ARM testers, make note.

[Johannes Pfau]

Am Fri, 16 Aug 2013 18:33:14 +0200
schrieb "Iain Buclaw" <ibuclaw at ubuntu.com>:

> I've pushed in pure implementations of functions in std.math, 
> removing the workaround in core.stdc.math.
> 
> This passes for x64/x32. Can any ARM testers please report any 
> problems causecd by this update?
> 
> Thanks
> Iain.

I did a complete pass through the std.math unit tests. As soon as these
issues are addressed, std.math unit tests should succeed on ARM: 

Some more small bugs:
(see also
https://github.com/jpf91/GDC/commit/63890f543f60d55bad3dc6bced4d14bc159128e6
)

==========================
In isInfinity we should check for 11 binary '1's, not 12 right?

        return ((*cast(ulong *)&x) & 0x7FFF_FFFF_FFFF_FFFF)
            == 0x7FF8_0000_0000_0000;

=>

        return ((*cast(ulong *)&x) & 0x7FFF_FFFF_FFFF_FFFF)
            == 0x7FF0_0000_0000_0000;
==========================
In frexp:

vu[F.EXPPOS_SHORT] = cast(ushort)((0x8000 & vu[F.EXPPOS_SHORT]) |
0x3FE0);

=>

vu[F.EXPPOS_SHORT] = cast(ushort)((0x800F & vu[F.EXPPOS_SHORT]) |
0x3FE0);
==========================
Why is ex in frexp unsigned? This line fails because of this:
exp = (ex - 0x3FE0) >> 4;
here ex is always zero so the subtraction doesn't work as ex is
unsigned
==========================




Failing unit tests:
(see also
https://github.com/jpf91/GDC/commit/0d7b3feafdb3629aeccb44b2a28d3344c7675d2f
)
==========================
assert(exp2(0.5L)== SQRT2); //Only 52 mantissa bits are equal
==========================
real n = frexp(0x1p-16384L, x); //value is too small to fit in double
==========================

real y = vals[i][1];
real z = vals[i][2];
real h = hypot(x, y);
For some values only 52 mantissa bits are equal
==========================
assert(pow(xf, neg8) == 1 / ((x * x) * (x * x) * (x * x) * (x * x)));
//Only 52 mantissa bits are equal
==========================
assert(pow(xf, neg8) == 1 / ((x * x) * (x * x) * (x * x) * (x * x)));
Fails in exactly the same way on dpaste:
http://dpaste.dzfl.pl/4c794ab8
==========================
assert(pow(x, neg3) == 1 / (x * x * x));
//Only 52 mantissa bits are equal
==========================
assert(feqrel(real.min_normal / 8, real.min_normal / 17) == 3);
//feqrel returns spectacular -732 equal bits. But it's the same on x86
//with double so it's a bug in the test case. I can't fix it as I
//don't know what it's supposed to do