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11210 libm should be cstyle(1ONBLD) clean
@@ -20,18 +20,19 @@
*/
/*
* Copyright 2011 Nexenta Systems, Inc. All rights reserved.
*/
+
/*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma weak __expm1 = expm1
-/* INDENT OFF */
+
/*
* expm1(x)
* Returns exp(x)-1, the exponential of x minus 1.
*
* Method
@@ -123,30 +124,35 @@
* The hexadecimal values are the intended ones for the following
* constants. The decimal values may be used, provided that the
* compiler will convert from decimal to binary accurately enough
* to produce the hexadecimal values shown.
*/
-/* INDENT ON */
#include "libm_macros.h"
#include <math.h>
static const double xxx[] = {
-/* one */ 1.0,
+/* one */
+ 1.0,
/* huge */ 1.0e+300,
/* tiny */ 1.0e-300,
/* o_threshold */ 7.09782712893383973096e+02, /* 40862E42 FEFA39EF */
/* ln2_hi */ 6.93147180369123816490e-01, /* 3FE62E42 FEE00000 */
/* ln2_lo */ 1.90821492927058770002e-10, /* 3DEA39EF 35793C76 */
/* invln2 */ 1.44269504088896338700e+00, /* 3FF71547 652B82FE */
-/* scaled coefficients related to expm1 */
-/* Q1 */ -3.33333333333331316428e-02, /* BFA11111 111110F4 */
+
+/*
+ * scaled coefficients related to expm1
+ * Q1
+ */
+ -3.33333333333331316428e-02, /* BFA11111 111110F4 */
/* Q2 */ 1.58730158725481460165e-03, /* 3F5A01A0 19FE5585 */
/* Q3 */ -7.93650757867487942473e-05, /* BF14CE19 9EAADBB7 */
/* Q4 */ 4.00821782732936239552e-06, /* 3ED0CFCA 86E65239 */
/* Q5 */ -2.01099218183624371326e-07 /* BE8AFDB7 6E09C32D */
};
+
#define one xxx[0]
#define huge xxx[1]
#define tiny xxx[2]
#define o_threshold xxx[3]
#define ln2_hi xxx[4]
@@ -157,39 +163,45 @@
#define Q3 xxx[9]
#define Q4 xxx[10]
#define Q5 xxx[11]
double
-expm1(double x) {
+expm1(double x)
+{
double y, hi, lo, c = 0.0L, t, e, hxs, hfx, r1;
int k, xsb;
unsigned hx;
- hx = ((unsigned *) &x)[HIWORD]; /* high word of x */
+ hx = ((unsigned *)&x)[HIWORD]; /* high word of x */
xsb = hx & 0x80000000; /* sign bit of x */
+
if (xsb == 0)
y = x;
else
y = -x; /* y = |x| */
+
hx &= 0x7fffffff; /* high word of |x| */
- /* filter out huge and non-finite argument */
- /* for example exp(38)-1 is approximately 3.1855932e+16 */
+ /*
+ * filter out huge and non-finite argument
+ * for example exp(38)-1 is approximately 3.1855932e+16
+ */
if (hx >= 0x4043687A) {
/* if |x|>=56*ln2 (~38.8162...) */
if (hx >= 0x40862E42) { /* if |x|>=709.78... -> inf */
if (hx >= 0x7ff00000) {
- if (((hx & 0xfffff) | ((int *) &x)[LOWORD])
- != 0)
+ if (((hx & 0xfffff) | ((int *)&x)[LOWORD]) != 0)
return (x * x); /* + -> * for Cheetah */
else
/* exp(+-inf)={inf,-1} */
return (xsb == 0 ? x : -1.0);
}
+
if (x > o_threshold)
return (huge * huge); /* overflow */
}
+
if (xsb != 0) { /* x < -56*ln2, return -1.0 w/inexact */
if (x + tiny < 0.0) /* raise inexact */
return (tiny - one); /* return -1 */
}
}
@@ -207,59 +219,68 @@
lo = -ln2_lo;
k = -1;
}
} else {
/* |x| > 1.5 ln2 */
- k = (int) (invln2 * x + (xsb == 0 ? 0.5 : -0.5));
+ k = (int)(invln2 * x + (xsb == 0 ? 0.5 : -0.5));
t = k;
hi = x - t * ln2_hi; /* t*ln2_hi is exact here */
lo = t * ln2_lo;
}
+
x = hi - lo;
c = (hi - x) - lo; /* still at |x| > 0.5 ln2 */
} else if (hx < 0x3c900000) {
/* when |x|<2**-54, return x */
t = huge + x; /* return x w/inexact when x != 0 */
return (x - (t - (huge + x)));
- } else
+ } else {
/* |x| <= 0.5 ln2 */
k = 0;
+ }
/* x is now in primary range */
hfx = 0.5 * x;
hxs = x * hfx;
r1 = one + hxs * (Q1 + hxs * (Q2 + hxs * (Q3 + hxs * (Q4 + hxs * Q5))));
t = 3.0 - r1 * hfx;
e = hxs * ((r1 - t) / (6.0 - x * t));
- if (k == 0) /* |x| <= 0.5 ln2 */
+
+ if (k == 0) { /* |x| <= 0.5 ln2 */
return (x - (x * e - hxs));
- else { /* |x| > 0.5 ln2 */
+ } else { /* |x| > 0.5 ln2 */
e = (x * (e - c) - c);
e -= hxs;
+
if (k == -1)
return (0.5 * (x - e) - 0.5);
+
if (k == 1) {
if (x < -0.25)
return (-2.0 * (e - (x + 0.5)));
else
return (one + 2.0 * (x - e));
}
+
if (k <= -2 || k > 56) { /* suffice to return exp(x)-1 */
y = one - (e - x);
- ((int *) &y)[HIWORD] += k << 20;
+ ((int *)&y)[HIWORD] += k << 20;
return (y - one);
}
+
t = one;
+
if (k < 20) {
- ((int *) &t)[HIWORD] = 0x3ff00000 - (0x200000 >> k);
+ ((int *)&t)[HIWORD] = 0x3ff00000 - (0x200000 >> k);
/* t = 1 - 2^-k */
y = t - (e - x);
- ((int *) &y)[HIWORD] += k << 20;
+ ((int *)&y)[HIWORD] += k << 20;
} else {
- ((int *) &t)[HIWORD] = (0x3ff - k) << 20; /* 2^-k */
+ ((int *)&t)[HIWORD] = (0x3ff - k) << 20; /* 2^-k */
y = x - (e + t);
y += one;
- ((int *) &y)[HIWORD] += k << 20;
+ ((int *)&y)[HIWORD] += k << 20;
}
}
+
return (y);
}