ext-cryptopp/sse-simd.cpp
2018-07-06 01:22:38 -04:00

111 lines
2.8 KiB
C++

// sse-simd.cpp - written and placed in the public domain by
// Jeffrey Walton, Uri Blumenthal and Marcel Raad.
//
// This source file uses intrinsics to gain access to SSE for CPU
// feature testing. A separate source file is needed because additional
// CXXFLAGS are required to enable the appropriate instructions set in
// some build configurations.
#include "pch.h"
#include "config.h"
#include "cpu.h"
// Needed by MIPS for definition of NULL
#include "stdcpp.h"
#ifdef CRYPTOPP_GNU_STYLE_INLINE_ASSEMBLY
# include <signal.h>
# include <setjmp.h>
#endif
#ifndef EXCEPTION_EXECUTE_HANDLER
# define EXCEPTION_EXECUTE_HANDLER 1
#endif
// Needed by SunCC and MSVC
#if (CRYPTOPP_BOOL_X86 || CRYPTOPP_BOOL_X32 || CRYPTOPP_BOOL_X64)
# include <emmintrin.h>
#endif
// Squash MS LNK4221 and libtool warnings
extern const char SSE_SIMD_FNAME[] = __FILE__;
NAMESPACE_BEGIN(CryptoPP)
#ifndef CRYPTOPP_MS_STYLE_INLINE_ASSEMBLY
extern "C" {
typedef void (*SigHandler)(int);
}
extern "C"
{
static jmp_buf s_jmpNoSSE2;
static void SigIllHandlerSSE2(int)
{
longjmp(s_jmpNoSSE2, 1);
}
}
#endif // Not CRYPTOPP_MS_STYLE_INLINE_ASSEMBLY
bool CPU_ProbeSSE2()
{
// Apple switched to Intel desktops in 2005/2006 using
// Core2 Duo's, which provides SSE2 and above.
#if CRYPTOPP_BOOL_X64 || defined(__APPLE__)
return true;
#elif defined(CRYPTOPP_NO_CPU_FEATURE_PROBES)
return false;
#elif defined(CRYPTOPP_MS_STYLE_INLINE_ASSEMBLY)
__try
{
# if CRYPTOPP_SSE2_ASM_AVAILABLE
AS2(por xmm0, xmm0) // executing SSE2 instruction
# elif CRYPTOPP_SSE2_INTRIN_AVAILABLE
__m128i x = _mm_setzero_si128();
return _mm_cvtsi128_si32(x) == 0;
# endif
}
// GetExceptionCode() == EXCEPTION_ILLEGAL_INSTRUCTION
__except (EXCEPTION_EXECUTE_HANDLER)
{
return false;
}
return true;
#else
// longjmp and clobber warnings. Volatile is required.
// http://github.com/weidai11/cryptopp/issues/24 and http://stackoverflow.com/q/7721854
volatile bool result = true;
volatile SigHandler oldHandler = signal(SIGILL, SigIllHandlerSSE2);
if (oldHandler == SIG_ERR)
return false;
# ifndef __MINGW32__
volatile sigset_t oldMask;
if (sigprocmask(0, NULLPTR, (sigset_t*)&oldMask))
return false;
# endif
if (setjmp(s_jmpNoSSE2))
result = false;
else
{
# if CRYPTOPP_SSE2_ASM_AVAILABLE
__asm __volatile ("por %xmm0, %xmm0");
# elif CRYPTOPP_SSE2_INTRIN_AVAILABLE
__m128i x = _mm_setzero_si128();
result = _mm_cvtsi128_si32(x) == 0;
# endif
}
# ifndef __MINGW32__
sigprocmask(SIG_SETMASK, (sigset_t*)&oldMask, NULLPTR);
# endif
signal(SIGILL, oldHandler);
return result;
#endif
}
NAMESPACE_END