[Bug debug/63284] New: [4.9/5 Regression] -fcompare-debug issue due to redirection to __builtin_unreachable ()

[Bug debug/63284] New: [4.9/5 Regression] -fcompare-debug issue due to redirection to __builtin_unreachable ()

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63284

            Bug ID: 63284
           Summary: [4.9/5 Regression] -fcompare-debug issue due to
                    redirection to __builtin_unreachable ()
           Product: gcc
           Version: 4.9.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: debug
          Assignee: jakub at gcc dot gnu.org
          Reporter: jakub at gcc dot gnu.org

/* { dg-do compile } */
/* { dg-options "-O2 -fcompare-debug" } */

int a[10], *b, *d, c, f;
int fn2 (void);
void fn3 (void);
void fn4 (int);

static int
fn1 (int x)
{
  int e = a[0];
  if (e)
    return 1;
  if (b)
    switch (x)
      {
      case 1:
        if (d)
          e = fn2 ();
        else
          fn3 ();
        break;
      case 0:
        if (d)
          {
            fn3 ();
            if (c)
              fn4 (1);
          }
        else
          fn4 (0);
      }
  return e;
}

void
fn6 (void)
{
  f = fn1 (0);
}

fails on the 4.9 branch, it happens to succeed on the trunk, but when one looks
at *.optimized dumps differences, there are still undesirable differences in
the order of predecessors of one bb (and thus also PHI argument order).

[Bug debug/63284] [4.9/5 Regression] -fcompare-debug issue due to redirection to __builtin_unreachable ()

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63284

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.9.2

[Bug debug/63284] [4.9/5 Regression] -fcompare-debug issue due to redirection to __builtin_unreachable ()

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63284

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 33507
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=33507&action=edit
gcc49-pr63284.patch

Untested fix.

[Bug debug/63284] [4.9/5 Regression] -fcompare-debug issue due to redirection to __builtin_unreachable ()

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63284

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Author: jakub
Date: Wed Sep 17 19:05:49 2014
New Revision: 215331

URL: https://gcc.gnu.org/viewcvs?rev=215331&root=gcc&view=rev
Log:
    PR debug/63284
    * tree-cfgcleanup.c (fixup_noreturn_call): Don't split block
    if there are only debug stmts after the noreturn call, instead
    remove the debug stmts.

    * gcc.dg/pr63284.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/pr63284.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-cfgcleanup.c

[Bug debug/63284] [4.9/5 Regression] -fcompare-debug issue due to redirection to __builtin_unreachable ()

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63284

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Author: jakub
Date: Wed Sep 17 19:07:04 2014
New Revision: 215332

URL: https://gcc.gnu.org/viewcvs?rev=215332&root=gcc&view=rev
Log:
    PR debug/63284
    * tree-cfgcleanup.c (fixup_noreturn_call): Don't split block
    if there are only debug stmts after the noreturn call, instead
    remove the debug stmts.

    * gcc.dg/pr63284.c: New test.

Added:
    branches/gcc-4_9-branch/gcc/testsuite/gcc.dg/pr63284.c
Modified:
    branches/gcc-4_9-branch/gcc/ChangeLog
    branches/gcc-4_9-branch/gcc/testsuite/ChangeLog
    branches/gcc-4_9-branch/gcc/tree-cfgcleanup.c

[Bug debug/63284] [4.9/5 Regression] -fcompare-debug issue due to redirection to __builtin_unreachable ()

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63284

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Author: jakub
Date: Wed Sep 17 19:08:06 2014
New Revision: 215333

URL: https://gcc.gnu.org/viewcvs?rev=215333&root=gcc&view=rev
Log:
    PR debug/63284
    * tree-cfgcleanup.c (fixup_noreturn_call): Don't split block
    if there are only debug stmts after the noreturn call, instead
    remove the debug stmts.

    * gcc.dg/pr63284.c: New test.

Added:
    branches/gcc-4_8-branch/gcc/testsuite/gcc.dg/pr63284.c
Modified:
    branches/gcc-4_8-branch/gcc/ChangeLog
    branches/gcc-4_8-branch/gcc/testsuite/ChangeLog
    branches/gcc-4_8-branch/gcc/tree-cfgcleanup.c

[Bug debug/63284] [4.9/5 Regression] -fcompare-debug issue due to redirection to __builtin_unreachable ()

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63284

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

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

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed.