[llvm] [NVPTX][InferAS] assume alloca instructions are in local AS (PR #121710)

[Justin Fargnoli via llvm-commits]

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@@ -334,29 +335,34 @@ bool NVPTXDAGToDAGISel::tryEXTRACT_VECTOR_ELEMENT(SDNode *N) {
   return true;
 }
 
-static unsigned int getCodeAddrSpace(MemSDNode *N) {
-  const Value *Src = N->getMemOperand()->getValue();
-
-  if (!Src)
+static std::optional<unsigned> convertAS(unsigned AS) {
+  switch (AS) {
+  case llvm::ADDRESS_SPACE_LOCAL:
+    return NVPTX::AddressSpace::Local;
+  case llvm::ADDRESS_SPACE_GLOBAL:
+    return NVPTX::AddressSpace::Global;
+  case llvm::ADDRESS_SPACE_SHARED:
+    return NVPTX::AddressSpace::Shared;
+  case llvm::ADDRESS_SPACE_GENERIC:
     return NVPTX::AddressSpace::Generic;
-
-  if (auto *PT = dyn_cast<PointerType>(Src->getType())) {
-    switch (PT->getAddressSpace()) {
-    case llvm::ADDRESS_SPACE_LOCAL:
-      return NVPTX::AddressSpace::Local;
-    case llvm::ADDRESS_SPACE_GLOBAL:
-      return NVPTX::AddressSpace::Global;
-    case llvm::ADDRESS_SPACE_SHARED:
-      return NVPTX::AddressSpace::Shared;
-    case llvm::ADDRESS_SPACE_GENERIC:
-      return NVPTX::AddressSpace::Generic;
-    case llvm::ADDRESS_SPACE_PARAM:
-      return NVPTX::AddressSpace::Param;
-    case llvm::ADDRESS_SPACE_CONST:
-      return NVPTX::AddressSpace::Const;
-    default: break;
-    }
+  case llvm::ADDRESS_SPACE_PARAM:
+    return NVPTX::AddressSpace::Param;
+  case llvm::ADDRESS_SPACE_CONST:
+    return NVPTX::AddressSpace::Const;
+  default:
+    return std::nullopt;
   }
+}
+
+static unsigned int getCodeAddrSpace(const MemSDNode *N) {
+  if (const Value *Src = N->getMemOperand()->getValue())
+    if (auto *PT = dyn_cast<PointerType>(Src->getType()))
+      if (auto AS = convertAS(PT->getAddressSpace()))
+        return AS.value();
+
+  if (auto AS = convertAS(N->getMemOperand()->getAddrSpace()))
+    return AS.value();
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justinfargnoli wrote:

Why do we need both of these cases? 

https://github.com/llvm/llvm-project/pull/121710