--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/kerneltest/e32utils/nistsecurerng/src/cephes.cpp Wed Sep 15 13:42:27 2010 +0300
@@ -0,0 +1,357 @@
+/*
+* Portions Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).
+* All rights reserved.
+* This component and the accompanying materials are made available
+* under the terms of "Eclipse Public License v1.0"
+* which accompanies this distribution, and is available
+* at the URL "http://www.eclipse.org/legal/epl-v10.html".
+*
+* Initial Contributors:
+* Nokia Corporation - initial contribution.
+*
+* Contributors:
+*
+* Description:
+* The original NIST Statistical Test Suite code is placed in public domain.
+* (http://csrc.nist.gov/groups/ST/toolkit/rng/documentation_software.html)
+*
+* This software was developed at the National Institute of Standards and Technology by
+* employees of the Federal Government in the course of their official duties. Pursuant
+* to title 17 Section 105 of the United States Code this software is not subject to
+* copyright protection and is in the public domain. The NIST Statistical Test Suite is
+* an experimental system. NIST assumes no responsibility whatsoever for its use by other
+* parties, and makes no guarantees, expressed or implied, about its quality, reliability,
+* or any other characteristic. We would appreciate acknowledgment if the software is used.
+*/
+
+
+
+#include "openc.h"
+#include "../include/cephes.h"
+
+static const double rel_error = 1E-12;
+
+double MACHEP = 1.11022302462515654042E-16; // 2**-53
+double MAXLOG = 7.09782712893383996732224E2; // log(MAXNUM)
+double MAXNUM = 1.7976931348623158E308; // 2**1024*(1-MACHEP)
+double PI = 3.14159265358979323846; // pi, duh!
+
+static double big = 4.503599627370496e15;
+static double biginv = 2.22044604925031308085e-16;
+
+int sgngam = 0;
+
+double
+cephes_igamc(double a, double x)
+{
+ double ans, ax, c, yc, r, t, y, z;
+ double pk, pkm1, pkm2, qk, qkm1, qkm2;
+
+ if ( (x <= 0) || ( a <= 0) )
+ return( 1.0 );
+
+ if ( (x < 1.0) || (x < a) )
+ return( 1.e0 - cephes_igam(a,x) );
+
+ ax = a * log(x) - x - cephes_lgam(a);
+
+ if ( ax < -MAXLOG ) {
+ printf("igamc: UNDERFLOW\n");
+ return 0.0;
+ }
+ ax = exp(ax);
+
+ /* continued fraction */
+ y = 1.0 - a;
+ z = x + y + 1.0;
+ c = 0.0;
+ pkm2 = 1.0;
+ qkm2 = x;
+ pkm1 = x + 1.0;
+ qkm1 = z * x;
+ ans = pkm1/qkm1;
+
+ do {
+ c += 1.0;
+ y += 1.0;
+ z += 2.0;
+ yc = y * c;
+ pk = pkm1 * z - pkm2 * yc;
+ qk = qkm1 * z - qkm2 * yc;
+ if ( qk != 0 ) {
+ r = pk/qk;
+ t = fabs( (ans - r)/r );
+ ans = r;
+ }
+ else
+ t = 1.0;
+ pkm2 = pkm1;
+ pkm1 = pk;
+ qkm2 = qkm1;
+ qkm1 = qk;
+ if ( fabs(pk) > big ) {
+ pkm2 *= biginv;
+ pkm1 *= biginv;
+ qkm2 *= biginv;
+ qkm1 *= biginv;
+ }
+ } while ( t > MACHEP );
+
+ return ans*ax;
+}
+
+double
+cephes_igam(double a, double x)
+{
+ double ans, ax, c, r;
+
+ if ( (x <= 0) || ( a <= 0) )
+ return 0.0;
+
+ if ( (x > 1.0) && (x > a ) )
+ return 1.e0 - cephes_igamc(a,x);
+
+ /* Compute x**a * exp(-x) / gamma(a) */
+ ax = a * log(x) - x - cephes_lgam(a);
+ if ( ax < -MAXLOG ) {
+ printf("igam: UNDERFLOW\n");
+ return 0.0;
+ }
+ ax = exp(ax);
+
+ /* power series */
+ r = a;
+ c = 1.0;
+ ans = 1.0;
+
+ do {
+ r += 1.0;
+ c *= x/r;
+ ans += c;
+ } while ( c/ans > MACHEP );
+
+ return ans * ax/a;
+}
+
+
+/* A[]: Stirling's formula expansion of log gamma
+ * B[], C[]: log gamma function between 2 and 3
+ */
+static unsigned short A[] = {
+ 0x6661,0x2733,0x9850,0x3f4a,
+ 0xe943,0xb580,0x7fbd,0xbf43,
+ 0x5ebb,0x20dc,0x019f,0x3f4a,
+ 0xa5a1,0x16b0,0xc16c,0xbf66,
+ 0x554b,0x5555,0x5555,0x3fb5
+};
+static unsigned short B[] = {
+ 0x6761,0x8ff3,0x8901,0xc095,
+ 0xb93e,0x355b,0xf234,0xc0e2,
+ 0x89e5,0xf890,0x3d73,0xc114,
+ 0xdb51,0xf994,0xbc82,0xc131,
+ 0xf20b,0x0219,0x4589,0xc13a,
+ 0x055e,0x5418,0x0c67,0xc12a
+};
+static unsigned short C[] = {
+ /*0x0000,0x0000,0x0000,0x3ff0,*/
+ 0x12b2,0x1cf3,0xfd0d,0xc075,
+ 0xd757,0x7b89,0xaa0d,0xc0d0,
+ 0x4c9b,0xb974,0xeb84,0xc10a,
+ 0x0043,0x7195,0x6286,0xc131,
+ 0xf34c,0x892f,0x5255,0xc143,
+ 0xe14a,0x6a11,0xce4b,0xc13e
+};
+
+#define MAXLGM 2.556348e305
+
+
+/* Logarithm of gamma function */
+double
+cephes_lgam(double x)
+{
+ double p, q, u, w, z;
+ int i;
+
+ sgngam = 1;
+
+ if ( x < -34.0 ) {
+ q = -x;
+ w = cephes_lgam(q); /* note this modifies sgngam! */
+ p = floor(q);
+ if ( p == q ) {
+lgsing:
+ goto loverf;
+ }
+ i = (int)p;
+ if ( (i & 1) == 0 )
+ sgngam = -1;
+ else
+ sgngam = 1;
+ z = q - p;
+ if ( z > 0.5 ) {
+ p += 1.0;
+ z = p - q;
+ }
+ z = q * sin( PI * z );
+ if ( z == 0.0 )
+ goto lgsing;
+ /* z = log(PI) - log( z ) - w;*/
+ z = log(PI) - log( z ) - w;
+ return z;
+ }
+
+ if ( x < 13.0 ) {
+ z = 1.0;
+ p = 0.0;
+ u = x;
+ while ( u >= 3.0 ) {
+ p -= 1.0;
+ u = x + p;
+ z *= u;
+ }
+ while ( u < 2.0 ) {
+ if ( u == 0.0 )
+ goto lgsing;
+ z /= u;
+ p += 1.0;
+ u = x + p;
+ }
+ if ( z < 0.0 ) {
+ sgngam = -1;
+ z = -z;
+ }
+ else
+ sgngam = 1;
+ if ( u == 2.0 )
+ return( log(z) );
+ p -= 2.0;
+ x = x + p;
+ p = x * cephes_polevl( x, (double *)B, 5 ) / cephes_p1evl( x, (double *)C, 6);
+
+ return log(z) + p;
+ }
+
+ if ( x > MAXLGM ) {
+loverf:
+ printf("lgam: OVERFLOW\n");
+
+ return sgngam * MAXNUM;
+ }
+
+ q = ( x - 0.5 ) * log(x) - x + log( sqrt( 2*PI ) );
+ if ( x > 1.0e8 )
+ return q;
+
+ p = 1.0/(x*x);
+ if ( x >= 1000.0 )
+ q += (( 7.9365079365079365079365e-4 * p
+ - 2.7777777777777777777778e-3) *p
+ + 0.0833333333333333333333) / x;
+ else
+ q += cephes_polevl( p, (double *)A, 4 ) / x;
+
+ return q;
+}
+
+double
+cephes_polevl(double x, double *coef, int N)
+{
+ double ans;
+ int i;
+ double *p;
+
+ p = coef;
+ ans = *p++;
+ i = N;
+
+ do
+ ans = ans * x + *p++;
+ while ( --i );
+
+ return ans;
+}
+
+double
+cephes_p1evl(double x, double *coef, int N)
+{
+ double ans;
+ double *p;
+ int i;
+
+ p = coef;
+ ans = x + *p++;
+ i = N-1;
+
+ do
+ ans = ans * x + *p++;
+ while ( --i );
+
+ return ans;
+}
+
+double
+cephes_erf(double x)
+{
+ static const double two_sqrtpi = 1.128379167095512574;
+ double sum = x, term = x, xsqr = x * x;
+ int j = 1;
+
+ if ( fabs(x) > 2.2 )
+ return 1.0 - cephes_erfc(x);
+
+ do {
+ term *= xsqr/j;
+ sum -= term/(2*j+1);
+ j++;
+ term *= xsqr/j;
+ sum += term/(2*j+1);
+ j++;
+ } while ( fabs(term)/sum > rel_error );
+
+ return two_sqrtpi*sum;
+}
+
+double
+cephes_erfc(double x)
+{
+ static const double one_sqrtpi = 0.564189583547756287;
+ double a = 1, b = x, c = x, d = x*x + 0.5;
+ double q1, q2 = b/d, n = 1.0, t;
+
+ if ( fabs(x) < 2.2 )
+ return 1.0 - cephes_erf(x);
+ if ( x < 0 )
+ return 2.0 - cephes_erfc(-x);
+
+ do {
+ t = a*n + b*x;
+ a = b;
+ b = t;
+ t = c*n + d*x;
+ c = d;
+ d = t;
+ n += 0.5;
+ q1 = q2;
+ q2 = b/d;
+ } while ( fabs(q1-q2)/q2 > rel_error );
+
+ return one_sqrtpi*exp(-x*x)*q2;
+}
+
+
+double
+cephes_normal(double x)
+{
+ double arg, result, sqrt2=1.414213562373095048801688724209698078569672;
+
+ if (x > 0) {
+ arg = x/sqrt2;
+ result = 0.5 * ( 1 + erf(arg) );
+ }
+ else {
+ arg = -x/sqrt2;
+ result = 0.5 * ( 1 - erf(arg) );
+ }
+
+ return( result);
+}