[llvm] [AIX] Support per global code model. (PR #79202)

[Sean Fertile via llvm-commits]

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@@ -466,6 +466,63 @@ static void collectTOCStats(PPCAsmPrinter::TOCEntryType Type) {
   }
 }
 
+static CodeModel::Model getCodeModel(const PPCSubtarget &S,
+                                     const TargetMachine &TM,
+                                     const MachineOperand &MO) {
+  assert(S.isAIXABI() && "ELF per global code model not supported yet");
+
+  CodeModel::Model ModuleModel = TM.getCodeModel();
+
+  // If the operand is not a global address then there is no
+  // global variable to carry an attribute.
+  if (!(MO.getType() == MachineOperand::MO_GlobalAddress))
+    return ModuleModel;
+
+  const GlobalValue *GV = MO.getGlobal();
+  assert(GV && "expected global for MO_GlobalAddress");
+
+  if (!isa<GlobalVariable>(GV))
+    return ModuleModel;
+
+  std::optional<CodeModel::Model> MaybeCodeModel =
+      dyn_cast<GlobalVariable>(GV)->getCodeModel();
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mandlebug wrote:

We have an early return on `!isa<GlobalVariable>(GV))` so we know dyn_cast must not fail - and because of that I should be using cast<> instead. I'll update it.

https://github.com/llvm/llvm-project/pull/79202