[llvm-branch-commits] [llvm] [AArch64][PAC] Lower authenticated calls with ptrauth bundles. (PR #85736)

[Daniil Kovalev via llvm-branch-commits]

================
@@ -1694,6 +1718,35 @@ let Predicates = [HasPAuth] in {
     def BLRABZ  : AuthOneOperand<0b001, 1, "blrabz">;
   }
 
+  // BLRA pseudo, generalized version of BLRAA/BLRAB/Z.
+  // This directly manipulates x16/x17, which are the only registers the OS
+  // guarantees are safe to use for sensitive operations.
----------------
kovdan01 wrote:

Yes, having a more detailed comment here would be nice. As for now, from the comment it was unclear that this is Darwin-specific. It's also probably worth mentioning that it's harmless for non-Darwin, as you said.

https://github.com/llvm/llvm-project/pull/85736