From: Edward Smith-Rowland <3dw4rd@verizon.net>
Date: Mon, 7 May 2018 16:23:29 +0000 (+0000)
Subject: backport: re PR libstdc++/80506 (Wrong magic number in std::gamma_distribution)
X-Git-Tag: releases/gcc-7.4.0~490
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=12eb60f827c0443f32b2884ac068025c89f8c04c;p=thirdparty%2Fgcc.git

backport: re PR libstdc++/80506 (Wrong magic number in std::gamma_distribution)

2018-05-07  Edward Smith-Rowland  <3dw4rd@verizon.net>
	    Jonathan Wakely  <jwakely@redhat.com>

	Backport from mainline
	2018-05-07  Edward Smith-Rowland  <3dw4rd@verizon.net>

	PR libstdc++/80506
	* include/bits/random.tcc (gamma_distribution::operator()): Fix magic
	number used in loop condition.
	(gamma_distribution::__generate_impl()): Ditto.


Co-Authored-By: Jonathan Wakely <jwakely@redhat.com>

From-SVN: r260006
---

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 9456415a4b4a..aa35f4927770 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,14 @@
+2018-05-07  Edward Smith-Rowland  <3dw4rd@verizon.net>
+	    Jonathan Wakely  <jwakely@redhat.com>
+
+	Backport from mainline
+	2018-05-07  Edward Smith-Rowland  <3dw4rd@verizon.net>
+
+	PR libstdc++/80506
+	* include/bits/random.tcc (gamma_distribution::operator()): Fix magic
+	number used in loop condition.
+	(gamma_distribution::__generate_impl()): Ditto.
+
 2018-05-03  Jonathan Wakely  <jwakely@redhat.com>
 
 	PR libstdc++/84769
diff --git a/libstdc++-v3/include/bits/random.tcc b/libstdc++-v3/include/bits/random.tcc
index df05ebea6e9a..c43d85551c35 100644
--- a/libstdc++-v3/include/bits/random.tcc
+++ b/libstdc++-v3/include/bits/random.tcc
@@ -2356,7 +2356,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	    __v = __v * __v * __v;
 	    __u = __aurng();
 	  }
-	while (__u > result_type(1.0) - 0.331 * __n * __n * __n * __n
+	while (__u > result_type(1.0) - 0.0331 * __n * __n * __n * __n
 	       && (std::log(__u) > (0.5 * __n * __n + __a1
 				    * (1.0 - __v + std::log(__v)))));
 
@@ -2405,7 +2405,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 		  __v = __v * __v * __v;
 		  __u = __aurng();
 		}
-	      while (__u > result_type(1.0) - 0.331 * __n * __n * __n * __n
+	      while (__u > result_type(1.0) - 0.0331 * __n * __n * __n * __n
 		     && (std::log(__u) > (0.5 * __n * __n + __a1
 					  * (1.0 - __v + std::log(__v)))));
 
@@ -2426,7 +2426,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 		  __v = __v * __v * __v;
 		  __u = __aurng();
 		}
-	      while (__u > result_type(1.0) - 0.331 * __n * __n * __n * __n
+	      while (__u > result_type(1.0) - 0.0331 * __n * __n * __n * __n
 		     && (std::log(__u) > (0.5 * __n * __n + __a1
 					  * (1.0 - __v + std::log(__v)))));