Re: Possible bug in GCC 5, need help

[Stephen Powell <zlinuxman@wowway.com>]

On Sat, 15 Aug 2015 05:44:42 -0400 (EDT), Mike Hommey wrote:
> ...
> The current version of Iceweasel in unstable fails to build because of
> an internal error in the javascript engine which looks like it could be
> caused by some miscompilation.
> ...
> I was able to narrow it down as follows:
> ...
> - Building js/src/Parser.o with a #pragma GCC optimize("O0") at the
>   beginning fixes it.
> - Then I was able to go down at the function level, whereby moving the
>   following function at the end of the file and preceding it with the
>   pragma above fixes it:
>     template <>
>     /* static */ bool
>     Parser<FullParseHandler>::bindLexical(BindData<FullParseHandler>* data,
>                                           HandlePropertyName name,
>                                           Parser<FullParseHandler>* parser)
> 
>   (somehow, adding a #pragma GCC optimize("O3") after a O0 one doesn't
>    raise optimization level for the rest of the file, what's why I
>    double checked by moving the function)
> 
> Could someone with s390x assembly knowledge look at the assembly for
> that function and narrow it down further, possibly filing a GCC bug?

If you will produce a compiler listing that shows the generated machine
language and pseudo-assembly language for the problem piece of code,
both for the good case and the failing case, and send me a link to it,
I'll take a look at it.  I can't promise you success, but I'll look at it.

-- 
  .''`.     Stephen Powell    <zlinuxman@wowway.com>
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