Re: Fix simulator timeout for testsuite/26_numerics/random/poisson_distribution/operators/values.cc

[Jonathan Wakely <jwakely at redhat dot com>]

On 23/05/19 15:14 +0200, Hans-Peter Nilsson wrote:
> This test regressed for cris-elf (testing in a simulator) with
> the fixing of libstdc++/83237, as the part suggested to be
> wrapped in #ifndef was *added* to the existing test and causes a
> timeout.  Tsk tsk.  Please don't pile-on existing tests, instead
> add a *separate* test-file.
>
> From what I understand of the libstdc++/83237 thread at
> <https://gcc.gnu.org/ml/gcc-patches/2017-12/msg00573.html>, the
> high numbers are not arbitrary, so it seems wrong to try
> lowering them, or we'd just waste cycles testing nothing, or
> worse, ending up with a bogus error indication.  Better to just
> plain disable this part of the test for simulator targets; I
> assume the results should be the same on any IEEE-float target,
> i.e. no target-specific things going on here that'd raise a need
> to cover it everywhere.
>
> With this part of the test disabled, I saw the test finishing in
> (time) "124.74s user" where it was before "1120.26s user"
> running the cris-elf-run simulator on a "i7-4770K CPU @ 3.50GHz"
> host.  Most certainly that indidates that the remainder of the
> test is still too much for *some* host+simulator combos, but I'm
> happy with the runtime lowered to 1/5 of the timeout (10
> minutes) on this particular combination, and I'd think this
> fixes timeouts for many other simulator combos too.
>
> This construct (disabling or lowering limits for simulators) is
> used elsewhere in the libstdc++ test-suite and in particular the
> SIMULATOR_TEST macro is used in the testsuite machinery (though
> AFAICT not in testDiscreteDist).
>
> Ok to commit?

OK, thanks. OK to backport too if you want.


> (I didn't open a ticket for this problem.)
> libstdc++-v3:
> 	* testsuite/26_numerics/random/poisson_distribution/operators/values.cc:
> 	Don't run the libstdc++/83237 part on simulator targets.
>
> diff --git libstdc++-v3/testsuite/26_numerics/random/poisson_distribution/operators/values.cc libstdc++-v3/testsuite/26_numerics/random/poisson_distribution/operators/values.cc
> index 0b03d94..2a45081 100644
> --- libstdc++-v3/testsuite/26_numerics/random/poisson_distribution/operators/values.cc
> +++ libstdc++-v3/testsuite/26_numerics/random/poisson_distribution/operators/values.cc
> @@ -1,3 +1,4 @@
> +// { dg-options "-DSIMULATOR_TEST" { target simulator } }
> // { dg-do run { target c++11 } }
> // { dg-require-cstdint "" }
> // { dg-require-cmath "" }
> @@ -43,11 +44,14 @@ void test01()
>   auto bpd3 = std::bind(pd3, eng);
>   testDiscreteDist(bpd3, [](int n) { return poisson_pdf(n, 30.0); } );
>
> +  // This can take extremely long on simulators, timing out the test.
> +#ifndef SIMULATOR_TEST
>   // libstdc++/83237
>   std::poisson_distribution<> pd4(37.17);
>   auto bpd4 = std::bind(pd4, eng);
>   testDiscreteDist<100, 2000000>(bpd4, [](int n)
> 				 { return poisson_pdf(n, 37.17); } );
> +#endif
> }
>
> int main()
>
> brgds, H-P