[PATCH] D68244: [InstCombine] don't assume 'inbounds' for bitcast pointer to GEP transform (PR43501)

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri added inline comments.


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Comment at: llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp:2351
+          DerefBytes >= EltBitWidth / 8)
+        GEP->setIsInBounds();
+      return GEP;
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spatel wrote:
> lebedev.ri wrote:
> > @jdoerfert @uenoku @sstefan1 
> > attributor potential missing feature: i'd expect that it could set this `inbounds`, but it does not: https://godbolt.org/z/zkUt1-
> Right...so I proposed this change based on the comments in PR43501, but it raises a question:
> Do we want instcombine doing these limited improvements, or is it better to leave that entire responsibility to Attributor?
Once attributor is enabled and can do this, if it will run frequent-enough in the pipeline,
i'd strongly insist that it should do this.

But currently it does not, so let's keep this for now.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D68244/new/

https://reviews.llvm.org/D68244