[PATCH][PING]: Obvious fix for PR target/29794 - [4.2/4.3 Regression]

[Maxim Kuvyrkov <mkuvyrkov at ispras dot ru>]

Maxim Kuvyrkov wrote:
> Hi!
>
> This patch fixes PR target/29794 on ia64.
>
> The bug is due to wrong loop variable initialization.  This results in 
> use of out-of-bounds index and subsequent segmentation fault.  The 
> obvious patch is attached.
>
> OK for trunk and gcc-4_2-branch?

PING!

This patch obviously fixes an off-by-one error in sched-rgn.c .

Maybe I should just commit it as obvious?


Thanks,

Maxim

> Thanks,
> Maxim
>
>
> ------------------------------------------------------------------------
>
> 2006-11-20  Maxim Kuvyrkov  <mkuvyrkov@ispras.ru>
>
> 	PR target/29794
> 	* sched-rgn.c (add_block1): Use correct initializer.
>
>
> ------------------------------------------------------------------------
>
> --- sched-rgn.c	(/gcc-local/trunk/gcc)	(revision 23010)
> +++ sched-rgn.c	(/gcc-local/fix-pr29794/gcc)	(revision 23010)
> @@ -3147,9 +3147,15 @@ add_block1 (basic_block bb, basic_block 
>  	 is _always_ valid for access.  */
>  
>        i = BLOCK_TO_BB (after->index) + 1;
> -      for (pos = ebb_head[i]; rgn_bb_table[pos] != after->index; pos--);
> +      pos = ebb_head[i] - 1;
> +      /* Now POS is the index of the last block in the region.  */
> +
> +      /* Find index of basic block AFTER.  */
> +      for (; rgn_bb_table[pos] != after->index; pos--);
> +
>        pos++;
>        gcc_assert (pos > ebb_head[i - 1]);
> +
>        /* i - ebb right after "AFTER".  */
>        /* ebb_head[i] - VALID.  */
>