diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/utils/bswap.h | 33 |
1 files changed, 29 insertions, 4 deletions
diff --git a/src/utils/bswap.h b/src/utils/bswap.h index 49962f076..7865d59d0 100644 --- a/src/utils/bswap.h +++ b/src/utils/bswap.h @@ -18,37 +18,56 @@ namespace Botan { -/* -* Byte Swapping Functions +/** +* Swap a 16 bit integer */ inline u16bit reverse_bytes(u16bit input) { return rotate_left(input, 8); } +/** +* Swap a 32 bit integer +*/ inline u32bit reverse_bytes(u32bit input) { -#if BOTAN_USE_GCC_INLINE_ASM && defined(BOTAN_TARGET_CPU_IS_X86_FAMILY) +#if BOTAN_GCC_VERSION >= 420 + + // GCC intrinsic added in 4.3, works for a number of CPUs + return __builtin_bswap32(input); + +#elif BOTAN_USE_GCC_INLINE_ASM && defined(BOTAN_TARGET_CPU_IS_X86_FAMILY) // GCC-style inline assembly for x86 or x86-64 asm("bswapl %0" : "=r" (input) : "0" (input)); return input; #elif defined(_MSC_VER) && defined(BOTAN_TARGET_ARCH_IS_IA32) + // Visual C++ inline asm for 32-bit x86, by Yves Jerschow __asm mov eax, input; __asm bswap eax; #else + // Generic implementation return (rotate_right(input, 8) & 0xFF00FF00) | (rotate_left (input, 8) & 0x00FF00FF); + #endif } +/** +* Swap a 64 bit integer +*/ inline u64bit reverse_bytes(u64bit input) { -#if BOTAN_USE_GCC_INLINE_ASM && defined(BOTAN_TARGET_ARCH_IS_AMD64) +#if BOTAN_GCC_VERSION >= 430 + + // GCC intrinsic added in 4.3, works for a number of CPUs + return __builtin_bswap64(input); + +#elif BOTAN_USE_GCC_INLINE_ASM && defined(BOTAN_TARGET_ARCH_IS_AMD64) // GCC-style inline assembly for x86-64 asm("bswapq %0" : "=r" (input) : "0" (input)); return input; @@ -69,6 +88,9 @@ inline u64bit reverse_bytes(u64bit input) #endif } +/** +* Swap 4 Ts in an array +*/ template<typename T> inline void bswap_4(T x[4]) { @@ -80,6 +102,9 @@ inline void bswap_4(T x[4]) #if defined(BOTAN_TARGET_CPU_HAS_SSE2) +/** +* Swap 4 u32bits in an array using SSE2 shuffle instructions +*/ template<> inline void bswap_4(u32bit x[4]) { |