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Re: [PATCH] [ARM] [RFC] Fix longstanding push_minipool_fix ICE (PR49423, lp1296601)

On Wed, Apr 2, 2014 at 2:29 PM, Charles Baylis
<> wrote:
> Hi
> This patch fixes the push_minipool_fix ICE, which occurs when the ARM
> backend encounters a zero/sign extending load from a constant pool.
> I don't have a current test case for trunk, lp1296601 has a test case
> which affects the linaro-4.8 branch. As far as I know, there has been
> no fix for this on trunk.
> The approach taken in this patch is to extend each pattern where this
> can occur,  so that it triggers a define_split to synthesise a
> constant move instead. Some but not all extend patterns have
> previously added pool_range attributes to work-around this problem,
> this patch removes those, and also fixes the remaining patterns. Some
> patterns have slightly more complex workarounds, which I have not yet
> analysed, but it seems worth posting the patch at this stage to get
> feedback on the general approach.
> Tested on arm-unknown-linux-gnueabihf (qemu), bootstrap in progress.
> If this looks good, I'll clean it up for a more detailed review.

Interesting workaround but can we investigate further how to fix this
at the source rather than working around in the backend in this form.
It's still a kludge that we carry in the backend rather than fix the
problem at it's source. I'd rather try to fix the problem at the
source rather than working around this in the backend.


> Thanks
> Charles

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