| e_rem_pio2f.c (176467) | e_rem_pio2f.c (176476) |
|---|---|
| 1/* e_rem_pio2f.c -- float version of e_rem_pio2.c 2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. 3 * Debugged and 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#include <sys/cdefs.h> | 1/* e_rem_pio2f.c -- float version of e_rem_pio2.c 2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. 3 * Debugged and 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#include <sys/cdefs.h> |
| 18__FBSDID("$FreeBSD: head/lib/msun/src/e_rem_pio2f.c 176467 2008-02-22 18:43:23Z bde $"); | 18__FBSDID("$FreeBSD: head/lib/msun/src/e_rem_pio2f.c 176476 2008-02-23 12:53:21Z bde $"); |
| 19 20/* __ieee754_rem_pio2f(x,y) 21 * 22 * return the remainder of x rem pi/2 in y[0]+y[1] 23 * use double precision internally 24 * use __kernel_rem_pio2() for large x 25 */ 26 --- 12 unchanged lines hidden (view full) --- 39half = 5.00000000000000000000e-01, /* 0x3FE00000, 0x00000000 */ 40invpio2 = 6.36619772367581382433e-01, /* 0x3FE45F30, 0x6DC9C883 */ 41pio2_1 = 1.57079632673412561417e+00, /* 0x3FF921FB, 0x54400000 */ 42pio2_1t = 6.07710050650619224932e-11; /* 0x3DD0B461, 0x1A626331 */ 43 44int 45__ieee754_rem_pio2f(float x, float *y) 46{ | 19 20/* __ieee754_rem_pio2f(x,y) 21 * 22 * return the remainder of x rem pi/2 in y[0]+y[1] 23 * use double precision internally 24 * use __kernel_rem_pio2() for large x 25 */ 26 --- 12 unchanged lines hidden (view full) --- 39half = 5.00000000000000000000e-01, /* 0x3FE00000, 0x00000000 */ 40invpio2 = 6.36619772367581382433e-01, /* 0x3FE45F30, 0x6DC9C883 */ 41pio2_1 = 1.57079632673412561417e+00, /* 0x3FF921FB, 0x54400000 */ 42pio2_1t = 6.07710050650619224932e-11; /* 0x3DD0B461, 0x1A626331 */ 43 44int 45__ieee754_rem_pio2f(float x, float *y) 46{ |
| 47 double w,t,r,fn; | 47 double w,r,fn; |
| 48 double tx[1],ty[2]; 49 float z; 50 int32_t e0,n,ix,hx; 51 52 GET_FLOAT_WORD(hx,x); 53 ix = hx&0x7fffffff; 54 /* 33+53 bit pi is good enough for medium size */ 55 if(ix<=0x49490f80) { /* |x| ~<= 2^19*(pi/2), medium size */ | 48 double tx[1],ty[2]; 49 float z; 50 int32_t e0,n,ix,hx; 51 52 GET_FLOAT_WORD(hx,x); 53 ix = hx&0x7fffffff; 54 /* 33+53 bit pi is good enough for medium size */ 55 if(ix<=0x49490f80) { /* |x| ~<= 2^19*(pi/2), medium size */ |
| 56 t = fabsf(x); | |
| 57 /* Use a specialized rint() to get fn. Assume round-to-nearest. */ | 56 /* Use a specialized rint() to get fn. Assume round-to-nearest. */ |
| 58 STRICT_ASSIGN(double,fn,t*invpio2+0x1.8p52); | 57 STRICT_ASSIGN(double,fn,x*invpio2+0x1.8p52); |
| 59 fn = fn-0x1.8p52; 60#ifdef HAVE_EFFICIENT_IRINT 61 n = irint(fn); 62#else 63 n = (int32_t)fn; 64#endif | 58 fn = fn-0x1.8p52; 59#ifdef HAVE_EFFICIENT_IRINT 60 n = irint(fn); 61#else 62 n = (int32_t)fn; 63#endif |
| 65 r = t-fn*pio2_1; | 64 r = x-fn*pio2_1; |
| 66 w = fn*pio2_1t; 67 y[0] = r-w; 68 y[1] = (r-y[0])-w; | 65 w = fn*pio2_1t; 66 y[0] = r-w; 67 y[1] = (r-y[0])-w; |
| 69 if(hx<0) {y[0] = -y[0]; y[1] = -y[1]; return -n;} 70 else return n; | 68 return n; |
| 71 } 72 /* 73 * all other (large) arguments 74 */ 75 if(ix>=0x7f800000) { /* x is inf or NaN */ 76 y[0]=y[1]=x-x; return 0; 77 } 78 /* set z = scalbn(|x|,ilogb(|x|)-23) */ 79 e0 = (ix>>23)-150; /* e0 = ilogb(|x|)-23; */ 80 SET_FLOAT_WORD(z, ix - ((int32_t)(e0<<23))); 81 tx[0] = z; 82 n = __kernel_rem_pio2(tx,ty,e0,1,1); 83 y[0] = ty[0]; 84 y[1] = ty[0] - y[0]; 85 if(hx<0) {y[0] = -y[0]; y[1] = -y[1]; return -n;} 86 return n; 87} | 69 } 70 /* 71 * all other (large) arguments 72 */ 73 if(ix>=0x7f800000) { /* x is inf or NaN */ 74 y[0]=y[1]=x-x; return 0; 75 } 76 /* set z = scalbn(|x|,ilogb(|x|)-23) */ 77 e0 = (ix>>23)-150; /* e0 = ilogb(|x|)-23; */ 78 SET_FLOAT_WORD(z, ix - ((int32_t)(e0<<23))); 79 tx[0] = z; 80 n = __kernel_rem_pio2(tx,ty,e0,1,1); 81 y[0] = ty[0]; 82 y[1] = ty[0] - y[0]; 83 if(hx<0) {y[0] = -y[0]; y[1] = -y[1]; return -n;} 84 return n; 85} |