Re: [PATCH] sra: Partial fix for BITINT_TYPEs [PR113120]

[Jakub Jelinek <jakub@redhat.com>]

On Wed, Jan 17, 2024 at 03:46:44PM +0100, Martin Jambor wrote:
> > Note, it would be good if we were able to punt on the optimization
> > (but this code doesn't seem to be able to punt, so it needs to be done
> > somewhere earlier) at least in cases where building it would be invalid.
> > E.g. right now BITINT_TYPE can support precisions up to 65535 (inclusive),
> > but 65536 will not work anymore (we can't have > 16-bit TYPE_PRECISION).
> > I've tried to replace 513 with 65532 in the testcase and it didn't ICE,
> > so maybe it ran into some other SRA limit.
> 
> Thank you very much for the patch.  Regarding punting, did you mean for
> all BITINT_TYPEs or just for big ones, like you did when you fixed PR
> 11333 (thanks for that too) or something entirely else?

I meant what I did in PR113330, but still wonder if we really need to use
a root->size which is multiple of BITS_PER_UNIT (or words or whatever it
actually is), at least on little endian if the _BitInt starts at the start
of a memory.  See
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113408#c1
for more details, wonder if it just couldn't use _BitInt(713) in there
directly rather than _BitInt(768).

	Jakub