Implement x86 SIMD framework
Add NASM support and stub routine for detecting SIMD extensions.
git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@15 632fc199-4ca6-4c93-a231-07263d6284db
diff --git a/simd/jsimdcpu.asm b/simd/jsimdcpu.asm
new file mode 100644
index 0000000..6bb4e32
--- /dev/null
+++ b/simd/jsimdcpu.asm
@@ -0,0 +1,63 @@
+;
+; 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
+
+.return:
+ mov eax,edi
+
+ pop edi
+; pop esi ; unused
+; pop edx ; need not be preserved
+; pop ecx ; need not be preserved
+ pop ebx
+ ret
+