This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [PATCH, Atom] Fix performance regression with -mtune=atom


This is a ping. Change affects Atom only and was made because it
really gives better performance on this architecture. This fact
actually leads to the thought that old value is just a simple
misprint.
  Please look.

Vladimir

2011/9/30 Vladimir Yakovlev <vbyakovl23@gmail.com>:
> This patch fixes performance regression with -mtune=atom. Changing
> atom cost removes regression in several tests of EEMBC and spec2000.
> Bootstrap amd make check Ok for both with and witout -mtune-atom.
> OK for trunk?
>
> 2011-09-30 ?Yakovlev Vladimir ?vladimir.b.yakovlev@intel.com
>
> ? ? ?* gcc/config/i386/i386.c (atom_cost): Changed cost for loading
> ? ? ? QImode using movzbl.
>
> diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
> index 7e89dbd..8a512a7 100644
> --- a/gcc/config/i386/i386.c
> +++ b/gcc/config/i386/i386.c
> @@ -1672,7 +1672,7 @@ struct processor_costs atom_cost = {
> ? COSTS_N_INSNS (1), ? ? ? ? ? ? ? ? ? /* cost of movzx */
> ? 8, ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? /* "large" insn */
> ? 17, ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?/* MOVE_RATIO */
> - ?2, ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?/* cost for loading QImode using movzbl */
> + ?4, ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? /* cost for loading QImode
> using movzbl */
> ? {4, 4, 4}, ? ? ? ? ? ? ? ? ? ? ? ? ? /* cost of loading integer registers
> ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? in QImode, HImode and SImode.
> ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? Relative to reg-reg move (2). ?*/
>


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]