diff options
Diffstat (limited to 'lib/msun/src/e_asinf.c')
| -rw-r--r-- | lib/msun/src/e_asinf.c | 53 |
1 files changed, 18 insertions, 35 deletions
diff --git a/lib/msun/src/e_asinf.c b/lib/msun/src/e_asinf.c index f830878..a4c3f00 100644 --- a/lib/msun/src/e_asinf.c +++ b/lib/msun/src/e_asinf.c @@ -22,62 +22,45 @@ __FBSDID("$FreeBSD$"); static const float one = 1.0000000000e+00, /* 0x3F800000 */ huge = 1.000e+30, -pio2_hi = 1.5707962513e+00, /* 0x3fc90fda */ -pio2_lo = 7.5497894159e-08, /* 0x33a22168 */ -pio4_hi = 7.8539812565e-01, /* 0x3f490fda */ /* coefficient for R(x^2) */ -pS0 = 1.6666667163e-01, /* 0x3e2aaaab */ -pS1 = -3.2556581497e-01, /* 0xbea6b090 */ -pS2 = 2.0121252537e-01, /* 0x3e4e0aa8 */ -pS3 = -4.0055535734e-02, /* 0xbd241146 */ -pS4 = 7.9153501429e-04, /* 0x3a4f7f04 */ -pS5 = 3.4793309169e-05, /* 0x3811ef08 */ -qS1 = -2.4033949375e+00, /* 0xc019d139 */ -qS2 = 2.0209457874e+00, /* 0x4001572d */ -qS3 = -6.8828397989e-01, /* 0xbf303361 */ -qS4 = 7.7038154006e-02; /* 0x3d9dc62e */ +pS0 = 1.6666586697e-01, +pS1 = -4.2743422091e-02, +pS2 = -8.6563630030e-03, +qS1 = -7.0662963390e-01; + +static const double +pio2 = 1.570796326794896558e+00; float __ieee754_asinf(float x) { - float t=0.0,w,p,q,c,r,s; + double s; + float t=0.0,w,p,q,c,r; int32_t hx,ix; GET_FLOAT_WORD(hx,x); ix = hx&0x7fffffff; if(ix==0x3f800000) { /* asin(1)=+-pi/2 with inexact */ - return x*pio2_hi+x*pio2_lo; + return x*pio2; } else if(ix> 0x3f800000) { /* |x|>= 1 */ return (x-x)/(x-x); /* asin(|x|>1) is NaN */ } else if (ix<0x3f000000) { /* |x|<0.5 */ - if(ix<0x32000000) { /* if |x| < 2**-27 */ + if(ix<0x39800000) { /* if |x| < 2**-12 */ if(huge+x>one) return x;/* return x with inexact if x!=0*/ } else t = x*x; - p = t*(pS0+t*(pS1+t*(pS2+t*(pS3+t*(pS4+t*pS5))))); - q = one+t*(qS1+t*(qS2+t*(qS3+t*qS4))); + p = t*(pS0+t*(pS1+t*pS2)); + q = one+t*qS1; w = p/q; return x+x*w; } /* 1> |x|>= 0.5 */ w = one-fabsf(x); t = w*(float)0.5; - p = t*(pS0+t*(pS1+t*(pS2+t*(pS3+t*(pS4+t*pS5))))); - q = one+t*(qS1+t*(qS2+t*(qS3+t*qS4))); - s = __ieee754_sqrtf(t); - if(ix>=0x3F79999A) { /* if |x| > 0.975 */ - w = p/q; - t = pio2_hi-((float)2.0*(s+s*w)-pio2_lo); - } else { - int32_t iw; - w = s; - GET_FLOAT_WORD(iw,w); - SET_FLOAT_WORD(w,iw&0xfffff000); - c = (t-w*w)/(s+w); - r = p/q; - p = (float)2.0*s*r-(pio2_lo-(float)2.0*c); - q = pio4_hi-(float)2.0*w; - t = pio4_hi-(p-q); - } + p = t*(pS0+t*(pS1+t*pS2)); + q = one+t*qS1; + s = __ieee754_sqrt(t); + w = p/q; + t = pio2-2.0*(s+s*w); if(hx>0) return t; else return -t; } |
