Fixed a failure in cost calculation for vector GEP

[oota-llvm.git] / include / llvm / Analysis / TargetTransformInfoImpl.h

diff --git a/include/llvm/Analysis/TargetTransformInfoImpl.h b/include/llvm/Analysis/TargetTransformInfoImpl.h
index 415a85e990696cef36491862da8e348a96ff2d24..eedf1a61ba828da1c3b6cbd7352e107035f3c515 100644 (file)
--- a/include/llvm/Analysis/TargetTransformInfoImpl.h
+++ b/include/llvm/Analysis/TargetTransformInfoImpl.h
@@ -22,6 +22,7 @@
 #include "llvm/IR/GetElementPtrTypeIterator.h"
 #include "llvm/IR/Operator.h"
 #include "llvm/IR/Type.h"
+#include "llvm/Analysis/VectorUtils.h"
 
 namespace llvm {
 
@@ -415,21 +416,28 @@ public:
         (Ptr == nullptr ? 0 : Ptr->getType()->getPointerAddressSpace());
     auto GTI = gep_type_begin(PointerType::get(PointeeType, AS), Operands);
     for (auto I = Operands.begin(); I != Operands.end(); ++I, ++GTI) {
+      // We assume that the cost of Scalar GEP with constant index and the
+      // cost of Vector GEP with splat constant index are the same.
+      const ConstantInt *ConstIdx = dyn_cast<ConstantInt>(*I);
+      if (!ConstIdx)
+        if (auto Splat = getSplatValue(*I))
+          ConstIdx = dyn_cast<ConstantInt>(Splat);
       if (isa<SequentialType>(*GTI)) {
         int64_t ElementSize = DL.getTypeAllocSize(GTI.getIndexedType());
-        if (const ConstantInt *ConstIdx = dyn_cast<ConstantInt>(*I)) {
+        if (ConstIdx)
           BaseOffset += ConstIdx->getSExtValue() * ElementSize;
-        } else {
+        else {
           // Needs scale register.
-          if (Scale != 0) {
+          if (Scale != 0)
             // No addressing mode takes two scale registers.
             return TTI::TCC_Basic;
-          }
           Scale = ElementSize;
         }
       } else {
         StructType *STy = cast<StructType>(*GTI);
-        uint64_t Field = cast<ConstantInt>(*I)->getZExtValue();
+        // For structures the index is always splat or scalar constant
+        assert(ConstIdx && "Unexpected GEP index");
+        uint64_t Field = ConstIdx->getZExtValue();
         BaseOffset += DL.getStructLayout(STy)->getElementOffset(Field);
       }
     }