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authorSiddhesh Poyarekar <siddhesh@redhat.com>2013-10-08 16:23:16 +0530
committerSiddhesh Poyarekar <siddhesh@redhat.com>2013-10-08 16:23:16 +0530
commit885766357dee331079e6ab4d18320193d42d000c (patch)
treedaf74089a71868923fc46c43fd0e145b718c2643 /sysdeps/ieee754/dbl-64
parente7b2d1dd620f26341e431c212f3c0544448d9be5 (diff)
downloadglibc-885766357dee331079e6ab4d18320193d42d000c.tar.gz
Format e_pow.c
Diffstat (limited to 'sysdeps/ieee754/dbl-64')
-rw-r--r--sysdeps/ieee754/dbl-64/e_pow.c573
1 files changed, 313 insertions, 260 deletions
diff --git a/sysdeps/ieee754/dbl-64/e_pow.c b/sysdeps/ieee754/dbl-64/e_pow.c
index 9a766e7224..9cf2309174 100644
--- a/sysdeps/ieee754/dbl-64/e_pow.c
+++ b/sysdeps/ieee754/dbl-64/e_pow.c
@@ -49,354 +49,407 @@
static const double huge = 1.0e300, tiny = 1.0e-300;
-double __exp1(double x, double xx, double error);
-static double log1(double x, double *delta, double *error);
-static double my_log2(double x, double *delta, double *error);
-double __slowpow(double x, double y,double z);
-static double power1(double x, double y);
-static int checkint(double x);
+double __exp1 (double x, double xx, double error);
+static double log1 (double x, double *delta, double *error);
+static double my_log2 (double x, double *delta, double *error);
+double __slowpow (double x, double y, double z);
+static double power1 (double x, double y);
+static int checkint (double x);
-/***************************************************************************/
-/* An ultimate power routine. Given two IEEE double machine numbers y,x */
-/* it computes the correctly rounded (to nearest) value of X^y. */
-/***************************************************************************/
+/* An ultimate power routine. Given two IEEE double machine numbers y, x it
+ computes the correctly rounded (to nearest) value of X^y. */
double
SECTION
-__ieee754_pow(double x, double y) {
- double z,a,aa,error, t,a1,a2,y1,y2;
- mynumber u,v;
+__ieee754_pow (double x, double y)
+{
+ double z, a, aa, error, t, a1, a2, y1, y2;
+ mynumber u, v;
int k;
- int4 qx,qy;
- v.x=y;
- u.x=x;
- if (v.i[LOW_HALF] == 0) { /* of y */
- qx = u.i[HIGH_HALF]&0x7fffffff;
- /* Is x a NaN? */
- if (((qx == 0x7ff00000) && (u.i[LOW_HALF] != 0)) || (qx > 0x7ff00000))
- return x;
- if (y == 1.0) return x;
- if (y == 2.0) return x*x;
- if (y == -1.0) return 1.0/x;
- if (y == 0) return 1.0;
- }
+ int4 qx, qy;
+ v.x = y;
+ u.x = x;
+ if (v.i[LOW_HALF] == 0)
+ { /* of y */
+ qx = u.i[HIGH_HALF] & 0x7fffffff;
+ /* Is x a NaN? */
+ if (((qx == 0x7ff00000) && (u.i[LOW_HALF] != 0)) || (qx > 0x7ff00000))
+ return x;
+ if (y == 1.0)
+ return x;
+ if (y == 2.0)
+ return x * x;
+ if (y == -1.0)
+ return 1.0 / x;
+ if (y == 0)
+ return 1.0;
+ }
/* else */
- if(((u.i[HIGH_HALF]>0 && u.i[HIGH_HALF]<0x7ff00000)|| /* x>0 and not x->0 */
- (u.i[HIGH_HALF]==0 && u.i[LOW_HALF]!=0)) &&
- /* 2^-1023< x<= 2^-1023 * 0x1.0000ffffffff */
- (v.i[HIGH_HALF]&0x7fffffff) < 0x4ff00000) { /* if y<-1 or y>1 */
- double retval;
+ if (((u.i[HIGH_HALF] > 0 && u.i[HIGH_HALF] < 0x7ff00000) || /* x>0 and not x->0 */
+ (u.i[HIGH_HALF] == 0 && u.i[LOW_HALF] != 0)) &&
+ /* 2^-1023< x<= 2^-1023 * 0x1.0000ffffffff */
+ (v.i[HIGH_HALF] & 0x7fffffff) < 0x4ff00000)
+ { /* if y<-1 or y>1 */
+ double retval;
- SET_RESTORE_ROUND (FE_TONEAREST);
+ SET_RESTORE_ROUND (FE_TONEAREST);
- /* Avoid internal underflow for tiny y. The exact value of y does
- not matter if |y| <= 2**-64. */
- if (ABS (y) < 0x1p-64)
- y = y < 0 ? -0x1p-64 : 0x1p-64;
- z = log1(x,&aa,&error); /* x^y =e^(y log (X)) */
- t = y*CN;
- y1 = t - (t-y);
- y2 = y - y1;
- t = z*CN;
- a1 = t - (t-z);
- a2 = (z - a1)+aa;
- a = y1*a1;
- aa = y2*a1 + y*a2;
- a1 = a+aa;
- a2 = (a-a1)+aa;
- error = error*ABS(y);
- t = __exp1(a1,a2,1.9e16*error); /* return -10 or 0 if wasn't computed exactly */
- retval = (t>0)?t:power1(x,y);
+ /* Avoid internal underflow for tiny y. The exact value of y does
+ not matter if |y| <= 2**-64. */
+ if (ABS (y) < 0x1p-64)
+ y = y < 0 ? -0x1p-64 : 0x1p-64;
+ z = log1 (x, &aa, &error); /* x^y =e^(y log (X)) */
+ t = y * CN;
+ y1 = t - (t - y);
+ y2 = y - y1;
+ t = z * CN;
+ a1 = t - (t - z);
+ a2 = (z - a1) + aa;
+ a = y1 * a1;
+ aa = y2 * a1 + y * a2;
+ a1 = a + aa;
+ a2 = (a - a1) + aa;
+ error = error * ABS (y);
+ t = __exp1 (a1, a2, 1.9e16 * error); /* return -10 or 0 if wasn't computed exactly */
+ retval = (t > 0) ? t : power1 (x, y);
- return retval;
- }
+ return retval;
+ }
- if (x == 0) {
- if (((v.i[HIGH_HALF] & 0x7fffffff) == 0x7ff00000 && v.i[LOW_HALF] != 0)
- || (v.i[HIGH_HALF] & 0x7fffffff) > 0x7ff00000) /* NaN */
- return y;
- if (ABS(y) > 1.0e20) return (y>0)?0:1.0/0.0;
- k = checkint(y);
- if (k == -1)
- return y < 0 ? 1.0/x : x;
- else
- return y < 0 ? 1.0/0.0 : 0.0; /* return 0 */
- }
+ if (x == 0)
+ {
+ if (((v.i[HIGH_HALF] & 0x7fffffff) == 0x7ff00000 && v.i[LOW_HALF] != 0)
+ || (v.i[HIGH_HALF] & 0x7fffffff) > 0x7ff00000) /* NaN */
+ return y;
+ if (ABS (y) > 1.0e20)
+ return (y > 0) ? 0 : 1.0 / 0.0;
+ k = checkint (y);
+ if (k == -1)
+ return y < 0 ? 1.0 / x : x;
+ else
+ return y < 0 ? 1.0 / 0.0 : 0.0; /* return 0 */
+ }
- qx = u.i[HIGH_HALF]&0x7fffffff; /* no sign */
- qy = v.i[HIGH_HALF]&0x7fffffff; /* no sign */
+ qx = u.i[HIGH_HALF] & 0x7fffffff; /* no sign */
+ qy = v.i[HIGH_HALF] & 0x7fffffff; /* no sign */
- if (qx >= 0x7ff00000 && (qx > 0x7ff00000 || u.i[LOW_HALF] != 0)) /* NaN */
+ if (qx >= 0x7ff00000 && (qx > 0x7ff00000 || u.i[LOW_HALF] != 0)) /* NaN */
return x;
- if (qy >= 0x7ff00000 && (qy > 0x7ff00000 || v.i[LOW_HALF] != 0)) /* NaN */
+ if (qy >= 0x7ff00000 && (qy > 0x7ff00000 || v.i[LOW_HALF] != 0)) /* NaN */
return x == 1.0 ? 1.0 : y;
/* if x<0 */
- if (u.i[HIGH_HALF] < 0) {
- k = checkint(y);
- if (k==0) {
- if (qy == 0x7ff00000) {
- if (x == -1.0) return 1.0;
- else if (x > -1.0) return v.i[HIGH_HALF] < 0 ? INF.x : 0.0;
- else return v.i[HIGH_HALF] < 0 ? 0.0 : INF.x;
- }
+ if (u.i[HIGH_HALF] < 0)
+ {
+ k = checkint (y);
+ if (k == 0)
+ {
+ if (qy == 0x7ff00000)
+ {
+ if (x == -1.0)
+ return 1.0;
+ else if (x > -1.0)
+ return v.i[HIGH_HALF] < 0 ? INF.x : 0.0;
+ else
+ return v.i[HIGH_HALF] < 0 ? 0.0 : INF.x;
+ }
+ else if (qx == 0x7ff00000)
+ return y < 0 ? 0.0 : INF.x;
+ return (x - x) / (x - x); /* y not integer and x<0 */
+ }
else if (qx == 0x7ff00000)
- return y < 0 ? 0.0 : INF.x;
- return (x - x) / (x - x); /* y not integer and x<0 */
+ {
+ if (k < 0)
+ return y < 0 ? nZERO.x : nINF.x;
+ else
+ return y < 0 ? 0.0 : INF.x;
+ }
+ /* if y even or odd */
+ return (k == 1) ? __ieee754_pow (-x, y) : -__ieee754_pow (-x, y);
}
- else if (qx == 0x7ff00000)
- {
- if (k < 0)
- return y < 0 ? nZERO.x : nINF.x;
- else
- return y < 0 ? 0.0 : INF.x;
- }
- return (k==1)?__ieee754_pow(-x,y):-__ieee754_pow(-x,y); /* if y even or odd */
- }
/* x>0 */
- if (qx == 0x7ff00000) /* x= 2^-0x3ff */
+ if (qx == 0x7ff00000) /* x= 2^-0x3ff */
return y > 0 ? x : 0;
- if (qy > 0x45f00000 && qy < 0x7ff00000) {
- if (x == 1.0) return 1.0;
- if (y>0) return (x>1.0)?huge*huge:tiny*tiny;
- if (y<0) return (x<1.0)?huge*huge:tiny*tiny;
- }
+ if (qy > 0x45f00000 && qy < 0x7ff00000)
+ {
+ if (x == 1.0)
+ return 1.0;
+ if (y > 0)
+ return (x > 1.0) ? huge * huge : tiny * tiny;
+ if (y < 0)
+ return (x < 1.0) ? huge * huge : tiny * tiny;
+ }
- if (x == 1.0) return 1.0;
- if (y>0) return (x>1.0)?INF.x:0;
- if (y<0) return (x<1.0)?INF.x:0;
- return 0; /* unreachable, to make the compiler happy */
+ if (x == 1.0)
+ return 1.0;
+ if (y > 0)
+ return (x > 1.0) ? INF.x : 0;
+ if (y < 0)
+ return (x < 1.0) ? INF.x : 0;
+ return 0; /* unreachable, to make the compiler happy */
}
+
#ifndef __ieee754_pow
strong_alias (__ieee754_pow, __pow_finite)
#endif
-/**************************************************************************/
-/* Computing x^y using more accurate but more slow log routine */
-/**************************************************************************/
+/* Compute x^y using more accurate but more slow log routine. */
static double
SECTION
-power1(double x, double y) {
- double z,a,aa,error, t,a1,a2,y1,y2;
- z = my_log2(x,&aa,&error);
- t = y*CN;
- y1 = t - (t-y);
+power1 (double x, double y)
+{
+ double z, a, aa, error, t, a1, a2, y1, y2;
+ z = my_log2 (x, &aa, &error);
+ t = y * CN;
+ y1 = t - (t - y);
y2 = y - y1;
- t = z*CN;
- a1 = t - (t-z);
+ t = z * CN;
+ a1 = t - (t - z);
a2 = z - a1;
- a = y*z;
- aa = ((y1*a1-a)+y1*a2+y2*a1)+y2*a2+aa*y;
- a1 = a+aa;
- a2 = (a-a1)+aa;
- error = error*ABS(y);
- t = __exp1(a1,a2,1.9e16*error);
- return (t >= 0)?t:__slowpow(x,y,z);
+ a = y * z;
+ aa = ((y1 * a1 - a) + y1 * a2 + y2 * a1) + y2 * a2 + aa * y;
+ a1 = a + aa;
+ a2 = (a - a1) + aa;
+ error = error * ABS (y);
+ t = __exp1 (a1, a2, 1.9e16 * error);
+ return (t >= 0) ? t : __slowpow (x, y, z);
}
-/****************************************************************************/
-/* Computing log(x) (x is left argument). The result is the returned double */
-/* + the parameter delta. */
-/* The result is bounded by error (rightmost argument) */
-/****************************************************************************/
+/* Compute log(x) (x is left argument). The result is the returned double + the
+ parameter DELTA. The result is bounded by ERROR. */
static double
SECTION
-log1(double x, double *delta, double *error) {
- int i,j,m;
- double uu,vv,eps,nx,e,e1,e2,t,t1,t2,res,add=0;
- mynumber u,v;
+log1 (double x, double *delta, double *error)
+{
+ int i, j, m;
+ double uu, vv, eps, nx, e, e1, e2, t, t1, t2, res, add = 0;
+ mynumber u, v;
#ifdef BIG_ENDI
- mynumber
-/**/ two52 = {{0x43300000, 0x00000000}}; /* 2**52 */
+ mynumber /**/ two52 = {{0x43300000, 0x00000000}}; /* 2**52 */
#else
-#ifdef LITTLE_ENDI
- mynumber
-/**/ two52 = {{0x00000000, 0x43300000}}; /* 2**52 */
-#endif
+# ifdef LITTLE_ENDI
+ mynumber /**/ two52 = {{0x00000000, 0x43300000}}; /* 2**52 */
+# endif
#endif
u.x = x;
m = u.i[HIGH_HALF];
*error = 0;
*delta = 0;
- if (m < 0x00100000) /* 1<x<2^-1007 */
- { x = x*t52.x; add = -52.0; u.x = x; m = u.i[HIGH_HALF];}
+ if (m < 0x00100000) /* 1<x<2^-1007 */
+ {
+ x = x * t52.x;
+ add = -52.0;
+ u.x = x;
+ m = u.i[HIGH_HALF];
+ }
- if ((m&0x000fffff) < 0x0006a09e)
- {u.i[HIGH_HALF] = (m&0x000fffff)|0x3ff00000; two52.i[LOW_HALF]=(m>>20); }
+ if ((m & 0x000fffff) < 0x0006a09e)
+ {
+ u.i[HIGH_HALF] = (m & 0x000fffff) | 0x3ff00000;
+ two52.i[LOW_HALF] = (m >> 20);
+ }
else
- {u.i[HIGH_HALF] = (m&0x000fffff)|0x3fe00000; two52.i[LOW_HALF]=(m>>20)+1; }
+ {
+ u.i[HIGH_HALF] = (m & 0x000fffff) | 0x3fe00000;
+ two52.i[LOW_HALF] = (m >> 20) + 1;
+ }
v.x = u.x + bigu.x;
uu = v.x - bigu.x;
- i = (v.i[LOW_HALF]&0x000003ff)<<2;
- if (two52.i[LOW_HALF] == 1023) /* nx = 0 */
- {
- if (i > 1192 && i < 1208) /* |x-1| < 1.5*2**-10 */
- {
+ i = (v.i[LOW_HALF] & 0x000003ff) << 2;
+ if (two52.i[LOW_HALF] == 1023) /* nx = 0 */
+ {
+ if (i > 1192 && i < 1208) /* |x-1| < 1.5*2**-10 */
+ {
t = x - 1.0;
- t1 = (t+5.0e6)-5.0e6;
- t2 = t-t1;
- e1 = t - 0.5*t1*t1;
- e2 = t*t*t*(r3+t*(r4+t*(r5+t*(r6+t*(r7+t*r8)))))-0.5*t2*(t+t1);
- res = e1+e2;
- *error = 1.0e-21*ABS(t);
- *delta = (e1-res)+e2;
+ t1 = (t + 5.0e6) - 5.0e6;
+ t2 = t - t1;
+ e1 = t - 0.5 * t1 * t1;
+ e2 = (t * t * t * (r3 + t * (r4 + t * (r5 + t * (r6 + t
+ * (r7 + t * r8)))))
+ - 0.5 * t2 * (t + t1));
+ res = e1 + e2;
+ *error = 1.0e-21 * ABS (t);
+ *delta = (e1 - res) + e2;
return res;
- } /* |x-1| < 1.5*2**-10 */
+ } /* |x-1| < 1.5*2**-10 */
else
- {
- v.x = u.x*(ui.x[i]+ui.x[i+1])+bigv.x;
- vv = v.x-bigv.x;
- j = v.i[LOW_HALF]&0x0007ffff;
- j = j+j+j;
- eps = u.x - uu*vv;
- e1 = eps*ui.x[i];
- e2 = eps*(ui.x[i+1]+vj.x[j]*(ui.x[i]+ui.x[i+1]));
- e = e1+e2;
- e2 = ((e1-e)+e2);
- t=ui.x[i+2]+vj.x[j+1];
- t1 = t+e;
- t2 = (((t-t1)+e)+(ui.x[i+3]+vj.x[j+2]))+e2+e*e*(p2+e*(p3+e*p4));
- res=t1+t2;
+ {
+ v.x = u.x * (ui.x[i] + ui.x[i + 1]) + bigv.x;
+ vv = v.x - bigv.x;
+ j = v.i[LOW_HALF] & 0x0007ffff;
+ j = j + j + j;
+ eps = u.x - uu * vv;
+ e1 = eps * ui.x[i];
+ e2 = eps * (ui.x[i + 1] + vj.x[j] * (ui.x[i] + ui.x[i + 1]));
+ e = e1 + e2;
+ e2 = ((e1 - e) + e2);
+ t = ui.x[i + 2] + vj.x[j + 1];
+ t1 = t + e;
+ t2 = ((((t - t1) + e) + (ui.x[i + 3] + vj.x[j + 2])) + e2 + e * e
+ * (p2 + e * (p3 + e * p4)));
+ res = t1 + t2;
*error = 1.0e-24;
- *delta = (t1-res)+t2;
+ *delta = (t1 - res) + t2;
return res;
- }
- } /* nx = 0 */
- else /* nx != 0 */
- {
+ }
+ } /* nx = 0 */
+ else /* nx != 0 */
+ {
eps = u.x - uu;
- nx = (two52.x - two52e.x)+add;
- e1 = eps*ui.x[i];
- e2 = eps*ui.x[i+1];
- e=e1+e2;
- e2 = (e1-e)+e2;
- t=nx*ln2a.x+ui.x[i+2];
- t1=t+e;
- t2=(((t-t1)+e)+nx*ln2b.x+ui.x[i+3]+e2)+e*e*(q2+e*(q3+e*(q4+e*(q5+e*q6))));
- res = t1+t2;
+ nx = (two52.x - two52e.x) + add;
+ e1 = eps * ui.x[i];
+ e2 = eps * ui.x[i + 1];
+ e = e1 + e2;
+ e2 = (e1 - e) + e2;
+ t = nx * ln2a.x + ui.x[i + 2];
+ t1 = t + e;
+ t2 = ((((t - t1) + e) + nx * ln2b.x + ui.x[i + 3] + e2) + e * e
+ * (q2 + e * (q3 + e * (q4 + e * (q5 + e * q6)))));
+ res = t1 + t2;
*error = 1.0e-21;
- *delta = (t1-res)+t2;
+ *delta = (t1 - res) + t2;
return res;
- } /* nx != 0 */
+ } /* nx != 0 */
}
-/****************************************************************************/
-/* More slow but more accurate routine of log */
-/* Computing log(x)(x is left argument).The result is return double + delta.*/
-/* The result is bounded by error (right argument) */
-/****************************************************************************/
+/* Slower but more accurate routine of log. The returned result is double +
+ DELTA. The result is bounded by ERROR. */
static double
SECTION
-my_log2(double x, double *delta, double *error) {
- int i,j,m;
- double uu,vv,eps,nx,e,e1,e2,t,t1,t2,res,add=0;
- double ou1,ou2,lu1,lu2,ov,lv1,lv2,a,a1,a2;
- double y,yy,z,zz,j1,j2,j7,j8;
+my_log2 (double x, double *delta, double *error)
+{
+ int i, j, m;
+ double uu, vv, eps, nx, e, e1, e2, t, t1, t2, res, add = 0;
+ double ou1, ou2, lu1, lu2, ov, lv1, lv2, a, a1, a2;
+ double y, yy, z, zz, j1, j2, j7, j8;
#ifndef DLA_FMS
- double j3,j4,j5,j6;
+ double j3, j4, j5, j6;
#endif
- mynumber u,v;
+ mynumber u, v;
#ifdef BIG_ENDI
- mynumber
-/**/ two52 = {{0x43300000, 0x00000000}}; /* 2**52 */
+ mynumber /**/ two52 = {{0x43300000, 0x00000000}}; /* 2**52 */
#else
-#ifdef LITTLE_ENDI
- mynumber
-/**/ two52 = {{0x00000000, 0x43300000}}; /* 2**52 */
-#endif
+# ifdef LITTLE_ENDI
+ mynumber /**/ two52 = {{0x00000000, 0x43300000}}; /* 2**52 */
+# endif
#endif
u.x = x;
m = u.i[HIGH_HALF];
*error = 0;
*delta = 0;
- add=0;
- if (m<0x00100000) { /* x < 2^-1022 */
- x = x*t52.x; add = -52.0; u.x = x; m = u.i[HIGH_HALF]; }
+ add = 0;
+ if (m < 0x00100000)
+ { /* x < 2^-1022 */
+ x = x * t52.x;
+ add = -52.0;
+ u.x = x;
+ m = u.i[HIGH_HALF];
+ }
- if ((m&0x000fffff) < 0x0006a09e)
- {u.i[HIGH_HALF] = (m&0x000fffff)|0x3ff00000; two52.i[LOW_HALF]=(m>>20); }
+ if ((m & 0x000fffff) < 0x0006a09e)
+ {
+ u.i[HIGH_HALF] = (m & 0x000fffff) | 0x3ff00000;
+ two52.i[LOW_HALF] = (m >> 20);
+ }
else
- {u.i[HIGH_HALF] = (m&0x000fffff)|0x3fe00000; two52.i[LOW_HALF]=(m>>20)+1; }
+ {
+ u.i[HIGH_HALF] = (m & 0x000fffff) | 0x3fe00000;
+ two52.i[LOW_HALF] = (m >> 20) + 1;
+ }
v.x = u.x + bigu.x;
uu = v.x - bigu.x;
- i = (v.i[LOW_HALF]&0x000003ff)<<2;
+ i = (v.i[LOW_HALF] & 0x000003ff) << 2;
/*------------------------------------- |x-1| < 2**-11------------------------------- */
- if ((two52.i[LOW_HALF] == 1023) && (i == 1200))
- {
+ if ((two52.i[LOW_HALF] == 1023) && (i == 1200))
+ {
t = x - 1.0;
- EMULV(t,s3,y,yy,j1,j2,j3,j4,j5);
- ADD2(-0.5,0,y,yy,z,zz,j1,j2);
- MUL2(t,0,z,zz,y,yy,j1,j2,j3,j4,j5,j6,j7,j8);
- MUL2(t,0,y,yy,z,zz,j1,j2,j3,j4,j5,j6,j7,j8);
+ EMULV (t, s3, y, yy, j1, j2, j3, j4, j5);
+ ADD2 (-0.5, 0, y, yy, z, zz, j1, j2);
+ MUL2 (t, 0, z, zz, y, yy, j1, j2, j3, j4, j5, j6, j7, j8);
+ MUL2 (t, 0, y, yy, z, zz, j1, j2, j3, j4, j5, j6, j7, j8);
- e1 = t+z;
- e2 = (((t-e1)+z)+zz)+t*t*t*(ss3+t*(s4+t*(s5+t*(s6+t*(s7+t*s8)))));
- res = e1+e2;
- *error = 1.0e-25*ABS(t);
- *delta = (e1-res)+e2;
+ e1 = t + z;
+ e2 = ((((t - e1) + z) + zz) + t * t * t
+ * (ss3 + t * (s4 + t * (s5 + t * (s6 + t * (s7 + t * s8))))));
+ res = e1 + e2;
+ *error = 1.0e-25 * ABS (t);
+ *delta = (e1 - res) + e2;
return res;
- }
+ }
/*----------------------------- |x-1| > 2**-11 -------------------------- */
else
- { /*Computing log(x) according to log table */
- nx = (two52.x - two52e.x)+add;
+ { /*Computing log(x) according to log table */
+ nx = (two52.x - two52e.x) + add;
ou1 = ui.x[i];
- ou2 = ui.x[i+1];
- lu1 = ui.x[i+2];
- lu2 = ui.x[i+3];
- v.x = u.x*(ou1+ou2)+bigv.x;
- vv = v.x-bigv.x;
- j = v.i[LOW_HALF]&0x0007ffff;
- j = j+j+j;
- eps = u.x - uu*vv;
- ov = vj.x[j];
- lv1 = vj.x[j+1];
- lv2 = vj.x[j+2];
- a = (ou1+ou2)*(1.0+ov);
- a1 = (a+1.0e10)-1.0e10;
- a2 = a*(1.0-a1*uu*vv);
- e1 = eps*a1;
- e2 = eps*a2;
- e = e1+e2;
- e2 = (e1-e)+e2;
- t=nx*ln2a.x+lu1+lv1;
- t1 = t+e;
- t2 = (((t-t1)+e)+(lu2+lv2+nx*ln2b.x+e2))+e*e*(p2+e*(p3+e*p4));
- res=t1+t2;
+ ou2 = ui.x[i + 1];
+ lu1 = ui.x[i + 2];
+ lu2 = ui.x[i + 3];
+ v.x = u.x * (ou1 + ou2) + bigv.x;
+ vv = v.x - bigv.x;
+ j = v.i[LOW_HALF] & 0x0007ffff;
+ j = j + j + j;
+ eps = u.x - uu * vv;
+ ov = vj.x[j];
+ lv1 = vj.x[j + 1];
+ lv2 = vj.x[j + 2];
+ a = (ou1 + ou2) * (1.0 + ov);
+ a1 = (a + 1.0e10) - 1.0e10;
+ a2 = a * (1.0 - a1 * uu * vv);
+ e1 = eps * a1;
+ e2 = eps * a2;
+ e = e1 + e2;
+ e2 = (e1 - e) + e2;
+ t = nx * ln2a.x + lu1 + lv1;
+ t1 = t + e;
+ t2 = ((((t - t1) + e) + (lu2 + lv2 + nx * ln2b.x + e2)) + e * e
+ * (p2 + e * (p3 + e * p4)));
+ res = t1 + t2;
*error = 1.0e-27;
- *delta = (t1-res)+t2;
+ *delta = (t1 - res) + t2;
return res;
- }
+ }
}
-/**********************************************************************/
-/* Routine receives a double x and checks if it is an integer. If not */
-/* it returns 0, else it returns 1 if even or -1 if odd. */
-/**********************************************************************/
+/* This function receives a double x and checks if it is an integer. If not,
+ it returns 0, else it returns 1 if even or -1 if odd. */
static int
SECTION
-checkint(double x) {
- union {int4 i[2]; double x;} u;
- int k,m,n;
+checkint (double x)
+{
+ union
+ {
+ int4 i[2];
+ double x;
+ } u;
+ int k, m, n;
u.x = x;
- m = u.i[HIGH_HALF]&0x7fffffff; /* no sign */
- if (m >= 0x7ff00000) return 0; /* x is +/-inf or NaN */
- if (m >= 0x43400000) return 1; /* |x| >= 2**53 */
- if (m < 0x40000000) return 0; /* |x| < 2, can not be 0 or 1 */
+ m = u.i[HIGH_HALF] & 0x7fffffff; /* no sign */
+ if (m >= 0x7ff00000)
+ return 0; /* x is +/-inf or NaN */
+ if (m >= 0x43400000)
+ return 1; /* |x| >= 2**53 */
+ if (m < 0x40000000)
+ return 0; /* |x| < 2, can not be 0 or 1 */
n = u.i[LOW_HALF];
- k = (m>>20)-1023; /* 1 <= k <= 52 */
- if (k == 52) return (n&1)? -1:1; /* odd or even*/
- if (k>20) {
- if (n<<(k-20)) return 0; /* if not integer */
- return (n<<(k-21))?-1:1;
- }
- if (n) return 0; /*if not integer*/
- if (k == 20) return (m&1)? -1:1;
- if (m<<(k+12)) return 0;
- return (m<<(k+11))?-1:1;
+ k = (m >> 20) - 1023; /* 1 <= k <= 52 */
+ if (k == 52)
+ return (n & 1) ? -1 : 1; /* odd or even */
+ if (k > 20)
+ {
+ if (n << (k - 20))
+ return 0; /* if not integer */
+ return (n << (k - 21)) ? -1 : 1;
+ }
+ if (n)
+ return 0; /*if not integer */
+ if (k == 20)
+ return (m & 1) ? -1 : 1;
+ if (m << (k + 12))
+ return 0;
+ return (m << (k + 11)) ? -1 : 1;
}