This is the mail archive of the mailing list for the glibc project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: RFC: What inputs to use for sqrt perf testing

On 4 October 2013 09:26, Carlos O'Donell <> wrote:
> On 10/03/2013 10:39 PM, Siddhesh Poyarekar wrote:
>> On 4 October 2013 02:55, Steve Ellcey <> wrote:
>>> While making a sqrt performance improvement for MIPS I noticed that there
>>> was no sqrt performance test in the 'make bench' tests and Joseph suggested
>>> that we should have one.  It looks like adding it is trivial (see patch),
>>> but the real question is what input to use.  I just threw in 1.9 and 10000.0
>>> to test this patch, but I don't think those are necessarily good choices.
>>> Are there any math experts out there could suggest a better selection of
>>> inputs for sqrt to use in the performance tests?
>>> Here is my strawman patch, I don't expect this to get checked in as it
>>> is, I am just including it for reference purposes.
>> The method I'm using for this is to add probes at various branch
>> points within the function and use a systemtap script to print out the
>> input whenever the probe point is hit.  This is a bit slow (in terms
>> of effort), but would ensure good coverage.  Also, as a starting
>> point, I wouldn't mind having your strawman patch in and then more
>> inputs added to it when you have them ready.
> Would it make sense to start off with all the inputs used by
> e.g. sqrt_test_data?

Oh yeah, why not.  In fact, it won't be a bad idea to do that for all
functions.  That would be a better starting point than using 42.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]