Re: Check mask all ones / all zeros


Roger Ferrer Ibanez
 

Hi Guy,

On 20/5/21 12:09, Guy Lemieux wrote:
so, what exactly do you plan to do after knowing the result is all-0
or all-1 ? do you want to initiate a branch or something else? does a
precise (synchronized) result matter, or can you tolerate decoupling
delays?
The code I've been looking at, uses this for a branch.

FWIW: this is the SLEEF library (vector math library). An example of how it uses the check can be found at https://github.com/shibatch/sleef/blob/master/src/libm/sleefsimddp.c#L340

(Not claiming that this specific library as written is a good or bad fit for RVV, just looking at the code to get an idea of what are its expectations)

Kind regards,

--
Roger Ferrer Ibáñez - roger.ferrer@...
Barcelona Supercomputing Center - Centro Nacional de Supercomputación


http://bsc.es/disclaimer

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