Alan Coopersmith wrote: > Jyri Virkki wrote: >> Roland Mainz wrote: >>> http://cr.opensolaris.org/~chriszhu/ruby-webrev/usr/src/cmd/ruby18/Makefile.sfw.html >>> >>> >>>> RUBY_CFLAGS="-fast -xipo -xtarget=generic" >>> Please do _not_ use "-fast". "-fast" is a macro which expands to many >>> options, including those who change the representation of the >>> floating-point datatypes (which is usually bad (unless you're sure the >>> code doesn't rely on some certain floating-point features)) and change >>> framepointer stuff on x86 (AFAIK the DTrace people won't like that...). >> >> AFAIK these come from the work done by the performance team while >> figuring out build options for CoolStack: >> http://src.opensolaris.org/source/xref/webstack/webstack/trunk/src/ruby-1.8.6/make_solaris.sh >> >> >> >> (Doesn't necessarily mean it is right.. would like to hear from the >> perf team about it though.) > > "-fast" is definitely wrong in anything you're publishing for others to > use. > It makes binaries tuned specifically for the hardware on your build machine > which may not even run on other machines, depending on what hardware your > build machine has. The Studio compiler manuals on docs.sun.com are pretty > clear about this. >
This is incorrect. Notice that -fast is followed by '-xtarget=generic'. This specifically removes any build machine hardware dependencies. We have worked with the compiler team to come up with these options for Cool Stack and haven't heard any complaints from any users (about not running on their machine). Shanti
