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Add inline ASM for missing CRC intrinsics (Issue 428)

pull/242/merge
Jeffrey Walton 2017-05-20 18:03:53 -04:00
parent bc0f943c6b
commit 9d2455a699
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GPG Key ID: B36AB348921B1838
1 changed files with 30 additions and 3 deletions
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33
crc.cpp
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@ -13,6 +13,33 @@ NAMESPACE_BEGIN(CryptoPP)
# undef CRYPTOPP_BOOL_SSE4_INTRINSICS_AVAILABLE
#endif
// Use inline ASM to provide the instructions when the user omits -march=native
#if (CRYPTOPP_GCC_VERSION >= 40300 || CRYPTOPP_LLVM_CLANG_VERSION >= 30200 || CRYPTOPP_APPLE_CLANG_VERSION >= 30200) && !defined(__SSE4_2__)
GCC_INLINE unsigned int GCC_INLINE_ATTRIB
MM_CRC32_U8(unsigned int crc, unsigned char val)
{
asm ("crc32 %1, %0" : "+r"(crc) : "r"(val));
return crc;
}
GCC_INLINE unsigned int GCC_INLINE_ATTRIB
MM_CRC32_U16(unsigned int crc, unsigned short val)
{
asm ("crc32 %1, %0" : "+r"(crc) : "r"(val));
return crc;
}
GCC_INLINE unsigned int GCC_INLINE_ATTRIB
MM_CRC32_U32(unsigned int crc, unsigned int val)
{
asm ("crc32 %1, %0" : "+r"(crc) : "r"(val));
return crc;
}
#else
#define MM_CRC32_U8(a,b) _mm_crc32_u8(a,b)
#define MM_CRC32_U16(a,b) _mm_crc32_u16(a,b)
#define MM_CRC32_U32(a,b) _mm_crc32_u32(a,b)
#endif
/* Table of CRC-32's of all single byte values (made by makecrc.c) */
const word32 CRC32::m_tab[] = {
#ifdef IS_LITTLE_ENDIAN
@ -303,13 +330,13 @@ void CRC32C::Update(const byte *s, size_t n)
if (HasSSE4())
{
for(; !IsAligned<word32>(s) && n > 0; s++, n--)
m_crc = _mm_crc32_u8(m_crc, *s);
m_crc = MM_CRC32_U8(m_crc, *s);
for(; n > 4; s+=4, n-=4)
m_crc = _mm_crc32_u32(m_crc, *(const word32 *)(void*)s);
m_crc = MM_CRC32_U32(m_crc, *(const word32 *)(void*)s);
for(; n > 0; s++, n--)
m_crc = _mm_crc32_u8(m_crc, *s);
m_crc = MM_CRC32_U8(m_crc, *s);
return;
}