1/*- 2 * Copyright (c) 2011 David Schultz <das@FreeBSD.ORG> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright --- 11 unchanged lines hidden (view full) --- 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27#include <sys/cdefs.h> |
28__FBSDID("$FreeBSD: head/lib/msun/src/s_cexpf.c 226597 2011-10-21 06:27:56Z das $"); |
29 30#include <complex.h> 31#include <math.h> 32 33#include "math_private.h" 34 35static const uint32_t 36exp_ovfl = 0x42b17218, /* MAX_EXP * ln2 ~= 88.722839355 */ |
37cexp_ovfl = 0x43400074; /* (MAX_EXP - MIN_DENORM_EXP) * ln2 */ |
38 |
39float complex 40cexpf(float complex z) 41{ 42 float x, y, exp_x; 43 uint32_t hx, hy; |
44 45 x = crealf(z); 46 y = cimagf(z); 47 48 GET_FLOAT_WORD(hy, y); 49 hy &= 0x7fffffff; 50 51 /* cexp(x + I 0) = exp(x) + I 0 */ --- 15 unchanged lines hidden (view full) --- 67 /* cexp(+Inf +- I Inf|NaN) = Inf + I NaN */ 68 return (cpackf(x, y - y)); 69 } 70 } 71 72 if (hx >= exp_ovfl && hx <= cexp_ovfl) { 73 /* 74 * x is between 88.7 and 192, so we must scale to avoid |
75 * overflow in expf(x). |
76 */ |
77 return (__ldexp_cexpf(z, 0)); |
78 } else { 79 /* 80 * Cases covered here: 81 * - x < exp_ovfl and exp(x) won't overflow (common case) 82 * - x > cexp_ovfl, so exp(x) * s overflows for all s > 0 83 * - x = +-Inf (generated by exp()) 84 * - x = NaN (spurious inexact exception from y) 85 */ 86 exp_x = expf(x); 87 return (cpackf(exp_x * cosf(y), exp_x * sinf(y))); 88 } 89} |