[Bug tree-optimization/49161] New: [4.5/4.6/4.7 Regression] Fix VRP on switch stmts

[Bug tree-optimization/49161] New: [4.5/4.6/4.7 Regression] Fix VRP on switch stmts

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49161

           Summary: [4.5/4.6/4.7 Regression] Fix VRP on switch stmts
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: jakub@gcc.gnu.org
        ReportedBy: jakub@gcc.gnu.org


The following testcase is miscompiled at -O2 on x86_64/i686, starting with:
http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=155937

extern void abort (void);

int c;

__attribute__((noinline, noclone)) void
bar (int x)
{
  if (x != c++)
    abort ();
}

__attribute__((noinline, noclone)) void
foo (int x)
{
  switch (x)
    {
    case 3: goto l1;
    case 4: goto l2;
    case 6: goto l3;
    default: return;
    }
l1:
  goto l4;
l2:
  goto l4;
l3:
  bar (-1);
l4:
  bar (0);
  if (x != 4)
    bar (1);
  if (x != 3)
    bar (-1);
  bar (2);
}

int
main ()
{
  foo (3);
  if (c != 3)
    abort ();
  return 0;
}

[Bug tree-optimization/49161] [4.5/4.6/4.7 Regression] Fix VRP on switch stmts

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49161

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2011.05.25 14:10:38
      Known to work|                            |4.4.6
   Target Milestone|---                         |4.5.4
     Ever Confirmed|0                           |1
      Known to fail|                            |4.5.3, 4.6.0, 4.7.0

[Bug tree-optimization/49161] [4.5/4.6/4.7 Regression] Fix VRP on switch stmts

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49161

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-05-25 14:13:06 UTC ---
Created attachment 24356
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24356
gcc46-pr49161.patch

Untested fix.  The problem seems to be that GIMPLE_SWITCH uses until VRP
different CASE_LABEL_EXPRs for the same bb, so it adds to the same edge
assertion that x == 4 and that x == 3, while instead x >= 3 and x <= 4
assertions should be added.

[Bug tree-optimization/49161] [4.5/4.6/4.7 Regression] Fix VRP on switch stmts

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49161

--- Comment #2 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-05-25 14:35:14 UTC ---
Ick.  The patch looks ok to me.

[Bug tree-optimization/49161] [4.5/4.6/4.7 Regression] Fix VRP on switch stmts

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49161

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-05-26 10:05:08 UTC ---
Author: jakub
Date: Thu May 26 10:05:05 2011
New Revision: 174270

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=174270
Log:
    PR tree-optimization/49161
    * tree-vrp.c (struct case_info): New type.
    (compare_case_labels): Sort case_info structs instead of
    trees, and not primarily by CASE_LABEL uids but by
    label_for_block indexes.
    (find_switch_asserts): Put case labels into struct case_info
    array instead of TREE_VEC, adjust sorting, compare label_for_block
    values instead of CASE_LABELs.

    * gcc.c-torture/execute/pr49161.c: New test.

Added:
    trunk/gcc/testsuite/gcc.c-torture/execute/pr49161.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-vrp.c

[Bug tree-optimization/49161] [4.5/4.6/4.7 Regression] Fix VRP on switch stmts

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49161

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-05-26 10:20:37 UTC ---
Author: jakub
Date: Thu May 26 10:20:34 2011
New Revision: 174272

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=174272
Log:
    PR tree-optimization/49161
    * tree-vrp.c (struct case_info): New type.
    (compare_case_labels): Sort case_info structs instead of
    trees, and not primarily by CASE_LABEL uids but by
    label_for_block indexes.
    (find_switch_asserts): Put case labels into struct case_info
    array instead of TREE_VEC, adjust sorting, compare label_for_block
    values instead of CASE_LABELs.

    * gcc.c-torture/execute/pr49161.c: New test.

Added:
    branches/gcc-4_6-branch/gcc/testsuite/gcc.c-torture/execute/pr49161.c
Modified:
    branches/gcc-4_6-branch/gcc/ChangeLog
    branches/gcc-4_6-branch/gcc/testsuite/ChangeLog
    branches/gcc-4_6-branch/gcc/tree-vrp.c

[Bug tree-optimization/49161] [4.5 Regression] Fix VRP on switch stmts

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49161

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |4.6.1, 4.7.0
            Summary|[4.5/4.6/4.7 Regression]    |[4.5 Regression] Fix VRP on
                   |Fix VRP on switch stmts     |switch stmts
      Known to fail|4.7.0                       |

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-05-26 10:33:41 UTC ---
Fixed for 4.6+ so far.

[Bug tree-optimization/49161] [4.5 Regression] Fix VRP on switch stmts

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49161

--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-07-19 12:51:31 UTC ---
Author: jakub
Date: Tue Jul 19 12:51:29 2011
New Revision: 176451

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=176451
Log:
    Backport from mainline
    2011-05-26  Jakub Jelinek  <jakub@redhat.com>

    PR tree-optimization/49161
    * tree-vrp.c (struct case_info): New type.
    (compare_case_labels): Sort case_info structs instead of
    trees, and not primarily by CASE_LABEL uids but by
    label_for_block indexes.
    (find_switch_asserts): Put case labels into struct case_info
    array instead of TREE_VEC, adjust sorting, compare label_for_block
    values instead of CASE_LABELs.

    * gcc.c-torture/execute/pr49161.c: New test.

Added:
    branches/gcc-4_5-branch/gcc/testsuite/gcc.c-torture/execute/pr49161.c
Modified:
    branches/gcc-4_5-branch/gcc/ChangeLog
    branches/gcc-4_5-branch/gcc/testsuite/ChangeLog
    branches/gcc-4_5-branch/gcc/tree-vrp.c

[Bug tree-optimization/49161] [4.5 Regression] Fix VRP on switch stmts

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49161

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

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

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-07-19 13:42:48 UTC ---
Fixed.