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Re: [PATCH] Fix postreload constant merging (PR target/84899)
- From: Jeff Law <law at redhat dot com>
- To: Jakub Jelinek <jakub at redhat dot com>, Richard Biener <rguenther at suse dot de>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Fri, 16 Mar 2018 14:57:40 -0600
- Subject: Re: [PATCH] Fix postreload constant merging (PR target/84899)
- References: <20180316201722.GI8577@tucnak>
On 03/16/2018 02:17 PM, Jakub Jelinek wrote:
> Hi!
>
> The following testcase ICEs on powerpc-linux, because we merge
> SImode constants 0x7fffffff and 1 into 0x80000000, which is not valid SImode
> CONST_INT - -0x80000000 is. Fixed by calling trunc_int_for_mode, and to
> avoid UB in the compiler do the addition in unsigned type.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux and tested on the
> testcase with powerpc64-linux cross with -m32, ok for trunk?
>
> 2018-03-16 Jakub Jelinek <jakub@redhat.com>
>
> PR target/84899
> * postreload.c (reload_combine_recognize_pattern): Perform
> INTVAL addition in unsigned HOST_WIDE_INT type to avoid UB and
> truncate_int_for_mode the result for the destination's mode.
>
> * gcc.dg/pr84899.c: New test.
OK.
jeff