| ; |
| ; jsimdcpu.asm - SIMD instruction support check |
| ; |
| ; Copyright 2009 Pierre Ossman <ossman@cendio.se> 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 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 "simd/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: |
| |
| .return: |
| mov eax,edi |
| |
| pop edi |
| ; pop esi ; unused |
| ; pop edx ; need not be preserved |
| ; pop ecx ; need not be preserved |
| pop ebx |
| ret |
| |