cvs commit: src/sys/kern init_main.c kern_malloc.c md5c.c subr_autoconf.c subr_mbuf.c subr_prf.c tty_subr.c vfs_cluster.c vfs_subr.c

[Marcel Moolenaar]

On Wed, Jul 23, 2003 at 12:56:34AM +0200, Poul-Henning Kamp wrote:
> 
> And the only two criteria I think are trivial to use for proving an
> actual benefit is:
> 	1. less code is generated.
> 	2. it runs faster in tests.

criterium 1 is the worst possible. Only criterium 2 makes sense.

ia64 specifically moves all the hard work to the compiler. It's
not unsurprising that a normal -O yields marginal performance.
Only when one takes advantage of speculation, prefetching and
optimization techniques that increase ILP (which most of the time
imply code expansion -- loop unrolling, inlining, code duplication)
will you see a performance increase.

The old gcc metric of less code is better has been demonstrated
to not work in general nowadays.

-- 
 Marcel Moolenaar	  USPA: A-39004		 marcel at xcllnt.net