x86inc.asm 16.4 KB
Newer Older
1 2 3
;*****************************************************************************
;* x86inc.asm
;*****************************************************************************
4
;* Copyright (C) 2005-2008 x264 project
5
;*
6 7
;* Authors: Loren Merritt <lorenm@u.washington.edu>
;*          Anton Mitrofanov <BugMaster@narod.ru>
8
;*
9 10 11
;* Permission to use, copy, modify, and/or distribute this software for any
;* purpose with or without fee is hereby granted, provided that the above
;* copyright notice and this permission notice appear in all copies.
12
;*
13 14 15 16 17 18 19
;* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
;* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
;* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
;* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
;* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
;* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
;* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
20 21
;*****************************************************************************

22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
; This is a header file for the x264ASM assembly language, which uses
; NASM/YASM syntax combined with a large number of macros to provide easy
; abstraction between different calling conventions (x86_32, win64, linux64).
; It also has various other useful features to simplify writing the kind of
; DSP functions that are most often used in x264.

; Unlike the rest of x264, this file is available under an ISC license, as it
; has significant usefulness outside of x264 and we want it to be available
; to the largest audience possible.  Of course, if you modify it for your own
; purposes to add a new feature, we strongly encourage contributing a patch
; as this feature might be useful for others as well.  Send patches or ideas
; to x264-devel@videolan.org .

%define program_name ff

37 38 39 40 41 42 43 44
%ifdef ARCH_X86_64
    %ifidn __OUTPUT_FORMAT__,win32
        %define WIN64
    %else
        %define UNIX64
    %endif
%endif

45 46 47 48 49 50
%ifdef PREFIX
    %define mangle(x) _ %+ x
%else
    %define mangle(x) x
%endif

51 52 53 54 55 56 57 58
; FIXME: All of the 64bit asm functions that take a stride as an argument
; via register, assume that the high dword of that register is filled with 0.
; This is true in practice (since we never do any 64bit arithmetic on strides,
; and x264's strides are all positive), but is not guaranteed by the ABI.

; Name of the .rodata section.
; Kludge: Something on OS X fails to align .rodata even given an align attribute,
; so use a different read-only section.
59
%macro SECTION_RODATA 0-1 16
60
    %ifidn __OUTPUT_FORMAT__,macho64
61
        SECTION .text align=%1
62
    %elifidn __OUTPUT_FORMAT__,macho
63
        SECTION .text align=%1
64 65
        fakegot:
    %else
66
        SECTION .rodata align=%1
67 68 69
    %endif
%endmacro

70 71 72
%ifdef WIN64
    %define PIC
%elifndef ARCH_X86_64
73 74 75
; x86_32 doesn't require PIC.
; Some distros prefer shared objects to be PIC, but nothing breaks if
; the code contains a few textrels, so we'll skip that complexity.
76 77 78
    %undef PIC
%endif
%ifdef PIC
79
    default rel
80 81 82 83 84 85 86 87 88
%endif

; Macros to eliminate most code duplication between x86_32 and x86_64:
; Currently this works only for leaf functions which load all their arguments
; into registers at the start, and make no other use of the stack. Luckily that
; covers most of x264's asm.

; PROLOGUE:
; %1 = number of arguments. loads them from stack if needed.
89 90
; %2 = number of registers used. pushes callee-saved regs if needed.
; %3 = number of xmm registers used. pushes callee-saved xmm regs if needed.
91 92 93 94
; %4 = list of names to define to registers
; PROLOGUE can also be invoked by adding the same options to cglobal

; e.g.
Loren Merritt's avatar
Loren Merritt committed
95
; cglobal foo, 2,3,0, dst, src, tmp
96
; declares a function (foo), taking two args (dst and src) and one local variable (tmp)
97 98 99 100 101 102 103 104 105 106 107 108

; TODO Some functions can use some args directly from the stack. If they're the
; last args then you can just not declare them, but if they're in the middle
; we need more flexible macro.

; RET:
; Pops anything that was pushed by PROLOGUE

; REP_RET:
; Same, but if it doesn't pop anything it becomes a 2-byte ret, for athlons
; which are slow when a normal ret follows a branch.

109 110 111 112 113 114
; registers:
; rN and rNq are the native-size register holding function argument N
; rNd, rNw, rNb are dword, word, and byte size
; rNm is the original location of arg N (a register or on the stack), dword
; rNmp is native size

115 116 117 118 119 120
%macro DECLARE_REG 6
    %define r%1q %2
    %define r%1d %3
    %define r%1w %4
    %define r%1b %5
    %define r%1m %6
121 122 123 124 125 126 127
    %ifid %6 ; i.e. it's a register
        %define r%1mp %2
    %elifdef ARCH_X86_64 ; memory
        %define r%1mp qword %6
    %else
        %define r%1mp dword %6
    %endif
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
    %define r%1  %2
%endmacro

%macro DECLARE_REG_SIZE 2
    %define r%1q r%1
    %define e%1q r%1
    %define r%1d e%1
    %define e%1d e%1
    %define r%1w %1
    %define e%1w %1
    %define r%1b %2
    %define e%1b %2
%ifndef ARCH_X86_64
    %define r%1  e%1
%endif
%endmacro

DECLARE_REG_SIZE ax, al
DECLARE_REG_SIZE bx, bl
DECLARE_REG_SIZE cx, cl
DECLARE_REG_SIZE dx, dl
DECLARE_REG_SIZE si, sil
DECLARE_REG_SIZE di, dil
DECLARE_REG_SIZE bp, bpl

153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173
; t# defines for when per-arch register allocation is more complex than just function arguments

%macro DECLARE_REG_TMP 1-*
    %assign %%i 0
    %rep %0
        CAT_XDEFINE t, %%i, r%1
        %assign %%i %%i+1
        %rotate 1
    %endrep
%endmacro

%macro DECLARE_REG_TMP_SIZE 0-*
    %rep %0
        %define t%1q t%1 %+ q
        %define t%1d t%1 %+ d
        %define t%1w t%1 %+ w
        %define t%1b t%1 %+ b
        %rotate 1
    %endrep
%endmacro

174
DECLARE_REG_TMP_SIZE 0,1,2,3,4,5,6,7,8,9
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
%ifdef ARCH_X86_64
    %define gprsize 8
%else
    %define gprsize 4
%endif

%macro PUSH 1
    push %1
    %assign stack_offset stack_offset+gprsize
%endmacro

%macro POP 1
    pop %1
    %assign stack_offset stack_offset-gprsize
%endmacro

%macro SUB 2
    sub %1, %2
    %ifidn %1, rsp
        %assign stack_offset stack_offset+(%2)
    %endif
%endmacro

%macro ADD 2
    add %1, %2
    %ifidn %1, rsp
        %assign stack_offset stack_offset-(%2)
    %endif
%endmacro

%macro movifnidn 2
    %ifnidn %1, %2
        mov %1, %2
    %endif
%endmacro

%macro movsxdifnidn 2
    %ifnidn %1, %2
        movsxd %1, %2
    %endif
%endmacro

%macro ASSERT 1
    %if (%1) == 0
        %error assert failed
    %endif
%endmacro

%macro DEFINE_ARGS 0-*
    %ifdef n_arg_names
        %assign %%i 0
        %rep n_arg_names
            CAT_UNDEF arg_name %+ %%i, q
            CAT_UNDEF arg_name %+ %%i, d
            CAT_UNDEF arg_name %+ %%i, w
            CAT_UNDEF arg_name %+ %%i, b
232
            CAT_UNDEF arg_name %+ %%i, m
233 234 235 236 237 238 239 240 241 242 243
            CAT_UNDEF arg_name, %%i
            %assign %%i %%i+1
        %endrep
    %endif

    %assign %%i 0
    %rep %0
        %xdefine %1q r %+ %%i %+ q
        %xdefine %1d r %+ %%i %+ d
        %xdefine %1w r %+ %%i %+ w
        %xdefine %1b r %+ %%i %+ b
244
        %xdefine %1m r %+ %%i %+ m
245 246 247 248 249 250 251
        CAT_XDEFINE arg_name, %%i, %1
        %assign %%i %%i+1
        %rotate 1
    %endrep
    %assign n_arg_names %%i
%endmacro

252
%ifdef WIN64 ; Windows x64 ;=================================================
253 254 255 256 257 258 259 260 261 262 263 264 265

DECLARE_REG 0, rcx, ecx, cx,  cl,  ecx
DECLARE_REG 1, rdx, edx, dx,  dl,  edx
DECLARE_REG 2, r8,  r8d, r8w, r8b, r8d
DECLARE_REG 3, r9,  r9d, r9w, r9b, r9d
DECLARE_REG 4, rdi, edi, di,  dil, [rsp + stack_offset + 40]
DECLARE_REG 5, rsi, esi, si,  sil, [rsp + stack_offset + 48]
DECLARE_REG 6, rax, eax, ax,  al,  [rsp + stack_offset + 56]
%define r7m [rsp + stack_offset + 64]
%define r8m [rsp + stack_offset + 72]

%macro LOAD_IF_USED 2 ; reg_id, number_of_args
    %if %1 < %2
266 267 268 269
        mov r%1, [rsp + stack_offset + 8 + %1*8]
    %endif
%endmacro

270
%macro PROLOGUE 2-4+ 0 ; #args, #regs, #xmm_regs, arg_names...
271 272 273 274 275 276 277 278
    ASSERT %2 >= %1
    %assign regs_used %2
    ASSERT regs_used <= 7
    %if regs_used > 4
        push r4
        push r5
        %assign stack_offset stack_offset+16
    %endif
279 280 281 282 283 284 285 286 287 288
    WIN64_SPILL_XMM %3
    LOAD_IF_USED 4, %1
    LOAD_IF_USED 5, %1
    LOAD_IF_USED 6, %1
    DEFINE_ARGS %4
%endmacro

%macro WIN64_SPILL_XMM 1
    %assign xmm_regs_used %1
    ASSERT xmm_regs_used <= 16
289 290 291 292 293 294 295 296 297 298 299
    %if xmm_regs_used > 6
        sub rsp, (xmm_regs_used-6)*16+16
        %assign stack_offset stack_offset+(xmm_regs_used-6)*16+16
        %assign %%i xmm_regs_used
        %rep (xmm_regs_used-6)
            %assign %%i %%i-1
            movdqa [rsp + (%%i-6)*16+8], xmm %+ %%i
        %endrep
    %endif
%endmacro

300
%macro WIN64_RESTORE_XMM_INTERNAL 1
301 302 303 304 305 306 307 308 309 310
    %if xmm_regs_used > 6
        %assign %%i xmm_regs_used
        %rep (xmm_regs_used-6)
            %assign %%i %%i-1
            movdqa xmm %+ %%i, [%1 + (%%i-6)*16+8]
        %endrep
        add %1, (xmm_regs_used-6)*16+16
    %endif
%endmacro

311 312
%macro WIN64_RESTORE_XMM 1
    WIN64_RESTORE_XMM_INTERNAL %1
313 314 315 316 317
    %assign stack_offset stack_offset-(xmm_regs_used-6)*16+16
    %assign xmm_regs_used 0
%endmacro

%macro RET 0
318
    WIN64_RESTORE_XMM_INTERNAL rsp
319 320 321
    %if regs_used > 4
        pop r5
        pop r4
322
    %endif
323
    ret
324 325
%endmacro

326 327 328 329 330 331 332 333 334
%macro REP_RET 0
    %if regs_used > 4 || xmm_regs_used > 6
        RET
    %else
        rep ret
    %endif
%endmacro

%elifdef ARCH_X86_64 ; *nix x64 ;=============================================
335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351

DECLARE_REG 0, rdi, edi, di,  dil, edi
DECLARE_REG 1, rsi, esi, si,  sil, esi
DECLARE_REG 2, rdx, edx, dx,  dl,  edx
DECLARE_REG 3, rcx, ecx, cx,  cl,  ecx
DECLARE_REG 4, r8,  r8d, r8w, r8b, r8d
DECLARE_REG 5, r9,  r9d, r9w, r9b, r9d
DECLARE_REG 6, rax, eax, ax,  al,  [rsp + stack_offset + 8]
%define r7m [rsp + stack_offset + 16]
%define r8m [rsp + stack_offset + 24]

%macro LOAD_IF_USED 2 ; reg_id, number_of_args
    %if %1 < %2
        mov r%1, [rsp - 40 + %1*8]
    %endif
%endmacro

352
%macro PROLOGUE 2-4+ ; #args, #regs, #xmm_regs, arg_names...
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
    ASSERT %2 >= %1
    ASSERT %2 <= 7
    LOAD_IF_USED 6, %1
    DEFINE_ARGS %4
%endmacro

%macro RET 0
    ret
%endmacro

%macro REP_RET 0
    rep ret
%endmacro

%else ; X86_32 ;==============================================================

DECLARE_REG 0, eax, eax, ax, al,   [esp + stack_offset + 4]
DECLARE_REG 1, ecx, ecx, cx, cl,   [esp + stack_offset + 8]
DECLARE_REG 2, edx, edx, dx, dl,   [esp + stack_offset + 12]
DECLARE_REG 3, ebx, ebx, bx, bl,   [esp + stack_offset + 16]
DECLARE_REG 4, esi, esi, si, null, [esp + stack_offset + 20]
DECLARE_REG 5, edi, edi, di, null, [esp + stack_offset + 24]
DECLARE_REG 6, ebp, ebp, bp, null, [esp + stack_offset + 28]
%define r7m [esp + stack_offset + 32]
%define r8m [esp + stack_offset + 36]
%define rsp esp

%macro PUSH_IF_USED 1 ; reg_id
    %if %1 < regs_used
        push r%1
        %assign stack_offset stack_offset+4
    %endif
%endmacro

%macro POP_IF_USED 1 ; reg_id
    %if %1 < regs_used
        pop r%1
    %endif
%endmacro

%macro LOAD_IF_USED 2 ; reg_id, number_of_args
    %if %1 < %2
        mov r%1, [esp + stack_offset + 4 + %1*4]
    %endif
%endmacro

399
%macro PROLOGUE 2-4+ ; #args, #regs, #xmm_regs, arg_names...
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
    ASSERT %2 >= %1
    %assign regs_used %2
    ASSERT regs_used <= 7
    PUSH_IF_USED 3
    PUSH_IF_USED 4
    PUSH_IF_USED 5
    PUSH_IF_USED 6
    LOAD_IF_USED 0, %1
    LOAD_IF_USED 1, %1
    LOAD_IF_USED 2, %1
    LOAD_IF_USED 3, %1
    LOAD_IF_USED 4, %1
    LOAD_IF_USED 5, %1
    LOAD_IF_USED 6, %1
    DEFINE_ARGS %4
%endmacro

%macro RET 0
    POP_IF_USED 6
    POP_IF_USED 5
    POP_IF_USED 4
    POP_IF_USED 3
    ret
%endmacro

%macro REP_RET 0
    %if regs_used > 3
        RET
    %else
        rep ret
    %endif
%endmacro

%endif ;======================================================================

435 436 437 438 439 440 441
%ifndef WIN64
%macro WIN64_SPILL_XMM 1
%endmacro
%macro WIN64_RESTORE_XMM 1
%endmacro
%endif

442 443 444 445 446 447 448 449 450 451


;=============================================================================
; arch-independent part
;=============================================================================

%assign function_align 16

; Symbol prefix for C linkage
%macro cglobal 1-2+
452
    %xdefine %1 mangle(program_name %+ _ %+ %1)
Loren Merritt's avatar
Loren Merritt committed
453
    %xdefine %1.skip_prologue %1 %+ .skip_prologue
454
    %ifidn __OUTPUT_FORMAT__,elf
455
        global %1:function hidden
456
    %else
457
        global %1
458 459 460 461
    %endif
    align function_align
    %1:
    RESET_MM_PERMUTATION ; not really needed, but makes disassembly somewhat nicer
462
    %assign stack_offset 0
463 464 465 466 467 468
    %if %0 > 1
        PROLOGUE %2
    %endif
%endmacro

%macro cextern 1
469 470 471 472 473 474 475
    %xdefine %1 mangle(program_name %+ _ %+ %1)
    extern %1
%endmacro

;like cextern, but without the prefix
%macro cextern_naked 1
    %xdefine %1 mangle(%1)
476
    extern %1
477 478
%endmacro

479 480 481 482 483 484
%macro const 2+
    %xdefine %1 mangle(program_name %+ _ %+ %1)
    global %1
    %1: %2
%endmacro

485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507
; This is needed for ELF, otherwise the GNU linker assumes the stack is
; executable by default.
%ifidn __OUTPUT_FORMAT__,elf
SECTION .note.GNU-stack noalloc noexec nowrite progbits
%endif

; merge mmx and sse*

%macro CAT_XDEFINE 3
    %xdefine %1%2 %3
%endmacro

%macro CAT_UNDEF 2
    %undef %1%2
%endmacro

%macro INIT_MMX 0
    %define RESET_MM_PERMUTATION INIT_MMX
    %define mmsize 8
    %define num_mmregs 8
    %define mova movq
    %define movu movq
    %define movh movd
508
    %define movnta movntq
509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531
    %assign %%i 0
    %rep 8
    CAT_XDEFINE m, %%i, mm %+ %%i
    CAT_XDEFINE nmm, %%i, %%i
    %assign %%i %%i+1
    %endrep
    %rep 8
    CAT_UNDEF m, %%i
    CAT_UNDEF nmm, %%i
    %assign %%i %%i+1
    %endrep
%endmacro

%macro INIT_XMM 0
    %define RESET_MM_PERMUTATION INIT_XMM
    %define mmsize 16
    %define num_mmregs 8
    %ifdef ARCH_X86_64
    %define num_mmregs 16
    %endif
    %define mova movdqa
    %define movu movdqu
    %define movh movq
532
    %define movnta movntdq
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
    %assign %%i 0
    %rep num_mmregs
    CAT_XDEFINE m, %%i, xmm %+ %%i
    CAT_XDEFINE nxmm, %%i, %%i
    %assign %%i %%i+1
    %endrep
%endmacro

INIT_MMX

; I often want to use macros that permute their arguments. e.g. there's no
; efficient way to implement butterfly or transpose or dct without swapping some
; arguments.
;
; I would like to not have to manually keep track of the permutations:
; If I insert a permutation in the middle of a function, it should automatically
; change everything that follows. For more complex macros I may also have multiple
; implementations, e.g. the SSE2 and SSSE3 versions may have different permutations.
;
; Hence these macros. Insert a PERMUTE or some SWAPs at the end of a macro that
; permutes its arguments. It's equivalent to exchanging the contents of the
; registers, except that this way you exchange the register names instead, so it
; doesn't cost any cycles.

%macro PERMUTE 2-* ; takes a list of pairs to swap
%rep %0/2
    %xdefine tmp%2 m%2
    %xdefine ntmp%2 nm%2
    %rotate 2
%endrep
%rep %0/2
    %xdefine m%1 tmp%2
    %xdefine nm%1 ntmp%2
    %undef tmp%2
    %undef ntmp%2
    %rotate 2
%endrep
%endmacro

%macro SWAP 2-* ; swaps a single chain (sometimes more concise than pairs)
%rep %0-1
%ifdef m%1
    %xdefine tmp m%1
    %xdefine m%1 m%2
    %xdefine m%2 tmp
    CAT_XDEFINE n, m%1, %1
    CAT_XDEFINE n, m%2, %2
%else
    ; If we were called as "SWAP m0,m1" rather than "SWAP 0,1" infer the original numbers here.
    ; Be careful using this mode in nested macros though, as in some cases there may be
    ; other copies of m# that have already been dereferenced and don't get updated correctly.
    %xdefine %%n1 n %+ %1
    %xdefine %%n2 n %+ %2
    %xdefine tmp m %+ %%n1
    CAT_XDEFINE m, %%n1, m %+ %%n2
    CAT_XDEFINE m, %%n2, tmp
    CAT_XDEFINE n, m %+ %%n1, %%n1
    CAT_XDEFINE n, m %+ %%n2, %%n2
%endif
    %undef tmp
    %rotate 1
%endrep
%endmacro

597 598 599 600
; If SAVE_MM_PERMUTATION is placed at the end of a function and given the
; function name, then any later calls to that function will automatically
; load the permutation, so values can be returned in mmregs.
%macro SAVE_MM_PERMUTATION 1 ; name to save as
601 602 603 604 605 606 607
    %assign %%i 0
    %rep num_mmregs
    CAT_XDEFINE %1_m, %%i, m %+ %%i
    %assign %%i %%i+1
    %endrep
%endmacro

608
%macro LOAD_MM_PERMUTATION 1 ; name to load from
609 610 611
    %assign %%i 0
    %rep num_mmregs
    CAT_XDEFINE m, %%i, %1_m %+ %%i
612
    CAT_XDEFINE n, m %+ %%i, %%i
613 614 615 616 617 618 619 620 621 622 623
    %assign %%i %%i+1
    %endrep
%endmacro

%macro call 1
    call %1
    %ifdef %1_m0
        LOAD_MM_PERMUTATION %1
    %endif
%endmacro

624
; Substitutions that reduce instruction size but are functionally equivalent
625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647
%macro add 2
    %ifnum %2
        %if %2==128
            sub %1, -128
        %else
            add %1, %2
        %endif
    %else
        add %1, %2
    %endif
%endmacro

%macro sub 2
    %ifnum %2
        %if %2==128
            add %1, -128
        %else
            sub %1, %2
        %endif
    %else
        sub %1, %2
    %endif
%endmacro