value should be nonzero if functions must have frame pointers.
325 Zero means the frame pointer need not be set up (and parms
326 may be accessed via the stack pointer) in functions that seem suitable.
327 This is computed in `reload', in reload1.c. */
328 #define FRAME_POINTER_REQUIRED 0
329
330 /* Base register for access to arguments of the function. */
331 #define ARG_POINTER_REGNUM 16
332
333 /* Register in which static-chain is passed to a function. */
334 #define STATIC_CHAIN_REGNUM 2
335
336 /* Register to hold the addressing base for position independent
337 code access to data items. */
338 #define PIC_OFFSET_TABLE_REGNUM 3
339
340 /* Register in which address to store a structure value
341 arrives in the function. On the 386, the prologue
342 copies this from the stack to register %eax. */
343 #define STRUCT_VALUE_INCOMING 0
344
345 /* Place in which caller passes the structure value address.
346 0 means push the value on the stack like an argument. */
347 #define STRUCT_VALUE 0
348 \f
349 /* Define the classes of registers for register constraints in the
350 machine description. Also define ranges of constants.
351
352 One of the classes must always be named ALL_REGS and include all hard regs.
353 If there is more than one class, another class must be named NO_REGS
354 and contain no registers.
355
356 The name GENERAL_REGS must be the name of a class (or an alias for
357 another name such as ALL_REGS). This is the class of registers
358 that is allowed by "g" or "r" in a register constraint.
359 Also, registers outside this class are allocated only when
360 instructions express preferences for them.
361
362 The classes must be numbered in nondecreasing order; that is,
363 a larger-numbered class must never be contained completely
364 in a smaller-numbered class.
365
366 For any two classes, it is very desirable that there be another
367 class that represents their union.
368
369 It might seem that class BREG is unnecessary, since no useful 386
370 opcode needs reg %ebx. But some systems pass args to the OS in ebx,
371 and the "b" register constraint is useful in asms for syscalls. */
372
373 enum reg_class
374 {
375 NO_REGS,
376 AREG, DREG, CREG, BREG,
377 Q_REGS, /* %eax %ebx %ecx %edx */
378 SIREG, DIREG,
379 INDEX_REGS, /* %eax %ebx %ecx %edx %esi %edi %ebp */
380 GENERAL_REGS, /* %eax %ebx %ecx %edx %esi %edi %ebp %esp */
381 FP_TOP_REG, FP_SECOND_REG, /* %st(0) %st(1) */
382 FLOAT_REGS,
383 ALL_REGS, LIM_REG_CLASSES
384 };
385
386 #define N_REG_CLASSES (int) LIM_REG_CLASSES
387
388 /* Give names of register classes as strings for dump file. */
389
390 #define REG_CLASS_NAMES \
391 { "NO_REGS", \
392 "AREG", "DREG", "CREG", "BREG", \
393 "Q_REGS", \
394 "SIREG", "DIREG", \
395 "INDEX_REGS", \
396 "GENERAL_REGS", \
397 "FP_TOP_REG", "FP_SECOND_REG", \
398 "FLOAT_REGS", \
399 "ALL_REGS" }
400
401 /* Define which registers fit in which classes.
402 This is an initializer for a vector of HARD_REG_SET
403 of length N_REG_CLASSES. */
404
405 #define REG_CLASS_CONTENTS \
406 { 0, \
407 0x1, 0x2, 0x4, 0x8, /* AREG, DREG, CREG, BREG */ \
408 0xf, /* Q_REGS */ \
409 0x10, 0x20, /* SIREG, DIREG */ \
410 0x1007f, /* INDEX_REGS */ \
411 0x100ff, /* GENERAL_REGS */ \
412 0x0100, 0x0200, /* FP_TOP_REG, FP_SECOND_REG */ \
413 0xff00, /* FLOAT_REGS */ \
414 0x1ffff }
415
416 /* The same information, inverted:
417 Return the class number of the smallest class containing
418 reg number REGNO. This could be a conditional expression
419 or could index an array. */
420
421 extern enum reg_class regclass_map[FIRST_PSEUDO_REGISTER];
422 #define REGNO_REG_CLASS(REGNO) (regclass_map[REGNO])
423
424 /* When defined, the compiler allows registers explicitly used in the
425 rtl to be used as spill registers but prevents the compiler from
426 extending the lifetime of these registers. */
427
428 #define SMALL_REGISTER_CLASSES
429
430 #define QI_REG_P(X) \
431 (REG_P (X) && REGNO (X) < 4)
432 #define NON_QI_REG_P(X) \
433 (REG_P (X) && REGNO (X) >= 4 && REGNO (X) < FIRST_PSEUDO_REGISTER)
434
435 #define FP_REG_P(X) (REG_P (X) && FP_REGNO_P (REGNO (X)))
436 #define FP_REGNO_P(n) ((n) >= FIRST_STACK_REG && (n) <= LAST_STACK_REG)
437
438 #define STACK_REG_P(xop) (REG_P (xop) && \
439 REGNO (xop) >= FIRST_STACK_REG && \
440 REGNO (xop) <= LAST_STACK_REG)
441
442 #define NON_STACK_REG_P(xop) (REG_P (xop) && ! STACK_REG_P (xop))
443
444 #define STACK_TOP_P(xop) (REG_P (xop) && REGNO (xop) == FIRST_STACK_REG)
445
446 /* Try to maintain the accuracy of the death notes for regs satisfying the
447 following. Important for stack like regs, to know when to pop. */
448
449 /* #define PRESERVE_DEATH_INFO_REGNO_P(x) FP_REGNO_P(x) */
450
451 /* 1 if register REGNO can magically overlap other regs.
452 Note that nonzero values work only in very special circumstances. */
453
454 /* #define OVERLAPPING_REGNO_P(REGNO) FP_REGNO_P (REGNO) */
455
456 /* The class value for index registers, and the one for base regs. */
457
458 #define INDEX_REG_CLASS INDEX_REGS
459 #define BASE_REG_CLASS GENERAL_REGS
460
461 /* Get reg_class from a letter such as appears in the machine description. */
462
463 #define REG_CLASS_FROM_LETTER(C) \
464 ((C) == 'r' ? GENERAL_REGS : \
465 (C) == 'q' ? Q_REGS : \
466 (C) == 'f' ? (TARGET_80387 || TARGET_FLOAT_RETURNS_IN_80387 \
467 ? FLOAT_REGS \
468 : NO_REGS) : \
469 (C) == 't' ? (TARGET_80387 || TARGET_FLOAT_RETURNS_IN_80387 \
470 ? FP_TOP_REG \
471 : NO_REGS) : \
472 (C) == 'u' ? (TARGET_80387 || TARGET_FLOAT_RETURNS_IN_80387 \
473 ? FP_SECOND_REG \
474 : NO_REGS) : \
475 (C) == 'a' ? AREG : \
476 (C) == 'b' ? BREG : \
477 (C) == 'c' ? CREG : \
478 (C) == 'd' ? DREG : \
479 (C) == 'D' ? DIREG : \
480 (C) == 'S' ? SIREG : NO_REGS)
481
482 /* The letters I, J, K, L and M in a register constraint string
483 can be used to stand for particular ranges of immediate operands.
484 This macro defines what the ranges are.
485 C is the letter, and VALUE is a constant value.
486 Return 1 if VALUE is in the range specified by C.
487
488 I is for non-DImode shifts.
489 J is for DImode shifts.
490 K and L are for an `andsi' optimization.
491 M is for shifts that can be executed by the "lea" opcode.
492 */
493
494 #define CONST_OK_FOR_LETTER_P(VALUE, C) \
495 ((C) == 'I' ? (VALUE) >= 0 && (VALUE) <= 31 : \
496 (C) == 'J' ? (VALUE) >= 0 && (VALUE) <= 63 : \
497 (C) == 'K' ? (VALUE) == 0xff : \
498 (C) == 'L' ? (VALUE) == 0xffff : \
499 (C) == 'M' ? (VALUE) >= 0 && (VALUE) <= 3 : \
500 0)
501
502 /* Similar, but for floating constants, and defining letters G and H.
503 Here VALUE is the CONST_DOUBLE rtx itself. We allow constants even if
504 TARGET_387 isn't set, because the stack register converter may need to
505 load 0.0 into the function value register. */
506
507 #define CONST_DOUBLE_OK_FOR_LETTER_P(VALUE, C) \
508 ((C) == 'G' ? standard_80387_constant_p (VALUE) : 0)
509
510 /* Place additional restrictions on the register class to use when it
511 is necessary to be able to hold a value of mode @var{mode} in a reload
512 register for which class @var{class} would ordinarily be used. */
513
514 #define LIMIT_RELOAD_CLASS(MODE, CLASS) \
515 ((MODE) == QImode && ((CLASS) == ALL_REGS || (CLASS) == GENERAL_REGS) \
516 ? Q_REGS : (CLASS))
517
518 /* Given an rtx X being reloaded into a reg required to be
519 in class CLASS, return the class of reg to actually use.
520 In general this is just CLASS; but on some machines
521 in some cases it is preferable to use a more restrictive class.
522 On the 80386 series, we prevent floating constants from being
523 reloaded into floating registers (since no move-insn can do that)
524 and we ensure that QImodes aren't reloaded into the esi or edi reg. */
525
526 /* Don't put CONST_DOUBLE into FLOAT_REGS.
527 QImode must go into class Q_REGS.
528 MODE_INT must not go into FLOAT_REGS. */
529
530 #define PREFERRED_RELOAD_CLASS(X,CLASS) \
531 (GET_CODE (X) == CONST_DOUBLE \
532 ? (reg_class_subset_p ((CLASS), GENERAL_REGS) || (CLASS) == ALL_REGS \
533 ? (CLASS) : NO_REGS) \
534 : GET_MODE (X) == QImode \
535 ? (! reg_class_subset_p ((CLASS), Q_REGS) ? Q_REGS : (CLASS)) \
536 : (GET_MODE_CLASS (GET_MODE (X)) == MODE_INT && (CLASS) == FLOAT_REGS ? \
537 GENERAL_REGS : (CLASS)))
538
539 /* Return the maximum number of consecutive registers
540 needed to represent mode MODE in a register of class CLASS. */
541 /* On the 80386, this is the size of MODE in words,
542 except in the FP regs, where a single reg is always enough. */
543 #define CLASS_MAX_NREGS(CLASS, MODE) \
544 ((CLASS) == FLOAT_REGS ? 1 : \
545 (CLASS) == FP_TOP_REG ? 1 : \
546 (CLASS) == FP_SECOND_REG ? 1 : \
547 ((GET_MODE_SIZE (MODE) + UNITS_PER_WORD - 1) / UNITS_PER_WORD))
548 \f
549 /* Stack layout; function entry, exit and calling. */
550
551 /* Define this if pushing a word on the stack
552 makes the stack pointer a smaller address. */
553 #define STACK_GROWS_DOWNWARD
554
555 /* Define this if the nominal address of the stack frame
556 is at the high-address end of the local variables;
557 that is, each additional local variable allocated
558 goes at a more negative offset in the frame. */
559 #define FRAME_GROWS_DOWNWARD
560
561 /* Offset within stack frame to start allocating local variables at.
562 If FRAME_GROWS_DOWNWARD, this is the offset to the END of the
563 first local allocated. Otherwise, it is the offset to the BEGINNING
564 of the first local allocated. */
565 #define STARTING_FRAME_OFFSET 0
566
567 /* If we generate an insn to push BYTES bytes,
568 this says how many the stack pointer really advances by.
569 On 386 pushw decrements by exactly 2 no matter what the position was.
570 On the 386 there is no pushb; we use pushw instead, and this
571 has the effect of rounding up to 2. */
572
573 #define PUSH_ROUNDING(BYTES) (((BYTES) + 1) & (-2))
574
575 /* Offset of first parameter from the argument pointer register value. */
576 #define FIRST_PARM_OFFSET(FNDECL) 0
577
578 /* Value is the number of bytes of arguments automatically
579 popped when returning from a subroutine call.
580 FUNTYPE is the data type of the function (as a tree),
581 or for a library call it is an identifier node for the subroutine name.
582 SIZE is the number of bytes of arguments passed on the stack.
583
584 On the 80386, the RTD insn may be used to pop them if the number
585 of args is fixed, but if the number is variable then the caller
586 must pop them all. RTD can't be used for library calls now
587 because the library is compiled with the Unix compiler.
588 Use of RTD is a selectable option, since it is incompatible with
589 standard Unix calling sequences. If the option is not selected,
590 the caller must always pop the args. */
591
592 #define RETURN_POPS_ARGS(FUNTYPE,SIZE) \
593 (TREE_CODE (FUNTYPE) == IDENTIFIER_NODE ? 0 \
594 : (TARGET_RTD \
595 && (TYPE_ARG_TYPES (FUNTYPE) == 0 \
596 || (TREE_VALUE (tree_last (TYPE_ARG_TYPES (FUNTYPE))) \
597 == void_type_node))) ? (SIZE) \
598 : (aggregate_value_p (FUNTYPE)) ? GET_MODE_SIZE (Pmode) : 0)
599
600 /* Define how to find the value returned by a function.
601 VALTYPE is the data type of the value (as a tree).
602 If the precise function being called is known, FUNC is its FUNCTION_DECL;
603 otherwise, FUNC is 0. */
604 #define FUNCTION_VALUE(VALTYPE, FUNC) \
605 gen_rtx (REG, TYPE_MODE (VALTYPE), \
606 VALUE_REGNO (TYPE_MODE (VALTYPE)))
607
608 /* Define how to find the value returned by a library function
609 assuming the value has mode MODE. */
610
611 #define LIBCALL_VALUE(MODE) \
612 gen_rtx (REG, MODE, VALUE_REGNO (MODE))
613
614 /* 1 if N is a possible register number for function argument passing.
615 On the 80386, no registers are used in this way.
616 *NOTE* -mregparm does not work.
617 It exists only to test register calling conventions. */
618
619 #define FUNCTION_ARG_REGNO_P(N) 0
620
621 /* Define a data type for recording info about an argument list
622 during the scan of that argument list. This data type should
623 hold all necessary information about the function itself
624 and about the args processed so far, enough to enable macros
625 such as FUNCTION_ARG to determine where the next arg should go.
626
627 On the 80386, this is a single integer, which is a number of bytes
628 of arguments scanned so far. */
629
630 #define CUMULATIVE_ARGS int
631
632 /* Initialize a variable CUM of type CUMULATIVE_ARGS
633 for a call to a function whose data type is FNTYPE.
634 For a library call, FNTYPE is 0.
635
636 On the 80386, the offset starts at 0. */
637
638 #define INIT_CUMULATIVE_ARGS(CUM,FNTYPE,LIBNAME) \
639 ((CUM) = 0)
640
641 /* Update the data in CUM to advance over an argument
642 of mode MODE and data type TYPE.
643 (TYPE is null for libcalls where that information may not be available.) */
644
645 #define FUNCTION_ARG_ADVANCE(CUM, MODE, TYPE, NAMED) \
646 ((CUM) += ((MODE) != BLKmode \
647 ? (GET_MODE_SIZE (MODE) + 3) & ~3 \
648 : (int_size_in_bytes (TYPE) + 3) & ~3))
649
650 /* Define where to put the arguments to a function.
651 Value is zero to push the argument on the stack,
652 or a hard register in which to store the argument.
653
654 MODE is the argument's machine mode.
655 TYPE is the data type of the argument (as a tree).
656 This is null for libcalls where that information may
657 not be available.
658 CUM is a variable of type CUMULATIVE_ARGS which gives info about
659 the preceding args and about the function being called.
660 NAMED is nonzero if this argument is a named parameter
661 (otherwise it is an extra parameter matching an ellipsis). */
662
663
664 /* On the 80386 all args are pushed, except if -mregparm is specified
665 then the first two words of arguments are passed in EAX, EDX.
666 *NOTE* -mregparm does not work.
667 It exists only to test register calling conventions. */
668
669 #define FUNCTION_ARG(CUM, MODE, TYPE, NAMED) \
670 ((TARGET_REGPARM && (CUM) < 8) ? gen_rtx (REG, (MODE), (CUM) / 4) : 0)
671
672 /* For an arg passed partly in registers and partly in memory,
673 this is the number of registers used.
674 For args passed entirely in registers or entirely in memory, zero. */
675
676
677 #define FUNCTION_ARG_PARTIAL_NREGS(CUM, MODE, TYPE, NAMED) \
678 ((TARGET_REGPARM && (CUM) < 8 \
679 && 8 < ((CUM) + ((MODE) == BLKmode \
680 ? int_size_in_bytes (TYPE) \
681 : GET_MODE_SIZE (MODE)))) \
682 ? 2 - (CUM) / 4 : 0)
683
684 /* This macro generates the assembly code for function entry.
685 FILE is a stdio stream to output the code to.
686 SIZE is an int: how many units of temporary storage to allocate.
687 Refer to the array `regs_ever_live' to determine which registers
688 to save; `regs_ever_live[I]' is nonzero if register number I
689 is ever used in the function. This macro is responsible for
690 knowing which registers should not be saved even if used. */
691
692 #define FUNCTION_PROLOGUE(FILE, SIZE) \
693 function_prologue (FILE, SIZE)
694
695 /* Output assembler code to FILE to increment profiler label # LABELNO
696 for profiling a function entry. */
697
698 #define FUNCTION_PROFILER(FILE, LABELNO) \
699 { \
700 if (flag_pic) \
701 { \
702 fprintf (FILE, "\tleal %sP%d@GOTOFF(%%ebx),%%edx\n", \
703 LPREFIX, (LABELNO)); \
704 fprintf (FILE, "\tcall *_mcount@GOT(%%ebx)\n"); \
705 } \
706 else \
707 { \
708 fprintf (FILE, "\tmovl $%sP%d,%%edx\n", LPREFIX, (LABELNO)); \
709 fprintf (FILE, "\tcall _mcount\n"); \
710 } \
711 }
712
713 /* EXIT_IGNORE_STACK should be nonzero if, when returning from a function,
714 the stack pointer does not matter. The value is tested only in
715 functions that have frame pointers.
716 No definition is equivalent to always zero. */
717 /* Note on the 386 it might be more efficient not to define this since
718 we have to restore it ourselves from the frame pointer, in order to
719 use pop */
720
721 #define EXIT_IGNORE_STACK 1
722
723 /* This macro generates the assembly code for function exit,
724 on machines that need it. If FUNCTION_EPILOGUE is not defined
725 then individual return instructions are generated for each
726 return statement. Args are same as for FUNCTION_PROLOGUE.
727
728 The function epilogue should not depend on the current stack pointer!
729 It should use the frame pointer only. This is mandatory because
730 of alloca; we also take advantage of it to omit stack adjustments
731 before returning.
732
733 If the last non-note insn in the function is a BARRIER, then there
734 is no need to emit a function prologue, because control does not fall
735 off the end. This happens if the function ends in an "exit" call, or
736 if a `return' insn is emitted directly into the function. */
737
738 #define FUNCTION_EPILOGUE(FILE, SIZE) \
739 do { \
740 rtx last = get_last_insn (); \
741 if (last && GET_CODE (last) == NOTE) \
742 last = prev_nonnote_insn (last); \
743 if (! last || GET_CODE (last) != BARRIER) \
744 function_epilogue (FILE, SIZE); \
745 } while (0)
746
747 /* Output assembler code for a block containing the constant parts
748 of a trampoline, leaving space for the variable parts. */
749
750 /* On the 386, the trampoline contains three instructions:
751 mov #STATIC,ecx
752 mov #FUNCTION,eax
753 jmp @eax */
754 #define TRAMPOLINE_TEMPLATE(FILE) \
755 { \
756 ASM_OUTPUT_CHAR (FILE, GEN_INT (0xb9)); \
757 ASM_OUTPUT_SHORT (FILE, const0_rtx); \
758 ASM_OUTPUT_SHORT (FILE, const0_rtx); \
759 ASM_OUTPUT_CHAR (FILE, GEN_INT (0xb8)); \
760 ASM_OUTPUT_SHORT (FILE, const0_rtx); \
761 ASM_OUTPUT_SHORT (FILE, const0_rtx); \
762 ASM_OUTPUT_CHAR (FILE, GEN_INT (0xff)); \
763 ASM_OUTPUT_CHAR (FILE, GEN_INT (0xe0)); \
764 }
765
766 /* Length in units of the trampoline for entering a nested function. */
767
768 #define TRAMPOLINE_SIZE 12
769
770 /* Emit RTL insns to initialize the variable parts of a trampoline.
771 FNADDR is an RTX for the address of the function's pure code.
772 CXT is an RTX for the static chain value for the function. */
773
774 #define INITIALIZE_TRAMPOLINE(TRAMP, FNADDR, CXT) \
775 { \
776 emit_move_insn (gen_rtx (MEM, SImode, plus_constant (TRAMP, 1)), CXT); \
777 emit_move_insn (gen_rtx (MEM, SImode, plus_constant (TRAMP, 6)), FNADDR); \
778 }
779 \f
780 /* Definitions for register eliminations.
781
782 This is an array of structures. Each structure initializes one pair
783 of eliminable registers. The "from" register number is given first,
784 followed by "to". Eliminations of the same "from" register are listed
785 in order of preference.
786
787 We have two registers that can be eliminated on the i386. First, the
788 frame pointer register can often be eliminated in favor of the stack
789 pointer register. Secondly, the argument pointer register can always be
790 eliminated; it is replaced with either the stack or frame pointer. */
791
792 #define ELIMINABLE_REGS \
793 {{ ARG_POINTER_REGNUM, STACK_POINTER_REGNUM}, \
794 { ARG_POINTER_REGNUM, FRAME_POINTER_REGNUM}, \
795 { FRAME_POINTER_REGNUM, STACK_POINTER_REGNUM}}
796
797 /* Given FROM and TO register numbers, say whether this elimination is allowed.
798 Frame pointer elimination is automatically handled.
799
800 For the i386, if frame pointer elimination is being done, we would like to
801 convert ap into sp, not fp.
802
803 All other eliminations are valid. */
804
805 #define CAN_ELIMINATE(FROM, TO) \
806 ((FROM) == ARG_POINTER_REGNUM && (TO) == STACK_POINTER_REGNUM \
807 ? ! frame_pointer_needed \
808 : 1)
809
810 /* Define the offset between two registers, one to be eliminated, and the other
811 its replacement, at the start of a routine. */
812
813 #define INITIAL_ELIMINATION_OFFSET(FROM, TO, OFFSET) \
814 { \
815 if ((FROM) == ARG_POINTER_REGNUM && (TO) == FRAME_POINTER_REGNUM) \
816 (OFFSET) = 8; /* Skip saved PC and previous frame pointer */ \
817 else \
818 { \
819 int regno; \
820 int offset = 0; \
821 \
822 for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++) \
823 if ((regs_ever_live[regno] && ! call_used_regs[regno]) \
824 || (current_function_uses_pic_offset_table \
825 && regno == PIC_OFFSET_TABLE_REGNUM)) \
826 offset += 4; \
827 \
828 (OFFSET) = offset + get_frame_size (); \
829 \
830 if ((FROM) == ARG_POINTER_REGNUM && (TO) == STACK_POINTER_REGNUM) \
831 (OFFSET) += 4; /* Skip saved PC */ \
832 } \
833 }
834 \f
835 /* Addressing modes, and classification of registers for them. */
836
837 /* #define HAVE_POST_INCREMENT */
838 /* #define HAVE_POST_DECREMENT */
839
840 /* #define HAVE_PRE_DECREMENT */
841 /* #define HAVE_PRE_INCREMENT */
842
843 /* Macros to check register numbers against specific register classes. */
844
845 /* These assume that REGNO is a hard or pseudo reg number.
846 They give nonzero only if REGNO is a hard reg of the suitable class
847 or a pseudo reg currently allocated to a suitable hard reg.
848 Since they use reg_renumber, they are safe only once reg_renumber
849 has been allocated, which happens in local-alloc.c. */
850
851 #define REGNO_OK_FOR_INDEX_P(REGNO) \
852 ((REGNO) < STACK_POINTER_REGNUM \
853 || (unsigned) reg_renumber[REGNO] < STACK_POINTER_REGNUM)
854
855 #define REGNO_OK_FOR_BASE_P(REGNO) \
856 ((REGNO) <= STACK_POINTER_REGNUM \
857 || (REGNO) == ARG_POINTER_REGNUM \
858 || (unsigned) reg_renumber[REGNO] <= STACK_POINTER_REGNUM)
859
860 #define REGNO_OK_FOR_SIREG_P(REGNO) ((REGNO) == 4 || reg_renumber[REGNO] == 4)
861 #define REGNO_OK_FOR_DIREG_P(REGNO) ((REGNO) == 5 || reg_renumber[REGNO] == 5)
862
863 /* The macros REG_OK_FOR..._P assume that the arg is a REG rtx
864 and check its validity for a certain class.
865 We have two alternate definitions for each of them.
866 The usual definition accepts all pseudo regs; the other rejects
867 them unless they have been allocated suitable hard regs.
868 The symbol REG_OK_STRICT causes the latter definition to be used.
869
870 Most source files want to accept pseudo regs in the hope that
871 they will get allocated to the class that the insn wants them to be in.
872 Source files for reload pass need to be strict.
873 After reload, it makes no difference, since pseudo regs have
874 been eliminated by then. */
875
876 #ifndef REG_OK_STRICT
877
878 /* Nonzero if X is a hard reg that can be used as an index or if
879 it is a pseudo reg. */
880
881 #define REG_OK_FOR_INDEX_P(X) \
882 (REGNO (X) < STACK_POINTER_REGNUM \
883 || REGNO (X) >= FIRST_PSEUDO_REGISTER)
884
885 /* Nonzero if X is a hard reg that can be used as a base reg
886 of if it is a pseudo reg. */
887 /* ?wfs */
888
889 #define REG_OK_FOR_BASE_P(X) \
890 (REGNO (X) <= STACK_POINTER_REGNUM \
891 || REGNO (X) == ARG_POINTER_REGNUM \
892 || REGNO(X) >= FIRST_PSEUDO_REGISTER)
893
894 #define REG_OK_FOR_STRREG_P(X) \
895 (REGNO (X) == 4 || REGNO (X) == 5 || REGNO (X) >= FIRST_PSEUDO_REGISTER)
896
897 #else
898
899 /* Nonzero if X is a hard reg that can be used as an index. */
900 #define REG_OK_FOR_INDEX_P(X) REGNO_OK_FOR_INDEX_P (REGNO (X))
901 /* Nonzero if X is a hard reg that can be used as a base reg. */
902 #define REG_OK_FOR_BASE_P(X) REGNO_OK_FOR_BASE_P (REGNO (X))
903 #define REG_OK_FOR_STRREG_P(X) \
904 (REGNO_OK_FOR_DIREG_P (REGNO (X)) || REGNO_OK_FOR_SIREG_P (REGNO (X)))
905
906 #endif
907
908 /* GO_IF_LEGITIMATE_ADDRESS recognizes an RTL expression
909 that is a valid memory address for an instruction.
910 The MODE argument is the machine mode for the MEM expression
911 that wants to use this address.
912
913 The other macros defined here are used only in GO_IF_LEGITIMATE_ADDRESS,
914 except for CONSTANT_ADDRESS_P which is usually machine-independent.
915
916 See legitimize_pic_address in i386.c for details as to what
917 constitutes a legitimate address when -fpic is used. */
918
919 #define MAX_REGS_PER_ADDRESS 2
920
921 #define CONSTANT_ADDRESS_P(X) CONSTANT_P (X)
922
923 /* Nonzero if the constant value X is a legitimate general operand.
924 It is given that X satisfies CONSTANT_P or is a CONST_DOUBLE. */
925
926 #define LEGITIMATE_CONSTANT_P(X) 1
927
928 #define GO_IF_INDEXABLE_BASE(X, ADDR) \
929 if (GET_CODE (X) == REG && REG_OK_FOR_BASE_P (X)) goto ADDR
930
931 #define LEGITIMATE_INDEX_REG_P(X) \
932 (GET_CODE (X) == REG && REG_OK_FOR_INDEX_P (X))
933
934 /* Return 1 if X is an index or an index times a scale. */
935
936 #define LEGITIMATE_INDEX_P(X) \
937 (LEGITIMATE_INDEX_REG_P (X) \
938 || (GET_CODE (X) == MULT \
939 && LEGITIMATE_INDEX_REG_P (XEXP (X, 0)) \
940 && GET_CODE (XEXP (X, 1)) == CONST_INT \
941 && (INTVAL (XEXP (X, 1)) == 2 \
942 || INTVAL (XEXP (X, 1)) == 4 \
943 || INTVAL (XEXP (X, 1)) == 8)))
944
945 /* Go to ADDR if X is an index term, a base reg, or a sum of those. */
946
947 #define GO_IF_INDEXING(X, ADDR) \
948 { if (LEGITIMATE_INDEX_P (X)) goto ADDR; \
949 GO_IF_INDEXABLE_BASE (X, ADDR); \
950 if (GET_CODE (X) == PLUS && LEGITIMATE_INDEX_P (XEXP (X, 0))) \
951 { GO_IF_INDEXABLE_BASE (XEXP (X, 1), ADDR); } \
952 if (GET_CODE (X) == PLUS && LEGITIMATE_INDEX_P (XEXP (X, 1))) \
953 { GO_IF_INDEXABLE_BASE (XEXP (X, 0), ADDR); } }
954
955 /* We used to allow this, but it isn't ever used.
956 || ((GET_CODE (X) == POST_DEC || GET_CODE (X) == POST_INC) \
957 && REG_P (XEXP (X, 0)) \
958 && REG_OK_FOR_STRREG_P (XEXP (X, 0))) \
959 */
960
961 #define GO_IF_LEGITIMATE_ADDRESS(MODE, X, ADDR) \
962 { \
963 if (CONSTANT_ADDRESS_P (X) \
964 && (! flag_pic || LEGITIMATE_PIC_OPERAND_P (X))) \
965 goto ADDR; \
966 GO_IF_INDEXING (X, ADDR); \
967 if (GET_CODE (X) == PLUS && CONSTANT_ADDRESS_P (XEXP (X, 1))) \
968 { \
969 rtx x0 = XEXP (X, 0); \
970 if (! flag_pic || ! SYMBOLIC_CONST (XEXP (X, 1))) \
971 { GO_IF_INDEXING (x0, ADDR); } \
972 else if (x0 == pic_offset_table_rtx) \
973 goto ADDR; \
974 else if (GET_CODE (x0) == PLUS) \
975 { \
976 if (XEXP (x0, 0) == pic_offset_table_rtx) \
977 { GO_IF_INDEXABLE_BASE (XEXP (x0, 1), ADDR); } \
978 if (XEXP (x0, 1) == pic_offset_table_rtx) \
979 { GO_IF_INDEXABLE_BASE (XEXP (x0, 0), ADDR); } \
980 } \
981 } \
982 }
983
984 /* Try machine-dependent ways of modifying an illegitimate address
985 to be legitimate. If we find one, return the new, valid address.
986 This macro is used in only one place: `memory_address' in explow.c.
987
988 OLDX is the address as it was before break_out_memory_refs was called.
989 In some cases it is useful to look at this to decide what needs to be done.
990
991 MODE and WIN are passed so that this macro can use
992 GO_IF_LEGITIMATE_ADDRESS.
993
994 It is always safe for this macro to do nothing. It exists to recognize
995 opportunities to optimize the output.
996
997 For the 80386, we handle X+REG by loading X into a register R and
998 using R+REG. R will go in a general reg and indexing will be used.
999 However, if REG is a broken-out memory address or multiplication,
1000 nothing needs to be done because REG can certainly go in a general reg.
1001
1002 When -fpic is used, special handling is needed for symbolic references.
1003 See comments by legitimize_pic_address in i386.c for details. */
1004
1005 #define LEGITIMIZE_ADDRESS(X,OLDX,MODE,WIN) \
1006 { extern rtx legitimize_pic_address (); \
1007 int ch = (X) != (OLDX); \
1008 if (flag_pic && SYMBOLIC_CONST (X)) \
1009 { \
1010 (X) = legitimize_pic_address (X, 0); \
1011 if (memory_address_p (MODE, X)) \
1012 goto WIN; \
1013 } \
1014 if (GET_CODE (X) == PLUS) \
1015 { if (GET_CODE (XEXP (X, 0)) == MULT) \
1016 ch = 1, XEXP (X, 0) = force_operand (XEXP (X, 0), 0); \
1017 if (GET_CODE (XEXP (X, 1)) == MULT) \
1018 ch = 1, XEXP (X, 1) = force_operand (XEXP (X, 1), 0); \
1019 if (ch && GET_CODE (XEXP (X, 1)) == REG \
1020 && GET_CODE (XEXP (X, 0)) == REG) \
1021 goto WIN; \
1022 if (flag_pic && SYMBOLIC_CONST (XEXP (X, 1))) \
1023 ch = 1, (X) = legitimize_pic_address (X, 0); \
1024 if (ch) { GO_IF_LEGITIMATE_ADDRESS (MODE, X, WIN); } \
1025 if (GET_CODE (XEXP (X, 0)) == REG) \
1026 { register rtx temp = gen_reg_rtx (Pmode); \
1027 register rtx val = force_operand (XEXP (X, 1), temp); \
1028 if (val != temp) emit_move_insn (temp, val); \
1029 XEXP (X, 1) = temp; \
1030 goto WIN; } \
1031 else if (GET_CODE (XEXP (X, 1)) == REG) \
1032 { register rtx temp = gen_reg_rtx (Pmode); \
1033 register rtx val = force_operand (XEXP (X, 0), temp); \
1034 if (val != temp) emit_move_insn (temp, val); \
1035 XEXP (X, 0) = temp; \
1036 goto WIN; }}}
1037
1038 /* Nonzero if the constant value X is a legitimate general operand
1039 when generating PIC code. It is given that flag_pic is on and
1040 that X satisfies CONSTANT_P or is a CONST_DOUBLE. */
1041
1042 #define LEGITIMATE_PIC_OPERAND_P(X) \
1043 (! SYMBOLIC_CONST (X) \
1044 || (GET_CODE (X) == SYMBOL_REF && CONSTANT_POOL_ADDRESS_P (X)))
1045
1046 #define SYMBOLIC_CONST(X) \
1047 (GET_CODE (X) == SYMBOL_REF \
1048 || GET_CODE (X) == LABEL_REF \
1049 || (GET_CODE (X) == CONST && symbolic_reference_mentioned_p (X)))
1050
1051 /* Go to LABEL if ADDR (a legitimate address expression)
1052 has an effect that depends on the machine mode it is used for.
1053 On the 80386, only postdecrement and postincrement address depend thus
1054 (the amount of decrement or increment being the length of the operand). */
1055 #define GO_IF_MODE_DEPENDENT_ADDRESS(ADDR,LABEL) \
1056 if (GET_CODE (ADDR) == POST_INC || GET_CODE (ADDR) == POST_DEC) goto LABEL
1057 \f
1058 /* Define this macro if references to a symbol must be treated
1059 differently depending on something about the variable or
1060 function named by the symbol (such as what section it is in).
1061
1062 On i386, if using PIC, mark a SYMBOL_REF for a non-global symbol
1063 so that we may access it directly in the GOT. */
1064
1065 #define ENCODE_SECTION_INFO(DECL) \
1066 do \
1067 { \
1068 if (flag_pic) \
1069 { \
1070 rtx rtl = (TREE_CODE_CLASS (TREE_CODE (DECL)) != 'd' \
1071 ? TREE_CST_RTL (DECL) : DECL_RTL (DECL)); \
1072 SYMBOL_REF_FLAG (XEXP (rtl, 0)) \
1073 = (TREE_CODE_CLASS (TREE_CODE (DECL)) != 'd' \
1074 || ! TREE_PUBLIC (DECL)); \
1075 } \
1076 } \
1077 while (0)
1078 \f
1079 /* Specify the machine mode that this machine uses
1080 for the index in the tablejump instruction. */
1081 #define CASE_VECTOR_MODE Pmode
1082
1083 /* Define this if the tablejump instruction expects the table
1084 to contain offsets from the address of the table.
1085 Do not define this if the table should contain absolute addresses. */
1086 /* #define CASE_VECTOR_PC_RELATIVE */
1087
1088 /* Specify the tree operation to be used to convert reals to integers.
1089 This should be changed to take advantage of fist --wfs ??
1090 */
1091 #define IMPLICIT_FIX_EXPR FIX_ROUND_EXPR
1092
1093 /* This is the kind of divide that is easiest to do in the general case. */
1094 #define EASY_DIV_EXPR TRUNC_DIV_EXPR
1095
1096 /* Define this as 1 if `char' should by default be signed; else as 0. */
1097 #define DEFAULT_SIGNED_CHAR 1
1098
1099 /* Max number of bytes we can move from memory to memory
1100 in one reasonably fast instruction. */
1101 #define MOVE_MAX 4
1102
1103 /* MOVE_RATIO is the number of move instructions that is better than a
1104 block move. Make this large on i386, since the block move is very
1105 inefficient with small blocks, and the hard register needs of the
1106 block move require much reload work. */
1107 #define MOVE_RATIO 5
1108
1109 /* Define this if zero-extension is slow (more than one real instruction). */
1110 /* #define SLOW_ZERO_EXTEND */
1111
1112 /* Nonzero if access to memory by bytes is slow and undesirable. */
1113 #define SLOW_BYTE_ACCESS 0
1114
1115 /* Define if shifts truncate the shift count
1116 which implies one can omit a sign-extension or zero-extension
1117 of a shift count. */
1118 /* One i386, shifts do truncate the count. But bit opcodes don't. */
1119
1120 /* #define SHIFT_COUNT_TRUNCATED */
1121
1122 /* Value is 1 if truncating an integer of INPREC bits to OUTPREC bits
1123 is done just by pretending it is already truncated. */
1124 #define TRULY_NOOP_TRUNCATION(OUTPREC, INPREC) 1
1125
1126 /* We assume that the store-condition-codes instructions store 0 for false
1127 and some other value for true. This is the value stored for true. */
1128
1129 #define STORE_FLAG_VALUE 1
1130
1131 /* When a prototype says `char' or `short', really pass an `int'.
1132 (The 386 can't easily push less than an int.) */
1133
1134 #define PROMOTE_PROTOTYPES
1135
1136 /* Specify the machine mode that pointers have.
1137 After generation of rtl, the compiler makes no further distinction
1138 between pointers and any other objects of this machine mode. */
1139 #define Pmode SImode
1140
1141 /* A function address in a call instruction
1142 is a byte address (for indexing purposes)
1143 so give the MEM rtx a byte's mode. */
1144 #define FUNCTION_MODE QImode
1145
1146 /* Define this if addresses of constant functions
1147 shouldn't be put through pseudo regs where they can be cse'd.
1148 Desirable on the 386 because a CALL with a constant address is
1149 not much slower than one with a register address. */
1150 #define NO_FUNCTION_CSE
1151
1152 /* Provide the costs of a rtl expression. This is in the body of a
1153 switch on CODE. */
1154
1155 #define RTX_COSTS(X,CODE,OUTER_CODE) \
1156 case MULT: \
1157 return COSTS_N_INSNS (10); \
1158 case DIV: \
1159 case UDIV: \
1160 case MOD: \
1161 case UMOD: \
1162 return COSTS_N_INSNS (40); \
1163 case PLUS: \
1164 if (GET_CODE (XEXP (X, 0)) == REG \
1165 && GET_CODE (XEXP (X, 1)) == CONST_INT) \
1166 return 1; \
1167 break;
1168
1169
1170 /* Compute the cost of computing a constant rtl expression RTX
1171 whose rtx-code is CODE. The body of this macro is a portion
1172 of a switch statement. If the code is computed here,
1173 return it with a return statement. Otherwise, break from the switch. */
1174
1175 #define CONST_COSTS(RTX,CODE,OUTER_CODE) \
1176 case CONST_INT: \
1177 case CONST: \
1178 case LABEL_REF: \
1179 case SYMBOL_REF: \
1180 return flag_pic && SYMBOLIC_CONST (RTX) ? 2 : 0; \
1181 case CONST_DOUBLE: \
1182 { \
1183 int code = standard_80387_constant_p (RTX); \
1184 return code == 1 ? 0 : \
1185 code == 2 ? 1 : \
1186 2; \
1187 }
1188
1189 /* Compute the cost of an address. This is meant to approximate the size
1190 and/or execution delay of an insn using that address. If the cost is
1191 approximated by the RTL complexity, including CONST_COSTS above, as
1192 is usually the case for CISC machines, this macro should not be defined.
1193 For aggressively RISCy machines, only one insn format is allowed, so
1194 this macro should be a constant. The value of this macro only matters
1195 for valid addresses.
1196
1197 For i386, it is better to use a complex address than let gcc copy
1198 the address into a reg and make a new pseudo. But not if the address
1199 requires to two regs - that would mean more pseudos with longer
1200 lifetimes. */
1201
1202 #define ADDRESS_COST(RTX) \
1203 ((CONSTANT_P (RTX) \
1204 || (GET_CODE (RTX) == PLUS && CONSTANT_P (XEXP (RTX, 1)) \
1205 && REG_P (XEXP (RTX, 0)))) ? 0 \
1206 : REG_P (RTX) ? 1 \
1207 : 2)
1208 \f
1209 /* Add any extra modes needed to represent the condition code.
1210
1211 For the i386, we need separate modes when floating-point equality
1212 comparisons are being done. */
1213
1214 #define EXTRA_CC_MODES CCFPEQmode
1215
1216 /* Define the names for the modes specified above. */
1217 #define EXTRA_CC_NAMES "CCFPEQ"
1218
1219 /* Given a comparison code (EQ, NE, etc.) and the first operand of a COMPARE,
1220 return the mode to be used for the comparison.
1221
1222 For floating-point equality comparisons, CCFPEQmode should be used.
1223 VOIDmode should be used in all other cases. */
1224
1225 #define SELECT_CC_MODE(OP,X,Y) \
1226 (GET_MODE_CLASS (GET_MODE (X)) == MODE_FLOAT \
1227 && ((OP) == EQ || (OP) == NE) ? CCFPEQmode : CCmode)
1228
1229 /* Define the information needed to generate branch and scc insns. This is
1230 stored from the compare operation. Note that we can't use "rtx" here
1231 since it hasn't been defined! */
1232
1233 extern struct rtx_def *i386_compare_op0, *i386_compare_op1;
1234 extern struct rtx_def *(*i386_compare_gen)(), *(*i386_compare_gen_eq)();
1235
1236 /* Tell final.c how to eliminate redundant test instructions. */
1237
1238 /* Here we define machine-dependent flags and fields in cc_status
1239 (see `conditions.h'). */
1240
1241 /* Set if the cc value is actually in the 80387, so a floating point
1242 conditional branch must be output. */
1243 #define CC_IN_80387 04000
1244
1245 /* Set if the CC value was stored in a nonstandard way, so that
1246 the state of equality is indicated by zero in the carry bit. */
1247 #define CC_Z_IN_NOT_C 010000
1248
1249 /* Store in cc_status the expressions
1250 that the condition codes will describe
1251 after execution of an instruction whose pattern is EXP.
1252 Do not alter them if the instruction would not alter the cc's. */
1253
1254 #define NOTICE_UPDATE_CC(EXP, INSN) \
1255 notice_update_cc((EXP))
1256
1257 /* Output a signed jump insn. Use template NORMAL ordinarily, or
1258 FLOAT following a floating point comparison.
1259 Use NO_OV following an arithmetic insn that set the cc's
1260 before a test insn that was deleted.
1261 NO_OV may be zero, meaning final should reinsert the test insn
1262 because the jump cannot be handled properly without it. */
1263
1264 #define OUTPUT_JUMP(NORMAL, FLOAT, NO_OV) \
1265 { \
1266 if (cc_prev_status.flags & CC_IN_80387) \
1267 return FLOAT; \
1268 if (cc_prev_status.flags & CC_NO_OVERFLOW) \
1269 return NO_OV; \
1270 return NORMAL; \
1271 }
1272 \f
1273 /* Control the assembler format that we output, to the extent
1274 this does not vary between assemblers. */
1275
1276 /* How to refer to registers in assembler output.
1277 This sequence is indexed by compiler's hard-register-number (see above). */
1278
1279 /* In order to refer to the first 8 regs as 32 bit regs prefix an "e"
1280 For non floating point regs, the following are the HImode names.
1281
1282 For float regs, the stack top is sometimes referred to as "%st(0)"
1283 instead of just "%st". PRINT_REG handles this with the "y" code. */
1284
1285 #define HI_REGISTER_NAMES \
1286 {"ax","dx","cx","bx","si","di","bp","sp", \
1287 "st","st(1)","st(2)","st(3)","st(4)","st(5)","st(6)","st(7)","" }
1288
1289 #define REGISTER_NAMES HI_REGISTER_NAMES
1290
1291 /* Table of additional register names to use in user input. */
1292
1293 #define ADDITIONAL_REGISTER_NAMES \
1294 { "eax", 0, "edx", 1, "ecx", 2, "ebx", 3, \
1295 "esi", 4, "edi", 5, "ebp", 6, "esp", 7, \
1296 "al", 0, "dl", 1, "cl", 2, "bl", 3, \
1297 "ah", 0, "dh", 1, "ch", 2, "bh", 3 }
1298
1299 /* Note we are omitting these since currently I don't know how
1300 to get gcc to use these, since they want the same but different
1301 number as al, and ax.
1302 */
1303
1304 /* note the last four are not really qi_registers, but
1305 the md will have to never output movb into one of them
1306 only a movw . There is no movb into the last four regs */
1307
1308 #define QI_REGISTER_NAMES \
1309 {"al", "dl", "cl", "bl", "si", "di", "bp", "sp",}
1310
1311 /* These parallel the array above, and can be used to access bits 8:15
1312 of regs 0 through 3. */
1313
1314 #define QI_HIGH_REGISTER_NAMES \
1315 {"ah", "dh", "ch", "bh", }
1316
1317 /* How to renumber registers for dbx and gdb. */
1318
1319 /* {0,2,1,3,6,7,4,5,12,13,14,15,16,17} */
1320 #define DBX_REGISTER_NUMBER(n) \
1321 ((n) == 0 ? 0 : \
1322 (n) == 1 ? 2 : \
1323 (n) == 2 ? 1 : \
1324 (n) == 3 ? 3 : \
1325 (n) == 4 ? 6 : \
1326 (n) == 5 ? 7 : \
1327 (n) == 6 ? 4 : \
1328 (n) == 7 ? 5 : \
1329 (n) + 4)
1330
1331 /* This is how to output the definition of a user-level label named NAME,
1332 such as the label on a static function or variable NAME. */
1333
1334 #define ASM_OUTPUT_LABEL(FILE,NAME) \
1335 (assemble_name (FILE, NAME), fputs (":\n", FILE))
1336
1337 /* This is how to output an assembler line defining a `double' constant. */
1338
1339 #define ASM_OUTPUT_DOUBLE(FILE,VALUE) \
1340 fprintf (FILE, "%s %.22e\n", ASM_DOUBLE, (VALUE))
1341
1342
1343 /* This is how to output an assembler line defining a `float' constant. */
1344
1345 #define ASM_OUTPUT_FLOAT(FILE,VALUE) \
1346 do { union { float f; long l;} tem; \
1347 tem.f = (VALUE); \
1348 fprintf((FILE), "%s 0x%x\n", ASM_LONG, tem.l); \
1349 } while (0)
1350
1351
1352 /* Store in OUTPUT a string (made with alloca) containing
1353 an assembler-name for a local static variable named NAME.
1354 LABELNO is an integer which is different for each call. */
1355
1356 #define ASM_FORMAT_PRIVATE_NAME(OUTPUT, NAME, LABELNO) \
1357 ( (OUTPUT) = (char *) alloca (strlen ((NAME)) + 10), \
1358 sprintf ((OUTPUT), "%s.%d", (NAME), (LABELNO)))
1359
1360
1361
1362 /* This is how to output an assembler line defining an `int' constant. */
1363
1364 #define ASM_OUTPUT_INT(FILE,VALUE) \
1365 ( fprintf (FILE, "%s ", ASM_LONG), \
1366 output_addr_const (FILE,(VALUE)), \
1367 putc('\n',FILE))
1368
1369 /* Likewise for `char' and `short' constants. */
1370 /* is this supposed to do align too?? */
1371
1372 #define ASM_OUTPUT_SHORT(FILE,VALUE) \
1373 ( fprintf (FILE, "%s ", ASM_SHORT), \
1374 output_addr_const (FILE,(VALUE)), \
1375 putc('\n',FILE))
1376
1377 /*
1378 #define ASM_OUTPUT_SHORT(FILE,VALUE) \
1379 ( fprintf (FILE, "%s ", ASM_BYTE_OP), \
1380 output_addr_const (FILE,(VALUE)), \
1381 fputs (",", FILE), \
1382 output_addr_const (FILE,(VALUE)), \
1383 fputs (" >> 8\n",FILE))
1384 */
1385
1386
1387 #define ASM_OUTPUT_CHAR(FILE,VALUE) \
1388 ( fprintf (FILE, "%s ", ASM_BYTE_OP), \
1389 output_addr_const (FILE, (VALUE)), \
1390 putc ('\n', FILE))
1391
1392 /* This is how to output an assembler line for a numeric constant byte. */
1393
1394 #define ASM_OUTPUT_BYTE(FILE,VALUE) \
1395 fprintf ((FILE), "%s 0x%x\n", ASM_BYTE_OP, (VALUE))
1396
1397 /* This is how to output an insn to push a register on the stack.
1398 It need not be very fast code. */
1399
1400 #define ASM_OUTPUT_REG_PUSH(FILE,REGNO) \
1401 fprintf (FILE, "\tpushl e%s\n", reg_names[REGNO])
1402
1403 /* This is how to output an insn to pop a register from the stack.
1404 It need not be very fast code. */
1405
1406 #define ASM_OUTPUT_REG_POP(FILE,REGNO) \
1407 fprintf (FILE, "\tpopl e%s\n", reg_names[REGNO])
1408
1409 /* This is how to output an element of a case-vector that is absolute.
1410 */
1411
1412 #define ASM_OUTPUT_ADDR_VEC_ELT(FILE, VALUE) \
1413 fprintf (FILE, "%s %s%d\n", ASM_LONG, LPREFIX, VALUE)
1414
1415 /* This is how to output an element of a case-vector that is relative.
1416 We don't use these on the 386 yet, because the ATT assembler can't do
1417 forward reference the differences.
1418 */
1419
1420 #define ASM_OUTPUT_ADDR_DIFF_ELT(FILE, VALUE, REL) \
1421 fprintf (FILE, "\t.word %s%d-%s%d\n",LPREFIX, VALUE,LPREFIX, REL)
1422
1423 /* Define the parentheses used to group arithmetic operations
1424 in assembler code. */
1425
1426 #define ASM_OPEN_PAREN ""
1427 #define ASM_CLOSE_PAREN ""
1428
1429 /* Define results of standard character escape sequences. */
1430 #define TARGET_BELL 007
1431 #define TARGET_BS 010
1432 #define TARGET_TAB 011
1433 #define TARGET_NEWLINE 012
1434 #define TARGET_VT 013
1435 #define TARGET_FF 014
1436 #define TARGET_CR 015
1437 \f
1438 /* Print operand X (an rtx) in assembler syntax to file FILE.
1439 CODE is a letter or dot (`z' in `%z0') or 0 if no letter was specified.
1440 The CODE z takes the size of operand from the following digit, and
1441 outputs b,w,or l respectively.
1442
1443 On the 80386, we use several such letters:
1444 f -- float insn (print a CONST_DOUBLE as a float rather than in hex).
1445 L,W,B,Q,S -- print the opcode suffix for specified size of operand.
1446 R -- print the prefix for register names.
1447 z -- print the opcode suffix for the size of the current operand.
1448 * -- print a star (in certain assembler syntax)
1449 w -- print the operand as if it's a "word" (HImode) even if it isn't.
1450 b -- print the operand as if it's a byte (QImode) even if it isn't.
1451 c -- don't print special prefixes before constant operands. */
1452
1453 #define PRINT_OPERAND_PUNCT_VALID_P(CODE) \
1454 ((CODE) == '*')
1455
1456 /* Print the name of a register based on its machine mode and number.
1457 If CODE is 'w', pretend the mode is HImode.
1458 If CODE is 'b', pretend the mode is QImode.
1459 If CODE is 'k', pretend the mode is SImode.
1460 If CODE is 'h', pretend the reg is the `high' byte register.
1461 If CODE is 'y', print "st(0)" instead of "st", if the reg is stack op. */
1462
1463 #define PRINT_REG(X, CODE, FILE) \
1464 do { static char *hi_reg_name[] = HI_REGISTER_NAMES; \
1465 static char *qi_reg_name[] = QI_REGISTER_NAMES; \
1466 static char *qi_high_reg_name[] = QI_HIGH_REGISTER_NAMES; \
1467 if (REGNO (X) == ARG_POINTER_REGNUM) abort (); \
1468 fprintf (FILE, "%s", RP); \
1469 switch ((CODE == 'w' ? 2 \
1470 : CODE == 'b' ? 1 \
1471 : CODE == 'k' ? 4 \
1472 : CODE == 'y' ? 3 \
1473 : CODE == 'h' ? 0 \
1474 : GET_MODE_SIZE (GET_MODE (X)))) \
1475 { \
1476 case 3: \
1477 if (STACK_TOP_P (X)) \
1478 { fputs ("st(0)", FILE); break; } \
1479 case 4: case 8: \
1480 if (! FP_REG_P (X)) fputs ("e", FILE); \
1481 case 2: \
1482 fputs (hi_reg_name[REGNO (X)], FILE); \
1483 break; \
1484 case 1: \
1485 fputs (qi_reg_name[REGNO (X)], FILE); \
1486 break; \
1487 case 0: \
1488 fputs (qi_high_reg_name[REGNO (X)], FILE); \
1489 break; \
1490 } \
1491 } while (0)
1492
1493 #define PRINT_OPERAND(FILE, X, CODE) \
1494 print_operand (FILE, X, CODE)
1495
1496 #define PRINT_OPERAND_ADDRESS(FILE, ADDR) \
1497 print_operand_address (FILE, ADDR)
1498
1499 /* Output the prefix for an immediate operand, or for an offset operand. */
1500 #define PRINT_IMMED_PREFIX(FILE) fputs (IP, (FILE))
1501 #define PRINT_OFFSET_PREFIX(FILE) fputs (IP, (FILE))
1502
1503 /* Routines in libgcc that return floats must return them in an fp reg,
1504 just as other functions do which return such values.
1505 These macros make that happen. */
1506
1507 #define FLOAT_VALUE_TYPE float
1508 #define INTIFY(FLOATVAL) FLOATVAL
1509
1510 /* Nonzero if INSN magically clobbers register REGNO. */
1511
1512 /* #define INSN_CLOBBERS_REGNO_P(INSN, REGNO) \
1513 (FP_REGNO_P (REGNO) \
1514 && (GET_CODE (INSN) == JUMP_INSN || GET_CODE (INSN) == BARRIER))
1515 */
1516
1517 /* a letter which is not needed by the normal asm syntax, which
1518 we can use for operand syntax in the extended asm */
1519
1520 #define ASM_OPERAND_LETTER '#'
1521 \f
1522 #define RET return ""
1523 #define AT_SP(mode) (gen_rtx (MEM, (mode), stack_pointer_rtx))
1524 \f
1525 /*
1526 Local variables:
1527 version-control: t
1528 End:
1529 */
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