| author | nsz <nsz@port70.net> | 2012年03月19日 22:57:58 +0100 |
|---|---|---|
| committer | nsz <nsz@port70.net> | 2012年03月19日 22:57:58 +0100 |
| commit | 2786c7d21611b9fa3b2fe356542cf213e7dd0ba4 (patch) | |
| tree | b3954e9cec7580f5dc851491d3b60d808aae4259 /src/math/log2l.c | |
| parent | 01fdfd491b5d83b72099fbae14c4a71ed8e0b945 (diff) | |
| download | musl-2786c7d21611b9fa3b2fe356542cf213e7dd0ba4.tar.gz | |
| -rw-r--r-- | src/math/log2l.c | 20 |
diff --git a/src/math/log2l.c b/src/math/log2l.c index 4339c033..8ebce9c4 100644 --- a/src/math/log2l.c +++ b/src/math/log2l.c @@ -121,8 +121,8 @@ long double log2l(long double x) return x; if (x == INFINITY) return x; - if (x <= 0.0L) { - if (x == 0.0L) + if (x <= 0.0) { + if (x == 0.0) return -INFINITY; return NAN; } @@ -139,12 +139,12 @@ long double log2l(long double x) if (e > 2 || e < -2) { if (x < SQRTH) { /* 2(2x-1)/(2x+1) */ e -= 1; - z = x - 0.5L; - y = 0.5L * z + 0.5L; + z = x - 0.5; + y = 0.5 * z + 0.5; } else { /* 2 (x-1)/(x+1) */ - z = x - 0.5L; - z -= 0.5L; - y = 0.5L * x + 0.5L; + z = x - 0.5; + z -= 0.5; + y = 0.5 * x + 0.5; } x = z / y; z = x*x; @@ -155,13 +155,13 @@ long double log2l(long double x) /* logarithm using log(1+x) = x - .5x**2 + x**3 P(x)/Q(x) */ if (x < SQRTH) { e -= 1; - x = ldexpl(x, 1) - 1.0L; /* 2x - 1 */ + x = 2.0*x - 1.0; } else { - x = x - 1.0L; + x = x - 1.0; } z = x*x; y = x * (z * __polevll(x, P, 6) / __p1evll(x, Q, 7)); - y = y - ldexpl(z, -1); /* -0.5x^2 + ... */ + y = y - 0.5*z; done: /* Multiply log of fraction by log2(e) |