[Bug optimization/11555] [3.4 Regression] ICE in verify_loop_structure, at cfgloop.c:1270

[rakdver at atrey dot karlin dot mff dot cuni dot cz]

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11555



------- Additional Comments From rakdver at atrey dot karlin dot mff dot cuni dot cz  2003-07-24 18:55 -------
Subject: Re:  [3.4 Regression] ICE in verify_loop_structure, at cfgloop.c:1270

Hello,

I was mistakenly adding irreducible flag to all  edges instead
only to those in copied region.  I am commiting the following fix as
obvious.

Zdenek

	* cfgloopmanip.c (duplicate_loop_to_header_edge): Update irreducible
	flag correctly.

Index: cfgloopmanip.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cfgloopmanip.c,v
retrieving revision 1.14
diff -c -3 -p -r1.14 cfgloopmanip.c
*** cfgloopmanip.c	5 Jul 2003 15:17:26 -0000	1.14
--- cfgloopmanip.c	24 Jul 2003 18:45:05 -0000
*************** duplicate_loop_to_header_edge (struct lo
*** 988,993 ****
--- 988,1014 ----
        /* Copy bbs.  */
        copy_bbs (bbs, n, new_bbs, spec_edges, 2, new_spec_edges, loop, loops);
  
+       /* Note whether the blocks and edges belong to an irreducible loop.  */
+       if (add_irreducible_flag)
+ 	{
+ 	  for (i = 0; i < n; i++)
+ 	    new_bbs[i]->rbi->duplicated = 1;
+ 	  for (i = 0; i < n; i++)
+ 	    {
+ 	      new_bb = new_bbs[i];
+ 	      if (new_bb->loop_father == target)
+ 		new_bb->flags |= BB_IRREDUCIBLE_LOOP;
+ 
+ 	      for (ae = new_bb->succ; ae; ae = ae->succ_next)
+ 		if (ae->dest->rbi->duplicated
+ 		    && (ae->src->loop_father == target
+ 			|| ae->dest->loop_father == target))
+ 		  ae->flags |= EDGE_IRREDUCIBLE_LOOP;
+ 	    }
+ 	  for (i = 0; i < n; i++)
+ 	    new_bbs[i]->rbi->duplicated = 0;
+ 	}
+ 
        /* Redirect the special edges.  */
        if (is_latch)
  	{
*************** duplicate_loop_to_header_edge (struct lo
*** 1010,1031 ****
        /* Record exit edge in this copy.  */
        if (orig && TEST_BIT (wont_exit, j + 1))
  	to_remove[(*n_to_remove)++] = new_spec_edges[SE_ORIG];
- 
-       /* Note whether the blocks and edges belong to an irreducible loop.  */
-       if (add_irreducible_flag)
- 	{
- 	  for (i = 0; i < n; i++)
- 	    {
- 	      new_bb = new_bbs[i];
- 	      if (new_bb->loop_father == target)
- 		new_bb->flags |= BB_IRREDUCIBLE_LOOP;
- 
- 	      for (ae = new_bb->succ; ae; ae = ae->succ_next)
- 		if (ae->src->loop_father == target
- 		    || ae->dest->loop_father == target)
- 		  ae->flags |= EDGE_IRREDUCIBLE_LOOP;
- 	    }
- 	}
  
        /* Record the first copy in the control flow order if it is not
  	 the original loop (i.e. in case of peeling).  */
--- 1031,1036 ----