From eafc5cb80d58cb9447623a557be4d4f55f42fbc3 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Thu, 14 Oct 2010 00:05:07 +0000 Subject: add uadd_ov/usub_ov to apint, consolidate constant folding logic to use the new APInt methods. Among other things this implements rdar://8501501 - llvm.smul.with.overflow.i32 should constant fold which comes from "clang -ftrapv", originally brought to my attention from PR8221. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116457 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Analysis/ConstantFolding.cpp | 60 +++++++++++++++++++--------------------- 1 file changed, 28 insertions(+), 32 deletions(-) (limited to 'lib/Analysis/ConstantFolding.cpp') diff --git a/lib/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp index d3596d1c86..f512dd69a3 100644 --- a/lib/Analysis/ConstantFolding.cpp +++ b/lib/Analysis/ConstantFolding.cpp @@ -1001,6 +1001,7 @@ llvm::canConstantFoldCallTo(const Function *F) { case Intrinsic::usub_with_overflow: case Intrinsic::sadd_with_overflow: case Intrinsic::ssub_with_overflow: + case Intrinsic::smul_with_overflow: case Intrinsic::convert_from_fp16: case Intrinsic::convert_to_fp16: return true; @@ -1248,42 +1249,37 @@ llvm::ConstantFoldCall(Function *F, if (ConstantInt *Op2 = dyn_cast(Operands[1])) { switch (F->getIntrinsicID()) { default: break; - case Intrinsic::uadd_with_overflow: { - Constant *Res = ConstantExpr::getAdd(Op1, Op2); // result. + case Intrinsic::sadd_with_overflow: + case Intrinsic::uadd_with_overflow: + case Intrinsic::ssub_with_overflow: + case Intrinsic::usub_with_overflow: + case Intrinsic::smul_with_overflow: { + APInt Res; + bool Overflow; + switch (F->getIntrinsicID()) { + default: assert(0 && "Invalid case"); + case Intrinsic::sadd_with_overflow: + Res = Op1->getValue().sadd_ov(Op2->getValue(), Overflow); + break; + case Intrinsic::uadd_with_overflow: + Res = Op1->getValue().uadd_ov(Op2->getValue(), Overflow); + break; + case Intrinsic::ssub_with_overflow: + Res = Op1->getValue().ssub_ov(Op2->getValue(), Overflow); + break; + case Intrinsic::usub_with_overflow: + Res = Op1->getValue().usub_ov(Op2->getValue(), Overflow); + break; + case Intrinsic::smul_with_overflow: + Res = Op1->getValue().smul_ov(Op2->getValue(), Overflow); + break; + } Constant *Ops[] = { - Res, ConstantExpr::getICmp(CmpInst::ICMP_ULT, Res, Op1) // overflow. + ConstantInt::get(F->getContext(), Res), + ConstantInt::get(Type::getInt1Ty(F->getContext()), Overflow) }; return ConstantStruct::get(F->getContext(), Ops, 2, false); } - case Intrinsic::usub_with_overflow: { - Constant *Res = ConstantExpr::getSub(Op1, Op2); // result. - Constant *Ops[] = { - Res, ConstantExpr::getICmp(CmpInst::ICMP_UGT, Res, Op1) // overflow. - }; - 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); - } } } -- cgit v1.2.3