[llvm] r179060 - Update the docs about the fact that the loop vectorizer is enabled by default for -O3.

Sean Silva silvas at purdue.edu
Mon Apr 8 17:55:27 PDT 2013


On Mon, Apr 8, 2013 at 5:34 PM, Nadav Rotem <nrotem at apple.com> wrote:

> Author: nadav
> Date: Mon Apr  8 16:34:49 2013
> New Revision: 179060
>
> URL: http://llvm.org/viewvc/llvm-project?rev=179060&view=rev
> Log:
> Update the docs about the fact that the loop vectorizer is enabled by
> default for -O3.
>
> Modified:
>     llvm/trunk/docs/Vectorizers.rst
>
> Modified: llvm/trunk/docs/Vectorizers.rst
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/Vectorizers.rst?rev=179060&r1=179059&r2=179060&view=diff
>
> ==============================================================================
> --- llvm/trunk/docs/Vectorizers.rst (original)
> +++ llvm/trunk/docs/Vectorizers.rst Mon Apr  8 16:34:49 2013
> @@ -21,19 +21,14 @@ The Loop Vectorizer
>  Usage
>  -----
>
> -LLVM's Loop Vectorizer is now available and will be useful for many
> people.
> -It is not enabled by default, but can be enabled through clang using the
> -command line flag:
> +LLVM's Loop Vectorizer is now enabled by default for -O3.
> +The vectorizer can be disabled using the command line:
>
>  .. code-block:: console
>
> -   $ clang -fvectorize -O3 file.c
> +   $ clang ... -fno-vectorize  file.c
>
> -If the ``-fvectorize`` flag is used then the loop vectorizer will be
> enabled
> -when running with ``-O3``, ``-O2``. When ``-Os`` is used, the loop
> vectorizer
> -will only vectorize loops that do not require a major increase in code
> size.
> -
> -We plan to enable the Loop Vectorizer by default as part of the LLVM 3.3
> release.
> +At this point the loop vectorizer is only enabled for -O3, and will not
> work for -O2 or -Os.
>

On a first reading, I interpret "will not work" here as "is broken/buggy"
(and that seems like it would require a proper explanation anyway). Please
clarify the wording.

-- Sean Silva
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20130408/84c47620/attachment.html>


More information about the llvm-commits mailing list