diff options
| -rw-r--r-- | lib/Transforms/NaCl/ExpandI64.cpp | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/lib/Transforms/NaCl/ExpandI64.cpp b/lib/Transforms/NaCl/ExpandI64.cpp index f2a797439a..0bc7cab794 100644 --- a/lib/Transforms/NaCl/ExpandI64.cpp +++ b/lib/Transforms/NaCl/ExpandI64.cpp @@ -324,7 +324,18 @@ void ExpandI64::splitInst(Instruction *I, DataLayout& DL) { case Instruction::UDiv: F = UDiv; break; case Instruction::SRem: F = SRem; break; case Instruction::URem: F = URem; break; - case Instruction::LShr: F = LShr; break; + case Instruction::LShr: { + if (ConstantInt *CI = dyn_cast<ConstantInt>(I->getOperand(1))) { + unsigned Shifts = CI->getZExtValue(); + if (Shifts == 32) { + Low = CopyDebug(BinaryOperator::Create(Instruction::Or, Zero, Zero, "", I), I); // copy hackishly XXX TODO: eliminate x|0 to x in post-pass + High = Zero; + break; + } + } + F = LShr; + break; + } case Instruction::AShr: F = AShr; break; case Instruction::Shl: { if (ConstantInt *CI = dyn_cast<ConstantInt>(I->getOperand(1))) { @@ -683,10 +694,13 @@ void ExpandI64::finalizeInst(Instruction *I) { Call->setOperand(2, RightLH.Low); Call->setOperand(3, RightLH.High); } else { - // optimized case + // optimized case, 32-bit shifts switch (I->getOpcode()) { + case Instruction::LShr: { + cast<Instruction>(Split.LowHigh.Low)->setOperand(0, LeftLH.High); + break; + } case Instruction::Shl: { - // 32-bit shift cast<Instruction>(Split.LowHigh.High)->setOperand(0, LeftLH.Low); break; } |