Don't assume that only Uses can be kills. Defs are marked as kills initially
when there are no uses. This fixes a dangling-pointer bug, where pointers to
deleted instructions were not removed from kills lists. More info here:
http://lists.cs.uiuc.edu/pipermail/llvmdev/2007-July/009749.html
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40131 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LiveVariables.cpp b/lib/CodeGen/LiveVariables.cpp
index 504b607..d1ebaf1 100644
--- a/lib/CodeGen/LiveVariables.cpp
+++ b/lib/CodeGen/LiveVariables.cpp
@@ -582,15 +582,13 @@
if (VI.DefInst == OldMI)
VI.DefInst = NewMI;
}
- if (MO.isUse()) {
- if (MO.isKill()) {
- MO.unsetIsKill();
- addVirtualRegisterKilled(Reg, NewMI);
- }
- // If this is a kill of the value, update the VI kills list.
- if (VI.removeKill(OldMI))
- VI.Kills.push_back(NewMI); // Yes, there was a kill of it
+ if (MO.isKill()) {
+ MO.unsetIsKill();
+ addVirtualRegisterKilled(Reg, NewMI);
}
+ // If this is a kill of the value, update the VI kills list.
+ if (VI.removeKill(OldMI))
+ VI.Kills.push_back(NewMI); // Yes, there was a kill of it
}
}
}