6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-06-12 13:38:21 +00:00
Code Issues Projects Releases Wiki Activity

llvm/ConstantFolding.cpp: Make ReadDataFromGlobal() and FoldReinterpretLoadFromConstPtr() Big-endian-aware.

Browse Source 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167595 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
NAKAMURA Takumi
2012-11-08 20:34:25 +00:00
parent 6b370e615c
commit 562b1d883f
5 changed files with 131 additions and 52 deletions
Download Patch File Download Diff File Expand all files Collapse all files

28
lib/Analysis/ConstantFolding.cpp
View File

@ -292,7 +292,10 @@ static bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset,
unsigned IntBytes = unsigned(CI->getBitWidth()/8);
for (unsigned i = 0; i != BytesLeft && ByteOffset != IntBytes; ++i) {
CurPtr[i] = (unsigned char)(Val >> (ByteOffset * 8));
int n = ByteOffset;
if (!TD.isLittleEndian())
n = IntBytes - n - 1;
CurPtr[i] = (unsigned char)(Val >> (n * 8));
++ByteOffset;
}
return true;
@ -442,10 +445,19 @@ static Constant *FoldReinterpretLoadFromConstPtr(Constant *C,
BytesLoaded, TD))
return 0;
APInt ResultVal = APInt(IntType->getBitWidth(), RawBytes[BytesLoaded-1]);
for (unsigned i = 1; i != BytesLoaded; ++i) {
ResultVal <<= 8;
ResultVal |= RawBytes[BytesLoaded-1-i];
APInt ResultVal = APInt(IntType->getBitWidth(), 0);
if (TD.isLittleEndian()) {
ResultVal = RawBytes[BytesLoaded - 1];
for (unsigned i = 1; i != BytesLoaded; ++i) {
ResultVal <<= 8;
ResultVal |= RawBytes[BytesLoaded-1-i];
}
} else {
ResultVal = RawBytes[0];
for (unsigned i = 1; i != BytesLoaded; ++i) {
ResultVal <<= 8;
ResultVal |= RawBytes[i];
}
}
return ConstantInt::get(IntType->getContext(), ResultVal);
@ -521,10 +533,8 @@ Constant *llvm::ConstantFoldLoadFromConstPtr(Constant *C,
}
}
// Try hard to fold loads from bitcasted strange and non-type-safe things. We
// currently don't do any of this for big endian systems. It can be
// generalized in the future if someone is interested.
if (TD && TD->isLittleEndian())
// Try hard to fold loads from bitcasted strange and non-type-safe things.
if (TD)
return FoldReinterpretLoadFromConstPtr(CE, *TD);
return 0;
}