[llvm] [MC] [Win64EH] Produce packed unwind for the special case of X19+LR (PR #169697)

[Eli Friedman via llvm-commits]

Martin =?utf-8?q?Storsjö?= <martin at martin.st>
Message-ID:
In-Reply-To: <llvm.org/llvm/llvm-project/pull/169697 at github.com>


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@@ -1169,6 +1171,24 @@ static bool tryARM64PackedUnwind(WinEH::FrameInfo *info, uint32_t FuncLength,
           Location != FloatRegs && Location != InputArgs &&
           Location != StackAdjust)
         return false;
+      if (Location == Start2) { // Can't have this at Start3, after PACSignLR
+        auto NextIt = It + 1;
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efriedma-quic wrote:

This probably deserves a comment explaining that a special case in the packed encoding exists here because we don't have savelrpair_x.

https://github.com/llvm/llvm-project/pull/169697