import yasm macros from x264
[libav.git] / libavcodec / i386 / x86inc.asm
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1;*****************************************************************************
2;* x86inc.asm
3;*****************************************************************************
4;* Copyright (C) 2005-2008 Loren Merritt <lorenm@u.washington.edu>
5;*
6;* This file is part of FFmpeg.
7;*
8;* FFmpeg is free software; you can redistribute it and/or
9;* modify it under the terms of the GNU Lesser General Public
10;* License as published by the Free Software Foundation; either
11;* version 2.1 of the License, or (at your option) any later version.
12;*
13;* FFmpeg is distributed in the hope that it will be useful,
14;* but WITHOUT ANY WARRANTY; without even the implied warranty of
15;* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16;* Lesser General Public License for more details.
17;*
18;* You should have received a copy of the GNU Lesser General Public
19;* License along with FFmpeg; if not, write to the Free Software
20;* 51, Inc., Foundation Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21;*****************************************************************************
22
23; FIXME: All of the 64bit asm functions that take a stride as an argument
24; via register, assume that the high dword of that register is filled with 0.
25; This is true in practice (since we never do any 64bit arithmetic on strides,
26; and x264's strides are all positive), but is not guaranteed by the ABI.
27
28; Name of the .rodata section.
29; Kludge: Something on OS X fails to align .rodata even given an align attribute,
30; so use a different read-only section.
31%macro SECTION_RODATA 0
32 %ifidn __OUTPUT_FORMAT__,macho64
33 SECTION .text align=16
34 %elifidn __OUTPUT_FORMAT__,macho
35 SECTION .text align=16
36 fakegot:
37 %else
38 SECTION .rodata align=16
39 %endif
40%endmacro
41
42; PIC support macros. All these macros are totally harmless when PIC is
43; not defined but can ruin everything if misused in PIC mode. On x86_32, shared
44; objects cannot directly access global variables by address, they need to
45; go through the GOT (global offset table). Most OSes do not care about it
46; and let you load non-shared .so objects (Linux, Win32...). However, OS X
47; requires PIC code in its .dylib objects.
48;
49; - GLOBAL should be used as a suffix for global addressing, eg.
50; picgetgot ebx
51; mov eax, [foo GLOBAL]
52; instead of
53; mov eax, [foo]
54;
55; - picgetgot computes the GOT address into the given register in PIC
56; mode, otherwise does nothing. You need to do this before using GLOBAL.
57; Before in both execution order and compiled code order (so GLOBAL knows
58; which register the GOT is in).
59
60%ifndef PIC
61 %define GLOBAL
62 %macro picgetgot 1
63 %endmacro
64%elifdef ARCH_X86_64
65 %define PIC64
66 %define GLOBAL wrt rip
67 %macro picgetgot 1
68 %endmacro
69%else
70 %define PIC32
71 %ifidn __OUTPUT_FORMAT__,macho
72 ; There is no real global offset table on OS X, but we still
73 ; need to reference our variables by offset.
74 %macro picgetgot 1
75 call %%getgot
76 %%getgot:
77 pop %1
78 add %1, $$ - %%getgot
79 %undef GLOBAL
80 %define GLOBAL + %1 - fakegot
81 %endmacro
82 %else ; elf
83 extern _GLOBAL_OFFSET_TABLE_
84 %macro picgetgot 1
85 call %%getgot
86 %%getgot:
87 pop %1
88 add %1, _GLOBAL_OFFSET_TABLE_ + $$ - %%getgot wrt ..gotpc
89 %undef GLOBAL
90 %define GLOBAL + %1 wrt ..gotoff
91 %endmacro
92 %endif
93%endif
94
95; Macros to eliminate most code duplication between x86_32 and x86_64:
96; Currently this works only for leaf functions which load all their arguments
97; into registers at the start, and make no other use of the stack. Luckily that
98; covers most of x264's asm.
99
100; PROLOGUE:
101; %1 = number of arguments. loads them from stack if needed.
102; %2 = number of registers used, not including PIC. pushes callee-saved regs if needed.
103; %3 = whether global constants are used in this function. inits x86_32 PIC if needed.
104; %4 = list of names to define to registers
105; PROLOGUE can also be invoked by adding the same options to cglobal
106
107; e.g.
108; cglobal foo, 2,3,0, dst, src, tmp
109; declares a function (foo), taking two args (dst and src), one local variable (tmp), and not using globals
110
111; TODO Some functions can use some args directly from the stack. If they're the
112; last args then you can just not declare them, but if they're in the middle
113; we need more flexible macro.
114
115; RET:
116; Pops anything that was pushed by PROLOGUE
117
118; REP_RET:
119; Same, but if it doesn't pop anything it becomes a 2-byte ret, for athlons
120; which are slow when a normal ret follows a branch.
121
122%macro DECLARE_REG 6
123 %define r%1q %2
124 %define r%1d %3
125 %define r%1w %4
126 %define r%1b %5
127 %define r%1m %6
128 %define r%1 %2
129%endmacro
130
131%macro DECLARE_REG_SIZE 2
132 %define r%1q r%1
133 %define e%1q r%1
134 %define r%1d e%1
135 %define e%1d e%1
136 %define r%1w %1
137 %define e%1w %1
138 %define r%1b %2
139 %define e%1b %2
140%ifndef ARCH_X86_64
141 %define r%1 e%1
142%endif
143%endmacro
144
145DECLARE_REG_SIZE ax, al
146DECLARE_REG_SIZE bx, bl
147DECLARE_REG_SIZE cx, cl
148DECLARE_REG_SIZE dx, dl
149DECLARE_REG_SIZE si, sil
150DECLARE_REG_SIZE di, dil
151DECLARE_REG_SIZE bp, bpl
152
153%ifdef ARCH_X86_64
154 %define gprsize 8
155%else
156 %define gprsize 4
157%endif
158
159%macro PUSH 1
160 push %1
161 %assign stack_offset stack_offset+gprsize
162%endmacro
163
164%macro POP 1
165 pop %1
166 %assign stack_offset stack_offset-gprsize
167%endmacro
168
169%macro SUB 2
170 sub %1, %2
171 %ifidn %1, rsp
172 %assign stack_offset stack_offset+(%2)
173 %endif
174%endmacro
175
176%macro ADD 2
177 add %1, %2
178 %ifidn %1, rsp
179 %assign stack_offset stack_offset-(%2)
180 %endif
181%endmacro
182
183%macro movifnidn 2
184 %ifnidn %1, %2
185 mov %1, %2
186 %endif
187%endmacro
188
189%macro movsxdifnidn 2
190 %ifnidn %1, %2
191 movsxd %1, %2
192 %endif
193%endmacro
194
195%macro ASSERT 1
196 %if (%1) == 0
197 %error assert failed
198 %endif
199%endmacro
200
201%macro DEFINE_ARGS 0-*
202 %ifdef n_arg_names
203 %assign %%i 0
204 %rep n_arg_names
205 CAT_UNDEF arg_name %+ %%i, q
206 CAT_UNDEF arg_name %+ %%i, d
207 CAT_UNDEF arg_name %+ %%i, w
208 CAT_UNDEF arg_name %+ %%i, b
209 CAT_UNDEF arg_name, %%i
210 %assign %%i %%i+1
211 %endrep
212 %endif
213
214 %assign %%i 0
215 %rep %0
216 %xdefine %1q r %+ %%i %+ q
217 %xdefine %1d r %+ %%i %+ d
218 %xdefine %1w r %+ %%i %+ w
219 %xdefine %1b r %+ %%i %+ b
220 CAT_XDEFINE arg_name, %%i, %1
221 %assign %%i %%i+1
222 %rotate 1
223 %endrep
224 %assign n_arg_names %%i
225%endmacro
226
227%ifdef ARCH_X86_64 ;==========================================================
228%ifidn __OUTPUT_FORMAT__,win32
229
230DECLARE_REG 0, rcx, ecx, cx, cl, ecx
231DECLARE_REG 1, rdx, edx, dx, dl, edx
232DECLARE_REG 2, r8, r8d, r8w, r8b, r8d
233DECLARE_REG 3, r9, r9d, r9w, r9b, r9d
234DECLARE_REG 4, rdi, edi, di, dil, [rsp + stack_offset + 40]
235DECLARE_REG 5, rsi, esi, si, sil, [rsp + stack_offset + 48]
236DECLARE_REG 6, rax, eax, ax, al, [rsp + stack_offset + 56]
237%define r7m [rsp + stack_offset + 64]
238%define r8m [rsp + stack_offset + 72]
239
240%macro LOAD_IF_USED 2 ; reg_id, number_of_args
241 %if %1 < %2
242 mov r%1, [rsp + 8 + %1*8]
243 %endif
244%endmacro
245
246%else ;=======================================================================
247
248DECLARE_REG 0, rdi, edi, di, dil, edi
249DECLARE_REG 1, rsi, esi, si, sil, esi
250DECLARE_REG 2, rdx, edx, dx, dl, edx
251DECLARE_REG 3, rcx, ecx, cx, cl, ecx
252DECLARE_REG 4, r8, r8d, r8w, r8b, r8d
253DECLARE_REG 5, r9, r9d, r9w, r9b, r9d
254DECLARE_REG 6, rax, eax, ax, al, [rsp + stack_offset + 8]
255%define r7m [rsp + stack_offset + 16]
256%define r8m [rsp + stack_offset + 24]
257
258%macro LOAD_IF_USED 2 ; reg_id, number_of_args
259 %if %1 < %2
260 mov r%1, [rsp - 40 + %1*8]
261 %endif
262%endmacro
263
264%endif ; !WIN64
265
266%macro PROLOGUE 2-4+ 0 ; #args, #regs, pic, arg_names...
267 ASSERT %2 >= %1
268 ASSERT %2 <= 7
269 %assign stack_offset 0
270%ifidn __OUTPUT_FORMAT__,win32
271 LOAD_IF_USED 4, %1
272 LOAD_IF_USED 5, %1
273%endif
274 LOAD_IF_USED 6, %1
275 DEFINE_ARGS %4
276%endmacro
277
278%macro RET 0
279 ret
280%endmacro
281
282%macro REP_RET 0
283 rep ret
284%endmacro
285
286%else ; X86_32 ;==============================================================
287
288DECLARE_REG 0, eax, eax, ax, al, [esp + stack_offset + 4]
289DECLARE_REG 1, ecx, ecx, cx, cl, [esp + stack_offset + 8]
290DECLARE_REG 2, edx, edx, dx, dl, [esp + stack_offset + 12]
291DECLARE_REG 3, ebx, ebx, bx, bl, [esp + stack_offset + 16]
292DECLARE_REG 4, esi, esi, si, null, [esp + stack_offset + 20]
293DECLARE_REG 5, edi, edi, di, null, [esp + stack_offset + 24]
294DECLARE_REG 6, ebp, ebp, bp, null, [esp + stack_offset + 28]
295%define r7m [esp + stack_offset + 32]
296%define r8m [esp + stack_offset + 36]
297%define rsp esp
298
299%macro PUSH_IF_USED 1 ; reg_id
300 %if %1 < regs_used
301 push r%1
302 %assign stack_offset stack_offset+4
303 %endif
304%endmacro
305
306%macro POP_IF_USED 1 ; reg_id
307 %if %1 < regs_used
308 pop r%1
309 %endif
310%endmacro
311
312%macro LOAD_IF_USED 2 ; reg_id, number_of_args
313 %if %1 < %2
314 mov r%1, [esp + stack_offset + 4 + %1*4]
315 %endif
316%endmacro
317
318%macro PROLOGUE 2-4+ 0 ; #args, #regs, pic, arg_names...
319 ASSERT %2 >= %1
320 %assign stack_offset 0
321 %assign regs_used %2
322 %ifdef PIC
323 %if %3
324 %assign regs_used regs_used+1
325 %endif
326 %endif
327 ASSERT regs_used <= 7
328 PUSH_IF_USED 3
329 PUSH_IF_USED 4
330 PUSH_IF_USED 5
331 PUSH_IF_USED 6
332 LOAD_IF_USED 0, %1
333 LOAD_IF_USED 1, %1
334 LOAD_IF_USED 2, %1
335 LOAD_IF_USED 3, %1
336 LOAD_IF_USED 4, %1
337 LOAD_IF_USED 5, %1
338 LOAD_IF_USED 6, %1
339 %if %3
340 picgetgot r%2
341 %endif
342 DEFINE_ARGS %4
343%endmacro
344
345%macro RET 0
346 POP_IF_USED 6
347 POP_IF_USED 5
348 POP_IF_USED 4
349 POP_IF_USED 3
350 ret
351%endmacro
352
353%macro REP_RET 0
354 %if regs_used > 3
355 RET
356 %else
357 rep ret
358 %endif
359%endmacro
360
361%endif ;======================================================================
362
363
364
365;=============================================================================
366; arch-independent part
367;=============================================================================
368
369%assign function_align 16
370
371; Symbol prefix for C linkage
372%macro cglobal 1-2+
373 %ifidn __OUTPUT_FORMAT__,elf
374 %ifdef PREFIX
375 global _%1:function hidden
376 %define %1 _%1
377 %else
378 global %1:function hidden
379 %endif
380 %else
381 %ifdef PREFIX
382 global _%1
383 %define %1 _%1
384 %else
385 global %1
386 %endif
387 %endif
388 align function_align
389 %1:
390 RESET_MM_PERMUTATION ; not really needed, but makes disassembly somewhat nicer
391 %if %0 > 1
392 PROLOGUE %2
393 %endif
394%endmacro
395
396%macro cextern 1
397 %ifdef PREFIX
398 extern _%1
399 %define %1 _%1
400 %else
401 extern %1
402 %endif
403%endmacro
404
405; This is needed for ELF, otherwise the GNU linker assumes the stack is
406; executable by default.
407%ifidn __OUTPUT_FORMAT__,elf
408SECTION .note.GNU-stack noalloc noexec nowrite progbits
409%endif
410
411%assign FENC_STRIDE 16
412%assign FDEC_STRIDE 32
413
414; merge mmx and sse*
415
416%macro CAT_XDEFINE 3
417 %xdefine %1%2 %3
418%endmacro
419
420%macro CAT_UNDEF 2
421 %undef %1%2
422%endmacro
423
424%macro INIT_MMX 0
425 %define RESET_MM_PERMUTATION INIT_MMX
426 %define mmsize 8
427 %define num_mmregs 8
428 %define mova movq
429 %define movu movq
430 %define movh movd
431 %define movnt movntq
432 %assign %%i 0
433 %rep 8
434 CAT_XDEFINE m, %%i, mm %+ %%i
435 CAT_XDEFINE nmm, %%i, %%i
436 %assign %%i %%i+1
437 %endrep
438 %rep 8
439 CAT_UNDEF m, %%i
440 CAT_UNDEF nmm, %%i
441 %assign %%i %%i+1
442 %endrep
443%endmacro
444
445%macro INIT_XMM 0
446 %define RESET_MM_PERMUTATION INIT_XMM
447 %define mmsize 16
448 %define num_mmregs 8
449 %ifdef ARCH_X86_64
450 %define num_mmregs 16
451 %endif
452 %define mova movdqa
453 %define movu movdqu
454 %define movh movq
455 %define movnt movntdq
456 %assign %%i 0
457 %rep num_mmregs
458 CAT_XDEFINE m, %%i, xmm %+ %%i
459 CAT_XDEFINE nxmm, %%i, %%i
460 %assign %%i %%i+1
461 %endrep
462%endmacro
463
464INIT_MMX
465
466; I often want to use macros that permute their arguments. e.g. there's no
467; efficient way to implement butterfly or transpose or dct without swapping some
468; arguments.
469;
470; I would like to not have to manually keep track of the permutations:
471; If I insert a permutation in the middle of a function, it should automatically
472; change everything that follows. For more complex macros I may also have multiple
473; implementations, e.g. the SSE2 and SSSE3 versions may have different permutations.
474;
475; Hence these macros. Insert a PERMUTE or some SWAPs at the end of a macro that
476; permutes its arguments. It's equivalent to exchanging the contents of the
477; registers, except that this way you exchange the register names instead, so it
478; doesn't cost any cycles.
479
480%macro PERMUTE 2-* ; takes a list of pairs to swap
481%rep %0/2
482 %xdefine tmp%2 m%2
483 %xdefine ntmp%2 nm%2
484 %rotate 2
485%endrep
486%rep %0/2
487 %xdefine m%1 tmp%2
488 %xdefine nm%1 ntmp%2
489 %undef tmp%2
490 %undef ntmp%2
491 %rotate 2
492%endrep
493%endmacro
494
495%macro SWAP 2-* ; swaps a single chain (sometimes more concise than pairs)
496%rep %0-1
497%ifdef m%1
498 %xdefine tmp m%1
499 %xdefine m%1 m%2
500 %xdefine m%2 tmp
501 CAT_XDEFINE n, m%1, %1
502 CAT_XDEFINE n, m%2, %2
503%else
504 ; If we were called as "SWAP m0,m1" rather than "SWAP 0,1" infer the original numbers here.
505 ; Be careful using this mode in nested macros though, as in some cases there may be
506 ; other copies of m# that have already been dereferenced and don't get updated correctly.
507 %xdefine %%n1 n %+ %1
508 %xdefine %%n2 n %+ %2
509 %xdefine tmp m %+ %%n1
510 CAT_XDEFINE m, %%n1, m %+ %%n2
511 CAT_XDEFINE m, %%n2, tmp
512 CAT_XDEFINE n, m %+ %%n1, %%n1
513 CAT_XDEFINE n, m %+ %%n2, %%n2
514%endif
515 %undef tmp
516 %rotate 1
517%endrep
518%endmacro
519
520%macro SAVE_MM_PERMUTATION 1
521 %assign %%i 0
522 %rep num_mmregs
523 CAT_XDEFINE %1_m, %%i, m %+ %%i
524 %assign %%i %%i+1
525 %endrep
526%endmacro
527
528%macro LOAD_MM_PERMUTATION 1
529 %assign %%i 0
530 %rep num_mmregs
531 CAT_XDEFINE m, %%i, %1_m %+ %%i
532 %assign %%i %%i+1
533 %endrep
534%endmacro
535
536%macro call 1
537 call %1
538 %ifdef %1_m0
539 LOAD_MM_PERMUTATION %1
540 %endif
541%endmacro
542
543; substitutions which are functionally identical but reduce code size
544%define movdqa movaps
545%define movdqu movups
546