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Re: longlong.h macros for common PPC
- To: drepper at cygnus dot com (Ulrich Drepper)
- Subject: Re: longlong.h macros for common PPC
- From: Jeffrey A Law <law at cygnus dot com>
- Date: Tue, 23 Nov 1999 22:56:18 -0700
- cc: Geoff Keating <geoffk at ozemail dot com dot au>, gcc-bugs at gcc dot gnu dot org
- Reply-To: law at cygnus dot com
In message <m3r9hgh1va.fsf@localhost.localnet>you write:
> Geoff Keating <geoffk@ozemail.com.au> writes:
>
> > If I remember correctly, there simply isn't a 32x32->64 multiply that
> > is common to both the power and ppc instruction sets, so you're stuck.
> > The only multiply instruction available is a 32x32->32.
>
> Well, but then in longlong.h the definitions should be surrended by
> something like
>
> #ifndef COM
> #endif
>
> in case the common ISA is selected.
>
> > If you allow _both_ power and ppc, you want to use the power version
> > with the MQ register, because reading the MQ is faster than a
> > multiply-high instruction.
>
> Yeah, but POWER is going away. Almost all machines IBM is shipping
> nowadays are PowerPC based, esp all 64bit enabled versions. So
> PowerPC should become the only option.
POWER may not be of interest to you, but GCC must continue to support it.
jeff