Files
mozjpeg/simd/jsimdcpu.asm
DRC 123f7258a8 Format copyright headers more consistently
The IJG convention is to format copyright notices as:

Copyright (C) YYYY, Owner.

We try to maintain this convention for any code that is part of the
libjpeg API library (with the exception of preserving the copyright
notices from Cendio's code verbatim, since those predate
libjpeg-turbo.)

Note that the phrase "All Rights Reserved" is no longer necessary, since
all Buenos Aires Convention signatories signed onto the Berne Convention
in 2000.  However, our convention is to retain this phrase for any files
that have a self-contained copyright header but to leave it off of any
files that refer to another file for conditions of distribution and use.
For instance, all of the non-SIMD files in the libjpeg API library refer
to README.ijg, and the copyright message in that file contains "All
Rights Reserved", so it is unnecessary to add it to the individual
files.

The TurboJPEG code retains my preferred formatting convention for
copyright notices, which is based on that of VirtualGL (where the
TurboJPEG API originated.)
2016-05-28 19:16:58 -05:00

105 lines
2.9 KiB
NASM

;
; jsimdcpu.asm - SIMD instruction support check
;
; Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
;
; Based on the x86 SIMD extension for IJG JPEG library
; Copyright (C) 1999-2006, MIYASAKA Masaru.
; For conditions of distribution and use, see copyright notice in jsimdext.inc
;
; This file should be assembled with NASM (Netwide Assembler),
; can *not* be assembled with Microsoft's MASM or any compatible
; assembler (including Borland's Turbo Assembler).
; NASM is available from http://nasm.sourceforge.net/ or
; http://sourceforge.net/project/showfiles.php?group_id=6208
;
; [TAB8]
%include "jsimdext.inc"
; --------------------------------------------------------------------------
SECTION SEG_TEXT
BITS 32
;
; Check if the CPU supports SIMD instructions
;
; GLOBAL(unsigned int)
; jpeg_simd_cpu_support (void)
;
align 16
global EXTN(jpeg_simd_cpu_support)
EXTN(jpeg_simd_cpu_support):
push ebx
; push ecx ; need not be preserved
; push edx ; need not be preserved
; push esi ; unused
push edi
xor edi,edi ; simd support flag
pushfd
pop eax
mov edx,eax
xor eax, 1<<21 ; flip ID bit in EFLAGS
push eax
popfd
pushfd
pop eax
xor eax,edx
jz short .return ; CPUID is not supported
; Check for MMX instruction support
xor eax,eax
cpuid
test eax,eax
jz short .return
xor eax,eax
inc eax
cpuid
mov eax,edx ; eax = Standard feature flags
test eax, 1<<23 ; bit23:MMX
jz short .no_mmx
or edi, byte JSIMD_MMX
.no_mmx:
test eax, 1<<25 ; bit25:SSE
jz short .no_sse
or edi, byte JSIMD_SSE
.no_sse:
test eax, 1<<26 ; bit26:SSE2
jz short .no_sse2
or edi, byte JSIMD_SSE2
.no_sse2:
; Check for 3DNow! instruction support
mov eax, 0x80000000
cpuid
cmp eax, 0x80000000
jbe short .return
mov eax, 0x80000001
cpuid
mov eax,edx ; eax = Extended feature flags
test eax, 1<<31 ; bit31:3DNow!(vendor independent)
jz short .no_3dnow
or edi, byte JSIMD_3DNOW
.no_3dnow:
.return:
mov eax,edi
pop edi
; pop esi ; unused
; pop edx ; need not be preserved
; pop ecx ; need not be preserved
pop ebx
ret
; For some reason, the OS X linker does not honor the request to align the
; segment unless we do this.
align 16