NetNews Usenet Archive 1992 #27/NN_1992_27.iso/spool/comp/arch/10981

Text File | 1992-11-20 | 1.7 KB | 36 lines

Newsgroups: comp.arch
Path: sparky!uunet!munnari.oz.au!cs.mu.OZ.AU!munta.cs.mu.OZ.AU!fjh
From: [e-mail] (Fergus James HENDERSON)
Subject: Re: how to advocate new software/hardware features (Re: Hardware Support for Numeric Algorithms)
Message-ID: <[e-mail]>
Sender: [e-mail]
Organization: Computer Science, University of Melbourne, Australia
References: <[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]>
Date: Sat, 21 Nov 1992 04:07:32 GMT
Lines: 24

[e-mail] (Dik T. Winter) writes:

>But wait.  SPARC version 7 does not have an integer multiply instruction,
>it uses multiply step.  When you code the multiply in assembly you will
>find that you get a 64 bit result, but in C it is not possible to
>retrieve that result.  Doing it with inline assembly is not what you
>want in general (>32 instructions inline assembly), so you do it
>out-of-line.  Hence it is not sufficient to have good inliners, on
>some platforms you need out of line assembly routines to do what you
>want, and no, the compilers do not help.  (The same holds for HP-PA 1,
>IBM PC-RT, AMD 29k and a few more.)  So the operation is available but
>you do not get it.
>
>So let's see.  You promote the GCC interface with asm.  How do you
>code the 32x32->64 multiply on the SPARC in GCC?

Just put the asm code in a (non-inline) function, instead of in a macro or
inline function.

--
Fergus Henderson             [e-mail]
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