On Mon, Jun 27, 2011 at 7:33 PM, Kai Tietz <kti...@redhat.com> wrote:
> Hello,
>
> this is the separated patch for issues noticed by doing type-sinking on
> bitwise-operations. The tests exposed that bswap pattern-matching searches
> from top to down for each BB. As it replaces the found match for a bswap in
> tree, but doesn't know about handling its inserted builtin-swap on
> pattern-matching for wider-mode bswap, search failed.
> By reversing search order within BB from last to first, this issue can be
> fixed.
>
> ChangeLog
>
> 2011-06-27 Kai Tietz <kti...@redhat.com>
>
> * tree-ssa-math-opts.c (execute_optimize_bswap): Search
> within BB from last to first.
>
> Bootstrapped and regression-tested for x86_64-pc-linux-gnu. Ok for apply?
>
> Regards,
> Kai
>
> Index: gcc-head/gcc/tree-ssa-math-opts.c
> ===================================================================
> --- gcc-head.orig/gcc/tree-ssa-math-opts.c
> +++ gcc-head/gcc/tree-ssa-math-opts.c
> @@ -1820,8 +1820,10 @@ execute_optimize_bswap (void)
> FOR_EACH_BB (bb)
> {
> gimple_stmt_iterator gsi;
> -
> +/*
> for (gsi = gsi_after_labels (bb); !gsi_end_p (gsi); gsi_next (&gsi))
> + */
> + for (gsi = gsi_last_bb (bb); !gsi_end_p (gsi); gsi_prev (&gsi))
> {
Err ... please 1) don't comment out stuff this way, 2) add a comment
why we loop backwards
Richard.
> gimple stmt = gsi_stmt (gsi);
> tree bswap_src, bswap_type;
>
