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From: "avieira at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/108177] New: MVE predicated stores to same address get optimized away
Date: Mon, 19 Dec 2022 14:29:38 +0000	[thread overview]
Message-ID: <bug-108177-4@http.gcc.gnu.org/bugzilla/> (raw)

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108177

            Bug ID: 108177
           Summary: MVE predicated stores to same address get optimized
                    away
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: avieira at gcc dot gnu.org
  Target Milestone: ---

GCC currently generates wrong code for predicated MVE stores to the same
address. Like:

#include <arm_mve.h>

uint8x16_t foo (uint8x16_t a, uint8_t *pa, mve_pred16_t p1, mve_pred16_t p2)
{
    vstrbq_p_u8 (pa, a, p1);
    vstrbq_p_u8 (pa, a, p2);
}

with 'gcc -mcpu=cortex-m55 -mfloat-abi=hard -O3' it will only generate the
second MVE store. Though if (p2 | p1) != p2 then the second store will not
fully overwrite the first.

             reply	other threads:[~2022-12-19 14:29 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-12-19 14:29 avieira at gcc dot gnu.org [this message]
2022-12-19 14:30 ` [Bug target/108177] " avieira at gcc dot gnu.org
2022-12-19 15:47 ` rguenth at gcc dot gnu.org
2022-12-19 17:20 ` avieira at gcc dot gnu.org
2023-01-24 17:02 ` cvs-commit at gcc dot gnu.org
2023-04-06 17:32 ` stammark at gcc dot gnu.org
2023-05-18 10:43 ` cvs-commit at gcc dot gnu.org

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