At Tue, 30 Sep 2025 12:00:31 +0200, Jörg Sonnenberger <joerg%bec.de@localhost> wrote: Subject: Re: floating point woes on i386 > > On 9/30/25 9:30 AM, Greg A. Woods wrote: > > > At Sat, 27 Sep 2025 10:36:59 +0200, Joerg Sonnenberger <joerg%bec.de@localhost> wrote: > > Subject: Re: floating point woes on i386 > >> > >> There is on newer i386 also the option of > >> using -mfpmath=sse. That's strictly > >> speaking the only way to get IEEE754 > >> semantics on i386. > > > > On NetBSD/i386 10.0 with the system's GCC-10.5 the -mfpmath=sse option > > doesn't actually do anything: > > Well, of course. You also need to use a > CPU that supports SSE2 and/or enable the > feature with -msse2. Well, of course indeed! Thanks for the reminder! GCC is so much fun! It is all really well documented in NetBSD's gcc(1) manual page, if I had dared to read enough of it carefully! Yes, with "-msse2 -mfpmath=sse" paranoia completes with zero flaws. Adding "+387" to the latter also requires "-fexcess-precision=standard", i.e. "-std=c89", but then it also completes, possibly slightly faster, with zero flaws. -- Greg A. Woods <gwoods%acm.org@localhost> Kelowna, BC +1 250 762-7675 RoboHack <woods%robohack.ca@localhost> Planix, Inc. <woods%planix.com@localhost> Avoncote Farms <woods%avoncote.ca@localhost>
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