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livetrax/libs/pbd/msvc/fpu.cc

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#ifdef COMPILER_MSVC // Added by JE - 05-12-2009. Inline assembler instructions
// have been changed to Intel format and (in the case of
// cpuid) was replaced by the equivalent VC++ system call).
#define _XOPEN_SOURCE 600
#include <cstdlib>
#include <stdint.h>
#include <intrin.h> // Added by JE - 05-12-2009
#include <pbd/fpu.h>
#include <pbd/error.h>
#include "i18n.h"
using namespace PBD;
using namespace std;
FPU::FPU ()
{
unsigned long cpuflags = 0;
_flags = (Flags)0;
#ifndef ARCH_X86
return;
#else
#ifndef USE_X86_64_ASM
int cpuInfo[4];
__cpuid (cpuInfo, 1);
cpuflags = cpuInfo[3];
/*
__asm { // This is how the original section would look if converted to Intel syntax.
// However, I have grave doubts about whether it's doing the right thing.
// It seems as if the intention was to retrieve feature information from
// the processor. However, feature information is returned in the ebx register
// (if you believe Wikipedia) or in edx (if you believe Microsoft). Unfortunately,
// both registers get ignored in the original code!! Confused?? Join the club!!
mov eax, 1
push ebx
cpuid
mov edx, 0
pop ebx
mov cpuflags, ecx // This can't be right, surely???
}; */
#else
// Note that this syntax is currently still in AT&T format !
asm volatile (
"pushq %%rbx\n"
"movq $1, %%rax\n"
"cpuid\n"
"movq %%rdx, %0\n"
"popq %%rbx\n"
: "=r" (cpuflags)
:
: "%rax", "%rcx", "%rdx", "memory"
);
#endif /* USE_X86_64_ASM */
if (cpuflags & (1<<25)) {
_flags = Flags (_flags | (HasSSE|HasFlushToZero));
}
if (cpuflags & (1<<26)) {
_flags = Flags (_flags | HasSSE2);
}
if (cpuflags & (1 << 24)) {
bool aligned_malloc = false; // Added by JE - 05-12-2009
char* fxbuf = 0;
// This section changed by JE - 05-12-2009
#ifdef NO_POSIX_MEMALIGN
#if defined(COMPILER_MSVC) || defined(COMPILER_MINGW) // All of these support '_aligned_malloc()'
fxbuf = (char *) _aligned_malloc(512, 16); // (note that they all need at least MSVC runtime 7.0)
aligned_malloc = true;
#else
fxbuf = (char *) malloc(512);
#endif
#else
fxbuf = posix_memalign ((void**)&fxbuf, 16, 512);
#endif
// Verify that fxbuf is correctly aligned
unsigned long buf_addr = (unsigned long)(void*)fxbuf;
if ((0 == buf_addr) || (buf_addr % 16))
error << _("cannot allocate 16 byte aligned buffer for h/w feature detection") << endmsg;
else
{
memset(fxbuf, 0, 512); // Initialize the buffer !!! Added by JE - 12-12-2009
__asm {
mov eax, fxbuf
fxsave [eax]
};
uint32_t mxcsr_mask = *((uint32_t*) &fxbuf[28]);
/* if the mask is zero, set its default value (from intel specs) */
if (mxcsr_mask == 0) {
mxcsr_mask = 0xffbf;
}
if (mxcsr_mask & (1<<6)) {
_flags = Flags (_flags | HasDenormalsAreZero);
}
if (aligned_malloc)
_aligned_free (fxbuf);
else
free (fxbuf);
}
}
#endif // ARCH_X86
}
FPU::~FPU ()
{
}
#else // !COMPILER_MSVC
const char* pbd_fpu = "original pbd/fpu.cc takes precedence over this file";
#endif // COMPILER_MSVC