[Bug c/27381] New: ice on valid code with -O2

[Bug c/27381] New: ice on valid code with -O2

[dcb314 at hotmail dot com]

I just tried to compile Suse package gnome-print-0.37-18 with a recent
GNU C compiler version 4.2 snapshot 20060429. 

The compiler snapshot said

if gcc -DHAVE_CONFIG_H -I. -I. -I.. -I.. -I.. -I/usr/include/freetype2
-I/opt/gnome/include/gnome-1.0 -DNEED_GNOMESUPPORT_H
-I/opt/gnome/lib64/gnome-libs/include -I/opt/gnome/include
-I/opt/gnome/include/gtk-1.2 -I/opt/gnome/include/glib-1.2
-I/opt/gnome/lib64/glib/include -I/usr/X11R6/include
-I/opt/gnome/include/gdk-pixbuf-1.0 -I/usr/include/gnome-xml                   
   -DGNOMELOCALEDIR=\""/opt/gnome/share/locale"\" -DBINDIR=\""/opt/gnome/bin"\"
-DDATADIR=\""/opt/gnome/share"\" -DSYSCONFDIR=\""/etc/opt/gnome"\"
-DLIBDIR=\""/opt/gnome/lib64"\"
-DFONTMAPDIR_STATIC=\""/opt/gnome/share/gnome/fonts"\"
-DFONTMAPDIR_DYNAMIC=\""/etc/opt/gnome/gnome/fonts"\" -DVERSION=\""0.37"\"  -O2
-g -fmessage-length=0 -D_FORTIFY_SOURCE=2 -MT gf-fontmap.o -MD -MP -MF
".deps/gf-fontmap.Tpo" -c -o gf-fontmap.o gf-fontmap.c; \
then mv -f ".deps/gf-fontmap.Tpo" ".deps/gf-fontmap.Po"; else rm -f
".deps/gf-fontmap.Tpo"; exit 1;
fi
gf-fontmap.c: In function 'gf_fontmap_load_file':
gf-fontmap.c:257: internal compiler error: in propagate_rhs_into_lhs, at
tree-ssa-dom.c:2307
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.

Preprocessed source code attached.  Flag -O2 required.


-- 
           Summary: ice on valid code with -O2
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: dcb314 at hotmail dot com
  GCC host triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27381

[Bug c/27381] ice on valid code with -O2

[dcb314 at hotmail dot com]

------- Comment #1 from dcb314 at hotmail dot com  2006-05-02 11:19 -------
Created an attachment (id=11357)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=11357&action=view)
C source code


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27381

[Bug c/27381] ice on valid code with -O2

[rguenth at gcc dot gnu dot org]

------- Comment #2 from rguenth at gcc dot gnu dot org  2006-05-02 11:39 -------
Reducing.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27381

[Bug c/27381] ice on valid code with -O

[rguenth at gcc dot gnu dot org]

------- Comment #3 from rguenth at gcc dot gnu dot org  2006-05-02 12:26 -------
Confirmed.  Reduced testcase:

typedef char gchar;
typedef unsigned char xmlChar;
typedef struct _xmlNode xmlNode;
typedef xmlNode *xmlNodePtr;
struct _xmlNode {
    struct _xmlNode *next;
    struct _xmlNode *childs;
};
typedef struct _GFFileEntry GFFileEntry;
struct _GFFileEntry {
    gchar *path;
};
gf_fm_load_font_2_0_truetype (xmlNodePtr node)
{
    xmlNodePtr child;
    GFFileEntry ttf;
    ttf.path = ((void *)0);
    for (child = node->childs;
         child != ((void *)0);
         child = child->next) {
        xmlChar *type, *xmlpath;
        if (type
            && !__builtin_strcmp (type, "ttf")
            && !ttf.path) {
            if (xmlpath) {
                ttf.path = g_strdup (xmlpath);
            }
        }
        if (type) free((type));
        if (ttf.path) break;
    }
}


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |law at redhat dot com
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
           Keywords|                            |ice-on-valid-code
      Known to work|                            |4.1.0
   Last reconfirmed|0000-00-00 00:00:00         |2006-05-02 12:26:37
               date|                            |
            Summary|ice on valid code with -O2  |ice on valid code with -O


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27381

[Bug c/27381] ice on valid code with -O

[rguenth at gcc dot gnu dot org]

------- Comment #4 from rguenth at gcc dot gnu dot org  2006-05-02 12:37 -------
Caused by

Author: amacleod
Date: Fri Apr 28 20:39:18 2006
New Revision: 113356

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=113356
Log:

The condition the assert was flawed.

2006-04-28  Andrew MacLeod  <amacleod@redhat.com>

        * tree-ssa-dom.c (propagate_rhs_into_lhs): Fix assert clause.


Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/tree-ssa-dom.c


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |amacleod at redhat dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27381

[Bug tree-optimization/27381] [4.2 Regression] ice on valid code with -O

[pinskia at gcc dot gnu dot org]

-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |blocker
          Component|c                           |tree-optimization
            Summary|ice on valid code with -O   |[4.2 Regression] ice on
                   |                            |valid code with -O
   Target Milestone|---                         |4.2.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27381

[Bug tree-optimization/27381] [4.2 Regression] ice on valid code with -O

[amacleod at redhat dot com]

------- Comment #5 from amacleod at redhat dot com  2006-05-02 15:38 -------
The assert condition is not flawed.  It has exposed a second bug with the old
immuse iterator scheme that was also hidden by the old algorithm work around
Jeff had implemented.

When iterating over the immediate uses, and deleting a stmt (such as a
conditional) causes an edge to be removed, PHI nodes have an argument deleted.  

when we remove PHI arguments, we move the last phi argument to whatever
position we actually deleted, and reduce the argument count.  When arguments
are moved, they were simply being delinked and then linked back into the use
chain. 

In this particular example, the argument being moved was another occurence of
the ssa_name being iterated over, and by delinking it and linking it back in,
it was moved back to the beginning of the immuse list. This caused it to be
missed during the iteration pahse, and rightfully triggered the assert.

The fix is to simply keep the same linked position when the argument is moved
instead of removing it from the list and linking it back in.

Patch is currently being tested.

Andrew


-- 

amacleod at redhat dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |amacleod at redhat dot com
                   |dot org                     |
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2006-05-02 12:26:37         |2006-05-02 15:38:29
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27381

[Bug tree-optimization/27381] [4.2 Regression] ice on valid code with -O

[amacleod at redhat dot com]

------- Comment #6 from amacleod at redhat dot com  2006-05-02 15:40 -------
Created an attachment (id=11361)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=11361&action=view)
proposed patch

This is the patch undergoing testing.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27381

[Bug tree-optimization/27381] [4.2 Regression] ice on valid code with -O

[amacleod at gcc dot gnu dot org]

------- Comment #7 from amacleod at redhat dot com  2006-05-03 17:13 -------
Subject: Bug 27381

Author: amacleod
Date: Wed May  3 17:13:37 2006
New Revision: 113499

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=113499
Log:


2006-05-02  Andrew MacLeod  <amacleod@redhat.com>

        PR tree-optimization/27381
        * tree-phinodes.c (remove_phi_arg_num): When moving a phi argument, 
        maintain the same immediate_use links.
        * tree-ssa-operands.c (dump_immediate_uses_for): Show iteration marker 
        node rather than segfaulting.


Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/tree-phinodes.c
    trunk/gcc/tree-ssa-operands.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27381

[Bug tree-optimization/27381] [4.2 Regression] ice on valid code with -O

[pinskia at gcc dot gnu dot org]

------- Comment #8 from pinskia at gcc dot gnu dot org  2006-05-04 04:53 -------
Fixed.


-- 

pinskia at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27381