| Index: fusl/src/math/pow.c
|
| diff --git a/fusl/src/math/pow.c b/fusl/src/math/pow.c
|
| index b66f632d8eea9fce118c087677c755f391c6df85..7a9f1a6d91dc00d1cdb957e41e167509b4aebac4 100644
|
| --- a/fusl/src/math/pow.c
|
| +++ b/fusl/src/math/pow.c
|
| @@ -31,14 +31,17 @@
|
| * 9. -1 ** +-INF is 1
|
| * 10. +0 ** (+anything except 0, NAN) is +0
|
| * 11. -0 ** (+anything except 0, NAN, odd integer) is +0
|
| - * 12. +0 ** (-anything except 0, NAN) is +INF, raise divbyzero
|
| - * 13. -0 ** (-anything except 0, NAN, odd integer) is +INF, raise divbyzero
|
| + * 12. +0 ** (-anything except 0, NAN) is +INF, raise
|
| + * divbyzero
|
| + * 13. -0 ** (-anything except 0, NAN, odd integer) is +INF, raise
|
| + * divbyzero
|
| * 14. -0 ** (+odd integer) is -0
|
| * 15. -0 ** (-odd integer) is -INF, raise divbyzero
|
| * 16. +INF ** (+anything except 0,NAN) is +INF
|
| * 17. +INF ** (-anything except 0,NAN) is +0
|
| * 18. -INF ** (+odd integer) is -INF
|
| - * 19. -INF ** (anything) = -0 ** (-anything), (anything except odd integer)
|
| + * 19. -INF ** (anything) = -0 ** (-anything), (anything except odd
|
| + * integer)
|
| * 20. (anything) ** 1 is (anything)
|
| * 21. (anything) ** -1 is 1/(anything)
|
| * 22. (-anything) ** (integer) is (-1)**(integer)*(+anything**integer)
|
| @@ -59,270 +62,285 @@
|
|
|
| #include "libm.h"
|
|
|
| -static const double
|
| -bp[] = {1.0, 1.5,},
|
| -dp_h[] = { 0.0, 5.84962487220764160156e-01,}, /* 0x3FE2B803, 0x40000000 */
|
| -dp_l[] = { 0.0, 1.35003920212974897128e-08,}, /* 0x3E4CFDEB, 0x43CFD006 */
|
| -two53 = 9007199254740992.0, /* 0x43400000, 0x00000000 */
|
| -huge = 1.0e300,
|
| -tiny = 1.0e-300,
|
| -/* poly coefs for (3/2)*(log(x)-2s-2/3*s**3 */
|
| -L1 = 5.99999999999994648725e-01, /* 0x3FE33333, 0x33333303 */
|
| -L2 = 4.28571428578550184252e-01, /* 0x3FDB6DB6, 0xDB6FABFF */
|
| -L3 = 3.33333329818377432918e-01, /* 0x3FD55555, 0x518F264D */
|
| -L4 = 2.72728123808534006489e-01, /* 0x3FD17460, 0xA91D4101 */
|
| -L5 = 2.30660745775561754067e-01, /* 0x3FCD864A, 0x93C9DB65 */
|
| -L6 = 2.06975017800338417784e-01, /* 0x3FCA7E28, 0x4A454EEF */
|
| -P1 = 1.66666666666666019037e-01, /* 0x3FC55555, 0x5555553E */
|
| -P2 = -2.77777777770155933842e-03, /* 0xBF66C16C, 0x16BEBD93 */
|
| -P3 = 6.61375632143793436117e-05, /* 0x3F11566A, 0xAF25DE2C */
|
| -P4 = -1.65339022054652515390e-06, /* 0xBEBBBD41, 0xC5D26BF1 */
|
| -P5 = 4.13813679705723846039e-08, /* 0x3E663769, 0x72BEA4D0 */
|
| -lg2 = 6.93147180559945286227e-01, /* 0x3FE62E42, 0xFEFA39EF */
|
| -lg2_h = 6.93147182464599609375e-01, /* 0x3FE62E43, 0x00000000 */
|
| -lg2_l = -1.90465429995776804525e-09, /* 0xBE205C61, 0x0CA86C39 */
|
| -ovt = 8.0085662595372944372e-017, /* -(1024-log2(ovfl+.5ulp)) */
|
| -cp = 9.61796693925975554329e-01, /* 0x3FEEC709, 0xDC3A03FD =2/(3ln2) */
|
| -cp_h = 9.61796700954437255859e-01, /* 0x3FEEC709, 0xE0000000 =(float)cp */
|
| -cp_l = -7.02846165095275826516e-09, /* 0xBE3E2FE0, 0x145B01F5 =tail of cp_h*/
|
| -ivln2 = 1.44269504088896338700e+00, /* 0x3FF71547, 0x652B82FE =1/ln2 */
|
| -ivln2_h = 1.44269502162933349609e+00, /* 0x3FF71547, 0x60000000 =24b 1/ln2*/
|
| -ivln2_l = 1.92596299112661746887e-08; /* 0x3E54AE0B, 0xF85DDF44 =1/ln2 tail*/
|
| +static const double bp[] =
|
| + {
|
| + 1.0, 1.5,
|
| +},
|
| + dp_h[] =
|
| + {
|
| + 0.0, 5.84962487220764160156e-01,
|
| +}, /* 0x3FE2B803, 0x40000000 */
|
| + dp_l[] =
|
| + {
|
| + 0.0, 1.35003920212974897128e-08,
|
| +}, /* 0x3E4CFDEB, 0x43CFD006 */
|
| + two53 = 9007199254740992.0, /* 0x43400000, 0x00000000 */
|
| + huge = 1.0e300,
|
| + tiny = 1.0e-300,
|
| + /* poly coefs for (3/2)*(log(x)-2s-2/3*s**3 */
|
| + L1 = 5.99999999999994648725e-01, /* 0x3FE33333, 0x33333303 */
|
| + L2 = 4.28571428578550184252e-01, /* 0x3FDB6DB6, 0xDB6FABFF */
|
| + L3 = 3.33333329818377432918e-01, /* 0x3FD55555, 0x518F264D */
|
| + L4 = 2.72728123808534006489e-01, /* 0x3FD17460, 0xA91D4101 */
|
| + L5 = 2.30660745775561754067e-01, /* 0x3FCD864A, 0x93C9DB65 */
|
| + L6 = 2.06975017800338417784e-01, /* 0x3FCA7E28, 0x4A454EEF */
|
| + P1 = 1.66666666666666019037e-01, /* 0x3FC55555, 0x5555553E */
|
| + P2 = -2.77777777770155933842e-03, /* 0xBF66C16C, 0x16BEBD93 */
|
| + P3 = 6.61375632143793436117e-05, /* 0x3F11566A, 0xAF25DE2C */
|
| + P4 = -1.65339022054652515390e-06, /* 0xBEBBBD41, 0xC5D26BF1 */
|
| + P5 = 4.13813679705723846039e-08, /* 0x3E663769, 0x72BEA4D0 */
|
| + lg2 = 6.93147180559945286227e-01, /* 0x3FE62E42, 0xFEFA39EF */
|
| + lg2_h = 6.93147182464599609375e-01, /* 0x3FE62E43, 0x00000000 */
|
| + lg2_l = -1.90465429995776804525e-09, /* 0xBE205C61, 0x0CA86C39 */
|
| + ovt = 8.0085662595372944372e-017, /* -(1024-log2(ovfl+.5ulp)) */
|
| + cp = 9.61796693925975554329e-01, /* 0x3FEEC709, 0xDC3A03FD =2/(3ln2) */
|
| + cp_h = 9.61796700954437255859e-01, /* 0x3FEEC709, 0xE0000000 =(float)cp */
|
| + cp_l =
|
| + -7.02846165095275826516e-09, /* 0xBE3E2FE0, 0x145B01F5 =tail of cp_h*/
|
| + ivln2 = 1.44269504088896338700e+00, /* 0x3FF71547, 0x652B82FE =1/ln2 */
|
| + ivln2_h = 1.44269502162933349609e+00, /* 0x3FF71547, 0x60000000 =24b 1/ln2*/
|
| + ivln2_l =
|
| + 1.92596299112661746887e-08; /* 0x3E54AE0B, 0xF85DDF44 =1/ln2 tail*/
|
|
|
| -double pow(double x, double y)
|
| -{
|
| - double z,ax,z_h,z_l,p_h,p_l;
|
| - double y1,t1,t2,r,s,t,u,v,w;
|
| - int32_t i,j,k,yisint,n;
|
| - int32_t hx,hy,ix,iy;
|
| - uint32_t lx,ly;
|
| +double pow(double x, double y) {
|
| + double z, ax, z_h, z_l, p_h, p_l;
|
| + double y1, t1, t2, r, s, t, u, v, w;
|
| + int32_t i, j, k, yisint, n;
|
| + int32_t hx, hy, ix, iy;
|
| + uint32_t lx, ly;
|
|
|
| - EXTRACT_WORDS(hx, lx, x);
|
| - EXTRACT_WORDS(hy, ly, y);
|
| - ix = hx & 0x7fffffff;
|
| - iy = hy & 0x7fffffff;
|
| + EXTRACT_WORDS(hx, lx, x);
|
| + EXTRACT_WORDS(hy, ly, y);
|
| + ix = hx & 0x7fffffff;
|
| + iy = hy & 0x7fffffff;
|
|
|
| - /* x**0 = 1, even if x is NaN */
|
| - if ((iy|ly) == 0)
|
| - return 1.0;
|
| - /* 1**y = 1, even if y is NaN */
|
| - if (hx == 0x3ff00000 && lx == 0)
|
| - return 1.0;
|
| - /* NaN if either arg is NaN */
|
| - if (ix > 0x7ff00000 || (ix == 0x7ff00000 && lx != 0) ||
|
| - iy > 0x7ff00000 || (iy == 0x7ff00000 && ly != 0))
|
| - return x + y;
|
| + /* x**0 = 1, even if x is NaN */
|
| + if ((iy | ly) == 0)
|
| + return 1.0;
|
| + /* 1**y = 1, even if y is NaN */
|
| + if (hx == 0x3ff00000 && lx == 0)
|
| + return 1.0;
|
| + /* NaN if either arg is NaN */
|
| + if (ix > 0x7ff00000 || (ix == 0x7ff00000 && lx != 0) || iy > 0x7ff00000 ||
|
| + (iy == 0x7ff00000 && ly != 0))
|
| + return x + y;
|
|
|
| - /* determine if y is an odd int when x < 0
|
| - * yisint = 0 ... y is not an integer
|
| - * yisint = 1 ... y is an odd int
|
| - * yisint = 2 ... y is an even int
|
| - */
|
| - yisint = 0;
|
| - if (hx < 0) {
|
| - if (iy >= 0x43400000)
|
| - yisint = 2; /* even integer y */
|
| - else if (iy >= 0x3ff00000) {
|
| - k = (iy>>20) - 0x3ff; /* exponent */
|
| - if (k > 20) {
|
| - j = ly>>(52-k);
|
| - if ((j<<(52-k)) == ly)
|
| - yisint = 2 - (j&1);
|
| - } else if (ly == 0) {
|
| - j = iy>>(20-k);
|
| - if ((j<<(20-k)) == iy)
|
| - yisint = 2 - (j&1);
|
| - }
|
| - }
|
| - }
|
| + /* determine if y is an odd int when x < 0
|
| + * yisint = 0 ... y is not an integer
|
| + * yisint = 1 ... y is an odd int
|
| + * yisint = 2 ... y is an even int
|
| + */
|
| + yisint = 0;
|
| + if (hx < 0) {
|
| + if (iy >= 0x43400000)
|
| + yisint = 2; /* even integer y */
|
| + else if (iy >= 0x3ff00000) {
|
| + k = (iy >> 20) - 0x3ff; /* exponent */
|
| + if (k > 20) {
|
| + j = ly >> (52 - k);
|
| + if ((j << (52 - k)) == ly)
|
| + yisint = 2 - (j & 1);
|
| + } else if (ly == 0) {
|
| + j = iy >> (20 - k);
|
| + if ((j << (20 - k)) == iy)
|
| + yisint = 2 - (j & 1);
|
| + }
|
| + }
|
| + }
|
|
|
| - /* special value of y */
|
| - if (ly == 0) {
|
| - if (iy == 0x7ff00000) { /* y is +-inf */
|
| - if (((ix-0x3ff00000)|lx) == 0) /* (-1)**+-inf is 1 */
|
| - return 1.0;
|
| - else if (ix >= 0x3ff00000) /* (|x|>1)**+-inf = inf,0 */
|
| - return hy >= 0 ? y : 0.0;
|
| - else /* (|x|<1)**+-inf = 0,inf */
|
| - return hy >= 0 ? 0.0 : -y;
|
| - }
|
| - if (iy == 0x3ff00000) { /* y is +-1 */
|
| - if (hy >= 0)
|
| - return x;
|
| - y = 1/x;
|
| -#if FLT_EVAL_METHOD!=0
|
| - {
|
| - union {double f; uint64_t i;} u = {y};
|
| - uint64_t i = u.i & -1ULL/2;
|
| - if (i>>52 == 0 && (i&(i-1)))
|
| - FORCE_EVAL((float)y);
|
| - }
|
| + /* special value of y */
|
| + if (ly == 0) {
|
| + if (iy == 0x7ff00000) { /* y is +-inf */
|
| + if (((ix - 0x3ff00000) | lx) == 0) /* (-1)**+-inf is 1 */
|
| + return 1.0;
|
| + else if (ix >= 0x3ff00000) /* (|x|>1)**+-inf = inf,0 */
|
| + return hy >= 0 ? y : 0.0;
|
| + else /* (|x|<1)**+-inf = 0,inf */
|
| + return hy >= 0 ? 0.0 : -y;
|
| + }
|
| + if (iy == 0x3ff00000) { /* y is +-1 */
|
| + if (hy >= 0)
|
| + return x;
|
| + y = 1 / x;
|
| +#if FLT_EVAL_METHOD != 0
|
| + {
|
| + union {
|
| + double f;
|
| + uint64_t i;
|
| + } u = {y};
|
| + uint64_t i = u.i & -1ULL / 2;
|
| + if (i >> 52 == 0 && (i & (i - 1)))
|
| + FORCE_EVAL((float)y);
|
| + }
|
| #endif
|
| - return y;
|
| - }
|
| - if (hy == 0x40000000) /* y is 2 */
|
| - return x*x;
|
| - if (hy == 0x3fe00000) { /* y is 0.5 */
|
| - if (hx >= 0) /* x >= +0 */
|
| - return sqrt(x);
|
| - }
|
| - }
|
| + return y;
|
| + }
|
| + if (hy == 0x40000000) /* y is 2 */
|
| + return x * x;
|
| + if (hy == 0x3fe00000) { /* y is 0.5 */
|
| + if (hx >= 0) /* x >= +0 */
|
| + return sqrt(x);
|
| + }
|
| + }
|
|
|
| - ax = fabs(x);
|
| - /* special value of x */
|
| - if (lx == 0) {
|
| - if (ix == 0x7ff00000 || ix == 0 || ix == 0x3ff00000) { /* x is +-0,+-inf,+-1 */
|
| - z = ax;
|
| - if (hy < 0) /* z = (1/|x|) */
|
| - z = 1.0/z;
|
| - if (hx < 0) {
|
| - if (((ix-0x3ff00000)|yisint) == 0) {
|
| - z = (z-z)/(z-z); /* (-1)**non-int is NaN */
|
| - } else if (yisint == 1)
|
| - z = -z; /* (x<0)**odd = -(|x|**odd) */
|
| - }
|
| - return z;
|
| - }
|
| - }
|
| + ax = fabs(x);
|
| + /* special value of x */
|
| + if (lx == 0) {
|
| + if (ix == 0x7ff00000 || ix == 0 ||
|
| + ix == 0x3ff00000) { /* x is +-0,+-inf,+-1 */
|
| + z = ax;
|
| + if (hy < 0) /* z = (1/|x|) */
|
| + z = 1.0 / z;
|
| + if (hx < 0) {
|
| + if (((ix - 0x3ff00000) | yisint) == 0) {
|
| + z = (z - z) / (z - z); /* (-1)**non-int is NaN */
|
| + } else if (yisint == 1)
|
| + z = -z; /* (x<0)**odd = -(|x|**odd) */
|
| + }
|
| + return z;
|
| + }
|
| + }
|
|
|
| - s = 1.0; /* sign of result */
|
| - if (hx < 0) {
|
| - if (yisint == 0) /* (x<0)**(non-int) is NaN */
|
| - return (x-x)/(x-x);
|
| - if (yisint == 1) /* (x<0)**(odd int) */
|
| - s = -1.0;
|
| - }
|
| + s = 1.0; /* sign of result */
|
| + if (hx < 0) {
|
| + if (yisint == 0) /* (x<0)**(non-int) is NaN */
|
| + return (x - x) / (x - x);
|
| + if (yisint == 1) /* (x<0)**(odd int) */
|
| + s = -1.0;
|
| + }
|
|
|
| - /* |y| is huge */
|
| - if (iy > 0x41e00000) { /* if |y| > 2**31 */
|
| - if (iy > 0x43f00000) { /* if |y| > 2**64, must o/uflow */
|
| - if (ix <= 0x3fefffff)
|
| - return hy < 0 ? huge*huge : tiny*tiny;
|
| - if (ix >= 0x3ff00000)
|
| - return hy > 0 ? huge*huge : tiny*tiny;
|
| - }
|
| - /* over/underflow if x is not close to one */
|
| - if (ix < 0x3fefffff)
|
| - return hy < 0 ? s*huge*huge : s*tiny*tiny;
|
| - if (ix > 0x3ff00000)
|
| - return hy > 0 ? s*huge*huge : s*tiny*tiny;
|
| - /* now |1-x| is tiny <= 2**-20, suffice to compute
|
| - log(x) by x-x^2/2+x^3/3-x^4/4 */
|
| - t = ax - 1.0; /* t has 20 trailing zeros */
|
| - w = (t*t)*(0.5 - t*(0.3333333333333333333333-t*0.25));
|
| - u = ivln2_h*t; /* ivln2_h has 21 sig. bits */
|
| - v = t*ivln2_l - w*ivln2;
|
| - t1 = u + v;
|
| - SET_LOW_WORD(t1, 0);
|
| - t2 = v - (t1-u);
|
| - } else {
|
| - double ss,s2,s_h,s_l,t_h,t_l;
|
| - n = 0;
|
| - /* take care subnormal number */
|
| - if (ix < 0x00100000) {
|
| - ax *= two53;
|
| - n -= 53;
|
| - GET_HIGH_WORD(ix,ax);
|
| - }
|
| - n += ((ix)>>20) - 0x3ff;
|
| - j = ix & 0x000fffff;
|
| - /* determine interval */
|
| - ix = j | 0x3ff00000; /* normalize ix */
|
| - if (j <= 0x3988E) /* |x|<sqrt(3/2) */
|
| - k = 0;
|
| - else if (j < 0xBB67A) /* |x|<sqrt(3) */
|
| - k = 1;
|
| - else {
|
| - k = 0;
|
| - n += 1;
|
| - ix -= 0x00100000;
|
| - }
|
| - SET_HIGH_WORD(ax, ix);
|
| + /* |y| is huge */
|
| + if (iy > 0x41e00000) { /* if |y| > 2**31 */
|
| + if (iy > 0x43f00000) { /* if |y| > 2**64, must o/uflow */
|
| + if (ix <= 0x3fefffff)
|
| + return hy < 0 ? huge * huge : tiny * tiny;
|
| + if (ix >= 0x3ff00000)
|
| + return hy > 0 ? huge * huge : tiny * tiny;
|
| + }
|
| + /* over/underflow if x is not close to one */
|
| + if (ix < 0x3fefffff)
|
| + return hy < 0 ? s * huge * huge : s * tiny * tiny;
|
| + if (ix > 0x3ff00000)
|
| + return hy > 0 ? s * huge * huge : s * tiny * tiny;
|
| + /* now |1-x| is tiny <= 2**-20, suffice to compute
|
| + log(x) by x-x^2/2+x^3/3-x^4/4 */
|
| + t = ax - 1.0; /* t has 20 trailing zeros */
|
| + w = (t * t) * (0.5 - t * (0.3333333333333333333333 - t * 0.25));
|
| + u = ivln2_h * t; /* ivln2_h has 21 sig. bits */
|
| + v = t * ivln2_l - w * ivln2;
|
| + t1 = u + v;
|
| + SET_LOW_WORD(t1, 0);
|
| + t2 = v - (t1 - u);
|
| + } else {
|
| + double ss, s2, s_h, s_l, t_h, t_l;
|
| + n = 0;
|
| + /* take care subnormal number */
|
| + if (ix < 0x00100000) {
|
| + ax *= two53;
|
| + n -= 53;
|
| + GET_HIGH_WORD(ix, ax);
|
| + }
|
| + n += ((ix) >> 20) - 0x3ff;
|
| + j = ix & 0x000fffff;
|
| + /* determine interval */
|
| + ix = j | 0x3ff00000; /* normalize ix */
|
| + if (j <= 0x3988E) /* |x|<sqrt(3/2) */
|
| + k = 0;
|
| + else if (j < 0xBB67A) /* |x|<sqrt(3) */
|
| + k = 1;
|
| + else {
|
| + k = 0;
|
| + n += 1;
|
| + ix -= 0x00100000;
|
| + }
|
| + SET_HIGH_WORD(ax, ix);
|
|
|
| - /* compute ss = s_h+s_l = (x-1)/(x+1) or (x-1.5)/(x+1.5) */
|
| - u = ax - bp[k]; /* bp[0]=1.0, bp[1]=1.5 */
|
| - v = 1.0/(ax+bp[k]);
|
| - ss = u*v;
|
| - s_h = ss;
|
| - SET_LOW_WORD(s_h, 0);
|
| - /* t_h=ax+bp[k] High */
|
| - t_h = 0.0;
|
| - SET_HIGH_WORD(t_h, ((ix>>1)|0x20000000) + 0x00080000 + (k<<18));
|
| - t_l = ax - (t_h-bp[k]);
|
| - s_l = v*((u-s_h*t_h)-s_h*t_l);
|
| - /* compute log(ax) */
|
| - s2 = ss*ss;
|
| - r = s2*s2*(L1+s2*(L2+s2*(L3+s2*(L4+s2*(L5+s2*L6)))));
|
| - r += s_l*(s_h+ss);
|
| - s2 = s_h*s_h;
|
| - t_h = 3.0 + s2 + r;
|
| - SET_LOW_WORD(t_h, 0);
|
| - t_l = r - ((t_h-3.0)-s2);
|
| - /* u+v = ss*(1+...) */
|
| - u = s_h*t_h;
|
| - v = s_l*t_h + t_l*ss;
|
| - /* 2/(3log2)*(ss+...) */
|
| - p_h = u + v;
|
| - SET_LOW_WORD(p_h, 0);
|
| - p_l = v - (p_h-u);
|
| - z_h = cp_h*p_h; /* cp_h+cp_l = 2/(3*log2) */
|
| - z_l = cp_l*p_h+p_l*cp + dp_l[k];
|
| - /* log2(ax) = (ss+..)*2/(3*log2) = n + dp_h + z_h + z_l */
|
| - t = (double)n;
|
| - t1 = ((z_h + z_l) + dp_h[k]) + t;
|
| - SET_LOW_WORD(t1, 0);
|
| - t2 = z_l - (((t1 - t) - dp_h[k]) - z_h);
|
| - }
|
| + /* compute ss = s_h+s_l = (x-1)/(x+1) or (x-1.5)/(x+1.5) */
|
| + u = ax - bp[k]; /* bp[0]=1.0, bp[1]=1.5 */
|
| + v = 1.0 / (ax + bp[k]);
|
| + ss = u * v;
|
| + s_h = ss;
|
| + SET_LOW_WORD(s_h, 0);
|
| + /* t_h=ax+bp[k] High */
|
| + t_h = 0.0;
|
| + SET_HIGH_WORD(t_h, ((ix >> 1) | 0x20000000) + 0x00080000 + (k << 18));
|
| + t_l = ax - (t_h - bp[k]);
|
| + s_l = v * ((u - s_h * t_h) - s_h * t_l);
|
| + /* compute log(ax) */
|
| + s2 = ss * ss;
|
| + r = s2 * s2 *
|
| + (L1 + s2 * (L2 + s2 * (L3 + s2 * (L4 + s2 * (L5 + s2 * L6)))));
|
| + r += s_l * (s_h + ss);
|
| + s2 = s_h * s_h;
|
| + t_h = 3.0 + s2 + r;
|
| + SET_LOW_WORD(t_h, 0);
|
| + t_l = r - ((t_h - 3.0) - s2);
|
| + /* u+v = ss*(1+...) */
|
| + u = s_h * t_h;
|
| + v = s_l * t_h + t_l * ss;
|
| + /* 2/(3log2)*(ss+...) */
|
| + p_h = u + v;
|
| + SET_LOW_WORD(p_h, 0);
|
| + p_l = v - (p_h - u);
|
| + z_h = cp_h * p_h; /* cp_h+cp_l = 2/(3*log2) */
|
| + z_l = cp_l * p_h + p_l * cp + dp_l[k];
|
| + /* log2(ax) = (ss+..)*2/(3*log2) = n + dp_h + z_h + z_l */
|
| + t = (double)n;
|
| + t1 = ((z_h + z_l) + dp_h[k]) + t;
|
| + SET_LOW_WORD(t1, 0);
|
| + t2 = z_l - (((t1 - t) - dp_h[k]) - z_h);
|
| + }
|
|
|
| - /* split up y into y1+y2 and compute (y1+y2)*(t1+t2) */
|
| - y1 = y;
|
| - SET_LOW_WORD(y1, 0);
|
| - p_l = (y-y1)*t1 + y*t2;
|
| - p_h = y1*t1;
|
| - z = p_l + p_h;
|
| - EXTRACT_WORDS(j, i, z);
|
| - if (j >= 0x40900000) { /* z >= 1024 */
|
| - if (((j-0x40900000)|i) != 0) /* if z > 1024 */
|
| - return s*huge*huge; /* overflow */
|
| - if (p_l + ovt > z - p_h)
|
| - return s*huge*huge; /* overflow */
|
| - } else if ((j&0x7fffffff) >= 0x4090cc00) { /* z <= -1075 */ // FIXME: instead of abs(j) use unsigned j
|
| - if (((j-0xc090cc00)|i) != 0) /* z < -1075 */
|
| - return s*tiny*tiny; /* underflow */
|
| - if (p_l <= z - p_h)
|
| - return s*tiny*tiny; /* underflow */
|
| - }
|
| - /*
|
| - * compute 2**(p_h+p_l)
|
| - */
|
| - i = j & 0x7fffffff;
|
| - k = (i>>20) - 0x3ff;
|
| - n = 0;
|
| - if (i > 0x3fe00000) { /* if |z| > 0.5, set n = [z+0.5] */
|
| - n = j + (0x00100000>>(k+1));
|
| - k = ((n&0x7fffffff)>>20) - 0x3ff; /* new k for n */
|
| - t = 0.0;
|
| - SET_HIGH_WORD(t, n & ~(0x000fffff>>k));
|
| - n = ((n&0x000fffff)|0x00100000)>>(20-k);
|
| - if (j < 0)
|
| - n = -n;
|
| - p_h -= t;
|
| - }
|
| - t = p_l + p_h;
|
| - SET_LOW_WORD(t, 0);
|
| - u = t*lg2_h;
|
| - v = (p_l-(t-p_h))*lg2 + t*lg2_l;
|
| - z = u + v;
|
| - w = v - (z-u);
|
| - t = z*z;
|
| - t1 = z - t*(P1+t*(P2+t*(P3+t*(P4+t*P5))));
|
| - r = (z*t1)/(t1-2.0) - (w + z*w);
|
| - z = 1.0 - (r-z);
|
| - GET_HIGH_WORD(j, z);
|
| - j += n<<20;
|
| - if ((j>>20) <= 0) /* subnormal output */
|
| - z = scalbn(z,n);
|
| - else
|
| - SET_HIGH_WORD(z, j);
|
| - return s*z;
|
| + /* split up y into y1+y2 and compute (y1+y2)*(t1+t2) */
|
| + y1 = y;
|
| + SET_LOW_WORD(y1, 0);
|
| + p_l = (y - y1) * t1 + y * t2;
|
| + p_h = y1 * t1;
|
| + z = p_l + p_h;
|
| + EXTRACT_WORDS(j, i, z);
|
| + if (j >= 0x40900000) { /* z >= 1024 */
|
| + if (((j - 0x40900000) | i) != 0) /* if z > 1024 */
|
| + return s * huge * huge; /* overflow */
|
| + if (p_l + ovt > z - p_h)
|
| + return s * huge * huge; /* overflow */
|
| + } else if ((j & 0x7fffffff) >= 0x4090cc00) {
|
| + /* z <= -1075 */ // FIXME: instead of abs(j) use unsigned j
|
| + if (((j - 0xc090cc00) | i) != 0) /* z < -1075 */
|
| + return s * tiny * tiny; /* underflow */
|
| + if (p_l <= z - p_h)
|
| + return s * tiny * tiny; /* underflow */
|
| + }
|
| + /*
|
| + * compute 2**(p_h+p_l)
|
| + */
|
| + i = j & 0x7fffffff;
|
| + k = (i >> 20) - 0x3ff;
|
| + n = 0;
|
| + if (i > 0x3fe00000) { /* if |z| > 0.5, set n = [z+0.5] */
|
| + n = j + (0x00100000 >> (k + 1));
|
| + k = ((n & 0x7fffffff) >> 20) - 0x3ff; /* new k for n */
|
| + t = 0.0;
|
| + SET_HIGH_WORD(t, n & ~(0x000fffff >> k));
|
| + n = ((n & 0x000fffff) | 0x00100000) >> (20 - k);
|
| + if (j < 0)
|
| + n = -n;
|
| + p_h -= t;
|
| + }
|
| + t = p_l + p_h;
|
| + SET_LOW_WORD(t, 0);
|
| + u = t * lg2_h;
|
| + v = (p_l - (t - p_h)) * lg2 + t * lg2_l;
|
| + z = u + v;
|
| + w = v - (z - u);
|
| + t = z * z;
|
| + t1 = z - t * (P1 + t * (P2 + t * (P3 + t * (P4 + t * P5))));
|
| + r = (z * t1) / (t1 - 2.0) - (w + z * w);
|
| + z = 1.0 - (r - z);
|
| + GET_HIGH_WORD(j, z);
|
| + j += n << 20;
|
| + if ((j >> 20) <= 0) /* subnormal output */
|
| + z = scalbn(z, n);
|
| + else
|
| + SET_HIGH_WORD(z, j);
|
| + return s * z;
|
| }
|
|
|