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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 __log2 = log2
-/* INDENT OFF */
+
/*
* log2(x) = log(x)/log2
*
* Base on Table look-up algorithm with product polynomial
* approximation for log(x).
@@ -83,19 +84,19 @@
* 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.h"
#include "libm_protos.h"
extern const double _TBL_log[];
static const double P[] = {
-/* ONE */ 1.0,
+/* ONE */
+ 1.0,
/* TWO52 */ 4503599627370496.0,
/* LN10V */ 1.4426950408889634073599246810018920433347, /* 1/log10 */
/* ZERO */ 0.0,
/* A1 */ -9.6809362455249638217841932228967194640116e-02,
/* A2 */ 1.99628461483039965074226529395673424005508422852e+0000,
@@ -147,80 +148,98 @@
#define B8 P[23]
#define LGH P[24]
#define LGL P[25]
double
-log2(double x) {
+log2(double x)
+{
int i, hx, ix, n, lx;
n = 0;
- hx = ((int *) &x)[HIWORD]; ix = hx & 0x7fffffff;
- lx = ((int *) &x)[LOWORD];
+ hx = ((int *)&x)[HIWORD];
+ ix = hx & 0x7fffffff;
+ lx = ((int *)&x)[LOWORD];
/* subnormal,0,negative,inf,nan */
if ((hx + 0x100000) < 0x200000) {
#if defined(FPADD_TRAPS_INCOMPLETE_ON_NAN)
if (ix >= 0x7ff80000) /* assumes sparc-like QNaN */
return (x); /* for Cheetah when x is QNaN */
#endif
+
if (((hx << 1) | lx) == 0) /* log(0.0) = -inf */
return (A5 / fabs(x));
+
if (hx < 0) { /* x < 0 */
if (ix >= 0x7ff00000)
return (x - x); /* x is -inf or NaN */
else
return (ZERO / (x - x));
}
+
if (((hx - 0x7ff00000) | lx) == 0) /* log(inf) = inf */
return (x);
+
if (ix >= 0x7ff00000) /* log(NaN) = NaN */
return (x - x);
+
x *= TWO52;
n = -52;
- hx = ((int *) &x)[HIWORD]; ix = hx & 0x7fffffff;
- lx = ((int *) &x)[LOWORD];
+ hx = ((int *)&x)[HIWORD];
+ ix = hx & 0x7fffffff;
+ lx = ((int *)&x)[LOWORD];
}
/* 0.09375 (0x3fb80000) <= x < 24 (0x40380000) */
i = ix >> 19;
+
if (i >= 0x7f7 && i <= 0x806) {
/* 0.875 <= x < 1.125 */
if (ix >= 0x3fec0000 && ix < 0x3ff20000) {
double s, z, r, w;
- s = x - ONE; z = s * s; r = (A10 * s) * (A11 + s);
+
+ s = x - ONE;
+ z = s * s;
+ r = (A10 * s) * (A11 + s);
w = z * s;
- if (((ix << 12) | lx) == 0)
+
+ if (((ix << 12) | lx) == 0) {
return (z);
- else
- return (LGH * s - (LGL * s - ((A1 * z) *
- ((A2 + (A3 * s) * (A4 + s)) + w * (A5 + s))) *
+ } else {
+ return (LGH * s - (LGL * s - ((A1 * z) * ((A2 +
+ (A3 * s) * (A4 + s)) + w * (A5 + s))) *
(((A6 + s * (A7 + s)) + w * (A8 + s)) *
((A9 + r) + w * (A12 + s)))));
+ }
} else {
double *tb, s;
+
i = (ix - 0x3fb80000) >> 15;
- tb = (double *) _TBL_log + (i + i + i);
+ tb = (double *)_TBL_log + (i + i + i);
+
if (((ix << 12) | lx) == 0) /* 2's power */
- return ((double) ((ix >> 20) - 0x3ff));
+ return ((double)((ix >> 20) - 0x3ff));
+
s = (x - tb[0]) * tb[1];
return (LGH * tb[2] - (LGL * tb[2] - ((B1 * s) *
- (B2 + s * (B3 + s))) *
- (((B4 + s * B5) + (s * s) * (B6 + s)) *
- (B7 + s * (B8 + s)))));
+ (B2 + s * (B3 + s))) * (((B4 + s * B5) + (s * s) *
+ (B6 + s)) * (B7 + s * (B8 + s)))));
}
} else {
double *tb, dn, s;
- dn = (double) (n + ((ix >> 20) - 0x3ff));
+
+ dn = (double)(n + ((ix >> 20) - 0x3ff));
ix <<= 12;
+
if ((ix | lx) == 0)
return (dn);
- i = ((unsigned) ix >> 12) | 0x3ff00000; /* scale x to [1,2) */
- ((int *) &x)[HIWORD] = i;
+
+ i = ((unsigned)ix >> 12) | 0x3ff00000; /* scale x to [1,2) */
+ ((int *)&x)[HIWORD] = i;
i = (i - 0x3fb80000) >> 15;
- tb = (double *) _TBL_log + (i + i + i);
+ tb = (double *)_TBL_log + (i + i + i);
s = (x - tb[0]) * tb[1];
- return (dn + (tb[2] * LN10V + ((B1 * s) *
- (B2 + s * (B3 + s))) *
+ return (dn + (tb[2] * LN10V + ((B1 * s) * (B2 + s * (B3 + s))) *
(((B4 + s * B5) + (s * s) * (B6 + s)) *
(B7 + s * (B8 + s)))));
}
}