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Diffstat (limited to 'src/complex/ccoshf.c')
-rw-r--r-- | src/complex/ccoshf.c | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/src/complex/ccoshf.c b/src/complex/ccoshf.c new file mode 100644 index 00000000..683e77fa --- /dev/null +++ b/src/complex/ccoshf.c @@ -0,0 +1,90 @@ +/* origin: FreeBSD /usr/src/lib/msun/src/s_ccoshf.c */ +/*- + * Copyright (c) 2005 Bruce D. Evans and Steven G. Kargl + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice unmodified, this list of conditions, and the following + * disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ +/* + * Hyperbolic cosine of a complex argument. See s_ccosh.c for details. + */ + +#include "libm.h" + +static const float huge = 0x1p127; + +float complex ccoshf(float complex z) +{ + float x, y, h; + int32_t hx, hy, ix, iy; + + x = crealf(z); + y = cimagf(z); + + GET_FLOAT_WORD(hx, x); + GET_FLOAT_WORD(hy, y); + + ix = 0x7fffffff & hx; + iy = 0x7fffffff & hy; + + if (ix < 0x7f800000 && iy < 0x7f800000) { + if (iy == 0) + return cpackf(coshf(x), x * y); + if (ix < 0x41100000) /* small x: normal case */ + return cpackf(coshf(x) * cosf(y), sinhf(x) * sinf(y)); + + /* |x| >= 9, so cosh(x) ~= exp(|x|) */ + if (ix < 0x42b17218) { + /* x < 88.7: expf(|x|) won't overflow */ + h = expf(fabsf(x)) * 0.5f; + return cpackf(h * cosf(y), copysignf(h, x) * sinf(y)); + } else if (ix < 0x4340b1e7) { + /* x < 192.7: scale to avoid overflow */ + z = __ldexp_cexpf(cpackf(fabsf(x), y), -1); + return cpackf(crealf(z), cimagf(z) * copysignf(1, x)); + } else { + /* x >= 192.7: the result always overflows */ + h = huge * x; + return cpackf(h * h * cosf(y), h * sinf(y)); + } + } + + if (ix == 0 && iy >= 0x7f800000) + return cpackf(y - y, copysignf(0, x * (y - y))); + + if (iy == 0 && ix >= 0x7f800000) { + if ((hx & 0x7fffff) == 0) + return cpackf(x * x, copysignf(0, x) * y); + return cpackf(x * x, copysignf(0, (x + x) * y)); + } + + if (ix < 0x7f800000 && iy >= 0x7f800000) + return cpackf(y - y, x * (y - y)); + + if (ix >= 0x7f800000 && (hx & 0x7fffff) == 0) { + if (iy >= 0x7f800000) + return cpackf(x * x, x * (y - y)); + return cpackf((x * x) * cosf(y), x * sinf(y)); + } + + return cpackf((x * x) * (y - y), (x + x) * (y - y)); +} |