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From: mitchalsup@aol.com (MitchAlsup1)
Newsgroups: comp.arch
Subject: Re: Calling conventions (particularly 32-bit ARM)
Date: Tue, 14 Jan 2025 18:03:36 +0000
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On Tue, 14 Jan 2025 6:48:45 +0000, Thomas Koenig wrote:

> I wrote:
>> Stephen Fuld <sfuld@alumni.cmu.edu.invalid> schrieb:
>>> Has Lapack (and the other old style Fortran numeric
>>> code that Waldek mentioned) lost its/their importance as a major user of
>>> CPU cycles?
>>
>> It's less than it used to be in the days when supercomputers
>> roamed the computer centers, but for these applications where
>> it matters, it can be significant.
>>
>>> Or do these subroutines consume so many CPU cycles that the
>>> overhead of the large number of parameters is lost in the noise?
>>
>> If you have many small matrices to multiply, startup overhead
>> can be quite significant.  Not on a 2000*2000 matrix, though.
>>
>>> Or is
>>> there some other explanation for Mitch not considering their importance?
>>
>> I think eight arguments, passed by reference in registers, is not
>> too bad.
>
> .... when the rest can be passed on the stack.

And those passed in registers can be stored into memory adjacent
to the memory arguments easily.