------- Comment #6 from sebpop at gmail dot com 2010-03-01 18:10 -------
Subject: Re: [4.5 Regression] ICE in
try_improve_iv_set, at tree-ssa-loop-ivopts.c:5238
On Mon, Mar 1, 2010 at 12:02, changpeng dot fang at amd dot com
> I have a fix for this problem. We should not decrease the cost if the cost is
> infinite.
>
Looks good. Thanks for fixing this. Please test with the minor
modification below, and submit a patch to gcc-patches@
> diff --git a/gcc/tree-ssa-loop-ivopts.c b/gcc/tree-ssa-loop-ivopts.c
> index 74dadf7..9accda9 100644
> --- a/gcc/tree-ssa-loop-ivopts.c
> +++ b/gcc/tree-ssa-loop-ivopts.c
> @@ -4124,7 +4124,11 @@ determine_use_iv_cost_condition (struct ivopts_data
> *data,
> if (integer_zerop (*bound_cst)
> && (operand_equal_p (*control_var, cand->var_after, 0)
> || operand_equal_p (*control_var, cand->var_before, 0)))
> - elim_cost.cost -= 1;
> + {
> + /* Should not decrease the cost if it is infinite */
> + if (!infinite_cost_p (elim_cost))
You should fuse this condition into the previous condition expression
to avoid the inner if.
> + elim_cost.cost -= 1;
> + }
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43209
