From 21a01d1ea89dba97c4f9e1f9f41485729a4046bc Mon Sep 17 00:00:00 2001 From: Rafael Espindola Date: Mon, 15 Apr 2013 14:44:24 +0000 Subject: [PATCH] Make the host endianness check an integer constant expression. I will remove the isBigEndianHost function once I update clang. The ifdef logic is designed to * not use configure/cmake to avoid breaking -arch i686 -arch ppc. * default to little endian * be as small as possible It looks like sys/endian.h is the preferred header on most modern BSD systems, but it is better to change this in a followup patch as machine/endian.h is available on FreeBSD, OpenBSD, NetBSD and OS X. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179527 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/ADT/Hashing.h | 4 ++-- include/llvm/Support/Endian.h | 2 +- include/llvm/Support/Host.h | 26 +++++++++++++++-------- lib/ExecutionEngine/ExecutionEngine.cpp | 6 +++--- lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h | 6 +++--- lib/Object/MachOObject.cpp | 2 +- lib/Support/DataExtractor.cpp | 2 +- lib/Support/FoldingSet.cpp | 4 ++-- 8 files changed, 30 insertions(+), 22 deletions(-) diff --git a/include/llvm/ADT/Hashing.h b/include/llvm/ADT/Hashing.h index cda31a261df..e434417da7c 100644 --- a/include/llvm/ADT/Hashing.h +++ b/include/llvm/ADT/Hashing.h @@ -151,7 +151,7 @@ namespace detail { inline uint64_t fetch64(const char *p) { uint64_t result; memcpy(&result, p, sizeof(result)); - if (sys::isBigEndianHost()) + if (sys::IsBigEndianHost) return sys::SwapByteOrder(result); return result; } @@ -159,7 +159,7 @@ inline uint64_t fetch64(const char *p) { inline uint32_t fetch32(const char *p) { uint32_t result; memcpy(&result, p, sizeof(result)); - if (sys::isBigEndianHost()) + if (sys::IsBigEndianHost) return sys::SwapByteOrder(result); return result; } diff --git a/include/llvm/Support/Endian.h b/include/llvm/Support/Endian.h index d438facfa4e..0d358498839 100644 --- a/include/llvm/Support/Endian.h +++ b/include/llvm/Support/Endian.h @@ -37,7 +37,7 @@ namespace detail { namespace endian { template inline value_type byte_swap(value_type value) { - if (endian != native && sys::isBigEndianHost() != (endian == big)) + if (endian != native && sys::IsBigEndianHost != (endian == big)) return sys::SwapByteOrder(value); return value; } diff --git a/include/llvm/Support/Host.h b/include/llvm/Support/Host.h index 3a444057391..2731529dfd7 100644 --- a/include/llvm/Support/Host.h +++ b/include/llvm/Support/Host.h @@ -15,22 +15,30 @@ #define LLVM_SUPPORT_HOST_H #include "llvm/ADT/StringMap.h" + +#if defined(__linux__) +#include +#else +#ifndef _MSC_VER +#include +#endif +#endif + #include namespace llvm { namespace sys { - inline bool isLittleEndianHost() { - union { - int i; - char c; - }; - i = 1; - return c; - } +#if BYTE_ORDER == BIG_ENDIAN + static const bool IsBigEndianHost = true; +#else + static const bool IsBigEndianHost = false; +#endif + + static const bool IsLittleEndianHost = !IsBigEndianHost; inline bool isBigEndianHost() { - return !isLittleEndianHost(); + return IsBigEndianHost; } /// getDefaultTargetTriple() - Return the default target triple the compiler diff --git a/lib/ExecutionEngine/ExecutionEngine.cpp b/lib/ExecutionEngine/ExecutionEngine.cpp index 906a3a3fda7..e43ba4f1dd0 100644 --- a/lib/ExecutionEngine/ExecutionEngine.cpp +++ b/lib/ExecutionEngine/ExecutionEngine.cpp @@ -948,7 +948,7 @@ static void StoreIntToMemory(const APInt &IntVal, uint8_t *Dst, assert((IntVal.getBitWidth()+7)/8 >= StoreBytes && "Integer too small!"); const uint8_t *Src = (const uint8_t *)IntVal.getRawData(); - if (sys::isLittleEndianHost()) { + if (sys::IsLittleEndianHost) { // Little-endian host - the source is ordered from LSB to MSB. Order the // destination from LSB to MSB: Do a straight copy. memcpy(Dst, Src, StoreBytes); @@ -1009,7 +1009,7 @@ void ExecutionEngine::StoreValueToMemory(const GenericValue &Val, break; } - if (sys::isLittleEndianHost() != getDataLayout()->isLittleEndian()) + if (sys::IsLittleEndianHost != getDataLayout()->isLittleEndian()) // Host and target are different endian - reverse the stored bytes. std::reverse((uint8_t*)Ptr, StoreBytes + (uint8_t*)Ptr); } @@ -1021,7 +1021,7 @@ static void LoadIntFromMemory(APInt &IntVal, uint8_t *Src, unsigned LoadBytes) { uint8_t *Dst = reinterpret_cast( const_cast(IntVal.getRawData())); - if (sys::isLittleEndianHost()) + if (sys::IsLittleEndianHost) // Little-endian host - the destination must be ordered from LSB to MSB. // The source is ordered from LSB to MSB: Do a straight copy. memcpy(Dst, Src, LoadBytes); diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h index f1009945775..555ea96943e 100644 --- a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h +++ b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h @@ -202,14 +202,14 @@ protected: void writeInt16BE(uint8_t *Addr, uint16_t Value) { - if (sys::isLittleEndianHost()) + if (sys::IsLittleEndianHost) Value = sys::SwapByteOrder(Value); *Addr = (Value >> 8) & 0xFF; *(Addr+1) = Value & 0xFF; } void writeInt32BE(uint8_t *Addr, uint32_t Value) { - if (sys::isLittleEndianHost()) + if (sys::IsLittleEndianHost) Value = sys::SwapByteOrder(Value); *Addr = (Value >> 24) & 0xFF; *(Addr+1) = (Value >> 16) & 0xFF; @@ -218,7 +218,7 @@ protected: } void writeInt64BE(uint8_t *Addr, uint64_t Value) { - if (sys::isLittleEndianHost()) + if (sys::IsLittleEndianHost) Value = sys::SwapByteOrder(Value); *Addr = (Value >> 56) & 0xFF; *(Addr+1) = (Value >> 48) & 0xFF; diff --git a/lib/Object/MachOObject.cpp b/lib/Object/MachOObject.cpp index c9c341a207c..d88f96f298c 100644 --- a/lib/Object/MachOObject.cpp +++ b/lib/Object/MachOObject.cpp @@ -61,7 +61,7 @@ static void ReadInMemoryStruct(const MachOObject &MOO, MachOObject::MachOObject(MemoryBuffer *Buffer_, bool IsLittleEndian_, bool Is64Bit_) : Buffer(Buffer_), IsLittleEndian(IsLittleEndian_), Is64Bit(Is64Bit_), - IsSwappedEndian(IsLittleEndian != sys::isLittleEndianHost()), + IsSwappedEndian(IsLittleEndian != sys::IsLittleEndianHost), HasStringTable(false), LoadCommands(0), NumLoadedCommands(0) { // Load the common header. memcpy(&Header, Buffer->getBuffer().data(), sizeof(Header)); diff --git a/lib/Support/DataExtractor.cpp b/lib/Support/DataExtractor.cpp index 3d5cce05358..a564d211b1d 100644 --- a/lib/Support/DataExtractor.cpp +++ b/lib/Support/DataExtractor.cpp @@ -20,7 +20,7 @@ static T getU(uint32_t *offset_ptr, const DataExtractor *de, uint32_t offset = *offset_ptr; if (de->isValidOffsetForDataOfSize(offset, sizeof(val))) { std::memcpy(&val, &Data[offset], sizeof(val)); - if (sys::isLittleEndianHost() != isLittleEndian) + if (sys::IsLittleEndianHost != isLittleEndian) val = sys::SwapByteOrder(val); // Advance the offset diff --git a/lib/Support/FoldingSet.cpp b/lib/Support/FoldingSet.cpp index 36e33b5aafa..145f12dc1e5 100644 --- a/lib/Support/FoldingSet.cpp +++ b/lib/Support/FoldingSet.cpp @@ -101,7 +101,7 @@ void FoldingSetNodeID::AddString(StringRef String) { // Otherwise do it the hard way. // To be compatible with above bulk transfer, we need to take endianness // into account. - if (sys::isBigEndianHost()) { + if (sys::IsBigEndianHost) { for (Pos += 4; Pos <= Size; Pos += 4) { unsigned V = ((unsigned char)String[Pos - 4] << 24) | ((unsigned char)String[Pos - 3] << 16) | @@ -110,7 +110,7 @@ void FoldingSetNodeID::AddString(StringRef String) { Bits.push_back(V); } } else { - assert(sys::isLittleEndianHost() && "Unexpected host endianness"); + assert(sys::IsLittleEndianHost && "Unexpected host endianness"); for (Pos += 4; Pos <= Size; Pos += 4) { unsigned V = ((unsigned char)String[Pos - 1] << 24) | ((unsigned char)String[Pos - 2] << 16) | -- 2.11.0