[Bug tree-optimization/16443] New: ICE during linux kernel compilation

[Bug tree-optimization/16443] New: ICE during linux kernel compilation

[ak at muc dot de]

Attached preprocessed file from the linux 2.6 kernel makes the compiler ICE:

Program received signal SIGSEGV, Segmentation fault.
register_new_def (def=0x2a966447e0, block_defs_p=0xb106f8)
    at tree-flow-inline.h:32
32      {
#0  register_new_def (def=0x2a966447e0, block_defs_p=0xb106f8)
    at tree-flow-inline.h:32
#1  0x000000000047abe4 in optimize_stmt (walk_data=0x7fbfffc230, 
    bb=0x2a9667f7e0, si=
      {tsi = {ptr = 0x2a9667ac60, container = 0x2a9667f540}, bb = 0x0})
    at tree-flow-inline.h:275
#2  0x000000000047d5c6 in walk_dominator_tree (walk_data=0x7fbfffc230, 
    bb=0x2a9667f7e0) at /averell/src/src/gcc-head/gcc/gcc/domwalk.c:189
#3  0x000000000047d3c9 in walk_dominator_tree (walk_data=0x7fbfffc230, 
    bb=0x2a9667f540) at /averell/src/src/gcc-head/gcc/gcc/domwalk.c:205
#4  0x000000000047d3c9 in walk_dominator_tree (walk_data=0x7fbfffc230, 
    bb=0x2a9667f1c0) at /averell/src/src/gcc-head/gcc/gcc/domwalk.c:205
#5  0x000000000047c81c in tree_ssa_dominator_optimize ()

gcc version 3.5.0 20040708 (experimental)

Compile with 

cc1  -m32      -Wall -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing
-fno-common  -msoft-float -mpreferred-stack-boundary=2 -fno-unit-at-a-time
-march=i686 -mregparm=3  -Os -g -Wdeclaration-after-statement

-- 
           Summary: ICE during linux kernel compilation
           Product: gcc
           Version: 3.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: ak at muc dot de
                CC: gcc-bugs at gcc dot gnu dot org
  GCC host triplet: x86_64-linux
GCC target triplet: x86_64-linux -m32 (= i386-linux)


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16443

[Bug tree-optimization/16443] ICE during linux kernel compilation

[ak at muc dot de]

------- Additional Comments From ak at muc dot de  2004-07-08 21:30 -------
Created an attachment (id=6714)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=6714&action=view)
preprocessed test case


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16443

[Bug tree-optimization/16443] [3.5 Regression] ICE during linux kernel compilation

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-07-08 21:59 -------
I cannot reproduce it on i686-linux-gnu

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   GCC host triplet|x86_64-linux                |
 GCC target triplet|x86_64-linux -m32 (= i386-  |x86_64-linux-gnu
                   |linux)                      |
           Keywords|                            |ice-on-valid-code
            Summary|ICE during linux kernel     |[3.5 Regression] ICE during
                   |compilation                 |linux kernel compilation
   Target Milestone|---                         |3.5.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16443

[Bug tree-optimization/16443] [3.5 Regression] ICE during linux kernel compilation

[ak at muc dot de]

------- Additional Comments From ak at muc dot de  2004-07-09 04:13 -------
Perhaps it needs a x86-64 host to trigger. Can someone else try that
with a 64bit host?

Also the compiler was compiled with --disable-checking (maybe that makes
a difference).

I saw it several times at the same location so it wasn't flakey memory or somesuch.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16443

[Bug tree-optimization/16443] [3.5 Regression] ICE during linux kernel compilation

[ak at muc dot de]

------- Additional Comments From ak at muc dot de  2004-07-10 05:54 -------
I played a bit with the options and -m32 -Os -fno-unit-at-a-time 
gives a ICE too, at a slightly different place but with the same
cause:

 gss_mech_svc_setup

Program received signal SIGSEGV, Segmentation fault.
0x00000000004802e3 in get_phi_state (var=0xc1a7e0)
    at ../../gcc/gcc/tree-into-ssa.c:165
165         return var_ann (var)->need_phi_state;
(gdb) bt
#0  0x00000000004802e3 in get_phi_state (var=0xc1a7e0)
    at ../../gcc/gcc/tree-into-ssa.c:165
#1  0x000000000047ebde in register_new_def (def=0x2a9644c380, 
    block_defs_p=0xc24e38) at ../../gcc/gcc/tree-into-ssa.c:1363
#2  0x00000000004a9603 in register_definitions_for_stmt (ann=0x2a9647f900, 
    block_defs_p=0xc24e38) at ../../gcc/gcc/tree-ssa-dom.c:3684
#3  0x00000000004a87f2 in optimize_stmt (walk_data=0x7fbfffdd40, 
    bb=0x2a9647da80, si=
      {tsi = {ptr = 0x2a96476bc0, container = 0x2a9647c270}, bb = 0x2a9647da80})
at ../../gcc/gcc/tree-ssa-dom.c:3117
#4  0x00000000004a9d60 in walk_dominator_tree (walk_data=0x7fbfffdd40, 
    bb=0x2a9647da80) at ../../gcc/gcc/domwalk.c:189


var_ann returns a bogus pointer:

(gdb) p var_ann(var)
$1 = (struct var_ann_d *) 0x5f7373672f737367

Someone corrupted var->common.ann. 0x5f7373672f737367 is ASCII 
gss/gss_, which is a common prefix used in identifiers in the file

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16443

[Bug tree-optimization/16443] [3.5 Regression] ICE during linux kernel compilation

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-07-12 06:27 -------
Can you provide the output of compiling after adding -v as this might be a GC related problem which 
is why I cannot reproduce it on my machine with the GC params for my machine.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16443

[Bug tree-optimization/16443] [3.5 Regression] ICE during linux kernel compilation

[reichelt at gcc dot gnu dot org]

------- Additional Comments From reichelt at gcc dot gnu dot org  2004-07-13 02:22 -------
Here's a reduced testcase that crashes mainline (with checking enabled)
on i686-pc-linux-gnu. Just compile with -Os:

==================================
void foo(char *p)
{
    __asm__ ("" ::: "memory");
}

void bar()
{
    static char *p;
    foo(p);
}
==================================

The error message is:

PR16443.c: In function `bar':
PR16443.c:7: error: Expected an SSA_NAME object
p<D1122>

#   p<D1122> = V_MAY_DEF <p<D1122>>;
__asm__("":::"memory");

PR16443.c:7: internal compiler error: tree check: expected ssa_name, have
var_decl in verify_def, at tree-ssa.c:126
Please submit a full bug report, [etc.]


-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |reichelt at gcc dot gnu dot
                   |                            |org
           Severity|normal                      |critical
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
           Keywords|                            |monitored
      Known to fail|                            |3.5.0
      Known to work|                            |3.3.4 3.4.1
   Last reconfirmed|0000-00-00 00:00:00         |2004-07-13 02:22:06
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16443

[Bug tree-optimization/16443] [3.5 Regression] ICE during linux kernel compilation

[ak at muc dot de]

------- Additional Comments From ak at muc dot de  2004-07-13 07:34 -------
Hmm, are you sure your testcase is the same bug? I didn't see an error,
just internal memory corruption in the compiler.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16443

[Bug tree-optimization/16443] [3.5 Regression] ICE during linux kernel compilation

[reichelt at gcc dot gnu dot org]

------- Additional Comments From reichelt at gcc dot gnu dot org  2004-07-13 08:08 -------
It's a tree checking failure. So

a) You won't see the error message, because you disabled checking.
b) The tree structure is corrupted somehow. Often you end up with a
   segfault later when the compiler tries to dereference something
   that is not a properly initialized pointer.

So chances are high that this is really the underlying bug.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16443

[Bug tree-optimization/16443] [3.5 Regression] ICE during linux kernel compilation

[reichelt at gcc dot gnu dot org]

------- Additional Comments From reichelt at gcc dot gnu dot org  2004-07-13 09:07 -------
Diego, it looks like your patch
http://gcc.gnu.org/ml/gcc-cvs/2004-07/msg00349.html
is responsible for the regression. Could you please have a look?


-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dnovillo at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16443

[Bug tree-optimization/16443] [3.5 Regression] ICE during linux kernel compilation

[dnovillo at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |dnovillo at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16443

[Bug tree-optimization/16443] [3.5 Regression] ICE during linux kernel compilation

[ehrhardt at mathematik dot uni-ulm dot de]

------- Additional Comments From ehrhardt at mathematik dot uni-ulm dot de  2004-07-13 15:16 -------
Hi,

the following part from the patch identified by Volker looks
very suspicious:

+		EXECUTE_IF_SET_IN_BITMAP (call_clobbered_vars, 0, i,
+		    {
+		      tree var = referenced_var (i);
+		      add_stmt_operand (&var, stmt, opf_is_def, prev_vops);
+		    });

We're passing the address of a local var down to add_stmt_operand.
add_stmt_operand will add this _address_, i.e. &var to the statement
operands. This is bound to fail as soon as we leave the scope of var.

The following might be a temporary solution:

Index: tree-ssa-operands.c
===================================================================
RCS file: /cvsroot/gcc/gcc/gcc/tree-ssa-operands.c,v
retrieving revision 2.15
diff -u -r2.15 tree-ssa-operands.c
--- tree-ssa-operands.c	8 Jul 2004 15:03:10 -0000	2.15
+++ tree-ssa-operands.c	13 Jul 2004 15:08:53 -0000
@@ -1229,36 +1229,7 @@
   for (link = ASM_CLOBBERS (stmt); link; link = TREE_CHAIN (link))
     if (strcmp (TREE_STRING_POINTER (TREE_VALUE (link)), "memory") == 0)
       {
-	size_t i;
-
-	/* If we still have not computed aliasing information, we
-	   won't know what variables are call-clobbered and/or
-	   addressable.  Just mark the statement as having volatile
-	   operands for now.  */
-	if (!aliases_computed_p)
-	  {
-	    stmt_ann (stmt)->has_volatile_ops = true;
-	    break;
-	  }
-
-	/* Clobber all call-clobbered variables (or .GLOBAL_VAR if we
-	   decided to group them).  */
-	if (global_var)
-	  add_stmt_operand (&global_var, stmt, opf_is_def, prev_vops);
-	else
-	  EXECUTE_IF_SET_IN_BITMAP (call_clobbered_vars, 0, i,
-	      {
-		tree var = referenced_var (i);
-		add_stmt_operand (&var, stmt, opf_is_def, prev_vops);
-	      });
-
-	/* Now clobber all addressables.  */
-	EXECUTE_IF_SET_IN_BITMAP (addressable_vars, 0, i,
-	    {
-	      tree var = referenced_var (i);
-	      add_stmt_operand (&var, stmt, opf_is_def, prev_vops);
-	    });
-
+	stmt_ann (stmt)->has_volatile_ops = true;
 	break;
       }
 }


     regards   Christian



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16443

[Bug tree-optimization/16443] [3.5 Regression] ICE during linux kernel compilation

[dnovillo at redhat dot com]

------- Additional Comments From dnovillo at redhat dot com  2004-07-13 15:44 -------
Subject: Re:  [3.5 Regression] ICE during
	linux kernel compilation

On Tue, 2004-07-13 at 11:16, ehrhardt at mathematik dot uni-ulm dot de
wrote:

> the following part from the patch identified by Volker looks
> very suspicious:
> 
> +		EXECUTE_IF_SET_IN_BITMAP (call_clobbered_vars, 0, i,
> +		    {
> +		      tree var = referenced_var (i);
> +		      add_stmt_operand (&var, stmt, opf_is_def, prev_vops);
> +		    });
> 
> We're passing the address of a local var down to add_stmt_operand.
> add_stmt_operand will add this _address_, i.e. &var to the statement
> operands. This is bound to fail as soon as we leave the scope of var.
>
Not really.  We are adding virtual definitions in this code, we don't
add &var, we add var.  We only need the address when adding real
operands.  I will agree that this is not a really good interface, but
add_stmt_operand is a local function.

> The following might be a temporary solution:
> 
Here you just papered over the whole bug :)



Diego.



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16443

[Bug tree-optimization/16443] [3.5 Regression] ICE during linux kernel compilation

[dnovillo at gcc dot gnu dot org]

------- Additional Comments From dnovillo at gcc dot gnu dot org  2004-07-13 18:14 -------

Testing patch.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16443

[Bug tree-optimization/16443] [3.5 Regression] ICE during linux kernel compilation

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2004-07-13 20:51 -------
Subject: Bug 16443

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	dnovillo@gcc.gnu.org	2004-07-13 20:51:03

Modified files:
	gcc            : ChangeLog tree-ssa-alias.c tree-ssa-operands.c 
	gcc/testsuite  : ChangeLog 
Added files:
	gcc/testsuite/gcc.dg/tree-ssa: 20040713-1.c 

Log message:
	PR tree-optimization/16443
	* tree-ssa-alias.c: Add more description for
	CALL_CLOBBERED_VARS and ADDRESSABLE_VARS.
	* tree-ssa-operands.c (get_asm_expr_operands): Re-order the
	clobbering of call-clobbered and addressable variables.  If
	there are any before aliases have been computed, add them.
	
	testsuite/ChangeLog
	
	PR tree-optimization/16443
	* gcc.dg/tree-ssa/20040713-1.c: New test.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.4509&r2=2.4510
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/tree-ssa-alias.c.diff?cvsroot=gcc&r1=2.10&r2=2.11
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/tree-ssa-operands.c.diff?cvsroot=gcc&r1=2.15&r2=2.16
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.3996&r2=1.3997
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/20040713-1.c.diff?cvsroot=gcc&r1=NONE&r2=1.1



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16443

[Bug tree-optimization/16443] [3.5 Regression] ICE during linux kernel compilation

[dnovillo at gcc dot gnu dot org]

------- Additional Comments From dnovillo at gcc dot gnu dot org  2004-07-13 20:55 -------

Fixed.

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16443

[Bug tree-optimization/16443] [3.5 Regression] ICE during linux kernel compilation

[ak at muc dot de]

------- Additional Comments From ak at muc dot de  2004-07-14 14:23 -------
I can confirm that the patch fixes the big test case on x86-64 too.
Thanks.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |VERIFIED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16443