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[llvm][CodeGen] Check for memory instructions when querying for alias status
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Authored by Kayjukh on Apr 24 2020, 12:06 PM.

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Summary

Add a check to make sure that MachineInstr::mayAlias returns prematurely if at least one of its instruction parameters does not access memory. This prevents calls to TargetInstrInfo::areMemAccessesTriviallyDisjoint with incompatible instructions.

A side effect of this change is to render the mayAlias helper in the AArch64 load/store optimizer obsolete. We can now directly call the MachineInstr::mayAlias member function.

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Event Timeline

Kayjukh created this revision.Apr 24 2020, 12:06 PM

Is this fixing a visible bug? Or is it just a cleanup?

It is just a cleanup. I ran into an issue related to this missing check in an out-of-tree project.

This revision is now accepted and ready to land.Apr 24 2020, 1:39 PM
This revision was automatically updated to reflect the committed changes.