3 files changed, 20 insertions, 3 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 77e648c152c..2c2dc859816 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -10892,10 +10892,17 @@ bool DAGCombiner::MergeConsecutiveStores(StoreSDNode* St) {
       }
     }
 
-    // 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)
diff --git a/llvm/lib/Target/R600/AMDGPUISelLowering.cpp b/llvm/lib/Target/R600/AMDGPUISelLowering.cpp
index b304488142a..880240c51a8 100644
--- a/llvm/lib/Target/R600/AMDGPUISelLowering.cpp
+++ b/llvm/lib/Target/R600/AMDGPUISelLowering.cpp
@@ -509,6 +509,12 @@ bool AMDGPUTargetLowering::isFNegFree(EVT VT) const {
   return VT == MVT::f32 || VT == MVT::f64;
 }
 
+bool AMDGPUTargetLowering:: storeOfVectorConstantIsCheap(EVT MemVT,
+                                                         unsigned NumElem,
+                                                         unsigned AS) const {
+  return true;
+}
+
 bool AMDGPUTargetLowering::isTruncateFree(EVT Source, EVT Dest) const {
   // Truncate is just accessing a subregister.
   return Dest.bitsLT(Source) && (Dest.getSizeInBits() % 32 == 0);
diff --git a/llvm/lib/Target/R600/AMDGPUISelLowering.h b/llvm/lib/Target/R600/AMDGPUISelLowering.h
index 8507cb3c745..c9f198129ef 100644
--- a/llvm/lib/Target/R600/AMDGPUISelLowering.h
+++ b/llvm/lib/Target/R600/AMDGPUISelLowering.h
@@ -133,6 +133,10 @@ public:
                              EVT ExtVT) const override;
 
   bool isLoadBitCastBeneficial(EVT, EVT) const override;
+
+  bool storeOfVectorConstantIsCheap(EVT MemVT,
+                                    unsigned NumElem,
+                                    unsigned AS) const override;
   bool isCheapToSpeculateCttz() const override;
   bool isCheapToSpeculateCtlz() const override;