[Bug tree-optimization/22037] [4.1 Regression] internal compiler error: verify_ssa failed

[Bug tree-optimization/22037] [4.1 Regression] internal compiler error: verify_ssa failed

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-06-12 16:00 -------
Confirmed, reduced testcase:
extern double sqrt (double __x) throw ();
int numDerivs1;
int ComputeAStep( double& error)
{
  int i, numDerivs;
  numDerivs = numDerivs1;
  for(i=0; i<numDerivs; i++)
    ;
  double err=0;
  for(i=0; i<numDerivs; i++)
      err += 1;
  error = sqrt(err);
  for(i=0; i<numDerivs; i++) 
    ;
  return 0;
}



-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2005-06-12 16:00:05
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22037

[Bug tree-optimization/22037] [4.1 Regression] internal compiler error: verify_ssa failed

[bangerth at dealii dot org]

------- Additional Comments From bangerth at dealii dot org  2005-06-28 23:06 -------
Cutting another line or two: 
------------------- 
extern double sqrt (double) throw (); 
 
void foo(double& d, int n) 
{ 
  double e=0; 
  for(int i=0; i<n; i++); 
  for(int i=0; i<n; i++) e=1; 
  d = sqrt(e); 
 
  for(int i=0; i<n; i++); 
} 
----------------------------- 
g/x> /home/bangerth/bin/gcc-4.1-pre/bin/c++ -c x.cc -O3 -fPIC 
x.cc: In function &#8216;void foo(double&, int)&#8217;: 
x.cc:3: error: Definition in block 6 follows the use 
for SSA_NAME: TMT.4_17 in statement: 
#   TMT.4_18 = V_MAY_DEF <TMT.4_17>; 
*d_10 = D.1741_9; 
x.cc:3: internal compiler error: verify_ssa failed. 
Please submit a full bug report, 
with preprocessed source if appropriate. 
See <URL:http://gcc.gnu.org/bugs.html> for instructions. 
 
W. 

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22037

[Bug tree-optimization/22037] [4.1 Regression] internal compiler error: verify_ssa failed

[dnovillo at gcc dot gnu dot org]

------- Additional Comments From dnovillo at gcc dot gnu dot org  2005-06-29 20:19 -------

We are folding sqrt(0) into 0 and not updating virtual operands properly.  Still
looking.

-- 
           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=22037

[Bug tree-optimization/22037] [4.1 Regression] internal compiler error: verify_ssa failed

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-07-01 16:27 -------
Actually I think this is worse than any can think.  The problem is that we have a VUSE on the sqrt which 
is wrong, we should have a V_MAY_DEF.

With an optimized (non bootstrapped) compiler, we get the correct results and on powerpc-darwin.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pinskia at gcc dot gnu dot
                   |                            |org
 GCC target triplet|                            |i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22037

[Bug tree-optimization/22037] [4.1 Regression] internal compiler error: verify_ssa failed

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-07-01 16:30 -------
(In reply to comment #7)
in reply to this.  On powerpc-darwin we get the right answer but on i686-pc-linux-gnu, we don't, I 
have no idea why.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22037

[Bug tree-optimization/22037] [4.1 Regression] internal compiler error: verify_ssa failed

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-07-01 16:36 -------
(In reply to comment #8)
> (In reply to comment #7)
> in reply to this.  On powerpc-darwin we get the right answer but on i686-pc-linux-gnu, we don't, I 
> have no idea why.

Ignore all this talk, the reason why I cannot reproduce it on ppc-darwin is because -fno-math-errno is 
default there.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
 GCC target triplet|i686-pc-linux-gnu           |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22037

[Bug tree-optimization/22037] [4.1 Regression] internal compiler error: verify_ssa failed

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-07-01 17:08 -------
The bug is really in cleanup_tree_cfg which is doing the merge of the two BBs.
This patch fixes the problem but I have not yet bootstrapped it yet:
Index: tree-cfg.c
===============================================================
====
RCS file: /cvs/gcc/gcc/gcc/tree-cfg.c,v
retrieving revision 2.207
diff -u -p -r2.207 tree-cfg.c
--- tree-cfg.c	28 Jun 2005 19:33:20 -0000	2.207
+++ tree-cfg.c	1 Jul 2005 17:07:35 -0000
@@ -1254,6 +1254,10 @@ replace_uses_by (tree name, tree val)
       tree rhs;
 
       fold_stmt_inplace (stmt);
+      mark_new_vars_to_rename (stmt);
+      
+      if (maybe_clean_or_replace_eh_stmt (stmt, stmt))
+	tree_purge_dead_eh_edges (bb_for_stmt (stmt));
 
       rhs = get_rhs (stmt);
       if (TREE_CODE (rhs) == ADDR_EXPR)
Index: tree-cfgcleanup.c
===============================================================
====
RCS file: /cvs/gcc/gcc/gcc/tree-cfgcleanup.c,v
retrieving revision 2.2
diff -u -p -r2.2 tree-cfgcleanup.c
--- tree-cfgcleanup.c	25 Jun 2005 02:01:15 -0000	2.2
+++ tree-cfgcleanup.c	1 Jul 2005 17:07:36 -0000
@@ -520,7 +520,11 @@ cleanup_tree_cfg (void)
 
   /* Merging the blocks creates no new opportunities for the other
      optimizations, so do it here.  */
-  retval |= merge_seq_blocks ();
+  if (merge_seq_blocks ())
+    {
+      retval = true;
+      update_ssa (TODO_update_ssa_only_virtuals);
+    }
 
   compact_blocks ();
 


-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|dnovillo at gcc dot gnu dot |pinskia at gcc dot gnu dot
                   |org                         |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22037

[Bug tree-optimization/22037] [4.1 Regression] internal compiler error: verify_ssa failed

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-07-02 14:30 -------
(In reply to comment #10)
> The bug is really in cleanup_tree_cfg which is doing the merge of the two BBs.
> This patch fixes the problem but I have not yet bootstrapped it yet:
This patch does not bootstrap.  I think it is better to disable the optimization in tree cfg and let leter 
tree passes fix it up.

I am looking into fix it still.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22037

[Bug tree-optimization/22037] [4.1 Regression] internal compiler error: verify_ssa failed

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-07-02 18:32 -------
Here is a patch fixes the problem:
Index: tree-cfg.c
===============================================================
====
RCS file: /cvs/gcc/gcc/gcc/tree-cfg.c,v
retrieving revision 2.207
diff -u -p -r2.207 tree-cfg.c
--- tree-cfg.c	28 Jun 2005 19:33:20 -0000	2.207
+++ tree-cfg.c	2 Jul 2005 18:29:46 -0000
@@ -1298,10 +1298,12 @@ tree_merge_blocks (basic_block a, basic_
       tree copy;
       
       if (!may_propagate_copy (def, use)
-	  /* Propagating pointers might cause the set of vops for statements
-	     to be changed, and thus require ssa form update.  */
+	  /* Propagating pointers and constants might cause the
+	     set of vops for statements to be changed, and thus
+	     require ssa form update.  */
 	  || (is_gimple_reg (def)
-	      && POINTER_TYPE_P (TREE_TYPE (def))))
+	      && (POINTER_TYPE_P (TREE_TYPE (def))
+		  || TREE_CONSTANT (use))))
 	{
 	  gcc_assert (is_gimple_reg (def));
 


Hopefully it is not too permissive, we do allow the later passes fix up the permissiveness.

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22037

[Bug tree-optimization/22037] [4.1 Regression] internal compiler error: verify_ssa failed

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-07-04 10:38 -------
Patch here: <http://gcc.gnu.org/ml/gcc-patches/2005-07/msg00155.html>.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                URL|                            |http://gcc.gnu.org/ml/gcc-
                   |                            |patches/2005-
                   |                            |07/msg00155.html
           Keywords|                            |patch


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22037

[Bug tree-optimization/22037] [4.1 Regression] internal compiler error: verify_ssa failed

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-08-04 18:16 -------
Subject: Bug 22037

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	dnovillo@gcc.gnu.org	2005-08-04 18:16:41

Modified files:
	gcc            : ChangeLog passes.c tree-cfg.c 
	gcc/testsuite  : ChangeLog 
Added files:
	gcc/testsuite/g++.dg/tree-ssa: pr22037.C 

Log message:
	PR 22037
	* tree-cfg.c (replace_uses_by): Call mark_new_vars_to_rename.
	(tree_merge_blocks): Propagate anything allowed by
	may_propagate_copy.
	Clarify documentation.
	* passes.c (execute_todo): If cleanup_tree_cfg invalidated the
	SSA form, schedule an update if necessary.
	
	testsuite/ChangeLog
	
	PR 22037
	* g++.dg/tree-ssa/pr22037.C:

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.9654&r2=2.9655
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/passes.c.diff?cvsroot=gcc&r1=2.108&r2=2.109
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/tree-cfg.c.diff?cvsroot=gcc&r1=2.213&r2=2.214
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.5877&r2=1.5878
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.dg/tree-ssa/pr22037.C.diff?cvsroot=gcc&r1=NONE&r2=1.1



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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22037

[Bug tree-optimization/22037] [4.1 Regression] internal compiler error: verify_ssa failed

[dnovillo at gcc dot gnu dot org]

------- Additional Comments From dnovillo at gcc dot gnu dot org  2005-08-04 18:17 -------

Fixed.  http://gcc.gnu.org/ml/gcc-patches/2005-08/msg00283.html.

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22037

[Bug tree-optimization/22037] [4.1 Regression] internal compiler error: verify_ssa failed

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-06-12 15:27 -------
Copyprop4 is causing the ICE, I wonder if this is related to the bug which I reported to gcc@ when 
removing forwprop pass.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dnovillo at gcc dot gnu dot
                   |                            |org
          Component|c++                         |tree-optimization
           Keywords|                            |ice-on-valid-code
            Summary|internal compiler error:    |[4.1 Regression] internal
                   |verify_ssa failed           |compiler error: verify_ssa
                   |                            |failed
   Target Milestone|---                         |4.1.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22037