Re: Make 'gcc/hash-map-tests.c:test_map_of_type_with_ctor_and_dtor_expand' work on 32-bit architectures [PR101959]

[Richard Biener <richard.guenther@gmail.com>]

On August 18, 2021 5:34:28 PM GMT+02:00, Thomas Schwinge <thomas@codesourcery.com> wrote:
>Hi!
>
>On 2021-08-18T09:35:25-0400, David Edelsohn <dje.gcc@gmail.com> wrote:
>> This causes a bootstrap failure for me.
>>
>> PR/101959
>
>Sorry for that; "details".  ;-|  OK to push the attached
>"Make 'gcc/hash-map-tests.c:test_map_of_type_with_ctor_and_dtor_expand'
>work on 32-bit architectures [PR101959]", which does resolve the issue
>for a '-m32' i686-pc-linux-gnu build?

Ok. 

Richard. 


>
>Grüße
> Thomas
>
>
>> On Tue, Aug 17, 2021 at 5:00 AM Richard Biener via Gcc <gcc@gcc.gnu.org> wrote:
>>>
>>> On Tue, Aug 17, 2021 at 8:40 AM Thomas Schwinge <thomas@codesourcery.com> wrote:
>>> >
>>> > Hi!
>>> >
>>> > On 2021-08-16T14:10:00-0600, Martin Sebor <msebor@gmail.com> wrote:
>>> > > On 8/16/21 6:44 AM, Thomas Schwinge wrote:
>>> > >> [...], to document the current behavior, I propose to
>>> > >> "Add more self-tests for 'hash_map' with Value type with non-trivial
>>> > >> constructor/destructor", see attached.  OK to push to master branch?
>>> > >> (Also cherry-pick into release branches, eventually?)
>>> >
>>> > (Attached again, for easy reference.)
>>> >
>>> > > Adding more tests sounds like an excellent idea.  I'm not sure about
>>> > > the idea of adding loopy selftests that iterate as many times as in
>>> > > the patch (looks like 1234 times two?)
>>> >
>>> > Correct, and I agree it's a sensible concern, generally.
>>> >
>>> > The current 1234 times two iterations is really arbitrary (should
>>> > document that in the test case), just so that we trigger a few hash table
>>> > expansions.
>>>
>>> You could lower N_init (the default init is just 13!),
>>> even with just 128 inserted elements you'll trigger
>>> expansions to 31, 61 and 127 elements.
>>>
>>> > For 'selftest-c', we've got originally:
>>> >
>>> >     -fself-test: 74775 pass(es) in 0.309299 seconds
>>> >     -fself-test: 74775 pass(es) in 0.366041 seconds
>>> >     -fself-test: 74775 pass(es) in 0.356663 seconds
>>> >     -fself-test: 74775 pass(es) in 0.355009 seconds
>>> >     -fself-test: 74775 pass(es) in 0.367575 seconds
>>> >     -fself-test: 74775 pass(es) in 0.320406 seconds
>>> >
>>> > ..., and with my changes we've got:
>>> >
>>> >     -fself-test: 94519 pass(es) in 0.327755 seconds
>>> >     -fself-test: 94519 pass(es) in 0.369522 seconds
>>> >     -fself-test: 94519 pass(es) in 0.355531 seconds
>>> >     -fself-test: 94519 pass(es) in 0.362179 seconds
>>> >     -fself-test: 94519 pass(es) in 0.363176 seconds
>>> >     -fself-test: 94519 pass(es) in 0.318930 seconds
>>> >
>>> > So it really seems to be all in the noise?
>>>
>>> Yes.  I think the test is OK but it's also reasonable to lower
>>> the '1234' times and add a comment as to the count should
>>> trigger hashtable expansions "a few times".
>>>
>>> Richard.
>>>
>>> > Yet:
>>> >
>>> > > Selftests run each time GCC
>>> > > builds (i.e., even during day to day development).  It seems to me
>>> > > that it might be better to run such selftests only as part of
>>> > > the bootstrap process.
>>> >
>>> > I'd rather have thought about a '--param self-test-expensive' (or
>>> > similar), and then invoke the selftests via a new
>>> > 'gcc/testsuite/selftests/expensive.exp' (or similar).
>>> >
>>> > Or, adapt 'gcc/testsuite/gcc.dg/plugin/expensive_selftests_plugin.c',
>>> > that is, invoke them via the GCC plugin mechanism, which also seems to be
>>> > easy enough?
>>> >
>>> > I don't have a strong opinion about where/when these tests get run, so
>>> > will happily take any suggestions.
>>> >
>>> >
>>> > Grüße
>>> >  Thomas
>>> >
>>> >
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