FloatMathPlugin issues (was: [Vm-dev] Re: [squeak-dev] Re: [4.2] tests status)

[Nicolas Cellier]

2010/12/29 David T. Lewis <lewis at mail.msen.com>:
>>
>> I fail to see how modf() could possibly be inexact, it just has to cut
>> the mantissa in two parts...
>> Therefore, primitive 52 should lead to bit identical results across platforms.
>> The only thing to change in order to be FloatMathPlugin compatible
>> would be to fail the primitive for a nan receiver.
>>
>> The fdlibm do define a replacement __ieee754_modf() because it has to
>> (it is a replacement of libm and cannot use default libm).
>> Maybe we don't have to use it, and can safely revert to modf().
>>
>> Nicolas
>
> Judging by the results of FloatConsistencyTests>>testFractionStd,
> primitive 52 does in fact produce different results from
> FloatMathPlugin>>primitiveFractionalPart. Whether primitive 52
> would be consistent across platforms I cannot say.
>

Yes, they differ for NaN...
for fdlibm, NaN fractionPart is -/+ 0
for primitive 52, it is NaN

I'm a bit surprised that the FloatMathPlugin primitive doesn't fail in
case of NaN...
What is the use of SignalNaN class var then ?

> But more importantly, I'm afraid that the FloatMathPlugin is
> completely broken when compiled for 64 bits. I reverted the
> Float>>fractionPart method to use primitive 52 in order to be
> able to run the image, then ran the full suite of KernelTests-Numbers
> tests. The results are not encouraging:
>

Invalid C99 definition of __HI() __LO() macros and co ?

Nicolas

> ====
> 29 December 2010 1:21:48 pm
> Results of KernelTests-Numbers tests with 64-bit VM and FloatMathPlugin, no compiler optimization.
> Float>>fractionPart is reverted to prior version to permit the image to run, so FloatConsistencyTests>>testFractionStd is an expected failure.
> Test errors:
>        FloatConsistencyTests>>#testAddArray
>        FloatConsistencyTests>>#testArcCos
>        FloatConsistencyTests>>#testArcCosH
>        FloatConsistencyTests>>#testArcSin
>        FloatConsistencyTests>>#testArcSinH
>        FloatConsistencyTests>>#testArcTan
>        FloatConsistencyTests>>#testArcTan2
>        FloatConsistencyTests>>#testArcTanH
>        FloatConsistencyTests>>#testCos
>        FloatConsistencyTests>>#testCosH
>        FloatConsistencyTests>>#testDivArray
>        FloatConsistencyTests>>#testDot
>        FloatConsistencyTests>>#testExp
>        FloatConsistencyTests>>#testFloatAt
>        FloatConsistencyTests>>#testFraction
>        FloatConsistencyTests>>#testHypot
>        FloatConsistencyTests>>#testLog
>        FloatConsistencyTests>>#testLog10
>        FloatConsistencyTests>>#testMulArray
>        FloatConsistencyTests>>#testSin
>        FloatConsistencyTests>>#testSinH
>        FloatConsistencyTests>>#testSqrt
>        FloatConsistencyTests>>#testSubArray
>        FloatConsistencyTests>>#testTan
>        FloatConsistencyTests>>#testTanH
>        FloatConsistencyTests>>#testTimesTwoPower
>        FloatTest>>#testFractionAsFloat
>        LargePositiveIntegerTest>>#testReciprocalModulo
>        RandomTest>>#testNext
>        SqNumberParserTest>>#testFloatPrintString
> Test failures:
>        FloatConsistencyTests>>#testAddScalar
>        FloatConsistencyTests>>#testArcCosHStd
>        FloatConsistencyTests>>#testArcCosStd
>        FloatConsistencyTests>>#testArcSinHStd
>        FloatConsistencyTests>>#testArcSinStd
>        FloatConsistencyTests>>#testArcTanHStd
>        FloatConsistencyTests>>#testArcTanStd
>        FloatConsistencyTests>>#testCosHStd
>        FloatConsistencyTests>>#testCosStd
>        FloatConsistencyTests>>#testDivScalar
>        FloatConsistencyTests>>#testExpStd
>        FloatConsistencyTests>>#testFractionStd
>        FloatConsistencyTests>>#testLength
>        FloatConsistencyTests>>#testMulScalar
>        FloatConsistencyTests>>#testNormalize
>        FloatConsistencyTests>>#testSinHStd
>        FloatConsistencyTests>>#testSinStd
>        FloatConsistencyTests>>#testSubScalar
>        FloatConsistencyTests>>#testSum
>        FloatConsistencyTests>>#testTanHStd
>        FloatConsistencyTests>>#testTanStd
>        FloatTest>>#testArcTan
>        FloatTest>>#testCharacterization
>        FloatTest>>#testComparison
>        FloatTest>>#testDegreeCos
>        FloatTest>>#testDegreeSin
>        FloatTest>>#testDegreeSinForExceptionalValues
>        FloatTest>>#testFloatRounded
>        FloatTest>>#testFloatTruncated
>        FloatTest>>#testFractionAsFloat2
>        FloatTest>>#testInfinity1
>        FloatTest>>#testInfinity2
>        FloatTest>>#testIntegerAsFloat
>        FloatTest>>#testNonSignalingNaN
>        FloatTest>>#testSignalingNaN
>        FloatTest>>#testStoreBase16
>        FloatTest>>#testStoreOn
>        FractionTest>>#testDegreeCos
>        FractionTest>>#testDegreeSin
>        FractionTest>>#testLn
>        FractionTest>>#testLog
>        IntegerTest>>#testDegreeCos
>        IntegerTest>>#testDegreeSin
>        IntegerTest>>#testLn
>        IntegerTest>>#testLog
>        IntegerTest>>#testSqrtFloor
>        NumberParsingTest>>#testFloatFromStreamWithExponent
>        NumberParsingTest>>#testFloatFromStringWithExponent
>        NumberTest>>#testReadFrom
>        SqNumberParserTest>>#testFloatFromStreamWithExponent
>        SqNumberParserTest>>#testFloatGradualUnderflow