lgamma_r.c in rhodes-6.0.11

- old
+ new

@@ -6,10 +6,11 @@
             (New Algorithm handbook in C language) (Gijyutsu hyouron
             sha, Tokyo, 1991) [in Japanese]
             http://oku.edu.mie-u.ac.jp/~okumura/algo/
 */
 
+#include "ruby/missing.h"
 /***********************************************************
     gamma.c -- Gamma function
 ***********************************************************/
 #include <math.h>
 #include <errno.h>
@@ -44,18 +45,29 @@
                 + (B8  / ( 8 *  7))) * w + (B6  / ( 6 *  5))) * w
                 + (B4  / ( 4 *  3))) * w + (B2  / ( 2 *  1))) / x
                 + 0.5 * LOG_2PI - log(v) - x + (x - 0.5) * log(x);
 }
 
+
+#ifdef __MINGW_ATTRIB_PURE
+/* get rid of bugs in math.h of mingw */
+#define modf(_X, _Y) __extension__ ({\
+    double intpart_modf_bug = intpart_modf_bug;\
+    double result_modf_bug = modf((_X), &intpart_modf_bug);\
+    *(_Y) = intpart_modf_bug;\
+    result_modf_bug;\
+})
+#endif
+
 /* the natural logarithm of the absolute value of the Gamma function */
 double
 lgamma_r(double x, int *signp)
 {
     if (x <= 0) {
         double i, f, s;
         f = modf(-x, &i);
         if (f == 0.0) { /* pole error */
-            *signp = 1;
+            *signp = signbit(x) ? -1 : 1;
             errno = ERANGE;
             return HUGE_VAL;
         }
         *signp = (fmod(i, 2.0) != 0.0) ? 1 : -1;
         s = sin(PI * f);