1 /*- 2 * ==================================================== 3 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 4 * 5 * Developed at SunPro, a Sun Microsystems, Inc. business. 6 * Permission to use, copy, modify, and distribute this 7 * software is freely granted, provided that this notice 8 * is preserved. 9 * ==================================================== 10 */ 11 12 /* s_sincosf.c -- float version of s_sincos.c. 13 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. 14 * Optimized by Bruce D. Evans. 15 * Merged s_sinf.c and s_cosf.c by Steven G. Kargl. 16 */ 17 18 #include <float.h> 19 #include "math.h" 20 21 #include "math_private.h" 22 #include "k_sincosf.h" 23 24 /* Small multiples of pi/2 rounded to double precision. */ 25 static const double 26 p1pio2 = 1*M_PI_2, /* 0x3FF921FB, 0x54442D18 */ 27 p2pio2 = 2*M_PI_2, /* 0x400921FB, 0x54442D18 */ 28 p3pio2 = 3*M_PI_2, /* 0x4012D97C, 0x7F3321D2 */ 29 p4pio2 = 4*M_PI_2; /* 0x401921FB, 0x54442D18 */ 30 31 void 32 sincosf(float x, float *sn, float *cs) 33 { 34 float c, s; 35 float y[2]; 36 int32_t n, hx, ix; 37 38 GET_FLOAT_WORD(hx, x); 39 ix = hx & 0x7fffffff; 40 41 if (ix <= 0x3f490fda) { /* |x| ~<= pi/4 */ 42 if (ix < 0x39800000) { /* |x| < 2**-12 */ 43 if ((int)x == 0) { 44 *sn = x; /* x with inexact if x != 0 */ 45 *cs = 1; 46 return; 47 } 48 } 49 __kernel_sincosdf(x, sn, cs); 50 return; 51 } 52 53 if (ix <= 0x407b53d1) { /* |x| ~<= 5*pi/4 */ 54 if (ix <= 0x4016cbe3) { /* |x| ~<= 3pi/4 */ 55 if (hx > 0) { 56 __kernel_sincosdf(x - p1pio2, cs, sn); 57 *cs = -*cs; 58 } else { 59 __kernel_sincosdf(x + p1pio2, cs, sn); 60 *sn = -*sn; 61 } 62 } else { 63 if (hx > 0) 64 __kernel_sincosdf(x - p2pio2, sn, cs); 65 else 66 __kernel_sincosdf(x + p2pio2, sn, cs); 67 *sn = -*sn; 68 *cs = -*cs; 69 } 70 return; 71 } 72 73 if (ix <= 0x40e231d5) { /* |x| ~<= 9*pi/4 */ 74 if (ix <= 0x40afeddf) { /* |x| ~<= 7*pi/4 */ 75 if (hx > 0) { 76 __kernel_sincosdf(x - p3pio2, cs, sn); 77 *sn = -*sn; 78 } else { 79 __kernel_sincosdf(x + p3pio2, cs, sn); 80 *cs = -*cs; 81 } 82 } else { 83 if (hx > 0) 84 __kernel_sincosdf(x - p4pio2, sn, cs); 85 else 86 __kernel_sincosdf(x + p4pio2, sn, cs); 87 } 88 return; 89 } 90 91 /* If x = Inf or NaN, then sin(x) = NaN and cos(x) = NaN. */ 92 if (ix >= 0x7f800000) { 93 *sn = x - x; 94 *cs = x - x; 95 return; 96 } 97 98 /* Argument reduction. */ 99 n = __ieee754_rem_pio2f(x, y); 100 s = __kernel_sinf(y[0], y[1], 1); 101 c = __kernel_cosf(y[0], y[1]); 102 103 switch(n & 3) { 104 case 0: 105 *sn = s; 106 *cs = c; 107 break; 108 case 1: 109 *sn = c; 110 *cs = -s; 111 break; 112 case 2: 113 *sn = -s; 114 *cs = -c; 115 break; 116 default: 117 *sn = -c; 118 *cs = s; 119 } 120 } 121