Remove non-live vregs from GC map on return.

Mark registers going into a return as conflict/bottom so that they aren't
considered for GC maps and deoptimization.

Bug 4191345.

Change-Id: I8af6c21824b6459788852be5417849e8ef999bcb

1 files changed, 17 insertions, 0 deletions

diff --git a/runtime/verifier/instruction_flags.h b/runtime/verifier/instruction_flags.h
index 9b2e595b9d..e50ba13932 100644
--- a/runtime/verifier/instruction_flags.h
+++ b/runtime/verifier/instruction_flags.h
@@ -93,6 +93,21 @@ class InstructionFlags {
     return IsVisited() || IsChanged();
   }
 
+  void SetReturn() {
+    flags_ |= 1 << kReturn;
+  }
+  void ClearReturn() {
+    flags_ &= ~(1 << kReturn);
+  }
+  bool IsReturn() const {
+    return (flags_ & (1 << kReturn)) != 0;
+  }
+
+  void SetCompileTimeInfoPointAndReturn() {
+    SetCompileTimeInfoPoint();
+    SetReturn();
+  }
+
   std::string ToString() const;
 
  private:
@@ -108,6 +123,8 @@ class InstructionFlags {
     kBranchTarget = 3,
     // Location of interest to the compiler for GC maps and verifier based method sharpening.
     kCompileTimeInfoPoint = 4,
+    // A return instruction.
+    kReturn = 5,
   };
 
   // Size of instruction in code units.