Add target hook to allow merging stores of nonzero constants
On GPU targets, materializing constants is cheap and stores are
expensive, so only doing this for zero vectors was silly.
Most of the new testcases aren't optimally merged, and are for
later improvements.
llvm-svn: 238108
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 77e648c..2c2dc85 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -10892,10 +10892,17 @@
}
}
- // We only use vectors if the constant is known to be zero and the
- // function is not marked with the noimplicitfloat attribute.
- if (NonZero || NoVectors)
+
+ // We only use vectors if the constant is known to be zero or the target
+ // allows it and the function is not marked with the noimplicitfloat
+ // attribute.
+ if (NoVectors) {
LastLegalVectorType = 0;
+ } else if (NonZero && !TLI.storeOfVectorConstantIsCheap(MemVT,
+ LastLegalVectorType,
+ FirstStoreAS)) {
+ LastLegalVectorType = 0;
+ }
// Check if we found a legal integer type to store.
if (LastLegalType == 0 && LastLegalVectorType == 0)