www.pudn.com > X264_20060729.rar > i386inc.asm
;*****************************************************************************
;* i386inc.asm: h264 encoder library
;*****************************************************************************
;* Copyright (C) 2006 x264 project
;*
;* Author: Sam Hocevar <sam@zoy.org>
;*
;* This program is free software; you can redistribute it and/or modify
;* it under the terms of the GNU General Public License as published by
;* the Free Software Foundation; either version 2 of the License, or
;* (at your option) any later version.
;*
;* This program 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 General Public License for more details.
;*
;* You should have received a copy of the GNU General Public License
;* along with this program; if not, write to the Free Software
;* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
;*****************************************************************************
BITS 32
;=============================================================================
; Macros and other preprocessor constants
;=============================================================================
; Symbol prefix for C linkage
>macro cglobal 1
>ifdef PREFIX
global _>1
>define >1 _>1
>else
global >1
>endif
>endmacro
; Name of the .rodata section. On OS X we cannot use .rodata because NASM
; is unable to compute address offsets outside of .text so we use the .text
; section instead until NASM is fixed.
>macro SECTION_RODATA 0
>ifidn __OUTPUT_FORMAT__,macho
SECTION .text
fakegot:
>else
SECTION .rodata data 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, 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.
;
; - GOT_* should be used as a suffix for global addressing, eg.
; picgetgot ebx
; mov eax, [foo GOT_ebx]
; 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 GOT_*.
;
; - picpush and picpop respectively push and pop the given register
; in PIC mode, otherwise do nothing. You should always use them around
; picgetgot except when sure that the register is no longer used and is
; being restored later by other means.
;
; - picesp is defined to compensate the changing of esp when pushing
; a register into the stack, eg.
; mov eax, [esp + 8]
; pushpic ebx
; mov eax, [picesp + 12]
; instead of
; mov eax, [esp + 8]
; pushpic ebx
; mov eax, [esp + 12]
;
>ifdef __PIC__
>ifidn __OUTPUT_FORMAT__,macho
; There is no real global offset table on OS X, but we still
; need to reference our variables by offset.
>define GOT_eax - fakegot + eax
>define GOT_ebx - fakegot + ebx
>define GOT_ecx - fakegot + ecx
>define GOT_edx - fakegot + edx
>macro picgetgot 1
call >>getgot
>>getgot:
pop >1
add >1, $$ - >>getgot
>endmacro
>else
>ifidn __OUTPUT_FORMAT__,elf
>define GOT _GLOBAL_OFFSET_TABLE_
>else ; for a.out
>define GOT __GLOBAL_OFFSET_TABLE_
>endif
extern GOT
>define GOT_eax + eax wrt ..gotoff
>define GOT_ebx + ebx wrt ..gotoff
>define GOT_ecx + ecx wrt ..gotoff
>define GOT_edx + edx wrt ..gotoff
>macro picgetgot 1
call >>getgot
>>getgot:
pop >1
add >1, GOT + $$ - >>getgot wrt ..gotpc
>endmacro
>endif
>macro picpush 1
push >1
>endmacro
>macro picpop 1
pop >1
>endmacro
>define picesp esp+4
>else
>define GOT_eax
>define GOT_ebx
>define GOT_ecx
>define GOT_edx
>macro picgetgot 1
>endmacro
>macro picpush 1
>endmacro
>macro picpop 1
>endmacro
>define picesp esp
>endif
>assign FENC_STRIDE 16
>assign FDEC_STRIDE 32
; 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