merge revision(s) 49913,54492,54494,54495,54496,54499,54503: [Backport #12249]

math.c: fix tgamma on mingw

	* math.c (mingw_tgamma): tgamma(3) on mingw returns a NaN for a
  big number, not infinity.
	* math.c (ruby_tgamma): fix tgamma(-0.0) on mingw.
	  [ruby-core:74817] [Bug #12249]

	* math.c (ruby_lgamma_r): fix lgamma(-0.0) on mingw and OSX.

	* math.c (ruby_lgamma_r): mswin's lgamma_r also seems to be wrong.
	  cf. [Bug #12249]

	* math.c (ruby_lgamma_r): missing/lgamma_r.c is used on Windows,
	  since msvcrt does not provide it.

	* missing/lgamma_r.c (lgamma_r): fix lgamma(-0.0).
	  [ruby-core:74823] [Bug #12249]

	* configure.in (rb_cv_lgamma_r_m0): check if lgamma_r(-0.0)
	  returns negative infinity.  [Bug #12249]

	* math.c (ruby_lgamma_r): define by the configured result.

	* configure.in (rb_cv_lgamma_r_m0): fix the condition for
	  lgamma_r(-0.0).  [Bug #12249]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_2@54687 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,33 @@
+Fri Apr 22 16:24:00 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* configure.in (rb_cv_lgamma_r_m0): fix the condition for
+	  lgamma_r(-0.0).  [Bug #12249]
+
+Fri Apr 22 16:24:00 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* configure.in (rb_cv_lgamma_r_m0): check if lgamma_r(-0.0)
+	  returns negative infinity.  [Bug #12249]
+
+	* math.c (ruby_lgamma_r): define by the configured result.
+
+Fri Apr 22 16:24:00 2016  cremno phobia  <cremno@mail.ru>
+
+	* math.c (ruby_lgamma_r): missing/lgamma_r.c is used on Windows,
+	  since msvcrt does not provide it.
+
+	* missing/lgamma_r.c (lgamma_r): fix lgamma(-0.0).
+	  [ruby-core:74823] [Bug #12249]
+
+Fri Apr 22 16:24:00 2016  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* math.c (ruby_lgamma_r): mswin's lgamma_r also seems to be wrong.
+	  cf. [Bug #12249]
+
+Fri Apr 22 16:24:00 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* math.c (ruby_tgamma): fix tgamma(-0.0) on mingw.
+	  [ruby-core:74817] [Bug #12249]
+
 Fri Apr 22 16:00:50 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* defs/keywords (alias, undef): symbol literals are allowed.

configure.in

@@ -2233,6 +2233,41 @@ main(int argc, char **argv)
 ])
 AS_IF([test "x$rb_cv_atan2_inf_c99" = xyes], [AC_DEFINE(ATAN2_INF_C99)])
 
+AS_IF([test "x$ac_cv_func_lgamma_r" = xyes], [
+    AC_CACHE_CHECK(whether lgamma_r handles -0.0, rb_cv_lgamma_r_m0, [
+	AC_TRY_RUN([
+@%:@include <math.h>
+@%:@ifdef HAVE_UNISTD_H
+@%:@include <unistd.h>
+@%:@endif
+@%:@ifndef EXIT_SUCCESS
+@%:@define EXIT_SUCCESS 0
+@%:@endif
+@%:@ifndef EXIT_FAILURE
+@%:@define EXIT_FAILURE 1
+@%:@endif
+
+int
+main(int argc, char **argv)
+{
+    int sign;
+    double x = lgamma_r(-0.0, &sign);
+
+    /* should be [+inf, -1] */
+    if (x <= 0) return EXIT_FAILURE;
+    if (!isinf(x)) return EXIT_FAILURE;
+    if (sign != -1) return EXIT_FAILURE;
+    return EXIT_SUCCESS;
+}
+],
+	[rb_cv_lgamma_r_m0=yes],
+	[rb_cv_lgamma_r_m0=no],
+	[rb_cv_lgamma_r_m0=yes]
+	)
+    ])
+    AS_IF([test "x$rb_cv_lgamma_r_m0" = xno], [AC_DEFINE(LGAMMA_R_M0_FIX)])
+])
+
 # Some platform need -lrt for clock_gettime, but the other don't.
 if test x"$ac_cv_func_clock_gettime" != xyes; then
     # glibc 2.17 moves clock_* functions from librt to the main C library.

math.c

@@ -774,6 +774,38 @@ math_erfc(VALUE obj, VALUE x)
     return DBL2NUM(erfc(RFLOAT_VALUE(x)));
 }
 
+#if defined __MINGW32__
+static inline double
+ruby_tgamma(const double d)
+{
+    const double g = tgamma(d);
+    if (isinf(g)) {
+	if (d == 0.0 && signbit(d)) return -INFINITY;
+    }
+    if (isnan(g)) {
+	if (!signbit(d)) return INFINITY;
+    }
+    return g;
+}
+#define tgamma(d) ruby_tgamma(d)
+#endif
+
+#if defined LGAMMA_R_M0_FIX
+static inline double
+ruby_lgamma_r(const double d, int *sign)
+{
+    const double g = lgamma_r(d, sign);
+    if (isinf(g)) {
+	if (d == 0.0 && signbit(d)) {
+	    *sign = -1;
+	    return INFINITY;
+	}
+    }
+    return g;
+}
+#define lgamma_r(d, sign) ruby_lgamma_r(d, sign)
+#endif
+
 /*
  * call-seq:
  *    Math.gamma(x)  -> Float

missing/lgamma_r.c

@@ -66,7 +66,7 @@ lgamma_r(double x, int *signp)
         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;
         }

test/ruby/test_math.rb

@@ -239,6 +239,10 @@ class TestMath < Test::Unit::TestCase
     end
 
     assert_raise(Math::DomainError) { Math.gamma(-Float::INFINITY) }
+    x = Math.gamma(-0.0)
+    mesg = "Math.gamma(-0.0) should be -INF"
+    assert_infinity(x, mesg)
+    assert_operator(x, :<, 0, mesg)
   end
 
   def test_lgamma
@@ -281,6 +285,11 @@ class TestMath < Test::Unit::TestCase
     assert_equal(s, 1)
 
     assert_raise(Math::DomainError) { Math.lgamma(-Float::INFINITY) }
+    x, sign = Math.lgamma(-0.0)
+    mesg = "Math.lgamma(-0.0) should be [INF, -1]"
+    assert_infinity(x, mesg)
+    assert_operator(x, :>, 0, mesg)
+    assert_equal(-1, sign, mesg)
   end
 
   def test_cbrt

version.h

@@ -1,6 +1,6 @@
 #define RUBY_VERSION "2.2.5"
 #define RUBY_RELEASE_DATE "2016-04-22"
-#define RUBY_PATCHLEVEL 304
+#define RUBY_PATCHLEVEL 305
 
 #define RUBY_RELEASE_YEAR 2016
 #define RUBY_RELEASE_MONTH 4