[Bug optimization/12640] [tree-ssa] strlen builtin causes stack overflow building tk

["dnovillo at redhat dot com" <gcc-bugzilla@gcc.gnu.org>]

------- Additional Comments From dnovillo at redhat dot com  2003-11-12 18:32 -------
Subject: Re:  [tree-ssa] strlen builtin causes
	stack overflow building tk

On Wed, 2003-11-12 at 13:22, steven at gcc dot gnu dot org wrote:

> ndex: tree-ssa-ccp.c 
> =================================================================== 
> RCS file: /cvs/gcc/gcc/gcc/Attic/tree-ssa-ccp.c,v 
> retrieving revision 1.1.2.108 
> diff -c -3 -p -r1.1.2.108 tree-ssa-ccp.c 
> *** tree-ssa-ccp.c      11 Nov 2003 18:04:46 -0000      1.1.2.108 
> --- tree-ssa-ccp.c      12 Nov 2003 18:20:25 -0000 
> *************** get_strlen (tree arg) 
> *** 1922,1928 **** 
>           arg_len = prev_arg_len = NULL_TREE; 
>           for (i = 0; i < PHI_NUM_ARGS (def_stmt); i++) 
>             { 
> !             arg_len = get_strlen (PHI_ARG_DEF (def_stmt, i)); 
>               if (arg_len == NULL_TREE) 
>                 return NULL_TREE; 
>  
> --- 1922,1939 ---- 
>           arg_len = prev_arg_len = NULL_TREE; 
>           for (i = 0; i < PHI_NUM_ARGS (def_stmt); i++) 
>             { 
> !             tree arg_def_stmt = PHI_ARG_DEF (def_stmt, i); 
> ! 
> !             /* If this PHI has itself as an argument, we cannot 
> !                determine the string length of this argument.  However, 
> !                if we can find a constant string length for the other 
> !                PHI args then we can still be sure that this is a 
> !                constant string length.  So be optimistic and just 
> !                continue with the next argument.  */ 
> !             if (arg_def_stmt == def_stmt) 
> !               continue; 
> ! 
> !             arg_len = get_strlen (arg_def_stmt); 
>               if (arg_len == NULL_TREE) 
>                 return NULL_TREE; 
>  
Looks correct.  Care to take it through a full bootstrap/test cycle?


Diego.



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12640