;***************************************************************************** ;* x86inc.asm ;***************************************************************************** ;* Copyright (C) 2005-2008 Loren Merritt ;* ;* This file is part of FFmpeg. ;* ;* FFmpeg is free software; you can redistribute it and/or ;* modify it under the terms of the GNU Lesser General Public ;* License as published by the Free Software Foundation; either ;* version 2.1 of the License, or (at your option) any later version. ;* ;* FFmpeg is distributed in the hope that it will be useful, ;* but WITHOUT ANY WARRANTY; without even the implied warranty of ;* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU ;* Lesser General Public License for more details. ;* ;* You should have received a copy of the GNU Lesser General Public ;* License along with FFmpeg; if not, write to the Free Software ;* 51, Inc., Foundation Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA ;***************************************************************************** ; 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 %ifidn __OUTPUT_FORMAT__,macho64 SECTION .text align=16 %elifidn __OUTPUT_FORMAT__,macho SECTION .text align=16 fakegot: %else SECTION .rodata align=16 %endif %endmacro ; PIC support macros. All these macros are totally harmless when PIC is ; not defined but can ruin everything if misused in PIC mode. On x86_32, shared ; objects cannot directly access global variables by address, they need to ; go through the GOT (global offset table). Most OSes do not care about it ; and let you load non-shared .so objects (Linux, Win32...). However, OS X ; requires PIC code in its .dylib objects. ; ; - GLOBAL should be used as a suffix for global addressing, eg. ; picgetgot ebx ; mov eax, [foo GLOBAL] ; instead of ; mov eax, [foo] ; ; - picgetgot computes the GOT address into the given register in PIC ; mode, otherwise does nothing. You need to do this before using GLOBAL. ; Before in both execution order and compiled code order (so GLOBAL knows ; which register the GOT is in). %ifndef PIC %define GLOBAL %macro picgetgot 1 %endmacro %elifdef ARCH_X86_64 %define PIC64 %define GLOBAL wrt rip %macro picgetgot 1 %endmacro %else %define PIC32 %ifidn __OUTPUT_FORMAT__,macho ; There is no real global offset table on OS X, but we still ; need to reference our variables by offset. %macro picgetgot 1 call %%getgot %%getgot: pop %1 add %1, $$ - %%getgot %undef GLOBAL %define GLOBAL + %1 - fakegot %endmacro %else ; elf extern _GLOBAL_OFFSET_TABLE_ %macro picgetgot 1 call %%getgot %%getgot: pop %1 add %1, _GLOBAL_OFFSET_TABLE_ + $$ - %%getgot wrt ..gotpc %undef GLOBAL %define GLOBAL + %1 wrt ..gotoff %endmacro %endif %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, not including PIC. pushes callee-saved regs if needed. ; %3 = whether global constants are used in this function. inits x86_32 PIC 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), one local variable (tmp), and not using globals ; 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. %macro DECLARE_REG 6 %define r%1q %2 %define r%1d %3 %define r%1w %4 %define r%1b %5 %define r%1m %6 %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 %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 %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 CAT_XDEFINE arg_name, %%i, %1 %assign %%i %%i+1 %rotate 1 %endrep %assign n_arg_names %%i %endmacro %ifdef ARCH_X86_64 ;========================================================== %ifidn __OUTPUT_FORMAT__,win32 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 + 8 + %1*8] %endif %endmacro %else ;======================================================================= 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 %endif ; !WIN64 %macro PROLOGUE 2-4+ 0 ; #args, #regs, pic, arg_names... ASSERT %2 >= %1 ASSERT %2 <= 7 %assign stack_offset 0 %ifidn __OUTPUT_FORMAT__,win32 LOAD_IF_USED 4, %1 LOAD_IF_USED 5, %1 %endif 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+ 0 ; #args, #regs, pic, arg_names... ASSERT %2 >= %1 %assign stack_offset 0 %assign regs_used %2 %ifdef PIC %if %3 %assign regs_used regs_used+1 %endif %endif 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 %if %3 picgetgot r%2 %endif 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 ff_%1 %ifdef PREFIX %xdefine %1 _ %+ %1 %endif %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 %if %0 > 1 PROLOGUE %2 %endif %endmacro %macro cextern 1 %ifdef PREFIX extern _%1 %define %1 _%1 %else extern %1 %endif %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 %assign FENC_STRIDE 16 %assign FDEC_STRIDE 32 ; 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 %macro SAVE_MM_PERMUTATION 1 %assign %%i 0 %rep num_mmregs CAT_XDEFINE %1_m, %%i, m %+ %%i %assign %%i %%i+1 %endrep %endmacro %macro LOAD_MM_PERMUTATION 1 %assign %%i 0 %rep num_mmregs CAT_XDEFINE m, %%i, %1_m %+ %%i %assign %%i %%i+1 %endrep %endmacro %macro call 1 call %1 %ifdef %1_m0 LOAD_MM_PERMUTATION %1 %endif %endmacro ; substitutions which are functionally identical but reduce code size %define movdqa movaps %define movdqu movups