[llvm] [AArch64] Codegen for AArch64 Return Address Signing Hardening (PR #176187)

[Anatoly Trosinenko via llvm-commits]

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@@ -352,9 +368,16 @@ void AArch64PointerAuthImpl::authenticateLR(
     // the DW_CFA_AARCH64_negate_ra_state can't be emitted. Additionally,
     // RET{A,B} requires the SP to match its incoming value on entry to the
     // function.
-    bool TerminatorIsCombinable = TI != MBB.end() &&
-                                  TI->getOpcode() == AArch64::RET &&
-                                  ArgumentStackToRestore == 0;
+    //
+    // If the PAC-RET hardening based on load of return address is enabled,
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atrosinenko wrote:

[nit] "**from** the return address"

https://github.com/llvm/llvm-project/pull/176187