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 <vbyakov...@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.yakov...@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). */
>
