[PATCH] D49281: [Unroll/UnrollAndJam/Vectorizer/Distribute] Add followup loop attributes.

[Michael Kruse via Phabricator via llvm-commits]

Meinersbur added inline comments.


================
Comment at: lib/Transforms/Scalar/WarnMissedTransforms.cpp:32
+                                          L->getStartLoc(), L->getHeader())
+        << "loop not unrolled: failed explicitly specified loop unrolling");
+  }
----------------
hfinkel wrote:
> Here and below, explicitly specified should have a hyphen (it is a compound adjective):
> 
>   explicitly-specified loop unrolling
> 
> that having been said, I'd prefer a different phrasing all together. These are end-user visible messages, and I think that we can make these slightly more user friendly. How about this:
> 
>   
>   "loop not unrolled: the optimizer was unable to perform the requested transformation"
> 
> (and similar for the others)
I think that "the optimizer was unable to perform" is less accurate: it gives the impression that the optimizer actually tried to perform the transformation, but one of the reasons the metadata is still present is that the corresponding pass is not in the pipeline (e.g. because of `-fno-vectorize` or `-mllvm -enable-unroll-and-jam` is missing). That is, the user should modify the compiler flags instead of tweaking the source code.

That being said, "failed to ..." is not much better. Any better suggestions?


Repository:
  rL LLVM

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  https://reviews.llvm.org/D49281/new/

https://reviews.llvm.org/D49281