[DAGCombine] foldBinOpIntoSelect can fail to constant fold in some cases.

For example, float operations may fail to constant fold under certain circumstances (inf/nan/denormal creation etc.)

Reduced from oss-fuzz #4802 test case

llvm-svn: 321488

1 files changed, 8 insertions, 6 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 1119a36849c..3218dce8f57 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -1922,14 +1922,16 @@ SDValue DAGCombiner::foldBinOpIntoSelect(SDNode *BO) {
   EVT VT = Sel.getValueType();
   SDLoc DL(Sel);
   SDValue NewCT = DAG.getNode(BinOpcode, DL, VT, CT, C1);
-  assert((NewCT.isUndef() || isConstantOrConstantVector(NewCT) ||
-          isConstantFPBuildVectorOrConstantFP(NewCT)) &&
-         "Failed to constant fold a binop with constant operands");
+  if (!NewCT.isUndef() &&
+      !isConstantOrConstantVector(NewCT, true) &&
+      !isConstantFPBuildVectorOrConstantFP(NewCT))
+    return SDValue();
 
   SDValue NewCF = DAG.getNode(BinOpcode, DL, VT, CF, C1);
-  assert((NewCF.isUndef() || isConstantOrConstantVector(NewCF) ||
-          isConstantFPBuildVectorOrConstantFP(NewCF)) &&
-         "Failed to constant fold a binop with constant operands");
+  if (!NewCF.isUndef() &&
+      !isConstantOrConstantVector(NewCF, true) &&
+      !isConstantFPBuildVectorOrConstantFP(NewCF))
+    return SDValue();
 
   return DAG.getSelect(DL, VT, Sel.getOperand(0), NewCT, NewCF);
 }