[llvm] [llvm-exegesis] [AArch64] Resolving Illegal Instruction Error (PR #132346)

[David Green via llvm-commits]

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@@ -35,6 +35,14 @@ const ExegesisTarget *ExegesisTarget::lookup(Triple TT) {
   return nullptr;
 }
 
+static bool isPointerAuthOpcode(unsigned Opcode) {
+  return (Opcode >= 1648 && Opcode <= 1667); // AUT instruction class range
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davemgreen wrote:

Which ones fail for you? I tried AUTDA and it seemed to do OK when I tried it. My understanding was that they corrupted bits in the return address, which only faults when they are used. FEAT_FPAC might enable more faulting of the instructions directly.

(In general, this being a developer tool, I wasn't sure of the benefit or downside of marking an instruction as unsupported as opposed to just trying it and seeing if it worked. Disabling it has the downside that no-one can use it even if it could work. But I can see how that might make analyzing many instructions more.. messy).

https://github.com/llvm/llvm-project/pull/132346