blob: a8869042a1c67d8865c6be5e6fc7ea77f68ba6db [file] [log] [blame]
; jsimdcpu.asm - SIMD instruction support check
; Copyright 2009 Pierre Ossman <> for Cendio AB
; Based on
; x86 SIMD extension for IJG JPEG library
; Copyright (C) 1999-2006, MIYASAKA Masaru.
; For conditions of distribution and use, see copyright notice in
; 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 or
; [TAB8]
%include ""
; --------------------------------------------------------------------------
; Check if the CPU supports SIMD instructions
; GLOBAL(unsigned int)
; jpeg_simd_cpu_support (void)
align 16
global EXTN(jpeg_simd_cpu_support) PRIVATE
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
pop eax
mov edx,eax
xor eax, 1<<21 ; flip ID bit in EFLAGS
push eax
pop eax
xor eax,edx
jz short .return ; CPUID is not supported
; Check for MMX instruction support
xor eax,eax
test eax,eax
jz short .return
xor eax,eax
inc eax
mov eax,edx ; eax = Standard feature flags
test eax, 1<<23 ; bit23:MMX
jz short .no_mmx
or edi, byte JSIMD_MMX
test eax, 1<<25 ; bit25:SSE
jz short .no_sse
or edi, byte JSIMD_SSE
test eax, 1<<26 ; bit26:SSE2
jz short .no_sse2
or edi, byte JSIMD_SSE2
; Check for 3DNow! instruction support
mov eax, 0x80000000
cmp eax, 0x80000000
jbe short .return
mov eax, 0x80000001
mov eax,edx ; eax = Extended feature flags
test eax, 1<<31 ; bit31:3DNow!(vendor independent)
jz short .no_3dnow
or edi, byte JSIMD_3DNOW
mov eax,edi
pop edi
; pop esi ; unused
; pop edx ; need not be preserved
; pop ecx ; need not be preserved
pop ebx
; For some reason, the OS X linker does not honor the request to align the
; segment unless we do this.
align 16