[PATCH] D58694: LLVM: Optimization Pass: Remove conflicting attribute, if any, before adding new read attribute to an argument

[Johannes Doerfert via Phabricator via llvm-commits]

jdoerfert added inline comments.


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Comment at: llvm/lib/Transforms/IPO/FunctionAttrs.cpp:684
+    A->removeAttr(Attribute::ReadNone);
+    --NumReadNoneArg;
+  }
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anhtuyen wrote:
> jdoerfert wrote:
> > Why do you decrement the statistics here?
> I thought we increment the count when we added it, so removing it would require a decrement. Is it not right ?
We usually don't do that (here). I would not recommend it anyway.


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Comment at: llvm/lib/Transforms/IPO/FunctionAttrs.cpp:685
+    --NumReadNoneArg;
+  }
+  A->addAttr(R);
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anhtuyen wrote:
> jdoerfert wrote:
> > There is no need to check if an attribute is present before removing it.
> Although we can remove the attribute even when the argument does not have it, the check is to make sure we decrement the corresponding counter. 
See above.


Repository:
  rL LLVM

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  https://reviews.llvm.org/D58694/new/

https://reviews.llvm.org/D58694