besselj Float32 calling incorrect function #15272
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Aha. Strange that this would be intermittent? |
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Yeah, very odd. I don't know enough about the ABI, but I guess in certain cases we happened across the right bit pattern. |
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Looks like we only have very limitted test for |
simonbyrne
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I've added some more tests. |
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test/math.jl
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| @test besselj(-3,-3) == j33 | ||
| @test besselj(-3,3) == -j33 | ||
| @test besselj(3,-3) == -j33 | ||
| @test besselj(3,3f0) ≈ j33 |
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do these have to be approximate because we can't reliably constrain different libm's accuracy here?
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No, it's because they're calling different precision functions, so they won't be exactly equal.
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but if we round the higher-precision value into the lower precision type can we reliably test exact equality?
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In that case, it's up to the libm/openspecfun (there are 3 different C functions involved)
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okay so if the answer is no even to the rounded version, then not worth worrying about
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and maybe it needs an even larger tolerance?
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Or maybe cast the RHS to Float32.
julia> 0.1320342f0 ≈ 0.1320341839246122
false
julia> 0.1320342f0 ≈ Float32(0.1320341839246122)
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Hmm, perhaps we should change isapprox to use the larger of the 2 tolerances.
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That would make more sense. Probably a different issue/pr though...
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Let's do Float32 on the rhs now, and think about tweaking isapprox separately
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I think I broke travis by doing a bunch of force pushes, and so the most recent commit doesn't appear. Any way I can get it to restart? |
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f0b8cc8 is merging the right commit, someone just clicked cancel... |
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Isn't it 63da79b? |
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ah, makes sense. I've restarted. |
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Okay, I've updated the |
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great, do merge when green |
besselj Float32 calling incorrect function
Hopefully should fix recent 32-bit build failures (e.g. #15259).