diff options
Diffstat (limited to 'libc-top-half/musl/src/math/atan2l.c')
| -rw-r--r-- | libc-top-half/musl/src/math/atan2l.c | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/libc-top-half/musl/src/math/atan2l.c b/libc-top-half/musl/src/math/atan2l.c new file mode 100644 index 0000000..f0937a9 --- /dev/null +++ b/libc-top-half/musl/src/math/atan2l.c @@ -0,0 +1,85 @@ +/* origin: FreeBSD /usr/src/lib/msun/src/e_atan2l.c */ +/* + * ==================================================== + * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. + * + * Developed at SunSoft, a Sun Microsystems, Inc. business. + * Permission to use, copy, modify, and distribute this + * software is freely granted, provided that this notice + * is preserved. + * ==================================================== + * + */ +/* + * See comments in atan2.c. + * Converted to long double by David Schultz <das@FreeBSD.ORG>. + */ + +#include "libm.h" + +#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024 +long double atan2l(long double y, long double x) +{ + return atan2(y, x); +} +#elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384 +#include "__invtrigl.h" + +long double atan2l(long double y, long double x) +{ + union ldshape ux, uy; + long double z; + int m, ex, ey; + + if (isnan(x) || isnan(y)) + return x+y; + if (x == 1) + return atanl(y); + ux.f = x; + uy.f = y; + ex = ux.i.se & 0x7fff; + ey = uy.i.se & 0x7fff; + m = 2*(ux.i.se>>15) | uy.i.se>>15; + if (y == 0) { + switch(m) { + case 0: + case 1: return y; /* atan(+-0,+anything)=+-0 */ + case 2: return 2*pio2_hi; /* atan(+0,-anything) = pi */ + case 3: return -2*pio2_hi; /* atan(-0,-anything) =-pi */ + } + } + if (x == 0) + return m&1 ? -pio2_hi : pio2_hi; + if (ex == 0x7fff) { + if (ey == 0x7fff) { + switch(m) { + case 0: return pio2_hi/2; /* atan(+INF,+INF) */ + case 1: return -pio2_hi/2; /* atan(-INF,+INF) */ + case 2: return 1.5*pio2_hi; /* atan(+INF,-INF) */ + case 3: return -1.5*pio2_hi; /* atan(-INF,-INF) */ + } + } else { + switch(m) { + case 0: return 0.0; /* atan(+...,+INF) */ + case 1: return -0.0; /* atan(-...,+INF) */ + case 2: return 2*pio2_hi; /* atan(+...,-INF) */ + case 3: return -2*pio2_hi; /* atan(-...,-INF) */ + } + } + } + if (ex+120 < ey || ey == 0x7fff) + return m&1 ? -pio2_hi : pio2_hi; + /* z = atan(|y/x|) without spurious underflow */ + if ((m&2) && ey+120 < ex) /* |y/x| < 0x1p-120, x<0 */ + z = 0.0; + else + z = atanl(fabsl(y/x)); + switch (m) { + case 0: return z; /* atan(+,+) */ + case 1: return -z; /* atan(-,+) */ + case 2: return 2*pio2_hi-(z-2*pio2_lo); /* atan(+,-) */ + default: /* case 3 */ + return (z-2*pio2_lo)-2*pio2_hi; /* atan(-,-) */ + } +} +#endif |