Re: -fno-strength-reduce

Michael Meissner (meissner@cygnus.com)
Fri, 22 Jan 1999 15:42:07 -0500

On Fri, Jan 22, 1999 at 07:02:08PM +0100, Henrik Olsen wrote:
> It was fixed with GCC 2.7.2.3, but it's still in because only one person
> actually bothered to make a speed comparison and post the result to the
> list, this comparison showed that any gain from dropping the option is too
> small to be measurable, end ends up in the noice.
> As a result, Linus didn't think removing it was worth the bother.

My personnel opinion is that strength reduction should be disabled on register
limited machines like the x86 family, since the gains that come from losing the
multiply are lost due to the additional register pressure the extra register
uses. However, I lost that battle many years ago (RMS wanted -O2 to be
consistant across machines), and have not openned it up much since then.

-- 
Michael Meissner, Cygnus Solutions (Massachusetts office)
4th floor, 955 Massachusetts Avenue, Cambridge, MA 02139, USA
meissner@cygnus.com,	617-354-5416 (office),	617-354-7161 (fax)


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