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Re: Errors building libgcc for powerpc64le-linux-gnu


On Sat, Dec 14, 2019 at 11:25 PM Segher Boessenkool
<segher@kernel.crashing.org> wrote:
>
> On Sat, Dec 14, 2019 at 10:51:50AM -0800, Ian Lance Taylor via gcc wrote:
> > I'm seeing compiler crashes building libgcc for powerpc64le-linux-gnu,
> > cross-compiling from x86_64-pc-linux-gnu.  I'm at SVN revision 279830.
> > I'm seeing the following.  Is anybody else seeing this crash?  Thanks.
>
> No, and that makes me wonder what is going on.  The error is simple enough
> of course, as you note in a later message; but why do we not see it on
> every other build?

I think it's because clang treats a left shift by a negative number as
undefined behavior but GCC does not.  So GCC is consistently producing
some number, and clang is producing different numbers.

I should note that I don't really understand what purpose that
constant is serving anyhow.

Ian


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