have dag combine zap "store undef", which can be formed during call lowering
with undef arguments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129185 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index a9afec8..6ad85fa 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -6264,6 +6264,10 @@
Ptr, ST->getPointerInfo(), ST->isVolatile(),
ST->isNonTemporal(), OrigAlign);
}
+
+ // Turn 'store undef, Ptr' -> nothing.
+ if (Value.getOpcode() == ISD::UNDEF && ST->isUnindexed())
+ return Chain;
// Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(Value)) {
@@ -6298,8 +6302,10 @@
return DAG.getStore(Chain, N->getDebugLoc(), Tmp,
Ptr, ST->getPointerInfo(), ST->isVolatile(),
ST->isNonTemporal(), ST->getAlignment());
- } else if (!ST->isVolatile() &&
- TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i32)) {
+ }
+
+ if (!ST->isVolatile() &&
+ TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i32)) {
// Many FP stores are not made apparent until after legalize, e.g. for
// argument passing. Since this is so common, custom legalize the
// 64-bit integer store into two 32-bit stores.