Add some generic expansion logic for SMULO and UMULO. Fixes UMULO
support for x86, and UMULO/SMULO for many architectures, including PPC
(PR4201), ARM, and Cell. The resulting expansion isn't perfect, but it's
not bad.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73477 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index f3c2833..1bb8090 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -2768,6 +2768,53 @@
ISD::SETULT : ISD::SETUGT));
break;
}
+ case ISD::UMULO:
+ case ISD::SMULO: {
+ MVT VT = Node->getValueType(0);
+ SDValue LHS = Node->getOperand(0);
+ SDValue RHS = Node->getOperand(1);
+ SDValue BottomHalf;
+ SDValue TopHalf;
+ static unsigned Ops[2][3] =
+ { { ISD::MULHU, ISD::UMUL_LOHI, ISD::ZERO_EXTEND },
+ { ISD::MULHS, ISD::SMUL_LOHI, ISD::SIGN_EXTEND }};
+ bool isSigned = Node->getOpcode() == ISD::SMULO;
+ if (TLI.isOperationLegalOrCustom(Ops[isSigned][0], VT)) {
+ BottomHalf = DAG.getNode(ISD::MUL, dl, VT, LHS, RHS);
+ TopHalf = DAG.getNode(Ops[isSigned][0], dl, VT, LHS, RHS);
+ } else if (TLI.isOperationLegalOrCustom(Ops[isSigned][1], VT)) {
+ BottomHalf = DAG.getNode(Ops[isSigned][1], dl, DAG.getVTList(VT, VT), LHS,
+ RHS);
+ TopHalf = BottomHalf.getValue(1);
+ } else if (TLI.isTypeLegal(MVT::getIntegerVT(VT.getSizeInBits() * 2))) {
+ MVT WideVT = MVT::getIntegerVT(VT.getSizeInBits() * 2);
+ LHS = DAG.getNode(Ops[isSigned][2], dl, WideVT, LHS);
+ RHS = DAG.getNode(Ops[isSigned][2], dl, WideVT, RHS);
+ Tmp1 = DAG.getNode(ISD::MUL, dl, WideVT, LHS, RHS);
+ BottomHalf = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, VT, Tmp1,
+ DAG.getIntPtrConstant(0));
+ TopHalf = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, VT, Tmp1,
+ DAG.getIntPtrConstant(1));
+ } else {
+ // FIXME: We should be able to fall back to a libcall with an illegal
+ // type in some cases cases.
+ // Also, we can fall back to a division in some cases, but that's a big
+ // performance hit in the general case.
+ assert(0 && "Don't know how to expand this operation yet!");
+ }
+ if (isSigned) {
+ Tmp1 = DAG.getConstant(VT.getSizeInBits() - 1, TLI.getShiftAmountTy());
+ Tmp1 = DAG.getNode(ISD::SRA, dl, VT, BottomHalf, Tmp1);
+ TopHalf = DAG.getSetCC(dl, TLI.getSetCCResultType(VT), TopHalf, Tmp1,
+ ISD::SETNE);
+ } else {
+ TopHalf = DAG.getSetCC(dl, TLI.getSetCCResultType(VT), TopHalf,
+ DAG.getConstant(0, VT), ISD::SETNE);
+ }
+ Results.push_back(BottomHalf);
+ Results.push_back(TopHalf);
+ break;
+ }
case ISD::BUILD_PAIR: {
MVT PairTy = Node->getValueType(0);
Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, PairTy, Node->getOperand(0));