[llvm] [AMDGPU] Handle lowering addrspace casts from LDS to FLAT address in amdgpu-sw-lower-lds. (PR #121214)

[Matt Arsenault via llvm-commits]

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@@ -668,22 +668,18 @@ Value *AMDGPUSwLowerLDS::getTranslatedGlobalMemoryPtrOfLDS(Value *LoadMallocPtr,
                                                            Value *LDSPtr) {
   assert(LDSPtr && "Invalid LDS pointer operand");
   Type *LDSPtrType = LDSPtr->getType();
-
-  if (LDSPtrType->isVectorTy()) {
+  auto &Ctx = M.getContext();
+  const auto &DL = M.getDataLayout();
+  auto *IntPtrTy = DL.getIntPtrType(Ctx, AMDGPUAS::LOCAL_ADDRESS);
+  if (auto *VecPtrTy = dyn_cast<VectorType>(LDSPtrType)) {
     // Handle vector of pointers
-    VectorType *VecPtrTy = cast<VectorType>(LDSPtrType);
     ElementCount NumElements = VecPtrTy->getElementCount();
-    Type *Int32VecTy = VectorType::get(IRB.getInt32Ty(), NumElements);
-    Value *PtrToInt = IRB.CreatePtrToInt(LDSPtr, Int32VecTy);
+    Type *IntVecTy = VectorType::get(IntPtrTy, NumElements);
+    Value *PtrToInt = IRB.CreatePtrToInt(LDSPtr, IntVecTy);
     // Create vector of pointers to global address space
-    Type *GlobalPtrVecTy =
-        VectorType::get(IRB.getPtrTy(AMDGPUAS::GLOBAL_ADDRESS), NumElements);
-    Value *GlobalPtrVec =
-        IRB.CreateInBoundsGEP(IRB.getInt8Ty(), LoadMallocPtr, PtrToInt);
-    GlobalPtrVec = IRB.CreateBitCast(GlobalPtrVec, GlobalPtrVecTy);
-    return GlobalPtrVec;
+    return IRB.CreateInBoundsGEP(IRB.getInt8Ty(), LoadMallocPtr, PtrToInt);
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arsenm wrote:

You can use the same code for the scalar case. The GEP supports scalar base with vector offset, you just need to use the correct type

https://github.com/llvm/llvm-project/pull/121214