optimization/5800: gcc -O0 produces wrong code

optimization/5800: gcc -O0 produces wrong code

[Mikhail.Jabitski]

>Number:         5800
>Category:       optimization
>Synopsis:       gcc -O0 produces wrong code
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    unassigned
>State:          open
>Class:          wrong-code
>Submitter-Id:   net
>Arrival-Date:   Fri Mar 01 03:46:01 PST 2002
>Closed-Date:
>Last-Modified:
>Originator:     gcc
>Release:        3.0.4
>Organization:
>Environment:
host: i686-pc-linux-gnu
build: i686-pc-linux-gnu
target: i686-pc-linux-gnu
configured with: ../gcc-3.0.4/configure
>Description:
gcc with optimization -O0 produces wrong code for the file comp.c:

#include <stdlib.h>

int main()
{
  int a[] = { 1, 1};
  printf("%i %i\n",a[0],a[1]);

  a[1] = a[0] && a[1];
  printf("%i %i\n",a[0],a[1]);

  return(1);
}

Compiled with: 
gcc -O0 comp.c

Program output:
1 1
1 0

Which is definitely wrong ("1 1" expected)
>How-To-Repeat:
Compile attached file with gcc -O0 comp.c and see results
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted:
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Content-Type: application/octet-stream; name="comp.c"
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="comp.c"

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Re: optimization/5800: gcc -O0 produces wrong code

[rodrigc]

Synopsis: gcc -O0 produces wrong code

State-Changed-From-To: open->closed
State-Changed-By: rodrigc
State-Changed-When: Sat Mar  2 19:50:16 2002
State-Changed-Why:
    I can reproduce your problem with gcc 3.0.4, but not with
    gcc version 3.1 20020217 (experimental).

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=5800