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ffmpeg/libavcodec/x86/x86inc.asm

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NASM
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;*****************************************************************************
;* x86inc.asm
;*****************************************************************************
;* Copyright (C) 2005-2008 x264 project
;*
;* Authors: Loren Merritt <lorenm@u.washington.edu>
;* Anton Mitrofanov <BugMaster@narod.ru>
;*
;* 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.
;*
;* 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.
;*****************************************************************************
; 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
%ifdef ARCH_X86_64
%ifidn __OUTPUT_FORMAT__,win32
%define WIN64
%else
%define UNIX64
%endif
%endif
%ifdef PREFIX
%define mangle(x) _ %+ x
%else
%define mangle(x) x
%endif
; 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.
%macro SECTION_RODATA 0-1 16
%ifidn __OUTPUT_FORMAT__,macho64
SECTION .text align=%1
%elifidn __OUTPUT_FORMAT__,macho
SECTION .text align=%1
fakegot:
%else
SECTION .rodata align=%1
%endif
%endmacro
%ifdef WIN64
%define PIC
%elifndef ARCH_X86_64
; 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.
%undef PIC
%endif
%ifdef PIC
default rel
%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.
; %2 = number of registers used. pushes callee-saved regs if needed.
; %3 = number of xmm registers used. pushes callee-saved xmm regs if needed.
; %4 = list of names to define to registers
; PROLOGUE can also be invoked by adding the same options to cglobal
; e.g.
; cglobal foo, 2,3,0, dst, src, tmp
; declares a function (foo), taking two args (dst and src) and one local variable (tmp)
; 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.
; 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
%macro DECLARE_REG 6
%define r%1q %2
%define r%1d %3
%define r%1w %4
%define r%1b %5
%define r%1m %6
%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
%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
; 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
DECLARE_REG_TMP_SIZE 0,1,2,3,4,5,6,7,8,9
%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
CAT_UNDEF arg_name %+ %%i, m
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
%xdefine %1m r %+ %%i %+ m
CAT_XDEFINE arg_name, %%i, %1
%assign %%i %%i+1
%rotate 1
%endrep
%assign n_arg_names %%i
%endmacro
%ifdef WIN64 ; Windows x64 ;=================================================
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
mov r%1, [rsp + stack_offset + 8 + %1*8]
%endif
%endmacro
%macro PROLOGUE 2-4+ 0 ; #args, #regs, #xmm_regs, arg_names...
ASSERT %2 >= %1
%assign regs_used %2
ASSERT regs_used <= 7
%assign xmm_regs_used %3
ASSERT xmm_regs_used <= 16
%if regs_used > 4
push r4
push r5
%assign stack_offset stack_offset+16
%endif
%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
LOAD_IF_USED 4, %1
LOAD_IF_USED 5, %1
LOAD_IF_USED 6, %1
DEFINE_ARGS %4
%endmacro
%macro RESTORE_XMM_INTERNAL 1
%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
%macro RESTORE_XMM 1
RESTORE_XMM_INTERNAL %1
%assign stack_offset stack_offset-(xmm_regs_used-6)*16+16
%assign xmm_regs_used 0
%endmacro
%macro RET 0
RESTORE_XMM_INTERNAL rsp
%if regs_used > 4
pop r5
pop r4
%endif
ret
%endmacro
%macro REP_RET 0
%if regs_used > 4 || xmm_regs_used > 6
RET
%else
rep ret
%endif
%endmacro
%elifdef ARCH_X86_64 ; *nix x64 ;=============================================
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
%macro PROLOGUE 2-4+ ; #args, #regs, #xmm_regs, arg_names...
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
%macro PROLOGUE 2-4+ ; #args, #regs, #xmm_regs, arg_names...
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 ;======================================================================
;=============================================================================
; arch-independent part
;=============================================================================
%assign function_align 16
; Symbol prefix for C linkage
%macro cglobal 1-2+
%xdefine %1 mangle(program_name %+ _ %+ %1)
%xdefine %1.skip_prologue %1 %+ .skip_prologue
%ifidn __OUTPUT_FORMAT__,elf
global %1:function hidden
%else
global %1
%endif
align function_align
%1:
RESET_MM_PERMUTATION ; not really needed, but makes disassembly somewhat nicer
%assign stack_offset 0
%if %0 > 1
PROLOGUE %2
%endif
%endmacro
%macro cextern 1
%xdefine %1 mangle(program_name %+ _ %+ %1)
extern %1
%endmacro
;like cextern, but without the prefix
%macro cextern_naked 1
%xdefine %1 mangle(%1)
extern %1
%endmacro
%macro const 2+
%xdefine %1 mangle(program_name %+ _ %+ %1)
global %1
%1: %2
%endmacro
; 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
%define movnt movntq
%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
%define movnt movntdq
%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
; 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
%assign %%i 0
%rep num_mmregs
CAT_XDEFINE %1_m, %%i, m %+ %%i
%assign %%i %%i+1
%endrep
%endmacro
%macro LOAD_MM_PERMUTATION 1 ; name to load from
%assign %%i 0
%rep num_mmregs
CAT_XDEFINE m, %%i, %1_m %+ %%i
CAT_XDEFINE n, m %+ %%i, %%i
%assign %%i %%i+1
%endrep
%endmacro
%macro call 1
call %1
%ifdef %1_m0
LOAD_MM_PERMUTATION %1
%endif
%endmacro
; Substitutions that reduce instruction size but are functionally equivalent
%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
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