1 /* s_sinf.c -- float version of s_sin.c. 2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian (at) cygnus.com. 3 * Optimized by Bruce D. Evans. 4 */ 5 6 /* 7 * ==================================================== 8 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 9 * 10 * Developed at SunPro, a Sun Microsystems, Inc. business. 11 * Permission to use, copy, modify, and distribute this 12 * software is freely granted, provided that this notice 13 * is preserved. 14 * ==================================================== 15 */ 16 17 #ifndef lint 18 static char rcsid[] = "$FreeBSD: src/lib/msun/src/s_sinf.c,v 1.14 2005/11/28 06:15:10 bde Exp $"; 19 #endif 20 21 #include "math.h" 22 #define INLINE_KERNEL_COSDF 23 #define INLINE_KERNEL_SINDF 24 #include "math_private.h" 25 #include "k_cosf.c" 26 #include "k_sinf.c" 27 28 /* Small multiples of pi/2 rounded to double precision. */ 29 static const double 30 s1pio2 = 1*M_PI_2, /* 0x3FF921FB, 0x54442D18 */ 31 s2pio2 = 2*M_PI_2, /* 0x400921FB, 0x54442D18 */ 32 s3pio2 = 3*M_PI_2, /* 0x4012D97C, 0x7F3321D2 */ 33 s4pio2 = 4*M_PI_2; /* 0x401921FB, 0x54442D18 */ 34 35 float 36 sinf(float x) 37 { 38 float y[2]; 39 int32_t n, hx, ix; 40 41 GET_FLOAT_WORD(hx,x); 42 ix = hx & 0x7fffffff; 43 44 if(ix <= 0x3f490fda) { /* |x| ~<= pi/4 */ 45 if(ix<0x39800000) /* |x| < 2**-12 */ 46 if(((int)x)==0) return x; /* x with inexact if x != 0 */ 47 return __kernel_sindf(x); 48 } 49 if(ix<=0x407b53d1) { /* |x| ~<= 5*pi/4 */ 50 if(ix<=0x4016cbe3) { /* |x| ~<= 3pi/4 */ 51 if(hx>0) 52 return __kernel_cosdf(x - s1pio2); 53 else 54 return -__kernel_cosdf(x + s1pio2); 55 } else 56 return __kernel_sindf((hx > 0 ? s2pio2 : -s2pio2) - x); 57 } 58 if(ix<=0x40e231d5) { /* |x| ~<= 9*pi/4 */ 59 if(ix<=0x40afeddf) { /* |x| ~<= 7*pi/4 */ 60 if(hx>0) 61 return -__kernel_cosdf(x - s3pio2); 62 else 63 return __kernel_cosdf(x + s3pio2); 64 } else 65 return __kernel_sindf(x + (hx > 0 ? -s4pio2 : s4pio2)); 66 } 67 68 /* sin(Inf or NaN) is NaN */ 69 else if (ix>=0x7f800000) return x-x; 70 71 /* general argument reduction needed */ 72 else { 73 n = __ieee754_rem_pio2f(x,y); 74 switch(n&3) { 75 case 0: return __kernel_sindf((double)y[0]+y[1]); 76 case 1: return __kernel_cosdf((double)y[0]+y[1]); 77 case 2: return __kernel_sindf(-(double)y[0]-y[1]); 78 default: 79 return -__kernel_cosdf((double)y[0]+y[1]); 80 } 81 } 82 } 83
