[SDAG] Use shift amount type in MULO promotion; NFC

Directly use the correct shift amount type if it is possible, and
future-proof the code against vectors. The added test makes sure that
bitwidths that do not fit into the shift amount type do not assert.

Split out from D57997.

llvm-svn: 354359

1 files changed, 4 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
index aee4194b86e..e664e06ccfd 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
@@ -952,9 +952,11 @@ SDValue DAGTypeLegalizer::PromoteIntRes_XMULO(SDNode *N, unsigned ResNo) {
   SDValue Overflow;
   if (N->getOpcode() == ISD::UMULO) {
     // Unsigned overflow occurred if the high part is non-zero.
+    unsigned Shift = SmallVT.getScalarSizeInBits();
+    EVT ShiftTy = getShiftAmountTyForConstant(Shift, Mul.getValueType(),
+                                              TLI, DAG);
     SDValue Hi = DAG.getNode(ISD::SRL, DL, Mul.getValueType(), Mul,
-                             DAG.getIntPtrConstant(SmallVT.getSizeInBits(),
-                                                   DL));
+                             DAG.getConstant(Shift, DL, ShiftTy));
     Overflow = DAG.getSetCC(DL, N->getValueType(1), Hi,
                             DAG.getConstant(0, DL, Hi.getValueType()),
                             ISD::SETNE);