[clang] [llvm] [AMDGPU] Infer amdgpu-no-flat-scratch-init attribute in AMDGPUAttributor (PR #94647)

[Matt Arsenault via cfe-commits]

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@@ -434,6 +434,15 @@ struct AAAMDAttributesFunction : public AAAMDAttributes {
       indicatePessimisticFixpoint();
       return;
     }
+
+    for (Instruction &I : instructions(F)) {
+      if (isa<AddrSpaceCastInst>(I) &&
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arsenm wrote:

5->3 is an illegal address space cast, but the round trip cast can fold away. You don't want the cast back to the original address space. 

https://github.com/llvm/llvm-project/pull/94647