/*- * SPDX-License-Identifier: BSD-2-Clause * * Copyright (c) 2011 David Schultz <das@FreeBSD.ORG> * 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, 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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. */ #include <complex.h> #include <math.h> #include "math_private.h" static const uint32_t exp_ovfl = 0x42b17218, /* MAX_EXP * ln2 ~= 88.722839355 */ cexp_ovfl = 0x43400074; /* (MAX_EXP - MIN_DENORM_EXP) * ln2 */ float complex cexpf(float complex z) { float c, exp_x, s, x, y; uint32_t hx, hy; x = crealf(z); y = cimagf(z); GET_FLOAT_WORD(hy, y); hy &= 0x7fffffff; /* cexp(x + I 0) = exp(x) + I 0 */ if (hy == 0) return (CMPLXF(expf(x), y)); GET_FLOAT_WORD(hx, x); /* cexp(0 + I y) = cos(y) + I sin(y) */ if ((hx & 0x7fffffff) == 0) { sincosf(y, &s, &c); return (CMPLXF(c, s)); } if (hy >= 0x7f800000) { if ((hx & 0x7fffffff) != 0x7f800000) { /* cexp(finite|NaN +- I Inf|NaN) = NaN + I NaN */ return (CMPLXF(y - y, y - y)); } else if (hx & 0x80000000) { /* cexp(-Inf +- I Inf|NaN) = 0 + I 0 */ return (CMPLXF(0.0, 0.0)); } else { /* cexp(+Inf +- I Inf|NaN) = Inf + I NaN */ return (CMPLXF(x, y - y)); } } if (hx >= exp_ovfl && hx <= cexp_ovfl) { /* * x is between 88.7 and 192, so we must scale to avoid * overflow in expf(x). */ return (__ldexp_cexpf(z, 0)); } else { /* * Cases covered here: * - x < exp_ovfl and exp(x) won't overflow (common case) * - x > cexp_ovfl, so exp(x) * s overflows for all s > 0 * - x = +-Inf (generated by exp()) * - x = NaN (spurious inexact exception from y) */ exp_x = expf(x); sincosf(y, &s, &c); return (CMPLXF(exp_x * c, exp_x * s)); } }