tesseract/arch/simddetect.cpp

83 lines
2.7 KiB
C++

///////////////////////////////////////////////////////////////////////
// File: simddetect.cpp
// Description: Architecture detector.
// Author: Stefan Weil (based on code from Ray Smith)
//
// (C) Copyright 2014, Google Inc.
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
///////////////////////////////////////////////////////////////////////
#include "simddetect.h"
#include "tprintf.h"
#undef X86_BUILD
#if defined(__x86_64__) || defined(__i386__) || defined(_WIN32)
#if !defined(ANDROID_BUILD)
#define X86_BUILD 1
#endif // !ANDROID_BUILD
#endif // x86 target
#if defined(X86_BUILD)
#if defined(__GNUC__)
#include <cpuid.h>
#elif defined(_WIN32)
#include <intrin.h>
#endif
#endif
SIMDDetect SIMDDetect::detector;
// If true, then AVX has been detected.
bool SIMDDetect::avx_available_;
bool SIMDDetect::avx2_available_;
bool SIMDDetect::avx512F_available_;
bool SIMDDetect::avx512BW_available_;
// If true, then SSe4.1 has been detected.
bool SIMDDetect::sse_available_;
// Constructor.
// Tests the architecture in a system-dependent way to detect AVX, SSE and
// any other available SIMD equipment.
// __GNUC__ is also defined by compilers that include GNU extensions such as
// clang.
SIMDDetect::SIMDDetect() {
#if defined(X86_BUILD)
#if defined(__GNUC__)
unsigned int eax, ebx, ecx, edx;
if (__get_cpuid(1, &eax, &ebx, &ecx, &edx) != 0) {
// Note that these tests all use hex because the older compilers don't have
// the newer flags.
sse_available_ = (ecx & 0x00080000) != 0;
avx_available_ = (ecx & 0x10000000) != 0;
if (avx_available_) {
// There is supposed to be a __get_cpuid_count function, but this is all
// there is in my cpuid.h. It is a macro for an asm statement and cannot
// be used inside an if.
__cpuid_count(7, 0, eax, ebx, ecx, edx);
avx2_available_ = (ebx & 0x00000020) != 0;
avx512F_available_ = (ebx & 0x00010000) != 0;
avx512BW_available_ = (ebx & 0x40000000) != 0;
}
}
#elif defined(_WIN32)
int cpuInfo[4];
__cpuid(cpuInfo, 0);
if (cpuInfo[0] >= 1) {
__cpuid(cpuInfo, 1);
sse_available_ = (cpuInfo[2] & 0x00080000) != 0;
avx_available_ = (cpuInfo[2] & 0x10000000) != 0;
}
#else
#error "I don't know how to test for SIMD with this compiler"
#endif
#endif // X86_BUILD
}