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Re: [patch] tuning gcc for Intel Core2
H. J. Lu wrote:
On Tue, Nov 14, 2006 at 07:49:56AM -0800, H. J. Lu wrote:I've got about the same numbers for generic + x86_rep_movl_optimal.
Although with -m32 generic + x86_rep_movl_optimal is a bit worse than
-mtune=core2 (1836 vs 1841 for SPECINT and 1477 vs 1484 for SPECFP). It
is in the range of measurement error. But again code size is smaller
(0.73% and 0.66% correspondingly for SPECInt and SPECFp).
Can you turn on x86_rep_movl_optimal for -mtune=generic to see what
it does for SPEC CPU 2K on both 32bit and 64bit?
So for 64bit, -O2 + x86_rep_movl_optimal is better than -O2 and
-O2 -mtune=core2 on Core 2 Duo and Nocona. I suspect that we will
see similar trend on Opteron.