s_sinf.c revision 152869
1/* s_sinf.c -- float version of s_sin.c. 2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. 3 */ 4 5/* 6 * ==================================================== 7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 8 * 9 * Developed at SunPro, a Sun Microsystems, Inc. business. 10 * Permission to use, copy, modify, and distribute this 11 * software is freely granted, provided that this notice 12 * is preserved. 13 * ==================================================== 14 */ 15 16#ifndef lint 17static char rcsid[] = "$FreeBSD: head/lib/msun/src/s_sinf.c 152869 2005-11-28 04:58:57Z bde $"; 18#endif 19 20#include "math.h" 21#define INLINE_KERNEL_COSDF 22#define INLINE_KERNEL_SINDF 23#include "math_private.h" 24#include "k_cosf.c" 25#include "k_sinf.c" 26 27/* Small multiples of pi/2 rounded to double precision. */ 28static const double 29s1pio2 = 1*M_PI_2, /* 0x3FF921FB, 0x54442D18 */ 30s2pio2 = 2*M_PI_2, /* 0x400921FB, 0x54442D18 */ 31s3pio2 = 3*M_PI_2, /* 0x4012D97C, 0x7F3321D2 */ 32s4pio2 = 4*M_PI_2; /* 0x401921FB, 0x54442D18 */ 33 34float 35sinf(float x) 36{ 37 float y[2]; 38 int32_t n, hx, ix; 39 40 GET_FLOAT_WORD(hx,x); 41 ix = hx & 0x7fffffff; 42 43 if(ix <= 0x3f490fda) { /* |x| ~<= pi/4 */ 44 if(ix<0x39800000) /* |x| < 2**-12 */ 45 if(((int)x)==0) return x; /* x with inexact if x != 0 */ 46 return __kernel_sindf(x); 47 } 48 if(ix<=0x407b53d1) { /* |x| <= ~5*pi/4 */ 49 if(ix<=0x4016cbe3) { /* |x| <= ~3pi/4 */ 50 if(hx>0) 51 return __kernel_cosdf(x - s1pio2); 52 else 53 return -__kernel_cosdf(x + s1pio2); 54 } else 55 return -__kernel_sindf(x + (hx > 0 ? -s2pio2 : s2pio2)); 56 } 57 if(ix<=0x40e231d5) { /* |x| <= ~9*pi/4 */ 58 if(ix<=0x40afeddf) { /* |x| <= ~7*pi/4 */ 59 if(hx>0) 60 return -__kernel_cosdf(x - s3pio2); 61 else 62 return __kernel_cosdf(x + s3pio2); 63 } else 64 return __kernel_sindf(x + (hx > 0 ? -s4pio2 : s4pio2)); 65 } 66 67 /* sin(Inf or NaN) is NaN */ 68 else if (ix>=0x7f800000) return x-x; 69 70 /* general argument reduction needed */ 71 else { 72 n = __ieee754_rem_pio2f(x,y); 73 switch(n&3) { 74 case 0: return __kernel_sindf((double)y[0]+y[1]); 75 case 1: return __kernel_cosdf((double)y[0]+y[1]); 76 case 2: return -__kernel_sindf((double)y[0]+y[1]); 77 default: 78 return -__kernel_cosdf((double)y[0]+y[1]); 79 } 80 } 81} 82