libstdc++: Simplify std::normal_distribution equality operator

libstdc++-v3/ChangeLog:

	* include/bits/random.tcc (operator==): Only check
	normal_distribution::_M_saved_available once.
	* testsuite/26_numerics/random/normal_distribution/operators/equal.cc:
	Check equality after state changes.
	* testsuite/26_numerics/random/pr60037-neg.cc: Adjust dg-error
	lineno.

3 files changed, 22 insertions, 10 deletions

diff --git a/libstdc++-v3/include/bits/random.tcc b/libstdc++-v3/include/bits/random.tcc
index 87a16a2..cb1d367 100644
--- a/libstdc++-v3/include/bits/random.tcc
+++ b/libstdc++-v3/include/bits/random.tcc
@@ -1907,15 +1907,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     {
       if (__d1._M_param == __d2._M_param
 	  && __d1._M_saved_available == __d2._M_saved_available)
-	{
-	  if (__d1._M_saved_available
-	      && __d1._M_saved == __d2._M_saved)
-	    return true;
-	  else if(!__d1._M_saved_available)
-	    return true;
-	  else
-	    return false;
-	}
+	return __d1._M_saved_available ? __d1._M_saved == __d2._M_saved : true;
       else
 	return false;
     }
diff --git a/libstdc++-v3/testsuite/26_numerics/random/normal_distribution/operators/equal.cc b/libstdc++-v3/testsuite/26_numerics/random/normal_distribution/operators/equal.cc
index a343523..81534e9 100644
--- a/libstdc++-v3/testsuite/26_numerics/random/normal_distribution/operators/equal.cc
+++ b/libstdc++-v3/testsuite/26_numerics/random/normal_distribution/operators/equal.cc
@@ -34,8 +34,28 @@ test01()
   VERIFY( !(u == v) );
 }
 
+void
+test02()
+{
+  std::normal_distribution<double> u(5.0, 2.0), v(u);
+  VERIFY( u == v );
+  u.reset();
+  VERIFY( u == v );
+
+  std::minstd_rand0 g1, g2;
+  (void) u(g1); // u._M_saved_available = true
+  VERIFY( !(u == v) );
+  (void) v(g2); // v._M_saved_available = true
+  VERIFY( u == v );
+  u.reset();    // u._M_saved_available = false
+  VERIFY( !(u == v) );
+  v.reset();    // v._M_saved_available = false
+  VERIFY( u == v );
+}
+
 int main()
 {
   test01();
+  test02();
   return 0;
 }
diff --git a/libstdc++-v3/testsuite/26_numerics/random/pr60037-neg.cc b/libstdc++-v3/testsuite/26_numerics/random/pr60037-neg.cc
index 3ab9c44..c58f480 100644
--- a/libstdc++-v3/testsuite/26_numerics/random/pr60037-neg.cc
+++ b/libstdc++-v3/testsuite/26_numerics/random/pr60037-neg.cc
@@ -12,4 +12,4 @@ auto x = std::generate_canonical<std::size_t,
 
 // { dg-error "static assertion failed: template argument must be a floating point type" "" { target *-*-* } 169 }
 
-// { dg-error "static assertion failed: template argument must be a floating point type" "" { target *-*-* } 3356 }
+// { dg-error "static assertion failed: template argument must be a floating point type" "" { target *-*-* } 3348 }