[llvm-dev] [cfe-dev] a proposed script to help with test-suite programs that output _lots_ of FP numbers

[Hal Finkel via llvm-dev]

----- Original Message -----
> From: "Abe Skolnik" <a.skolnik at samsung.com>
> To: "Hal Finkel" <hfinkel at anl.gov>, "Sebastian Pop" <sebpop.llvm at gmail.com>
> Cc: "llvm-dev" <llvm-dev at lists.llvm.org>, "Sebastian Paul Pop" <s.pop at samsung.com>, "cfe-dev"
> <cfe-dev at lists.llvm.org>, "Renato Golin" <renato.golin at linaro.org>
> Sent: Thursday, September 29, 2016 5:01:10 PM
> Subject: Re: [cfe-dev] [llvm-dev] a proposed script to help with test-suite programs that output _lots_ of FP numbers
> 
> ["Hal Finkel" <hfinkel at anl.gov> wrote:]
> 
> > Recording the output with -ffp-contract=on to use as a reference
> > output does not seem useful,
> > exactly for the reasons you specify.  We should generate the
> > reference outputs with -ffp-contract=off as we do now.
> > That's the only good target-independent configuration.  Maybe we
> > could do this:
> 
> >  - Have a reference output with -ffp-contract=off
> >  - Run program compiled with -ffp-contract=off and the default
> >  - Compare the former against the reference output for validation
> >  - Compare the latter (the default build) against the former with
> >  fpcmp with some tolerance
> 
> > This also has the advantage that we still only need the hashed
> > reference outputs in the repository.
> 
> Ah.  Interesting idea.  So please tell me if I have understood you
> correctly.  I think you
> [Hal] are suggesting something like this:
> 
>    1) compile the program with FP fusion off, run program, capture
>    output and save it, hash it
> and compare against reference hash.
> 
>    2) if comparison against reference hash says "not equal", fail the
>    test and stop [stop
> testing this particular subtest, that is]
> 
>    3) compile the program with FP fusion on/"fast", capture the
>    output,
>       compare using "fpcmp" and some positive tolerance against the
>       output of the non-fusion
> build of the same source code;
>       fail only if outside the tolerance limit[s]
> 
> 
> Is that right?

Correct.

Thanks again,
Hal

> 
> Regards,
> 
> Abe
> 
> 

-- 
Hal Finkel
Lead, Compiler Technology and Programming Languages
Leadership Computing Facility
Argonne National Laboratory