Files
mozjpeg/simd/jsimdcpu-64.asm

63 lines
1.6 KiB
NASM

;
; jsimdcpu-64.asm - SIMD instruction support check
;
; Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
; Copyright (C) 2016, D. R. Commander.
;
; 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 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 64
;
; Check if the CPU supports SIMD instructions
;
; GLOBAL(unsigned int)
; jpeg_simd_cpu_support (void)
;
align 32
global EXTN(jpeg_simd_cpu_support)
EXTN(jpeg_simd_cpu_support):
push rbx
push rdi
xor rdi,rdi ; simd support flag
; Check for AVX2 instruction support
mov rax, 7
xor rcx,rcx
cpuid
mov rax,rbx ; rax = Extended feature flags
or rdi, JSIMD_SSE2
or rdi, JSIMD_SSE
test rax, 1<<5 ; bit5:AVX2
jz short .return
or rdi, JSIMD_AVX2
.return:
mov rax,rdi
pop rdi
pop rbx
ret
; For some reason, the OS X linker does not honor the request to align the
; segment unless we do this.
align 32