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Re: [patch tree-optimization]: Try to sink type-casts for binary and/or/xor operations
- From: Richard Guenther <richard dot guenther at gmail dot com>
- To: Kai Tietz <ktietz at redhat dot com>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Mon, 27 Jun 2011 16:08:41 +0200
- Subject: Re: [patch tree-optimization]: Try to sink type-casts for binary and/or/xor operations
- References: <1336692780.787925.1309181501414.JavaMail.root@zmail06.collab.prod.int.phx2.redhat.com> <1504417947.788510.1309182384715.JavaMail.root@zmail06.collab.prod.int.phx2.redhat.com>
On Mon, Jun 27, 2011 at 3:46 PM, Kai Tietz <ktietz@redhat.com> wrote:
> Hello,
>
> this patch sink type conversions in forward-propagate for the following patterns:
> - ((type) X) op ((type) Y): If X and Y have compatible types.
> - ((type) X) op CST: If the conversion of (type) ((type-x) CST) == CST and X has integral type.
> - CST op ((type) X): If the conversion of (type) ((type-x) CST) == CST and X has integral type.
See IRC comments.
> Additionally it fixes another issue shown by this type-sinking in bswap detection. The bswap pattern matching algorithm goes for the first hit, and not tries to seek for best hit. ?So we search here two times. First for di case (if present) and then for si mode case.
Please split this piece out. I suppose either walking over stmts backwards
or simply handling __builtin_bswap in find_bswap_1 would be a better
fix than yours.
Richard.
> ChangeLog
>
> 2011-06-27 ?Kai Tietz ?<ktietz@redhat.com>
>
> ? ? ? ?* tree-ssa-forwprop.c (simplify_bitwise_binary): Improve
> ? ? ? ?type sinking.
> ? ? ? ?* tree-ssa-math-opts.c (execute_optimize_bswap): Separate
> ? ? ? ?search for di/si mode patterns for finding widest match.
>
> Bootstrapped and regression tested for x86_64-pc-linux-gnu. ?Ok for apply?
>
> Regards,
> Kai
>