[Bug tree-optimization/59038] New: [4.9 Regression] r204398 causes 186.crafty init.c to be miscompiled

[Bug tree-optimization/59038] New: [4.9 Regression] r204398 causes 186.crafty init.c to be miscompiled

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59038

            Bug ID: 59038
           Summary: [4.9 Regression] r204398 causes 186.crafty init.c to
                    be miscompiled
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: rguenth at gcc dot gnu.org

-fno-tree-loop-distribute-patterns fixes it.  Trying to reduce.

[Bug tree-optimization/59038] [4.9 Regression] r204398 causes 186.crafty init.c to be miscompiled

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59038

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
extern void abort (void);

unsigned char first_ones_8bit[256];
unsigned char connected_passed[256];

int
main ()
{
  int i, j;
  for (i=0;i<256;i++){
      connected_passed[i]=0;
      first_ones_8bit[i]=0;
      for (j=7;j>0;j--){
          if ((i & (3<<(7-j))) == (3<<(7-j))){
              connected_passed[i]=j;
              break;
          }
      }
  }
  if (connected_passed[3] != 7)
    abort ();
  return 0;
}

[Bug tree-optimization/59038] [4.9 Regression] r204398 causes 186.crafty init.c to be miscompiled

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59038

Richard Biener <rguenth at gcc dot gnu.org> changed:

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

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed.

[Bug tree-optimization/59038] [4.9 Regression] r204398 causes 186.crafty init.c to be miscompiled

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59038

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Fri Nov  8 08:44:02 2013
New Revision: 204561

URL: http://gcc.gnu.org/viewcvs?rev=204561&root=gcc&view=rev
Log:
2013-11-08  Richard Biener  <rguenther@suse.de>

    PR tree-optimization/59038
    PR tree-optimization/58955
    * tree-loop-distribution.c (pg_add_dependence_edges): Revert
    previous change.  Handle known dependences correctly.

    * gcc.dg/torture/pr59038.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.dg/torture/pr59038.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/tree-loop-distribution.c

[Bug tree-optimization/59038] [4.9 Regression] r204398 causes 186.crafty init.c to be miscompiled

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59038

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |su at cs dot ucdavis.edu

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
*** Bug 59045 has been marked as a duplicate of this bug. ***