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Diffstat (limited to 'sysdeps/ieee754/ldbl-128ibm/e_hypotl.c')
| -rw-r--r-- | sysdeps/ieee754/ldbl-128ibm/e_hypotl.c | 138 |
1 files changed, 0 insertions, 138 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/e_hypotl.c b/sysdeps/ieee754/ldbl-128ibm/e_hypotl.c deleted file mode 100644 index de5a66ab05..0000000000 --- a/sysdeps/ieee754/ldbl-128ibm/e_hypotl.c +++ /dev/null @@ -1,138 +0,0 @@ -/* @(#)e_hypotl.c 5.1 93/09/24 */ -/* - * ==================================================== - * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. - * - * Developed at SunPro, a Sun Microsystems, Inc. business. - * Permission to use, copy, modify, and distribute this - * software is freely granted, provided that this notice - * is preserved. - * ==================================================== - */ - -/* __ieee754_hypotl(x,y) - * - * Method : - * If (assume round-to-nearest) z=x*x+y*y - * has error less than sqrtl(2)/2 ulp, than - * sqrtl(z) has error less than 1 ulp (exercise). - * - * So, compute sqrtl(x*x+y*y) with some care as - * follows to get the error below 1 ulp: - * - * Assume x>y>0; - * (if possible, set rounding to round-to-nearest) - * 1. if x > 2y use - * x1*x1+(y*y+(x2*(x+x1))) for x*x+y*y - * where x1 = x with lower 53 bits cleared, x2 = x-x1; else - * 2. if x <= 2y use - * t1*y1+((x-y)*(x-y)+(t1*y2+t2*y)) - * where t1 = 2x with lower 53 bits cleared, t2 = 2x-t1, - * y1= y with lower 53 bits chopped, y2 = y-y1. - * - * NOTE: scaling may be necessary if some argument is too - * large or too tiny - * - * Special cases: - * hypotl(x,y) is INF if x or y is +INF or -INF; else - * hypotl(x,y) is NAN if x or y is NAN. - * - * Accuracy: - * hypotl(x,y) returns sqrtl(x^2+y^2) with error less - * than 1 ulps (units in the last place) - */ - -#include <math.h> -#include <math_private.h> - -long double -__ieee754_hypotl(long double x, long double y) -{ - long double a,b,a1,a2,b1,b2,w,kld; - int64_t j,k,ha,hb; - double xhi, yhi, hi, lo; - - xhi = ldbl_high (x); - EXTRACT_WORDS64 (ha, xhi); - yhi = ldbl_high (y); - EXTRACT_WORDS64 (hb, yhi); - ha &= 0x7fffffffffffffffLL; - hb &= 0x7fffffffffffffffLL; - if(hb > ha) {a=y;b=x;j=ha; ha=hb;hb=j;} else {a=x;b=y;} - a = fabsl(a); /* a <- |a| */ - b = fabsl(b); /* b <- |b| */ - if((ha-hb)>0x0780000000000000LL) {return a+b;} /* x/y > 2**120 */ - k=0; - kld = 1.0L; - if(ha > 0x5f30000000000000LL) { /* a>2**500 */ - if(ha >= 0x7ff0000000000000LL) { /* Inf or NaN */ - w = a+b; /* for sNaN */ - if (issignaling (a) || issignaling (b)) - return w; - if(ha == 0x7ff0000000000000LL) - w = a; - if(hb == 0x7ff0000000000000LL) - w = b; - return w; - } - /* scale a and b by 2**-600 */ - a *= 0x1p-600L; - b *= 0x1p-600L; - k = 600; - kld = 0x1p+600L; - } - else if(hb < 0x23d0000000000000LL) { /* b < 2**-450 */ - if(hb <= 0x000fffffffffffffLL) { /* subnormal b or 0 */ - if(hb==0) return a; - a *= 0x1p+1022L; - b *= 0x1p+1022L; - k = -1022; - kld = 0x1p-1022L; - } else { /* scale a and b by 2^600 */ - a *= 0x1p+600L; - b *= 0x1p+600L; - k = -600; - kld = 0x1p-600L; - } - } - /* medium size a and b */ - w = a-b; - if (w>b) { - ldbl_unpack (a, &hi, &lo); - a1 = hi; - a2 = lo; - /* a*a + b*b - = (a1+a2)*a + b*b - = a1*a + a2*a + b*b - = a1*(a1+a2) + a2*a + b*b - = a1*a1 + a1*a2 + a2*a + b*b - = a1*a1 + a2*(a+a1) + b*b */ - w = __ieee754_sqrtl(a1*a1-(b*(-b)-a2*(a+a1))); - } else { - a = a+a; - ldbl_unpack (b, &hi, &lo); - b1 = hi; - b2 = lo; - ldbl_unpack (a, &hi, &lo); - a1 = hi; - a2 = lo; - /* a*a + b*b - = a*a + (a-b)*(a-b) - (a-b)*(a-b) + b*b - = a*a + w*w - (a*a - 2*a*b + b*b) + b*b - = w*w + 2*a*b - = w*w + (a1+a2)*b - = w*w + a1*b + a2*b - = w*w + a1*(b1+b2) + a2*b - = w*w + a1*b1 + a1*b2 + a2*b */ - w = __ieee754_sqrtl(a1*b1-(w*(-w)-(a1*b2+a2*b))); - } - if(k!=0) - { - w *= kld; - math_check_force_underflow_nonneg (w); - return w; - } - else - return w; -} -strong_alias (__ieee754_hypotl, __hypotl_finite) |