[PATCH] D37611: [IfConversion] More simple, correct dead/kill liveness handling

Krzysztof Parzyszek via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Fri Sep 8 09:21:58 PDT 2017


kparzysz added inline comments.


================
Comment at: lib/CodeGen/MachineBasicBlock.cpp:456
+        MO->setIsKill(false);
+      if (MO->isDead())
+        MO->setIsDead(false);
----------------
Are you seeing any cases where a "dead" flag would be removed?  This is somewhat concerning.  Whether a use is a kill or not depends on the ordering relative to other uses, which can change.  Whether a def is dead or not is more closely related to the program's semantics: once a def is dead, new uses should not really appear.


https://reviews.llvm.org/D37611





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