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Re: avoid unstability of reg-stack results
- To: Jan Hubicka <jh at suse dot cz>
- Subject: Re: avoid unstability of reg-stack results
- From: Richard Henderson <rth at redhat dot com>
- Date: Mon, 30 Jul 2001 10:59:03 -0700
- Cc: gcc-patches at gcc dot gnu dot org, patches at x86-64 dot org
- References: <20010730124943.K5820@atrey.karlin.mff.cuni.cz>
On Mon, Jul 30, 2001 at 12:49:43PM +0200, Jan Hubicka wrote:
> * reg-stack.c (block_info_def): Add predecesors counter and stack_out.
> (reg_to_stack): Call mark_dfs_back_edges; count the predecesors.
> (compensate_edge): Break out from ...
> (convert_regs_1): ... here; do smart choosing of stack_out to copy.
> (convert_regs_2): Set block_done once block is really done;
> Do updating of the predecesors counts.
Ok.
> ! if (!(e->flags & EDGE_DFS_BACK)
> ! && (!beste
> ! || EDGE_FREQUENCY (beste) < EDGE_FREQUENCY (e)
> ! || beste->count < e->count
> ! || (beste->count == e->count
> ! && (((e->flags & EDGE_CRITICAL)
> ! && !(beste->flags & EDGE_CRITICAL))
> ! || (((e->flags & EDGE_CRITICAL)
> ! == (beste->flags & EDGE_CRITICAL))
> ! && e->src->index < beste->src->index)))))
This is a lot more readable split into multiple comparisons:
if (! beste)
beste = e;
else if (EDGE_FREQUENCY (beste) < EDGE_FREQUENCY (e))
beste = e;
else if (beste->count < e->count)
beste = e;
else if (beste->count > e->count)
;
else if ((e->flags & EDGE_CRITICAL) != (beste->flags & EDGE_CRITICAL))
{
if (e->flags & EDGE_CRITICAL)
beste = e;
}
else if (e->src->index < beste->src->index)
beste = e;
r~