[llvm] [AArch64] Add CodeGen support for FEAT_CPA (PR #79569)

[Matt Arsenault via llvm-commits]

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@@ -2075,6 +2075,10 @@ bool AArch64InstructionSelector::preISelLower(MachineInstr &I) {
     return Changed;
   }
   case TargetOpcode::G_PTR_ADD:
+    // If Checked Pointer Arithmetic (FEAT_CPA) is present, preserve the pointer
+    // arithmetic semantics instead of falling back to regular arithmetic.
+    if (TM.isPtrArithmeticChecked(MF.getFunction()))
+      return false;
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arsenm wrote:

How is this supposed to work for SDAG?

https://github.com/llvm/llvm-project/pull/79569