Emilio G. Cota <c...@braap.org> writes:
> On Mon, Sep 10, 2018 at 12:26:58 +0100, Alex Bennée wrote: >> >> Emilio G. Cota <c...@braap.org> writes: >> >> > A few fixes since yesterday's v1: >> > https://lists.gnu.org/archive/html/qemu-devel/2018-09/msg00884.html >> > >> > - Convert copy_qemu_to_soft80 to qemu_to_soft80, just like the other >> > conversion functions >> > - Set fp-test as the program name as reported by itself >> > - Fix Makefile to include .d files so that dependencies are >> > properly tracked >> > - Update commit log >> >> Just some general comments: >> >> - I think this is a better way to go than the IBM test suite >> - I'm ambivalent about maintaining our fp-test.c in close alignment to >> softfloat unless we expect much upstreaming of changes. > > I don't think there'll be any, to be honest. They have a git repo but > I doubt they'll take any patches. This was just a minimum attempt to > get some tests working (I don't have a lot of time to work on this) > >> - the coverage seems a bit low. Rebuilding everything with >> --enable-gcov and running -all1 -all2 I get: >> >> tests/fp/fp-test.c - 53.5 % coverage 43.3 % branch coverage >> fpu/softfloat.c - 32.5 % coverage 25.1 % branch coverage >> >> But maybe I didn't pass enough options to fp-test? I could really do >> with a --just-run-everything-and-summarise-failing-functions option so I >> can then go through in more detail with fp-test fFOO_BAR. > > Yes right now to get better coverage you need to run it several times. > After a few runs I got it to 58%, but still without testing some > rounding modes. So considering we're coming from 0% coverage, I'd > say coverage is pretty good! I agree ;-) > > But yes, we should add a flag to just test -all. > > There are some functions that we are not testing yet though, but > that can be fixed over time (we can add more tests to fp-test even > though they're not in testfloat, such as testing flush-to-zero/ > denormals-are-zero, or the muladd variants that we have). > > I have basically no time left to work on this. What do you think about > the following plan? > > 1. Have our own clones (forks) of testfloat/softfloat in qemu servers. > 2. Add those as submodules > 3. Add fp-test with as you said an -all flag that reports all > errors to get decent coverage. Works for me. > 4. Add hardfloat patches, with tests. This requires a small > change to testfloat: > https://github.com/cota/berkeley-testfloat-3/commit/ca9fa2ba05 It seems a shame to have our mirror of testfloat diverge but if it can't be avoided I guess it will have to do. Couldn't we just zero the HW flags in the wrapped up function? I may be misremembering but don't we fall-back to softfloat code anyway if we have reached any limits that trigger exception flags? > I'd then leave adding further tests to increase coverage and fixing > the existing bugs (prior to hardfloat) to someone else with > more time/resources. Agreed. I should have time to chase down the softfloat regressions once I'm back from Connect after next week. > > Thanks, > > Emilio -- Alex Bennée
