diff options
| author | Craig Topper <craig.topper@sifive.com> | 2022-05-21 14:02:22 -0700 |
|---|---|---|
| committer | Craig Topper <craig.topper@sifive.com> | 2022-05-21 14:08:15 -0700 |
| commit | 4638766794b0d9e9a9262e59e3a5cccde657b2ef (patch) | |
| tree | 9e1579f705e5263cc82c5f1b08eac67f36a913b3 /llvm/lib/CodeGen/TypePromotion.cpp | |
| parent | 55e8f721d4d0996cbe5dc802a2c5fbe48dac0d44 (diff) | |
[TypePromotion] Refine fix sext/zext for promoted constant from D125294.
Reviewing the code again, I believe the sext is needed on the LHS
or RHS for ICmp and only on the RHS for Add.
Add an opcode check before checking the operand number.
Fixes PR55627.
Differential Revision: https://reviews.llvm.org/D125654
Diffstat (limited to 'llvm/lib/CodeGen/TypePromotion.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/TypePromotion.cpp | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/llvm/lib/CodeGen/TypePromotion.cpp b/llvm/lib/CodeGen/TypePromotion.cpp index ea1369587609..8752a081623a 100644 --- a/llvm/lib/CodeGen/TypePromotion.cpp +++ b/llvm/lib/CodeGen/TypePromotion.cpp @@ -486,7 +486,10 @@ void IRPromoter::PromoteTree() { if (auto *Const = dyn_cast<ConstantInt>(Op)) { // For subtract, we don't need to sext the constant. We only put it in // SafeWrap because SafeWrap.size() is used elsewhere. - Constant *NewConst = (SafeWrap.contains(I) && i == 1 && + // For cmp, we need to sign extend a constant appearing in either + // operand. For add, we should only sign extend the RHS. + Constant *NewConst = (SafeWrap.contains(I) && + (I->getOpcode() == Instruction::ICmp || i == 1) && I->getOpcode() != Instruction::Sub) ? ConstantExpr::getSExt(Const, ExtTy) : ConstantExpr::getZExt(Const, ExtTy); |