1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
|
divert(-1)
dnl m4 macros for x86 assembler.
dnl Copyright 1999, 2000, 2001 Free Software Foundation, Inc.
dnl
dnl This file is part of the GNU MP Library.
dnl
dnl The GNU MP Library is free software; you can redistribute it and/or
dnl modify it under the terms of the GNU Lesser General Public License as
dnl published by the Free Software Foundation; either version 2.1 of the
dnl License, or (at your option) any later version.
dnl
dnl The GNU MP Library is distributed in the hope that it will be useful,
dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
dnl Lesser General Public License for more details.
dnl
dnl You should have received a copy of the GNU Lesser General Public
dnl License along with the GNU MP Library; see the file COPYING.LIB. If
dnl not, write to the Free Software Foundation, Inc., 59 Temple Place -
dnl Suite 330, Boston, MA 02111-1307, USA.
dnl Notes:
dnl
dnl m4 isn't perfect for processing BSD style x86 assembler code, the main
dnl problems are,
dnl
dnl 1. Doing define(foo,123) and then using foo in an addressing mode like
dnl foo(%ebx) expands as a macro rather than a constant. This is worked
dnl around by using deflit() from asm-defs.m4, instead of define().
dnl
dnl 2. Immediates in macro definitions need a space or `' to stop the $
dnl looking like a macro parameter. For example,
dnl
dnl define(foo, `mov $ 123, %eax')
dnl
dnl This is only a problem in macro definitions, not in ordinary text,
dnl nor in macro parameters like text passed to forloop() or ifdef().
deflit(BYTES_PER_MP_LIMB, 4)
dnl --------------------------------------------------------------------------
dnl Replacement PROLOGUE/EPILOGUE with more error checking. Nesting and
dnl overlapping not allowed.
dnl
dnl Usage: PROLOGUE(functionname)
dnl
dnl Generate a function prologue. functionname gets GSYM_PREFIX added.
dnl Examples,
dnl
dnl PROLOGUE(mpn_add_n)
dnl PROLOGUE(somefun)
define(`PROLOGUE',
m4_assert_numargs(1)
m4_assert_defined(`PROLOGUE_cpu')
`ifdef(`PROLOGUE_current_function',
`m4_error(`PROLOGUE'(`PROLOGUE_current_function') needs an `EPILOGUE'() before `PROLOGUE'($1)
)')dnl
m4_file_seen()dnl
define(`PROLOGUE_current_function',`$1')dnl
PROLOGUE_cpu(GSYM_PREFIX`'$1)')
dnl Usage: EPILOGUE()
dnl
dnl Notice the function name is passed to EPILOGUE_cpu(), letting it use $1
dnl instead of the long PROLOGUE_current_function symbol.
define(`EPILOGUE',
m4_assert_numargs(0)
m4_assert_defined(`EPILOGUE_cpu')
`ifdef(`PROLOGUE_current_function',,
`m4_error(`EPILOGUE'() with no `PROLOGUE'()
)')dnl
EPILOGUE_cpu(GSYM_PREFIX`'PROLOGUE_current_function)`'dnl
undefine(`PROLOGUE_current_function')')
m4wrap_prepend(
`ifdef(`PROLOGUE_current_function',
`m4_error(`EPILOGUE() for PROLOGUE('PROLOGUE_current_function`) never seen
')')')
dnl Usage: PROLOGUE_assert_inside()
dnl
dnl Use this unquoted on a line on its own at the start of a macro
dnl definition to add some code to check the macro is only used inside a
dnl PROLOGUE/EPILOGUE pair, and that hence PROLOGUE_current_function is
dnl defined.
define(PROLOGUE_assert_inside,
m4_assert_numargs(0)
``PROLOGUE_assert_inside_internal'(m4_doublequote($`'0))`dnl '')
define(PROLOGUE_assert_inside_internal,
m4_assert_numargs(1)
`ifdef(`PROLOGUE_current_function',,
`m4_error(`$1 used outside a PROLOGUE / EPILOGUE pair
')')')
dnl Usage: L(labelname)
dnl LF(functionname,labelname)
dnl
dnl Generate a local label in the current or given function. For LF(),
dnl functionname gets GSYM_PREFIX added, the same as with PROLOGUE().
dnl
dnl For example, in a function mpn_add_n (and with MPN_PREFIX __gmpn),
dnl
dnl L(bar) => L__gmpn_add_n__bar
dnl LF(somefun,bar) => Lsomefun__bar
dnl
dnl The function name and label name get two underscores between them
dnl rather than one to guard against clashing with a separate external
dnl symbol that happened to be called functionname_labelname. (Though this
dnl would only happen if the local label prefix is is empty.) Underscores
dnl are used so the whole label will still be a valid C identifier and so
dnl can be easily used in gdb.
dnl LSYM_PREFIX can be L$, so defn() is used to prevent L expanding as the
dnl L macro and making an infinite recursion.
define(LF,
m4_assert_numargs(2)
m4_assert_defined(`LSYM_PREFIX')
`defn(`LSYM_PREFIX')GSYM_PREFIX`'$1`'__$2')
define(`L',
m4_assert_numargs(1)
PROLOGUE_assert_inside()
`LF(PROLOGUE_current_function,`$1')')
dnl Called: PROLOGUE_cpu(gsym)
dnl EPILOGUE_cpu(gsym)
define(PROLOGUE_cpu,
m4_assert_numargs(1)
`GLOBL $1
TYPE($1,`function')
$1:
ifelse(WANT_PROFILING,`no',,`call_mcount
')')')
define(EPILOGUE_cpu,
m4_assert_numargs(1)
` SIZE($1,.-$1)')
dnl Usage: call_mcount
dnl
dnl For `gprof' style profiling, %ebp is setup as a frame pointer. None of
dnl the assembler routines use %ebp this way, so it's done only for the
dnl benefit of mcount. glibc sysdeps/i386/i386-mcount.S shows how mcount
dnl gets the current function from (%esp) and the parent from 4(%ebp).
dnl
dnl For `prof' style profiling gcc generates mcount calls without setting
dnl up %ebp, and the same is done here.
define(`call_mcount',
m4_assert_defined(`WANT_PROFILING')
m4_assert_defined(`MCOUNT_PIC_REG')
m4_assert_defined(`MCOUNT_NONPIC_REG')
m4_assert_defined(`MCOUNT_PIC_CALL')
m4_assert_defined(`MCOUNT_NONPIC_CALL')
`ifelse(ifdef(`PIC',`MCOUNT_PIC_REG',`MCOUNT_NONPIC_REG'),,,
` DATA
ALIGN(4)
L(mcount_data):
W32 0
TEXT
')dnl
ifelse(WANT_PROFILING,`gprof',
` pushl %ebp
movl %esp, %ebp
')dnl
ifdef(`PIC',
` pushl %ebx
mcount_movl_GOT_ebx
ifelse(MCOUNT_PIC_REG,,,
` leal L(mcount_data)@GOTOFF(%ebx), MCOUNT_PIC_REG')
MCOUNT_PIC_CALL
popl %ebx
',`dnl non-PIC
ifelse(MCOUNT_NONPIC_REG,,,
` movl `$'L(mcount_data), MCOUNT_NONPIC_REG
')dnl
MCOUNT_NONPIC_CALL
')dnl
ifelse(WANT_PROFILING,`gprof',
` popl %ebp
')')
dnl Called: mcount_movl_GOT_ebx
dnl Label H is "here", the %eip obtained from the call. C is the called
dnl subroutine. J is the jump across that subroutine. A fetch and "ret"
dnl is always done so calls and returns are balanced for the benefit of the
dnl various x86s that have return stack branch prediction.
define(mcount_movl_GOT_ebx,
m4_assert_numargs(-1)
` call L(mcount_movl_GOT_ebx_C`'mcount_movl_GOT_ebx_counter)
L(mcount_movl_GOT_ebx_H`'mcount_movl_GOT_ebx_counter):
jmp L(mcount_movl_GOT_ebx_J`'mcount_movl_GOT_ebx_counter)
L(mcount_movl_GOT_ebx_C`'mcount_movl_GOT_ebx_counter):
movl (%esp), %ebx
ret
L(mcount_movl_GOT_ebx_J`'mcount_movl_GOT_ebx_counter):
addl $_GLOBAL_OFFSET_TABLE_+[.-L(mcount_movl_GOT_ebx_H`'mcount_movl_GOT_ebx_counter)], %ebx
define(`mcount_movl_GOT_ebx_counter',incr(mcount_movl_GOT_ebx_counter))')
define(mcount_movl_GOT_ebx_counter,1)
dnl --------------------------------------------------------------------------
dnl Various x86 macros.
dnl
dnl Usage: ALIGN_OFFSET(bytes,offset)
dnl
dnl Align to `offset' away from a multiple of `bytes'.
dnl
dnl This is useful for testing, for example align to something very strict
dnl and see what effect offsets from it have, "ALIGN_OFFSET(256,32)".
dnl
dnl Generally you wouldn't execute across the padding, but it's done with
dnl nop's so it'll work.
define(ALIGN_OFFSET,
m4_assert_numargs(2)
`ALIGN($1)
forloop(`i',1,$2,` nop
')')
dnl Usage: defframe(name,offset)
dnl
dnl Make a definition like the following with which to access a parameter
dnl or variable on the stack.
dnl
dnl define(name,`FRAME+offset(%esp)')
dnl
dnl Actually m4_empty_if_zero(FRAME+offset) is used, which will save one
dnl byte if FRAME+offset is zero, by putting (%esp) rather than 0(%esp).
dnl Use define(`defframe_empty_if_zero_disabled',1) if for some reason the
dnl zero offset is wanted.
dnl
dnl The new macro also gets a check that when it's used FRAME is actually
dnl defined, and that the final %esp offset isn't negative, which would
dnl mean an attempt to access something below the current %esp.
dnl
dnl deflit() is used rather than a plain define(), so the new macro won't
dnl delete any following parenthesized expression. name(%edi) will come
dnl out say as 16(%esp)(%edi). This isn't valid assembler and should
dnl provoke an error, which is better than silently giving just 16(%esp).
dnl
dnl See README for more on the suggested way to access the stack frame.
define(defframe,
m4_assert_numargs(2)
`deflit(`$1',
m4_assert_defined(`FRAME')
`defframe_check_notbelow(`$1',$2,FRAME)dnl
defframe_empty_if_zero(FRAME+($2))(%esp)')')
dnl Called: defframe_empty_if_zero(expression)
define(defframe_empty_if_zero,
`ifelse(defframe_empty_if_zero_disabled,1,
`eval($1)',
`m4_empty_if_zero($1)')')
dnl Called: defframe_check_notbelow(`name',offset,FRAME)
define(defframe_check_notbelow,
m4_assert_numargs(3)
`ifelse(eval(($3)+($2)<0),1,
`m4_error(`$1 at frame offset $2 used when FRAME is only $3 bytes
')')')
dnl Usage: FRAME_pushl()
dnl FRAME_popl()
dnl FRAME_addl_esp(n)
dnl FRAME_subl_esp(n)
dnl
dnl Adjust FRAME appropriately for a pushl or popl, or for an addl or subl
dnl %esp of n bytes.
dnl
dnl Using these macros is completely optional. Sometimes it makes more
dnl sense to put explicit deflit(`FRAME',N) forms, especially when there's
dnl jumps and different sequences of FRAME values need to be used in
dnl different places.
define(FRAME_pushl,
m4_assert_numargs(0)
m4_assert_defined(`FRAME')
`deflit(`FRAME',eval(FRAME+4))')
define(FRAME_popl,
m4_assert_numargs(0)
m4_assert_defined(`FRAME')
`deflit(`FRAME',eval(FRAME-4))')
define(FRAME_addl_esp,
m4_assert_numargs(1)
m4_assert_defined(`FRAME')
`deflit(`FRAME',eval(FRAME-($1)))')
define(FRAME_subl_esp,
m4_assert_numargs(1)
m4_assert_defined(`FRAME')
`deflit(`FRAME',eval(FRAME+($1)))')
dnl Usage: defframe_pushl(name)
dnl
dnl Do a combination FRAME_pushl() and a defframe() to name the stack
dnl location just pushed. This should come after a pushl instruction.
dnl Putting it on the same line works and avoids lengthening the code. For
dnl example,
dnl
dnl pushl %eax defframe_pushl(VAR_COUNTER)
dnl
dnl Notice the defframe() is done with an unquoted -FRAME thus giving its
dnl current value without tracking future changes.
define(defframe_pushl,
`FRAME_pushl()defframe(`$1',-FRAME)')
dnl --------------------------------------------------------------------------
dnl Assembler instruction macros.
dnl
dnl Usage: emms_or_femms
dnl femms_available_p
dnl
dnl femms_available_p expands to 1 or 0 according to whether the AMD 3DNow
dnl femms instruction is available. emms_or_femms expands to femms if
dnl available, or emms if not.
dnl
dnl emms_or_femms is meant for use in the K6 directory where plain K6
dnl (without femms) and K6-2 and K6-3 (with a slightly faster femms) are
dnl supported together.
dnl
dnl On K7 femms is no longer faster and is just an alias for emms, so plain
dnl emms may as well be used.
define(femms_available_p,
m4_assert_numargs(-1)
`m4_ifdef_anyof_p(
`HAVE_HOST_CPU_k62',
`HAVE_HOST_CPU_k63',
`HAVE_HOST_CPU_athlon')')
define(emms_or_femms,
m4_assert_numargs(-1)
`ifelse(femms_available_p,1,`femms',`emms')')
dnl Usage: femms
dnl
dnl Gas 2.9.1 which comes with FreeBSD 3.4 doesn't support femms, so the
dnl following is a replacement using .byte.
dnl
dnl If femms isn't available, an emms is generated instead, for convenience
dnl when testing on a machine without femms.
define(femms,
m4_assert_numargs(-1)
`ifelse(femms_available_p,1,
`.byte 15,14 C AMD 3DNow femms',
`emms`'dnl
m4_warning(`warning, using emms in place of femms, use for testing only
')')')
dnl Usage: jadcl0(op)
dnl
dnl Generate a jnc/incl as a substitute for adcl $0,op. Note this isn't an
dnl exact replacement, since it doesn't set the flags like adcl does.
dnl
dnl This finds a use in K6 mpn_addmul_1, mpn_submul_1, mpn_mul_basecase and
dnl mpn_sqr_basecase because on K6 an adcl is slow, the branch
dnl misprediction penalty is small, and the multiply algorithm used leads
dnl to a carry bit on average only 1/4 of the time.
dnl
dnl jadcl0_disabled can be set to 1 to instead generate an ordinary adcl
dnl for comparison. For example,
dnl
dnl define(`jadcl0_disabled',1)
dnl
dnl When using a register operand, eg. "jadcl0(%edx)", the jnc/incl code is
dnl the same size as an adcl. This makes it possible to use the exact same
dnl computed jump code when testing the relative speed of the two.
define(jadcl0,
m4_assert_numargs(1)
`ifelse(jadcl0_disabled,1,
`adcl $`'0, $1',
`jnc L(jadcl0_`'jadcl0_counter)
incl $1
L(jadcl0_`'jadcl0_counter):
define(`jadcl0_counter',incr(jadcl0_counter))')')
define(jadcl0_counter,1)
dnl Usage: cmov_available_p
dnl
dnl Expand to 1 if cmov is available, 0 if not.
define(cmov_available_p,
`m4_ifdef_anyof_p(
`HAVE_HOST_CPU_pentiumpro',
`HAVE_HOST_CPU_pentium2',
`HAVE_HOST_CPU_pentium3',
`HAVE_HOST_CPU_athlon')')
dnl Usage: x86_lookup(target, key,value, key,value, ...)
dnl x86_lookup_p(target, key,value, key,value, ...)
dnl
dnl Look for `target' among the `key' parameters.
dnl
dnl x86_lookup expands to the corresponding `value', or generates an error
dnl if `target' isn't found.
dnl
dnl x86_lookup_p expands to 1 if `target' is found, or 0 if not.
define(x86_lookup,
`ifelse(eval($#<3),1,
`m4_error(`unrecognised part of x86 instruction: $1
')',
`ifelse(`$1',`$2', `$3',
`x86_lookup(`$1',shift(shift(shift($@))))')')')
define(x86_lookup_p,
`ifelse(eval($#<3),1, `0',
`ifelse(`$1',`$2', `1',
`x86_lookup_p(`$1',shift(shift(shift($@))))')')')
dnl Usage: x86_opcode_reg32(reg)
dnl x86_opcode_reg32_p(reg)
dnl
dnl x86_opcode_reg32 expands to the standard 3 bit encoding for the given
dnl 32-bit register, eg. `%ebp' turns into 5.
dnl
dnl x86_opcode_reg32_p expands to 1 if reg is a valid 32-bit register, or 0
dnl if not.
define(x86_opcode_reg32,
m4_assert_numargs(1)
`x86_lookup(`$1',x86_opcode_reg32_list)')
define(x86_opcode_reg32_p,
m4_assert_onearg()
`x86_lookup_p(`$1',x86_opcode_reg32_list)')
define(x86_opcode_reg32_list,
``%eax',0,
`%ecx',1,
`%edx',2,
`%ebx',3,
`%esp',4,
`%ebp',5,
`%esi',6,
`%edi',7')
dnl Usage: x86_opcode_tttn(cond)
dnl
dnl Expand to the 4-bit "tttn" field value for the given x86 branch
dnl condition (like `c', `ae', etc).
define(x86_opcode_tttn,
m4_assert_numargs(1)
`x86_lookup(`$1',x86_opcode_ttn_list)')
define(x86_opcode_tttn_list,
``o', 0,
`no', 1,
`b', 2, `c', 2, `nae',2,
`nb', 3, `nc', 3, `ae', 3,
`e', 4, `z', 4,
`ne', 5, `nz', 5,
`be', 6, `na', 6,
`nbe', 7, `a', 7,
`s', 8,
`ns', 9,
`p', 10, `pe', 10, `npo',10,
`np', 11, `npe',11, `po', 11,
`l', 12, `nge',12,
`nl', 13, `ge', 13,
`le', 14, `ng', 14,
`nle',15, `g', 15')
dnl Usage: cmovCC(srcreg,dstreg)
dnl
dnl Generate a cmov instruction if the host supports cmov, or simulate it
dnl with a conditional jump if not (the latter being meant only for
dnl testing). For example,
dnl
dnl cmovz( %eax, %ebx)
dnl
dnl cmov instructions are generated using .byte sequences, since only
dnl recent versions of gas know cmov.
dnl
dnl The source operand can only be a plain register. (m4 code implementing
dnl full memory addressing modes exists, believe it or not, but isn't
dnl currently needed and isn't included.)
dnl
dnl All the standard conditions are defined. Attempting to use one without
dnl the macro parentheses, such as just "cmovbe %eax, %ebx", will provoke
dnl an error. This ensures the necessary .byte sequences aren't
dnl accidentally missed.
dnl Called: define_cmov_many(cond,tttn,cond,tttn,...)
define(define_cmov_many,
`ifelse(m4_length(`$1'),0,,
`define_cmov(`$1',`$2')define_cmov_many(shift(shift($@)))')')
dnl Called: define_cmov(cond,tttn)
define(define_cmov,
m4_assert_numargs(2)
`define(`cmov$1',
m4_instruction_wrapper()
m4_assert_numargs(2)
`cmov_internal'(m4_doublequote($`'0),``$1',`$2'',dnl
m4_doublequote($`'1),m4_doublequote($`'2)))')
define_cmov_many(x86_opcode_tttn_list)
dnl Called: cmov_internal(name,cond,tttn,src,dst)
define(cmov_internal,
m4_assert_numargs(5)
`ifelse(cmov_available_p,1,
`cmov_bytes_tttn(`$1',`$3',`$4',`$5')',
`m4_warning(`warning, simulating cmov with jump, use for testing only
')cmov_simulate(`$2',`$4',`$5')')')
dnl Called: cmov_simulate(cond,src,dst)
dnl If this is going to be used with memory operands for the source it will
dnl need to be changed to do a fetch even if the condition is false, so as
dnl to trigger exceptions the same way a real cmov does.
define(cmov_simulate,
m4_assert_numargs(3)
`j$1 L(cmov_T`'cmov_counter) C cmov$1 $2, $3
jmp L(cmov_F`'cmov_counter)
L(cmov_T`'cmov_counter):
movl $2, $3
L(cmov_F`'cmov_counter):
define(`cmov_counter',incr(cmov_counter))')
define(cmov_counter,1)
dnl Called: cmov_bytes_tttn(name,tttn,src,dst)
define(cmov_bytes_tttn,
m4_assert_numargs(4)
`.byte dnl
15, dnl
eval(64+$2), dnl
eval(192+8*x86_opcode_reg32(`$4')+x86_opcode_reg32(`$3')) dnl
C `$1 $3, $4'')
dnl Usage: loop_or_decljnz label
dnl
dnl Generate either a "loop" instruction or a "decl %ecx / jnz", whichever
dnl is better. "loop" is better on K6 and probably on 386, on other chips
dnl separate decl/jnz is better.
dnl
dnl This macro is just for mpn/x86/divrem_1.asm and mpn/x86/mod_1.asm where
dnl this loop_or_decljnz variation is enough to let the code be shared by
dnl all chips.
define(loop_or_decljnz,
`ifelse(loop_is_better_p,1,
`loop',
`decl %ecx
jnz')')
define(loop_is_better_p,
`m4_ifdef_anyof_p(`HAVE_HOST_CPU_k6',
`HAVE_HOST_CPU_k62',
`HAVE_HOST_CPU_k63',
`HAVE_HOST_CPU_i386')')
dnl Usage: Zdisp(inst,op,op,op)
dnl
dnl Generate explicit .byte sequences if necessary to force a byte-sized
dnl zero displacement on an instruction. For example,
dnl
dnl Zdisp( movl, 0,(%esi), %eax)
dnl
dnl expands to
dnl
dnl .byte 139,70,0 C movl 0(%esi), %eax
dnl
dnl If the displacement given isn't 0, then normal assembler code is
dnl generated. For example,
dnl
dnl Zdisp( movl, 4,(%esi), %eax)
dnl
dnl expands to
dnl
dnl movl 4(%esi), %eax
dnl
dnl This means a single Zdisp() form can be used with an expression for the
dnl displacement, and .byte will be used only if necessary. The
dnl displacement argument is eval()ed.
dnl
dnl Because there aren't many places a 0(reg) form is wanted, Zdisp is
dnl implemented with a table of instructions and encodings. A new entry is
dnl needed for any different operation or registers. The table is split
dnl into separate macros to avoid overflowing BSD m4 macro expansion space.
define(Zdisp,
`define(`Zdisp_found',0)dnl
Zdisp_1($@)dnl
Zdisp_2($@)dnl
Zdisp_3($@)dnl
Zdisp_4($@)dnl
ifelse(Zdisp_found,0,
`m4_error(`unrecognised instruction in Zdisp: $1 $2 $3 $4
')')')
define(Zdisp_1,`dnl
Zdisp_match( adcl, 0,(%edx), %eax, `0x13,0x42,0x00', $@)`'dnl
Zdisp_match( adcl, 0,(%edx), %esi, `0x13,0x72,0x00', $@)`'dnl
Zdisp_match( addl, %ebx, 0,(%edi), `0x01,0x5f,0x00', $@)`'dnl
Zdisp_match( addl, %ecx, 0,(%edi), `0x01,0x4f,0x00', $@)`'dnl
Zdisp_match( addl, %esi, 0,(%edi), `0x01,0x77,0x00', $@)`'dnl
Zdisp_match( sbbl, 0,(%edx), %eax, `0x1b,0x42,0x00', $@)`'dnl
Zdisp_match( sbbl, 0,(%edx), %esi, `0x1b,0x72,0x00', $@)`'dnl
Zdisp_match( subl, %ecx, 0,(%edi), `0x29,0x4f,0x00', $@)`'dnl
Zdisp_match( movzbl, 0,(%eax,%ebp), %eax, `0x0f,0xb6,0x44,0x28,0x00', $@)`'dnl
Zdisp_match( movzbl, 0,(%ecx,%edi), %edi, `0x0f,0xb6,0x7c,0x39,0x00', $@)`'dnl
')
define(Zdisp_2,`dnl
Zdisp_match( movl, %eax, 0,(%edi), `0x89,0x47,0x00', $@)`'dnl
Zdisp_match( movl, %ebx, 0,(%edi), `0x89,0x5f,0x00', $@)`'dnl
Zdisp_match( movl, %esi, 0,(%edi), `0x89,0x77,0x00', $@)`'dnl
Zdisp_match( movl, 0,(%ebx), %eax, `0x8b,0x43,0x00', $@)`'dnl
Zdisp_match( movl, 0,(%ebx), %esi, `0x8b,0x73,0x00', $@)`'dnl
Zdisp_match( movl, 0,(%esi), %eax, `0x8b,0x46,0x00', $@)`'dnl
Zdisp_match( movl, 0,(%esi,%ecx,4), %eax, `0x8b,0x44,0x8e,0x00', $@)`'dnl
')
define(Zdisp_3,`dnl
Zdisp_match( movq, 0,(%eax,%ecx,8), %mm0, `0x0f,0x6f,0x44,0xc8,0x00', $@)`'dnl
Zdisp_match( movq, 0,(%ebx,%eax,4), %mm0, `0x0f,0x6f,0x44,0x83,0x00', $@)`'dnl
Zdisp_match( movq, 0,(%ebx,%eax,4), %mm2, `0x0f,0x6f,0x54,0x83,0x00', $@)`'dnl
Zdisp_match( movq, 0,(%ebx,%ecx,4), %mm0, `0x0f,0x6f,0x44,0x8b,0x00', $@)`'dnl
Zdisp_match( movq, 0,(%esi), %mm0, `0x0f,0x6f,0x46,0x00', $@)`'dnl
Zdisp_match( movq, %mm0, 0,(%edi), `0x0f,0x7f,0x47,0x00', $@)`'dnl
Zdisp_match( movq, %mm2, 0,(%ecx,%eax,4), `0x0f,0x7f,0x54,0x81,0x00', $@)`'dnl
Zdisp_match( movq, %mm2, 0,(%edx,%eax,4), `0x0f,0x7f,0x54,0x82,0x00', $@)`'dnl
Zdisp_match( movq, %mm0, 0,(%edx,%ecx,8), `0x0f,0x7f,0x44,0xca,0x00', $@)`'dnl
')
define(Zdisp_4,`dnl
Zdisp_match( movd, 0,(%eax,%ecx,8), %mm1, `0x0f,0x6e,0x4c,0xc8,0x00', $@)`'dnl
Zdisp_match( movd, 0,(%edx,%ecx,8), %mm0, `0x0f,0x6e,0x44,0xca,0x00', $@)`'dnl
Zdisp_match( movd, %mm0, 0,(%eax,%ecx,4), `0x0f,0x7e,0x44,0x88,0x00', $@)`'dnl
Zdisp_match( movd, %mm0, 0,(%ecx,%eax,4), `0x0f,0x7e,0x44,0x81,0x00', $@)`'dnl
Zdisp_match( movd, %mm2, 0,(%ecx,%eax,4), `0x0f,0x7e,0x54,0x81,0x00', $@)`'dnl
')
define(Zdisp_match,
`ifelse(eval(m4_stringequal_p(`$1',`$6')
&& m4_stringequal_p(`$2',0)
&& m4_stringequal_p(`$3',`$8')
&& m4_stringequal_p(`$4',`$9')),1,
`define(`Zdisp_found',1)dnl
ifelse(eval(`$7'),0,
` .byte $5 C `$1 0$3, $4'',
` $6 $7$8, $9')',
`ifelse(eval(m4_stringequal_p(`$1',`$6')
&& m4_stringequal_p(`$2',`$7')
&& m4_stringequal_p(`$3',0)
&& m4_stringequal_p(`$4',`$9')),1,
`define(`Zdisp_found',1)dnl
ifelse(eval(`$8'),0,
` .byte $5 C `$1 $2, 0$4'',
` $6 $7, $8$9')')')')
dnl Usage: shldl(count,src,dst)
dnl shrdl(count,src,dst)
dnl shldw(count,src,dst)
dnl shrdw(count,src,dst)
dnl
dnl Generate a double-shift instruction, possibly omitting a %cl count
dnl parameter if that's what the assembler requires, as indicated by
dnl WANT_SHLDL_CL in config.m4. For example,
dnl
dnl shldl( %cl, %eax, %ebx)
dnl
dnl turns into either
dnl
dnl shldl %cl, %eax, %ebx
dnl or
dnl shldl %eax, %ebx
dnl
dnl Immediate counts are always passed through unchanged. For example,
dnl
dnl shrdl( $2, %esi, %edi)
dnl becomes
dnl shrdl $2, %esi, %edi
dnl
dnl
dnl If you forget to use the macro form "shldl( ...)" and instead write
dnl just a plain "shldl ...", an error results. This ensures the necessary
dnl variant treatment of %cl isn't accidentally bypassed.
define(define_shd_instruction,
`define($1,
m4_instruction_wrapper()
m4_assert_numargs(3)
`shd_instruction'(m4_doublequote($`'0),m4_doublequote($`'1),dnl
m4_doublequote($`'2),m4_doublequote($`'3)))')
dnl Effectively: define(shldl,`shd_instruction(`$0',`$1',`$2',`$3')') etc
define_shd_instruction(shldl)
define_shd_instruction(shrdl)
define_shd_instruction(shldw)
define_shd_instruction(shrdw)
dnl Called: shd_instruction(op,count,src,dst)
define(shd_instruction,
m4_assert_numargs(4)
m4_assert_defined(`WANT_SHLDL_CL')
`ifelse(eval(m4_stringequal_p(`$2',`%cl') && !WANT_SHLDL_CL),1,
``$1' `$3', `$4'',
``$1' `$2', `$3', `$4'')')
dnl Usage: ASSERT([cond][,instructions])
dnl
dnl If WANT_ASSERT is 1, output the given instructions and expect the given
dnl flags condition to then be satisfied. For example,
dnl
dnl ASSERT(ne, `cmpl %eax, %ebx')
dnl
dnl The instructions can be omitted to just assert a flags condition with
dnl no extra calculation. For example,
dnl
dnl ASSERT(nc)
dnl
dnl When `instructions' is not empty, a pushf/popf is added to preserve the
dnl flags, but the instructions themselves must preserve any registers that
dnl matter. FRAME is adjusted for the push and pop, so the instructions
dnl given can use defframe() stack variables.
dnl
dnl The condition can be omitted to just output the given instructions when
dnl assertion checking is wanted. In this case the pushf/popf is omitted.
dnl For example,
dnl
dnl ASSERT(, `movl %eax, VAR_KEEPVAL')
define(ASSERT,
m4_assert_numargs_range(1,2)
`ifelse(WANT_ASSERT,1,
`ifelse(`$1',,
`$2',
`C ASSERT
ifelse(`$2',,,` pushf ifdef(`FRAME',`FRAME_pushl()')')
$2
j`$1' L(ASSERT_ok`'ASSERT_counter)
ud2 C assertion failed
L(ASSERT_ok`'ASSERT_counter):
ifelse(`$2',,,` popf ifdef(`FRAME',`FRAME_popl()')')
define(`ASSERT_counter',incr(ASSERT_counter))')')')
define(ASSERT_counter,1)
dnl Usage: movl_text_address(label,register)
dnl
dnl Get the address of a text segment label, using either a plain movl or a
dnl position-independent calculation, as necessary. For example,
dnl
dnl movl_code_address(L(foo),%eax)
dnl
dnl This macro is only meant for use in ASSERT()s or when testing, since
dnl the PIC sequence it generates will want to be done with a ret balancing
dnl the call on CPUs with return address branch predition.
dnl
dnl The addl generated here has a backward reference to the label, and so
dnl won't suffer from the two forwards references bug in old gas (described
dnl in mpn/x86/README).
define(movl_text_address,
`ifdef(`PIC',
`call L(movl_text_address_`'movl_text_address_counter)
L(movl_text_address_`'movl_text_address_counter):
popl $2 C %eip
addl `$'$1-L(movl_text_address_`'movl_text_address_counter), $2
define(`movl_text_address_counter',incr(movl_text_address_counter))',
`movl `$'$1, $2')')
define(movl_text_address_counter,1)
divert`'dnl
|