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author | Rich Felker <dalias@aerifal.cx> | 2012-03-16 21:01:34 -0400 |
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committer | Rich Felker <dalias@aerifal.cx> | 2012-03-16 21:01:34 -0400 |
commit | 93a50a26cd0f9efc59cc83daae7b2d916b327ab1 (patch) | |
tree | ada41a23c4b01f27d1d2cf8cd88948b061aa8f61 /src/math/sincosf.c | |
parent | 2cbb24bba39ad3529315098b5619b6fec078eb82 (diff) | |
parent | 40305f74bd70a575ce73260227ed3b64e0625b13 (diff) | |
download | musl-93a50a26cd0f9efc59cc83daae7b2d916b327ab1.tar.gz musl-93a50a26cd0f9efc59cc83daae7b2d916b327ab1.tar.bz2 musl-93a50a26cd0f9efc59cc83daae7b2d916b327ab1.tar.xz musl-93a50a26cd0f9efc59cc83daae7b2d916b327ab1.zip |
Merge remote branch 'nsz/master'
Diffstat (limited to 'src/math/sincosf.c')
-rw-r--r-- | src/math/sincosf.c | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/src/math/sincosf.c b/src/math/sincosf.c new file mode 100644 index 00000000..fede5f23 --- /dev/null +++ b/src/math/sincosf.c @@ -0,0 +1,113 @@ +/* origin: FreeBSD /usr/src/lib/msun/src/s_sinf.c */ +/* + * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. + * Optimized by Bruce D. Evans. + */ +/* + * ==================================================== + * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. + * + * Developed at SunPro, a Sun Microsystems, Inc. business. + * Permission to use, copy, modify, and distribute this + * software is freely granted, provided that this notice + * is preserved. + * ==================================================== + */ + +#include "libm.h" + +/* Small multiples of pi/2 rounded to double precision. */ +static const double +s1pio2 = 1*M_PI_2, /* 0x3FF921FB, 0x54442D18 */ +s2pio2 = 2*M_PI_2, /* 0x400921FB, 0x54442D18 */ +s3pio2 = 3*M_PI_2, /* 0x4012D97C, 0x7F3321D2 */ +s4pio2 = 4*M_PI_2; /* 0x401921FB, 0x54442D18 */ + +void sincosf(float x, float *sin, float *cos) +{ + double y, s, c; + uint32_t n, hx, ix; + + GET_FLOAT_WORD(hx, x); + ix = hx & 0x7fffffff; + + /* |x| ~<= pi/4 */ + if (ix <= 0x3f490fda) { + /* |x| < 2**-12 */ + if (ix < 0x39800000) { + /* raise inexact if x != 0 */ + if((int)x == 0) { + *sin = x; + *cos = 1.0f; + } + return; + } + *sin = __sindf(x); + *cos = __cosdf(x); + return; + } + + /* |x| ~<= 5*pi/4 */ + if (ix <= 0x407b53d1) { + if (ix <= 0x4016cbe3) { /* |x| ~<= 3pi/4 */ + if (hx < 0x80000000) { + *sin = __cosdf(x - s1pio2); + *cos = __sindf(s1pio2 - x); + } else { + *sin = -__cosdf(x + s1pio2); + *cos = __sindf(x + s1pio2); + } + return; + } + *sin = __sindf(hx < 0x80000000 ? s2pio2 - x : -s2pio2 - x); + *cos = -__cosdf(hx < 0x80000000 ? x - s2pio2 : x + s2pio2); + return; + } + + /* |x| ~<= 9*pi/4 */ + if (ix <= 0x40e231d5) { + if (ix <= 0x40afeddf) { /* |x| ~<= 7*pi/4 */ + if (hx < 0x80000000) { + *sin = -__cosdf(x - s3pio2); + *cos = __sindf(x - s3pio2); + } else { + *sin = __cosdf(x + s3pio2); + *cos = __sindf(-s3pio2 - x); + } + return; + } + *sin = __sindf(hx < 0x80000000 ? x - s4pio2 : x + s4pio2); + *cos = __cosdf(hx < 0x80000000 ? x - s4pio2 : x + s4pio2); + return; + } + + /* sin(Inf or NaN) is NaN */ + if (ix >= 0x7f800000) { + *sin = *cos = x - x; + return; + } + + /* general argument reduction needed */ + n = __rem_pio2f(x, &y); + s = __sindf(y); + c = __cosdf(y); + switch (n&3) { + case 0: + *sin = s; + *cos = c; + break; + case 1: + *sin = c; + *cos = -s; + break; + case 2: + *sin = -s; + *cos = -c; + break; + case 3: + default: + *sin = -c; + *cos = s; + break; + } +} |