[clang] [clang] put EmitParmDecl in the target-requested AS (PR #181256)

[Jameson Nash via cfe-commits]

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@@ -2766,9 +2757,26 @@ void CodeGenFunction::EmitParmDecl(const VarDecl &D, ParamValue Arg,
       DeclPtr = OpenMPLocalAddr;
       AllocaPtr = DeclPtr;
     } else {
-      // Otherwise, create a temporary to hold the value.
-      DeclPtr = CreateMemTemp(Ty, getContext().getDeclAlign(&D),
-                              D.getName() + ".addr", &AllocaPtr);
+      // Otherwise, create a temporary to hold the value, respecting the
+      // requested AS of the destination type.
+      RawAddress Result = CreateTempAlloca(
+          ConvertTypeForMem(Ty), DestLangAS, getContext().getDeclAlign(&D),
+          D.getName() + ".addr", nullptr, &AllocaPtr);
+      if (Ty->isConstantMatrixType()) {
+        auto *ArrayTy = cast<llvm::ArrayType>(Result.getElementType());
+        auto *ArrayElementTy = ArrayTy->getElementType();
+        auto ArrayElements = ArrayTy->getNumElements();
+        if (getContext().getLangOpts().HLSL) {
+          auto *VectorTy = cast<llvm::FixedVectorType>(ArrayElementTy);
+          ArrayElementTy = VectorTy->getElementType();
+          ArrayElements *= VectorTy->getNumElements();
+        }
+        auto *VectorTy =
+            llvm::FixedVectorType::get(ArrayElementTy, ArrayElements);
+
+        Result = Result.withElementType(VectorTy);
+      }
+      DeclPtr = Result;
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vtjnash wrote:

Alternatively, this could be added as a parameter to `CreateMemTemp` to override the `Ty` addrspace for frontends that can't set this addrspace directly in their Sema

https://github.com/llvm/llvm-project/pull/181256