diff options
Diffstat (limited to 'llvm/lib/IR/ConstantFold.cpp')
| -rw-r--r-- | llvm/lib/IR/ConstantFold.cpp | 30 |
1 files changed, 16 insertions, 14 deletions
diff --git a/llvm/lib/IR/ConstantFold.cpp b/llvm/lib/IR/ConstantFold.cpp index 3784405ecb0..3c01a482a44 100644 --- a/llvm/lib/IR/ConstantFold.cpp +++ b/llvm/lib/IR/ConstantFold.cpp @@ -268,19 +268,20 @@ static Constant *ExtractConstantBytes(Constant *C, unsigned ByteStart, ConstantInt *Amt = dyn_cast<ConstantInt>(CE->getOperand(1)); if (!Amt) return nullptr; - unsigned ShAmt = Amt->getZExtValue(); + APInt ShAmt = Amt->getValue(); // Cannot analyze non-byte shifts. if ((ShAmt & 7) != 0) return nullptr; - ShAmt >>= 3; + ShAmt.lshrInPlace(3); // If the extract is known to be all zeros, return zero. - if (ByteStart >= CSize-ShAmt) - return Constant::getNullValue(IntegerType::get(CE->getContext(), - ByteSize*8)); + if (ShAmt.uge(CSize - ByteStart)) + return Constant::getNullValue( + IntegerType::get(CE->getContext(), ByteSize * 8)); // If the extract is known to be fully in the input, extract it. - if (ByteStart+ByteSize+ShAmt <= CSize) - return ExtractConstantBytes(CE->getOperand(0), ByteStart+ShAmt, ByteSize); + if (ShAmt.ule(CSize - (ByteStart + ByteSize))) + return ExtractConstantBytes(CE->getOperand(0), + ByteStart + ShAmt.getZExtValue(), ByteSize); // TODO: Handle the 'partially zero' case. return nullptr; @@ -290,19 +291,20 @@ static Constant *ExtractConstantBytes(Constant *C, unsigned ByteStart, ConstantInt *Amt = dyn_cast<ConstantInt>(CE->getOperand(1)); if (!Amt) return nullptr; - unsigned ShAmt = Amt->getZExtValue(); + APInt ShAmt = Amt->getValue(); // Cannot analyze non-byte shifts. if ((ShAmt & 7) != 0) return nullptr; - ShAmt >>= 3; + ShAmt.lshrInPlace(3); // If the extract is known to be all zeros, return zero. - if (ByteStart+ByteSize <= ShAmt) - return Constant::getNullValue(IntegerType::get(CE->getContext(), - ByteSize*8)); + if (ShAmt.uge(ByteStart + ByteSize)) + return Constant::getNullValue( + IntegerType::get(CE->getContext(), ByteSize * 8)); // If the extract is known to be fully in the input, extract it. - if (ByteStart >= ShAmt) - return ExtractConstantBytes(CE->getOperand(0), ByteStart-ShAmt, ByteSize); + if (ShAmt.ule(ByteStart)) + return ExtractConstantBytes(CE->getOperand(0), + ByteStart - ShAmt.getZExtValue(), ByteSize); // TODO: Handle the 'partially zero' case. return nullptr; |
