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[Refactor] CPU feature detection logic for SHA256

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sipa committed Jun 24, 2018
1 parent b1dc39d commit 268400d3188200c9e3dcd3482c4853354388a721
Showing with 34 additions and 16 deletions.
  1. +34 −16 src/crypto/sha256.cpp
@@ -552,32 +552,50 @@ std::string SHA256AutoDetect()
{
std::string ret = "standard";
#if defined(USE_ASM) && (defined(__x86_64__) || defined(__amd64__) || defined(__i386__))
(void)AVXEnabled; // Silence unused warning (in case ENABLE_AVX2 is not defined)
bool have_sse4 = false;
bool have_xsave = false;
bool have_avx = false;
bool have_avx2 = false;
bool enabled_avx = false;

(void)AVXEnabled;
(void)have_sse4;
(void)have_avx;
(void)have_xsave;
(void)have_avx2;
(void)enabled_avx;

uint32_t eax, ebx, ecx, edx;
cpuid(1, 0, eax, ebx, ecx, edx);
if ((ecx >> 19) & 1) {
have_sse4 = (ecx >> 19) & 1;
have_xsave = (ecx >> 27) & 1;
have_avx = (ecx >> 28) & 1;
if (have_xsave && have_avx) {
enabled_avx = AVXEnabled();
}
if (have_sse4) {
cpuid(7, 0, eax, ebx, ecx, edx);
have_avx2 = (ebx >> 5) & 1;
}

if (have_sse4) {
#if defined(__x86_64__) || defined(__amd64__)
Transform = sha256_sse4::Transform;
TransformD64 = TransformD64Wrapper<sha256_sse4::Transform>;
ret = "sse4(1way)";
#endif
#if defined(ENABLE_SSE41) && !defined(BUILD_BITCOIN_INTERNAL)
TransformD64_4way = sha256d64_sse41::Transform_4way;
ret = "sse4(1way+4way)";
#if defined(ENABLE_AVX2) && !defined(BUILD_BITCOIN_INTERNAL)
if (((ecx >> 27) & 1) && ((ecx >> 28) & 1)) { // XSAVE and AVX
cpuid(7, 0, eax, ebx, ecx, edx);
if ((ebx >> 5) & 1) { // AVX2 flag
if (AVXEnabled()) { // OS has enabled AVX registers
TransformD64_8way = sha256d64_avx2::Transform_8way;
ret += ",avx2(8way)";
}
}
}
#endif
#else
ret = "sse4";
ret += ",sse41(4way)";
#endif
}

#if defined(ENABLE_AVX2) && !defined(BUILD_BITCOIN_INTERNAL)
if (have_avx2 && have_avx && enabled_avx) {
TransformD64_8way = sha256d64_avx2::Transform_8way;
ret += ",avx2(8way)";
}
#endif
#endif

assert(SelfTest());

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