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Re: Changing CFLAGS for i386 packages on x86_64



Arjan van de Ven wrote:
On Fri, 2006-07-14 at 09:03 +0000, Kevin Kofler wrote:
Arjan van de Ven <arjan <at> fenrus.demon.nl> writes:
SSE in 32 bit is not "just used" by gcc
What about -ftree-vectorize?

that is, on 32 bit, not so cheap since it means transfering FP from the
x87 fpu to sse and back a lot.

ok but why isn't it enabled on x86_64 (for 64bit apps)
the packages are compiled with
-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m64 -mtune=generic
(this is shown in about:buildconfig in 64bit mozilla)
And -mfpmath=sse?

doesn't that also change the ABI?

All this SSE stuff is really useful for 64 bit x86... but for 32 bit...
a LOT less so due to the ABI/calling convention restrictions that 32 bit
suffers from.



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