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author | Szabolcs Nagy <nsz@port70.net> | 2013-05-18 14:40:22 +0000 |
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committer | Szabolcs Nagy <nsz@port70.net> | 2013-05-18 14:40:22 +0000 |
commit | bfda37935867f9bf271d6074db0accf05c63ad10 (patch) | |
tree | 92d7fffcc6fb7fd9caad6f3bde14dcd768d32b66 /src/math/sincosl.c | |
parent | 1d5ba3bb5a3f55e10db05219638cfcd967d65417 (diff) | |
download | musl-bfda37935867f9bf271d6074db0accf05c63ad10.tar.gz musl-bfda37935867f9bf271d6074db0accf05c63ad10.tar.bz2 musl-bfda37935867f9bf271d6074db0accf05c63ad10.tar.xz musl-bfda37935867f9bf271d6074db0accf05c63ad10.zip |
math: sin cos cleanup
* use unsigned arithmetics
* use unsigned to store arg reduction quotient (so n&3 is understood)
* remove z=0.0 variables, use literal 0
* raise underflow and inexact exceptions properly when x is small
* fix spurious underflow in tanl
Diffstat (limited to 'src/math/sincosl.c')
-rw-r--r-- | src/math/sincosl.c | 20 |
1 files changed, 11 insertions, 9 deletions
diff --git a/src/math/sincosl.c b/src/math/sincosl.c index d632fe6f..5db69bd6 100644 --- a/src/math/sincosl.c +++ b/src/math/sincosl.c @@ -10,27 +10,29 @@ void sincosl(long double x, long double *sin, long double *cos) void sincosl(long double x, long double *sin, long double *cos) { union IEEEl2bits u; - int n; + unsigned n; long double y[2], s, c; u.e = x; u.bits.sign = 0; - /* x = +-0 or subnormal */ - if (!u.bits.exp) { - *sin = x; - *cos = 1.0; - return; - } - /* x = nan or inf */ if (u.bits.exp == 0x7fff) { *sin = *cos = x - x; return; } - /* |x| < pi/4 */ + /* |x| < (double)pi/4 */ if (u.e < M_PI_4) { + /* |x| < 0x1p-64 */ + if (u.bits.exp < 0x3fff - 64) { + /* raise underflow if subnormal */ + if (u.bits.exp == 0) FORCE_EVAL(x*0x1p-120f); + *sin = x; + /* raise inexact if x!=0 */ + *cos = 1.0 + x; + return; + } *sin = __sinl(x, 0, 0); *cos = __cosl(x, 0); return; |