--- /dev/null
+/* origin: FreeBSD /usr/src/lib/msun/src/e_lgammaf_r.c */
+/*
+ * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
+ */
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunPro, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+
+#include "libm.h"
+
+static const float
+two23= 8.3886080000e+06, /* 0x4b000000 */
+half= 5.0000000000e-01, /* 0x3f000000 */
+one = 1.0000000000e+00, /* 0x3f800000 */
+pi = 3.1415927410e+00, /* 0x40490fdb */
+a0 = 7.7215664089e-02, /* 0x3d9e233f */
+a1 = 3.2246702909e-01, /* 0x3ea51a66 */
+a2 = 6.7352302372e-02, /* 0x3d89f001 */
+a3 = 2.0580807701e-02, /* 0x3ca89915 */
+a4 = 7.3855509982e-03, /* 0x3bf2027e */
+a5 = 2.8905137442e-03, /* 0x3b3d6ec6 */
+a6 = 1.1927076848e-03, /* 0x3a9c54a1 */
+a7 = 5.1006977446e-04, /* 0x3a05b634 */
+a8 = 2.2086278477e-04, /* 0x39679767 */
+a9 = 1.0801156895e-04, /* 0x38e28445 */
+a10 = 2.5214456400e-05, /* 0x37d383a2 */
+a11 = 4.4864096708e-05, /* 0x383c2c75 */
+tc = 1.4616321325e+00, /* 0x3fbb16c3 */
+tf = -1.2148628384e-01, /* 0xbdf8cdcd */
+/* tt = -(tail of tf) */
+tt = 6.6971006518e-09, /* 0x31e61c52 */
+t0 = 4.8383611441e-01, /* 0x3ef7b95e */
+t1 = -1.4758771658e-01, /* 0xbe17213c */
+t2 = 6.4624942839e-02, /* 0x3d845a15 */
+t3 = -3.2788541168e-02, /* 0xbd064d47 */
+t4 = 1.7970675603e-02, /* 0x3c93373d */
+t5 = -1.0314224288e-02, /* 0xbc28fcfe */
+t6 = 6.1005386524e-03, /* 0x3bc7e707 */
+t7 = -3.6845202558e-03, /* 0xbb7177fe */
+t8 = 2.2596477065e-03, /* 0x3b141699 */
+t9 = -1.4034647029e-03, /* 0xbab7f476 */
+t10 = 8.8108185446e-04, /* 0x3a66f867 */
+t11 = -5.3859531181e-04, /* 0xba0d3085 */
+t12 = 3.1563205994e-04, /* 0x39a57b6b */
+t13 = -3.1275415677e-04, /* 0xb9a3f927 */
+t14 = 3.3552918467e-04, /* 0x39afe9f7 */
+u0 = -7.7215664089e-02, /* 0xbd9e233f */
+u1 = 6.3282704353e-01, /* 0x3f2200f4 */
+u2 = 1.4549225569e+00, /* 0x3fba3ae7 */
+u3 = 9.7771751881e-01, /* 0x3f7a4bb2 */
+u4 = 2.2896373272e-01, /* 0x3e6a7578 */
+u5 = 1.3381091878e-02, /* 0x3c5b3c5e */
+v1 = 2.4559779167e+00, /* 0x401d2ebe */
+v2 = 2.1284897327e+00, /* 0x4008392d */
+v3 = 7.6928514242e-01, /* 0x3f44efdf */
+v4 = 1.0422264785e-01, /* 0x3dd572af */
+v5 = 3.2170924824e-03, /* 0x3b52d5db */
+s0 = -7.7215664089e-02, /* 0xbd9e233f */
+s1 = 2.1498242021e-01, /* 0x3e5c245a */
+s2 = 3.2577878237e-01, /* 0x3ea6cc7a */
+s3 = 1.4635047317e-01, /* 0x3e15dce6 */
+s4 = 2.6642270386e-02, /* 0x3cda40e4 */
+s5 = 1.8402845599e-03, /* 0x3af135b4 */
+s6 = 3.1947532989e-05, /* 0x3805ff67 */
+r1 = 1.3920053244e+00, /* 0x3fb22d3b */
+r2 = 7.2193557024e-01, /* 0x3f38d0c5 */
+r3 = 1.7193385959e-01, /* 0x3e300f6e */
+r4 = 1.8645919859e-02, /* 0x3c98bf54 */
+r5 = 7.7794247773e-04, /* 0x3a4beed6 */
+r6 = 7.3266842264e-06, /* 0x36f5d7bd */
+w0 = 4.1893854737e-01, /* 0x3ed67f1d */
+w1 = 8.3333335817e-02, /* 0x3daaaaab */
+w2 = -2.7777778450e-03, /* 0xbb360b61 */
+w3 = 7.9365057172e-04, /* 0x3a500cfd */
+w4 = -5.9518753551e-04, /* 0xba1c065c */
+w5 = 8.3633989561e-04, /* 0x3a5b3dd2 */
+w6 = -1.6309292987e-03; /* 0xbad5c4e8 */
+
+static const float zero = 0.0000000000e+00;
+
+static float sin_pif(float x)
+{
+ float y,z;
+ int n,ix;
+
+ GET_FLOAT_WORD(ix, x);
+ ix &= 0x7fffffff;
+
+ if(ix < 0x3e800000)
+ return __sindf(pi*x);
+
+ y = -x; /* negative x is assumed */
+
+ /*
+ * argument reduction, make sure inexact flag not raised if input
+ * is an integer
+ */
+ z = floorf(y);
+ if (z != y) { /* inexact anyway */
+ y *= (float)0.5;
+ y = (float)2.0*(y - floorf(y)); /* y = |x| mod 2.0 */
+ n = (int) (y*(float)4.0);
+ } else {
+ if (ix >= 0x4b800000) {
+ y = zero; /* y must be even */
+ n = 0;
+ } else {
+ if (ix < 0x4b000000)
+ z = y + two23; /* exact */
+ GET_FLOAT_WORD(n, z);
+ n &= 1;
+ y = n;
+ n <<= 2;
+ }
+ }
+ switch (n) {
+ case 0: y = __sindf(pi*y); break;
+ case 1:
+ case 2: y = __cosdf(pi*((float)0.5-y)); break;
+ case 3:
+ case 4: y = __sindf(pi*(one-y)); break;
+ case 5:
+ case 6: y = -__cosdf(pi*(y-(float)1.5)); break;
+ default: y = __sindf(pi*(y-(float)2.0)); break;
+ }
+ return -y;
+}
+
+
+float lgammaf_r(float x, int *signgamp)
+{
+ float t,y,z,nadj,p,p1,p2,p3,q,r,w;
+ int32_t hx;
+ int i,ix;
+
+ GET_FLOAT_WORD(hx, x);
+
+ /* purge off +-inf, NaN, +-0, tiny and negative arguments */
+ *signgamp = 1;
+ ix = hx & 0x7fffffff;
+ if (ix >= 0x7f800000)
+ return x*x;
+ if (ix == 0)
+ return one/zero;
+ if (ix < 0x35000000) { /* |x| < 2**-21, return -log(|x|) */
+ if (hx < 0) {
+ *signgamp = -1;
+ return -logf(-x);
+ }
+ return -logf(x);
+ }
+ if (hx < 0) {
+ if (ix >= 0x4b000000) /* |x| >= 2**23, must be -integer */
+ return one/zero;
+ t = sin_pif(x);
+ if (t == zero) /* -integer */
+ return one/zero;
+ nadj = logf(pi/fabsf(t*x));
+ if (t < zero)
+ *signgamp = -1;
+ x = -x;
+ }
+
+ /* purge off 1 and 2 */
+ if (ix == 0x3f800000 || ix == 0x40000000)
+ r = 0;
+ /* for x < 2.0 */
+ else if (ix < 0x40000000) {
+ if (ix <= 0x3f666666) { /* lgamma(x) = lgamma(x+1)-log(x) */
+ r = -logf(x);
+ if (ix >= 0x3f3b4a20) {
+ y = one - x;
+ i = 0;
+ } else if (ix >= 0x3e6d3308) {
+ y = x - (tc-one);
+ i = 1;
+ } else {
+ y = x;
+ i = 2;
+ }
+ } else {
+ r = zero;
+ if (ix >= 0x3fdda618) { /* [1.7316,2] */
+ y = (float)2.0 - x;
+ i = 0;
+ } else if (ix >= 0x3F9da620) { /* [1.23,1.73] */
+ y = x - tc;
+ i = 1;
+ } else {
+ y = x - one;
+ i = 2;
+ }
+ }
+ switch(i) {
+ case 0:
+ z = y*y;
+ p1 = a0+z*(a2+z*(a4+z*(a6+z*(a8+z*a10))));
+ p2 = z*(a1+z*(a3+z*(a5+z*(a7+z*(a9+z*a11)))));
+ p = y*p1+p2;
+ r += (p-(float)0.5*y);
+ break;
+ case 1:
+ z = y*y;
+ w = z*y;
+ p1 = t0+w*(t3+w*(t6+w*(t9 +w*t12))); /* parallel comp */
+ p2 = t1+w*(t4+w*(t7+w*(t10+w*t13)));
+ p3 = t2+w*(t5+w*(t8+w*(t11+w*t14)));
+ p = z*p1-(tt-w*(p2+y*p3));
+ r += (tf + p);
+ break;
+ case 2:
+ p1 = y*(u0+y*(u1+y*(u2+y*(u3+y*(u4+y*u5)))));
+ p2 = one+y*(v1+y*(v2+y*(v3+y*(v4+y*v5))));
+ r += (-(float)0.5*y + p1/p2);
+ }
+ } else if (ix < 0x41000000) { /* x < 8.0 */
+ i = (int)x;
+ y = x-(float)i;
+ p = y*(s0+y*(s1+y*(s2+y*(s3+y*(s4+y*(s5+y*s6))))));
+ q = one+y*(r1+y*(r2+y*(r3+y*(r4+y*(r5+y*r6)))));
+ r = half*y+p/q;
+ z = one; /* lgamma(1+s) = log(s) + lgamma(s) */
+ switch (i) {
+ case 7: z *= y + (float)6.0; /* FALLTHRU */
+ case 6: z *= y + (float)5.0; /* FALLTHRU */
+ case 5: z *= y + (float)4.0; /* FALLTHRU */
+ case 4: z *= y + (float)3.0; /* FALLTHRU */
+ case 3: z *= y + (float)2.0; /* FALLTHRU */
+ r += logf(z);
+ break;
+ }
+ } else if (ix < 0x5c800000) { /* 8.0 <= x < 2**58 */
+ t = logf(x);
+ z = one/x;
+ y = z*z;
+ w = w0+z*(w1+y*(w2+y*(w3+y*(w4+y*(w5+y*w6)))));
+ r = (x-half)*(t-one)+w;
+ } else /* 2**58 <= x <= inf */
+ r = x*(logf(x)-one);
+ if (hx < 0)
+ r = nadj - r;
+ return r;
+}
projects / musl / blobdiff