From: djs@actnyc.UUCP (Dave Seward)
Subject: Re: Some VAX RTL 64 bit operations take only 32 bit operands.
Date: 7 Mar 88 21:15:47 GMT [thread overview]
Message-ID: <719@actnyc.UUCP> (raw)
In-Reply-To: 8803030021.AA12106@venera.isi.edu
In article <8803030021.AA12106@venera.isi.edu> stluka@software.ORG (Fred Stluka) writes:
>However, the LIB$EMUL and LIB$EDIV routines ... operate on 64 bit operands
>returning 64 bit results. To produce true 64 bit operators, you have
>to use break up the operation into smaller parts ...
>The biggest problem you encounter is in avoiding spurious integer overflows
>caused by intermediate results exceeding 32 bits. Many of the intermediate
>results you generate will be 32 bit quantities ...
I agree that the multiply and divide have to be broken up into constituent
operations, but I would expect to use 64 bit intermediate results that EMUL
and EDIV provide. Am I missing something?
Dave Seward
uucp!actnyc!djs
prev parent reply other threads:[~1988-03-07 21:15 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
1988-03-02 18:14 Some VAX RTL 64 bit operations take only 32 bit operands Fred Stluka
1988-03-07 21:15 ` Dave Seward [this message]
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