diff options
Diffstat (limited to 'lib/Analysis')
| -rw-r--r-- | lib/Analysis/ConstantFolding.cpp | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/lib/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp index 1ca7cb0..0ce1c24 100644 --- a/lib/Analysis/ConstantFolding.cpp +++ b/lib/Analysis/ConstantFolding.cpp @@ -678,6 +678,8 @@ llvm::canConstantFoldCallTo(const Function *F) { case Intrinsic::cttz: case Intrinsic::uadd_with_overflow: case Intrinsic::usub_with_overflow: + case Intrinsic::sadd_with_overflow: + case Intrinsic::ssub_with_overflow: return true; default: return false; @@ -902,6 +904,28 @@ llvm::ConstantFoldCall(Function *F, }; return ConstantStruct::get(F->getContext(), Ops, 2, false); } + case Intrinsic::sadd_with_overflow: { + Constant *Res = ConstantExpr::getAdd(Op1, Op2); // result. + Constant *Overflow = ConstantExpr::getSelect( + ConstantExpr::getICmp(CmpInst::ICMP_SGT, + ConstantInt::get(Op1->getType(), 0), Op1), + ConstantExpr::getICmp(CmpInst::ICMP_SGT, Res, Op2), + ConstantExpr::getICmp(CmpInst::ICMP_SLT, Res, Op2)); // overflow. + + Constant *Ops[] = { Res, Overflow }; + return ConstantStruct::get(F->getContext(), Ops, 2, false); + } + case Intrinsic::ssub_with_overflow: { + Constant *Res = ConstantExpr::getSub(Op1, Op2); // result. + Constant *Overflow = ConstantExpr::getSelect( + ConstantExpr::getICmp(CmpInst::ICMP_SGT, + ConstantInt::get(Op2->getType(), 0), Op2), + ConstantExpr::getICmp(CmpInst::ICMP_SLT, Res, Op1), + ConstantExpr::getICmp(CmpInst::ICMP_SGT, Res, Op1)); // overflow. + + Constant *Ops[] = { Res, Overflow }; + return ConstantStruct::get(F->getContext(), Ops, 2, false); + } } } |