no cost to using memcpy here: the fixed code is optimized by LLVM to perfect
machine code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162311
91177308-0d34-0410-b5e6-
96231b3b80d8
+template<typename T> void addUnaligned(void *Pos, T Delta) {
+ T Value;
+ std::memcpy(reinterpret_cast<char*>(&Value), reinterpret_cast<char*>(Pos),
+ sizeof(T));
+ Value += Delta;
+ std::memcpy(reinterpret_cast<char*>(Pos), reinterpret_cast<char*>(&Value),
+ sizeof(T));
+}
+
/// relocate - Before the JIT can run a block of code that has been emitted,
/// it must rewrite the code to contain the actual addresses of any
/// referenced global symbols.
/// relocate - Before the JIT can run a block of code that has been emitted,
/// it must rewrite the code to contain the actual addresses of any
/// referenced global symbols.
// PC relative relocation, add the relocated value to the value already in
// memory, after we adjust it for where the PC is.
ResultPtr = ResultPtr -(intptr_t)RelocPos - 4 - MR->getConstantVal();
// PC relative relocation, add the relocated value to the value already in
// memory, after we adjust it for where the PC is.
ResultPtr = ResultPtr -(intptr_t)RelocPos - 4 - MR->getConstantVal();
- *((unsigned*)RelocPos) += (unsigned)ResultPtr;
+ addUnaligned<unsigned>(RelocPos, ResultPtr);
break;
}
case X86::reloc_picrel_word: {
// PIC base relative relocation, add the relocated value to the value
// already in memory, after we adjust it for where the PIC base is.
ResultPtr = ResultPtr - ((intptr_t)Function + MR->getConstantVal());
break;
}
case X86::reloc_picrel_word: {
// PIC base relative relocation, add the relocated value to the value
// already in memory, after we adjust it for where the PIC base is.
ResultPtr = ResultPtr - ((intptr_t)Function + MR->getConstantVal());
- *((unsigned*)RelocPos) += (unsigned)ResultPtr;
+ addUnaligned<unsigned>(RelocPos, ResultPtr);
break;
}
case X86::reloc_absolute_word:
case X86::reloc_absolute_word_sext:
// Absolute relocation, just add the relocated value to the value already
// in memory.
break;
}
case X86::reloc_absolute_word:
case X86::reloc_absolute_word_sext:
// Absolute relocation, just add the relocated value to the value already
// in memory.
- *((unsigned*)RelocPos) += (unsigned)ResultPtr;
+ addUnaligned<unsigned>(RelocPos, ResultPtr);
break;
case X86::reloc_absolute_dword:
break;
case X86::reloc_absolute_dword:
- *((intptr_t*)RelocPos) += ResultPtr;
+ addUnaligned<intptr_t>(RelocPos, ResultPtr);