[patch,libgfortran] PR51119 - MATMUL slow for large matrices

[Jerry DeLisle]

On 11/13/2016 04:55 PM, Steve Kargl wrote:
> On Sun, Nov 13, 2016 at 04:08:50PM -0800, Jerry DeLisle wrote:
>> Hi all,
>>
>> Attached patch implements a fast blocked matrix multiply. The basic algorithm is
>> derived from netlib.org tuned blas dgemm. See matmul.m4 for reference.
>>
>> The matmul() function is compiled with -Ofast -funroll-loops. This can be
>> customized further if there is an undesired optimization being used. This is
>> accomplished using #pragma optimize ( string ).
>>
>
> Did you run any tests with '--param max-unroll-times=4' where
> the 4 could be something other than 4.  On troutmask, with my
> code I've found that 4 seems to work the best with -funroll-loops.
>

Have not tried this, will give it a try. Also, I have not tested on your FreeBSD 
machine yet.

Jerry