public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "vsevolod.livinskij at frtk dot ru" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/103037] New: [11/12 Regression] Wrong code with -O2
Date: Tue, 02 Nov 2021 07:17:23 +0000	[thread overview]
Message-ID: <bug-103037-4@http.gcc.gnu.org/bugzilla/> (raw)

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103037

            Bug ID: 103037
           Summary: [11/12 Regression] Wrong code with -O2
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: vsevolod.livinskij at frtk dot ru
  Target Milestone: ---

Link to the Compiler Explorer: https://godbolt.org/z/eaGzsPnax

Reproducer:
#include <stdio.h>

short var_3 = 2;
unsigned char var_9 = 23;
unsigned short var_11;
unsigned short arr_4 [23];

void test() __attribute__((noipa));

const unsigned short &min(unsigned short &d, const unsigned short &e) {
  return e < d ? e : d;
}

void test() {
  for (int a = 0; a < var_9; a += 3)
      var_11 = min(arr_4[a], 1) / (arr_4[a] ? arr_4[a] : var_3);
}


int main() {
    for (size_t i_0 = 0; i_0 < 23; ++i_0)
        arr_4 [i_0] = 2;
    test();
    printf("%hu\n", var_11);
    if (var_11 != 0)
        __builtin_abort();

}

Error:
>$ g++ driver.cpp -O0 && ./a.out
0
>$ g++ driver.cpp -O2 && ./a.out
1

GCC version:
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/testing/gcc/bin_master/libexec/gcc/x86_64-pc-linux-gnu/12.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /testing/gcc/gcc_src_master/configure --enable-multilib
--prefix=/testing/gcc/bin_master --disable-bootstrap
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 12.0.0 20211101 (679652a77da60078392a834ed4b6b910127dbf24) (GCC)

             reply	other threads:[~2021-11-02  7:17 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-02  7:17 vsevolod.livinskij at frtk dot ru [this message]
2021-11-02  7:36 ` [Bug tree-optimization/103037] [11/12 Regression] Wrong code with -O2 since r11-6100-gd41b097350d3c5d0 marxin at gcc dot gnu.org
2021-11-02  7:52 ` pinskia at gcc dot gnu.org
2021-11-02  8:43 ` rguenth at gcc dot gnu.org
2021-11-02  8:51 ` jakub at gcc dot gnu.org
2021-11-02  9:08 ` jakub at gcc dot gnu.org
2021-11-02 14:18 ` rguenther at suse dot de
2021-11-03 10:08 ` rguenth at gcc dot gnu.org
2021-11-05 13:39 ` rguenth at gcc dot gnu.org
2022-02-23 15:25 ` rguenth at gcc dot gnu.org
2022-02-25 12:21 ` cvs-commit at gcc dot gnu.org
2022-02-25 12:21 ` [Bug tree-optimization/103037] [11 " rguenth at gcc dot gnu.org
2022-04-21  7:50 ` rguenth at gcc dot gnu.org
2023-05-29 10:05 ` jakub at gcc dot gnu.org

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=bug-103037-4@http.gcc.gnu.org/bugzilla/ \
    --to=gcc-bugzilla@gcc.gnu.org \
    --cc=gcc-bugs@gcc.gnu.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).