[Bug tree-optimization/67889] New: ICE on valid code at -O1 and above on x86_64-linux-gnu in VN_INFO, at tree-ssa-sccvn.c:384

[Bug tree-optimization/67889] New: ICE on valid code at -O1 and above on x86_64-linux-gnu in VN_INFO, at tree-ssa-sccvn.c:384

[su at cs dot ucdavis.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67889

            Bug ID: 67889
           Summary: ICE on valid code at -O1 and above on x86_64-linux-gnu
                    in VN_INFO, at tree-ssa-sccvn.c:384
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: su at cs dot ucdavis.edu
  Target Milestone: ---

The following code causes an ICE when compiled with the current gcc trunk at
-O1 and above on x86_64-linux-gnu in both 32-bit and 64-bit modes.

It is a regression from 5.2.x.


$ gcc-trunk -v
Using built-in specs.
COLLECT_GCC=gcc-trunk
COLLECT_LTO_WRAPPER=/usr/local/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/6.0.0/lto-wrapper
Target: x86_64-pc-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 6.0.0 20151007 (experimental) [trunk revision 228566] (GCC) 
$ 
$ gcc-trunk -O0 -c small.c
$ gcc-5.2 -O1 -c small.c
$ 
$ gcc-trunk -O1 -c small.c
small.c: In function ‘fn1’:
small.c:11:1: internal compiler error: in VN_INFO, at tree-ssa-sccvn.c:384
 }
 ^
0xc5710b VN_INFO(tree_node*)
        ../../gcc-trunk/gcc/tree-ssa-sccvn.c:384
0xc57854 vn_valueize
        ../../gcc-trunk/gcc/tree-ssa-sccvn.h:236
0xe29afd do_valueize(tree_node* (*)(tree_node*), tree_node*)
        ../../gcc-trunk/gcc/gimple-match-head.c:802
0xe29afd gimple_simplify_CONVERT_EXPR
        /tmp/objdir/gcc/gimple-match.c:8085
0xe05b50 gimple_simplify
        /tmp/objdir/gcc/gimple-match.c:12600
0xe08115 gimple_resimplify1
        ../../gcc-trunk/gcc/gimple-match-head.c:123
0xe2a8ee gimple_simplify_CONVERT_EXPR
        /tmp/objdir/gcc/gimple-match.c:8306
0xe05b50 gimple_simplify
        /tmp/objdir/gcc/gimple-match.c:12600
0xe08115 gimple_resimplify1
        ../../gcc-trunk/gcc/gimple-match-head.c:123
0xe2a66f gimple_simplify_CONVERT_EXPR
        /tmp/objdir/gcc/gimple-match.c:8355
0xe05b50 gimple_simplify
        /tmp/objdir/gcc/gimple-match.c:12600
0xe08115 gimple_resimplify1
        ../../gcc-trunk/gcc/gimple-match-head.c:123
0xe065b7 gimple_simplify_VIEW_CONVERT_EXPR
        /tmp/objdir/gcc/gimple-match.c:8570
0xe065b7 gimple_simplify
        /tmp/objdir/gcc/gimple-match.c:12602
0xe07f71 gimple_simplify(tree_code, tree_node*, tree_node*, gimple**,
tree_node* (*)(tree_node*))
        ../../gcc-trunk/gcc/gimple-match-head.c:400
0xc5f073 visit_reference_op_load
        ../../gcc-trunk/gcc/tree-ssa-sccvn.c:3049
0xc5f073 visit_use
        ../../gcc-trunk/gcc/tree-ssa-sccvn.c:3416
0xc617d4 process_scc
        ../../gcc-trunk/gcc/tree-ssa-sccvn.c:3636
0xc617d4 extract_and_process_scc_for_name
        ../../gcc-trunk/gcc/tree-ssa-sccvn.c:3723
0xc617d4 DFS
        ../../gcc-trunk/gcc/tree-ssa-sccvn.c:3775
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <http://gcc.gnu.org/bugs.html> for instructions.
$ 


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


unsigned int a, *b;
unsigned short c;
int d;

void 
fn1 ()
{
  b = &d;
  *b = c = a; 
  *b = d;
}
>From gcc-bugs-return-498997-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org Thu Oct 08 02:46:28 2015
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From: "law at redhat dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/67830] [6 Regression] wrong code at -O1 and above on x86_64-linux-gnu
Date: Thu, 08 Oct 2015 02:46:00 -0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?idg830

--- Comment #5 from Jeffrey A. Law <law at redhat dot com> ---
Whoops.  c#4 was for an unrelated BZ.

[Bug tree-optimization/67889] ICE on valid code at -O1 and above on x86_64-linux-gnu in VN_INFO, at tree-ssa-sccvn.c:384

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67889

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2015-10-08
           Assignee|unassigned at gcc dot gnu.org      |rguenth at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Mine.

[Bug tree-optimization/67889] ICE on valid code at -O1 and above on x86_64-linux-gnu in VN_INFO, at tree-ssa-sccvn.c:384

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67889

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

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

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed.

[Bug tree-optimization/67889] ICE on valid code at -O1 and above on x86_64-linux-gnu in VN_INFO, at tree-ssa-sccvn.c:384

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67889

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
changelog got attributed to PR67891