[PATCH] D104546: [CSSPGO][llvm-profgen] Handle return to external transition.

[Hongtao Yu via Phabricator via llvm-commits]

This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rG5c8659801a49: [CSSPGO][llvm-profgen] Handle return to external transition. (authored by hoy).

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D104546/new/

https://reviews.llvm.org/D104546

Files:
  llvm/tools/llvm-profgen/PerfReader.cpp


Index: llvm/tools/llvm-profgen/PerfReader.cpp
===================================================================
--- llvm/tools/llvm-profgen/PerfReader.cpp
+++ llvm/tools/llvm-profgen/PerfReader.cpp
@@ -460,6 +460,16 @@
         // they are likely in different contexts.
         break;
       }
+
+      if (Binary->addressIsReturn(Src)) {
+        // In a callback case, a return from internal code, say A, to external
+        // runtime can happen. The external runtime can then call back to
+        // another internal routine, say B. Making an artificial branch that
+        // looks like a return from A to B can confuse the unwinder to treat
+        // the instruction before B as the call instruction.
+        break;
+      }
+
       // For transition to external code, group the Source with the next
       // availabe transition target.
       Dst = PrevTrDst;


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