[llvm] [VectorCombine] Try to scalarize vector loads feeding bitcast instructions. (PR #164682)

[Julian Nagele via llvm-commits]

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@@ -1845,49 +1847,42 @@ bool VectorCombine::foldSingleElementStore(Instruction &I) {
   return false;
 }
 
-/// Try to scalarize vector loads feeding extractelement instructions.
-bool VectorCombine::scalarizeLoadExtract(Instruction &I) {
-  if (!TTI.allowVectorElementIndexingUsingGEP())
-    return false;
-
+/// Try to scalarize vector loads feeding extractelement or bitcast
+/// instructions.
+bool VectorCombine::scalarizeLoad(Instruction &I) {
   Value *Ptr;
   if (!match(&I, m_Load(m_Value(Ptr))))
     return false;
 
   auto *LI = cast<LoadInst>(&I);
   auto *VecTy = cast<VectorType>(LI->getType());
-  if (LI->isVolatile() || !DL->typeSizeEqualsStoreSize(VecTy->getScalarType()))
+  if (!VecTy || LI->isVolatile() ||
+      !DL->typeSizeEqualsStoreSize(VecTy->getScalarType()))
     return false;
 
-  InstructionCost OriginalCost =
-      TTI.getMemoryOpCost(Instruction::Load, VecTy, LI->getAlign(),
-                          LI->getPointerAddressSpace(), CostKind);
-  InstructionCost ScalarizedCost = 0;
-
+  // Check what type of users we have and ensure no memory modifications betwwen
+  // the load and its users.
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juliannagele wrote:

done, thanks!

https://github.com/llvm/llvm-project/pull/164682