If we can, lower the multiply part of a umulo/smulo call to a libcall
with an invalid type then split the result and perform the overflow check
normally.
Fixes the 32-bit parts of rdar://8622122 and rdar://8774702.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123864 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index 6bad93a..f0ce284 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -3181,14 +3181,8 @@
BottomHalf = DAG.getNode(Ops[isSigned][1], dl, DAG.getVTList(VT, VT), LHS,
RHS);
TopHalf = BottomHalf.getValue(1);
- } else {
- // FIXME: We should be able to fall back to a libcall with an illegal
- // type in some cases.
- // Also, we can fall back to a division in some cases, but that's a big
- // performance hit in the general case.
- assert(TLI.isTypeLegal(EVT::getIntegerVT(*DAG.getContext(),
- VT.getSizeInBits() * 2)) &&
- "Don't know how to expand this operation yet!");
+ } else if (TLI.isTypeLegal(EVT::getIntegerVT(*DAG.getContext(),
+ VT.getSizeInBits() * 2))) {
EVT WideVT = EVT::getIntegerVT(*DAG.getContext(), VT.getSizeInBits() * 2);
LHS = DAG.getNode(Ops[isSigned][2], dl, WideVT, LHS);
RHS = DAG.getNode(Ops[isSigned][2], dl, WideVT, RHS);
@@ -3197,6 +3191,31 @@
DAG.getIntPtrConstant(0));
TopHalf = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, VT, Tmp1,
DAG.getIntPtrConstant(1));
+ } else {
+ // We can fall back to a libcall with an illegal type for the MUL if we
+ // have a libcall big enough.
+ // Also, we can fall back to a division in some cases, but that's a big
+ // performance hit in the general case.
+ EVT WideVT = EVT::getIntegerVT(*DAG.getContext(), VT.getSizeInBits() * 2);
+ RTLIB::Libcall LC = RTLIB::UNKNOWN_LIBCALL;
+ if (WideVT == MVT::i16)
+ LC = RTLIB::MUL_I16;
+ else if (WideVT == MVT::i32)
+ LC = RTLIB::MUL_I32;
+ else if (WideVT == MVT::i64)
+ LC = RTLIB::MUL_I64;
+ else if (WideVT == MVT::i128)
+ LC = RTLIB::MUL_I128;
+ assert(LC != RTLIB::UNKNOWN_LIBCALL && "Cannot expand this operation!");
+ LHS = DAG.getNode(Ops[isSigned][2], dl, WideVT, LHS);
+ RHS = DAG.getNode(Ops[isSigned][2], dl, WideVT, RHS);
+
+ SDValue Ops[2] = { LHS, RHS };
+ SDValue Ret = ExpandLibCall(LC, Node, Ops);
+ BottomHalf = DAG.getNode(ISD::TRUNCATE, dl, VT, Ret);
+ TopHalf = DAG.getNode(ISD::SRL, dl, Ret.getValueType(), Ret,
+ DAG.getConstant(VT.getSizeInBits(), TLI.getPointerTy()));
+ TopHalf = DAG.getNode(ISD::TRUNCATE, dl, VT, TopHalf);
}
if (isSigned) {
Tmp1 = DAG.getConstant(VT.getSizeInBits() - 1, TLI.getShiftAmountTy());