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Date: Tue, 31 Mar 2020 12:54:03 -0700 (PDT)
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Subject: Re: GNAT vs Matlab - operation on   multidimensional complex matrices
From: Shark8 <onewingedshark@gmail.com>
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Xref: reader01.eternal-september.org comp.lang.ada:58262
Date: 2020-03-31T12:54:03-07:00
List-Id: <comp.lang.ada>

On Tuesday, March 31, 2020 at 1:20:45 PM UTC-6, Simon Wright wrote:
> Shark8 writes:
> 
> > Ok then; the following should have convention Fortran IIRC:
> >
> > type tCubeReal is array (1..NumChannels, 1..NumAngles, 1..NumRanges) of mReal
> >   with Convention => Fortran;
> 
> I wondered about this; the code ran considerably slower with Convention
> => Fortran.

Interesting / unexpected.
I wonder... could it be that the CPU is itself optimized for row-major access?
It also looks like the For/Of loop takes longer than indexes on nested-for.