prevent CNAME/PTR parsing from reading data past the response end

[musl] / src / math / lgammaf_r.c

diff --git a/src/math/lgammaf_r.c b/src/math/lgammaf_r.c
index 976986a..3f353f1 100644 (file)
--- a/src/math/lgammaf_r.c
+++ b/src/math/lgammaf_r.c
@@ -16,7 +16,6 @@
 #include "libm.h"
 
 static const float
-two23= 8.3886080000e+06, /* 0x4b000000 */
 pi  =  3.1415927410e+00, /* 0x40490fdb */
 a0  =  7.7215664089e-02, /* 0x3d9e233f */
 a1  =  3.2246702909e-01, /* 0x3ea51a66 */
@@ -81,87 +80,58 @@ w4  = -5.9518753551e-04, /* 0xba1c065c */
 w5  =  8.3633989561e-04, /* 0x3a5b3dd2 */
 w6  = -1.6309292987e-03; /* 0xbad5c4e8 */
 
-static float sin_pif(float x)
+/* sin(pi*x) assuming x > 2^-100, if sin(pi*x)==0 the sign is arbitrary */
+static float sin_pi(float x)
 {
-       float y,z;
-       int n,ix;
+       double_t y;
+       int n;
 
-       GET_FLOAT_WORD(ix, x);
-       ix &= 0x7fffffff;
+       /* spurious inexact if odd int */
+       x = 2*(x*0.5f - floorf(x*0.5f));  /* x mod 2.0 */
 
-       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 *= 0.5f;
-               y  = 2.0f*(y - floorf(y));   /* y = |x| mod 2.0 */
-               n  = (int)(y*4.0f);
-       } else {
-               if (ix >= 0x4b800000) {
-                       y = 0.0f;  /* 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;
-               }
-       }
+       n = (int)(x*4);
+       n = (n+1)/2;
+       y = x - n*0.5f;
+       y *= 3.14159265358979323846;
        switch (n) {
-       case 0:  y =  __sindf(pi*y); break;
-       case 1:
-       case 2:  y =  __cosdf(pi*(0.5f - y)); break;
-       case 3:
-       case 4:  y =  __sindf(pi*(1.0f - y)); break;
-       case 5:
-       case 6:  y = -__cosdf(pi*(y - 1.5f)); break;
-       default: y =  __sindf(pi*(y - 2.0f)); break;
+       default: /* case 4: */
+       case 0: return __sindf(y);
+       case 1: return __cosdf(y);
+       case 2: return __sindf(-y);
+       case 3: return -__cosdf(y);
        }
-       return -y;
 }
 
-
 float __lgammaf_r(float x, int *signgamp)
 {
+       union {float f; uint32_t i;} u = {x};
        float t,y,z,nadj,p,p1,p2,p3,q,r,w;
-       int32_t hx;
-       int i,ix;
-
-       GET_FLOAT_WORD(hx, x);
+       uint32_t ix;
+       int i,sign;
 
        /* purge off +-inf, NaN, +-0, tiny and negative arguments */
        *signgamp = 1;
-       ix = hx & 0x7fffffff;
+       sign = u.i>>31;
+       ix = u.i & 0x7fffffff;
        if (ix >= 0x7f800000)
                return x*x;
-       if (ix == 0)
-               return 1.0f/0.0f;
        if (ix < 0x35000000) {  /* |x| < 2**-21, return -log(|x|) */
-               if (hx < 0) {
+               if (sign) {
                        *signgamp = -1;
-                       return -logf(-x);
+                       x = -x;
                }
                return -logf(x);
        }
-       if (hx < 0) {
-               if (ix >= 0x4b000000)  /* |x| >= 2**23, must be -integer */
-                       return 1.0f/0.0f;
-               t = sin_pif(x);
+       if (sign) {
+               x = -x;
+               t = sin_pi(x);
                if (t == 0.0f) /* -integer */
-                       return 1.0f/0.0f;
-               nadj = logf(pi/fabsf(t*x));
-               if (t < 0.0f)
+                       return 1.0f/(x-x);
+               if (t > 0.0f)
                        *signgamp = -1;
-               x = -x;
+               else
+                       t = -t;
+               nadj = logf(pi/(t*x));
        }
 
        /* purge off 1 and 2 */
@@ -240,7 +210,7 @@ float __lgammaf_r(float x, int *signgamp)
                r = (x-0.5f)*(t-1.0f)+w;
        } else                         /* 2**58 <= x <= inf */
                r =  x*(logf(x)-1.0f);
-       if (hx < 0)
+       if (sign)
                r = nadj - r;
        return r;
 }