diff options
Diffstat (limited to 'include/llvm')
| -rw-r--r-- | include/llvm/Support/MathExtras.h | 35 | ||||
| -rw-r--r-- | include/llvm/System/SwapByteOrder.h | 101 |
2 files changed, 105 insertions, 31 deletions
diff --git a/include/llvm/Support/MathExtras.h b/include/llvm/Support/MathExtras.h index 982813f..3b90780 100644 --- a/include/llvm/Support/MathExtras.h +++ b/include/llvm/Support/MathExtras.h @@ -15,6 +15,7 @@ #define LLVM_SUPPORT_MATHEXTRAS_H #include "llvm/System/DataTypes.h" +#include "llvm/System/SwapByteOrder.h" namespace llvm { @@ -112,47 +113,19 @@ inline bool isPowerOf2_64(uint64_t Value) { /// ByteSwap_16 - This function returns a byte-swapped representation of the /// 16-bit argument, Value. inline uint16_t ByteSwap_16(uint16_t Value) { -#if defined(_MSC_VER) && !defined(_DEBUG) - // The DLL version of the runtime lacks these functions (bug!?), but in a - // release build they're replaced with BSWAP instructions anyway. - return _byteswap_ushort(Value); -#else - uint16_t Hi = Value << 8; - uint16_t Lo = Value >> 8; - return Hi | Lo; -#endif + return sys::SwapByteOrder(Value); } /// ByteSwap_32 - This function returns a byte-swapped representation of the /// 32-bit argument, Value. inline uint32_t ByteSwap_32(uint32_t Value) { -#if defined(__llvm__) || \ - (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)) && !defined(__ICC) - return __builtin_bswap32(Value); -#elif defined(_MSC_VER) && !defined(_DEBUG) - return _byteswap_ulong(Value); -#else - uint32_t Byte0 = Value & 0x000000FF; - uint32_t Byte1 = Value & 0x0000FF00; - uint32_t Byte2 = Value & 0x00FF0000; - uint32_t Byte3 = Value & 0xFF000000; - return (Byte0 << 24) | (Byte1 << 8) | (Byte2 >> 8) | (Byte3 >> 24); -#endif + return sys::SwapByteOrder(Value); } /// ByteSwap_64 - This function returns a byte-swapped representation of the /// 64-bit argument, Value. inline uint64_t ByteSwap_64(uint64_t Value) { -#if defined(__llvm__) || \ - (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)) && !defined(__ICC) - return __builtin_bswap64(Value); -#elif defined(_MSC_VER) && !defined(_DEBUG) - return _byteswap_uint64(Value); -#else - uint64_t Hi = ByteSwap_32(uint32_t(Value)); - uint32_t Lo = ByteSwap_32(uint32_t(Value >> 32)); - return (Hi << 32) | Lo; -#endif + return sys::SwapByteOrder(Value); } /// CountLeadingZeros_32 - this function performs the platform optimal form of diff --git a/include/llvm/System/SwapByteOrder.h b/include/llvm/System/SwapByteOrder.h new file mode 100644 index 0000000..64a8acb --- /dev/null +++ b/include/llvm/System/SwapByteOrder.h @@ -0,0 +1,101 @@ +//===- SwapByteOrder.h - Generic and optimized byte swaps -------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file declares generic and optimized functions to swap the byte order of +// an integral type. +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_SYSTEM_SWAP_BYTE_ORDER_H +#define LLVM_SYSTEM_SWAP_BYTE_ORDER_H + +#include "llvm/Support/type_traits.h" +#include "llvm/System/DataTypes.h" +#include <cstddef> +#include <limits> + +namespace llvm { +namespace sys { + +template<typename value_type> +inline +typename enable_if_c<sizeof(value_type) == 1 + && std::numeric_limits<value_type>::is_integer, + value_type>::type +SwapByteOrder(value_type Value) { + // No swapping needed. + return Value; +} + +template<typename value_type> +inline +typename enable_if_c<sizeof(value_type) == 2 + && std::numeric_limits<value_type>::is_integer, + value_type>::type +SwapByteOrder(value_type Value) { + // Cast signed types to unsigned before swapping. + uint16_t value = static_cast<uint16_t>(Value); +#if defined(_MSC_VER) && !defined(_DEBUG) + // The DLL version of the runtime lacks these functions (bug!?), but in a + // release build they're replaced with BSWAP instructions anyway. + return _byteswap_ushort(value); +#else + uint16_t Hi = value << 8; + uint16_t Lo = value >> 8; + return value_type(Hi | Lo); +#endif +} + +template<typename value_type> +inline +typename enable_if_c<sizeof(value_type) == 4 + && std::numeric_limits<value_type>::is_integer, + value_type>::type +SwapByteOrder(value_type Value) { + // Cast signed types to unsigned before swapping. + uint32_t value = static_cast<uint32_t>(Value); +#if defined(__llvm__) || \ + (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)) && !defined(__ICC) + return __builtin_bswap32(value); +#elif defined(_MSC_VER) && !defined(_DEBUG) + return _byteswap_ulong(value); +#else + uint32_t Byte0 = value & 0x000000FF; + uint32_t Byte1 = value & 0x0000FF00; + uint32_t Byte2 = value & 0x00FF0000; + uint32_t Byte3 = value & 0xFF000000; + return value_type( + (Byte0 << 24) | (Byte1 << 8) | (Byte2 >> 8) | (Byte3 >> 24)); +#endif +} + +template<typename value_type> +inline +typename enable_if_c<sizeof(value_type) == 8 + && std::numeric_limits<value_type>::is_integer, + value_type>::type +SwapByteOrder(value_type Value) { + // Cast signed types to unsigned before swapping. + uint64_t value = static_cast<uint64_t>(Value); +#if defined(__llvm__) || \ + (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)) && !defined(__ICC) + return __builtin_bswap64(value); +#elif defined(_MSC_VER) && !defined(_DEBUG) + return _byteswap_uint64(value); +#else + uint64_t Hi = SwapByteOrder<uint32_t>(uint32_t(value)); + uint32_t Lo = SwapByteOrder<uint32_t>(uint32_t(value >> 32)); + return value_type((Hi << 32) | Lo); +#endif +} + +} // end namespace sys +} // end namespace llvm + +#endif |