[Bug tree-optimization/64957] New: wrong code at -O1, -O2 and -O3 on x86_64-linux-gnu

[Bug tree-optimization/64957] New: wrong code at -O1, -O2 and -O3 on x86_64-linux-gnu

[su at cs dot ucdavis.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64957

            Bug ID: 64957
           Summary: wrong code at -O1, -O2 and -O3 on x86_64-linux-gnu
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: su at cs dot ucdavis.edu

The current gcc trunk miscompiles the following code on x86_64-linux at -O1,
-O2 and -O3 in both 32-bit and 64-bit modes. 

This is a regression from 4.9.x. 

$ gcc-trunk -v
Using built-in specs.
COLLECT_GCC=gcc-trunk
COLLECT_LTO_WRAPPER=/usr/local/gcc-trunk/libexec/gcc/x86_64-unknown-linux-gnu/5.0.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: ../gcc-trunk/configure --prefix=/usr/local/gcc-trunk
--enable-languages=c,c++ --disable-werror --enable-multilib
Thread model: posix
gcc version 5.0.0 20150205 (experimental) [trunk revision 220434] (GCC) 
$ 
$ gcc-trunk -O0 small.c; a.out
$ gcc-4.9 -O1 small.c; a.out
$ 
$ gcc-trunk -O1 small.c
$ ./a.out
Aborted (core dumped)
$ 



--------------------------



int a, b;

int
main ()
{
  a = 0;
  for (; a < 2; a++)
    {
      b ^= 5;
      b |= 1;
    }

  if (b != 1)
    __builtin_abort ();

  return 0;
}

[Bug tree-optimization/64957] [5 Regression] wrong code at -O1, -O2 and -O3 on x86_64-linux-gnu

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64957

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2015-02-06
                 CC|                            |jakub at gcc dot gnu.org
           Assignee|unassigned at gcc dot gnu.org      |jakub at gcc dot gnu.org
   Target Milestone|---                         |5.0
            Summary|wrong code at -O1, -O2 and  |[5 Regression] wrong code
                   |-O3 on x86_64-linux-gnu     |at -O1, -O2 and -O3 on
                   |                            |x86_64-linux-gnu
     Ever confirmed|0                           |1

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Caused by r220405.  Will test the obvious fix.

[Bug rtl-optimization/64957] [5 Regression] wrong code at -O1, -O2 and -O3 on x86_64-linux-gnu

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64957

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 34682
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34682&action=edit
gcc5-pr64957.patch

Untested fix.

[Bug rtl-optimization/64957] [5 Regression] wrong code at -O1, -O2 and -O3 on x86_64-linux-gnu

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64957

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P1

[Bug rtl-optimization/64957] [5 Regression] wrong code at -O1, -O2 and -O3 on x86_64-linux-gnu

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64957

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Author: jakub
Date: Fri Feb  6 11:36:34 2015
New Revision: 220475

URL: https://gcc.gnu.org/viewcvs?rev=220475&root=gcc&view=rev
Log:
    PR rtl-optimization/64957
    PR debug/64817
    * simplify-rtx.c (simplify_binary_operation_1): Use ~cval for
    IOR rather than for AND.

    * gcc.c-torture/execute/pr64957.c: New test.

Added:
    trunk/gcc/testsuite/gcc.c-torture/execute/pr64957.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/simplify-rtx.c
    trunk/gcc/testsuite/ChangeLog

[Bug rtl-optimization/64957] [5 Regression] wrong code at -O1, -O2 and -O3 on x86_64-linux-gnu

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64957

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Fixed.