--- libstdc++-v3/include/c_global/cmath.jj	2024-10-29 11:13:47.741803660 +0100
+++ libstdc++-v3/include/c_global/cmath	2024-11-01 21:11:40.367678439 +0100
@@ -2838,7 +2838,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
   constexpr int
   ilogb(_Float16 __x)
-  { return _Float16(__builtin_ilogbf(__x)); }
+  { return __builtin_ilogbf(__x); }
 
   constexpr _Float16
   lgamma(_Float16 __x)
@@ -2846,11 +2846,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
   constexpr long long
   llrint(_Float16 __x)
-  { return _Float16(__builtin_llrintf(__x)); }
+  { return __builtin_llrintf(__x); }
 
   constexpr long long
   llround(_Float16 __x)
-  { return _Float16(__builtin_llroundf(__x)); }
+  { return __builtin_llroundf(__x); }
 
   constexpr _Float16
   log1p(_Float16 __x)
@@ -2867,11 +2867,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
   constexpr long
   lrint(_Float16 __x)
-  { return _Float16(__builtin_lrintf(__x)); }
+  { return __builtin_lrintf(__x); }
 
   constexpr long
   lround(_Float16 __x)
-  { return _Float16(__builtin_lroundf(__x)); }
+  { return __builtin_lroundf(__x); }
 
   constexpr _Float16
   nearbyint(_Float16 __x)
@@ -3560,7 +3560,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
   constexpr int
   ilogb(__gnu_cxx::__bfloat16_t __x)
-  { return __gnu_cxx::__bfloat16_t(__builtin_ilogbf(__x)); }
+  { return __builtin_ilogbf(__x); }
 
   constexpr __gnu_cxx::__bfloat16_t
   lgamma(__gnu_cxx::__bfloat16_t __x)
@@ -3568,11 +3568,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
   constexpr long long
   llrint(__gnu_cxx::__bfloat16_t __x)
-  { return __gnu_cxx::__bfloat16_t(__builtin_llrintf(__x)); }
+  { return __builtin_llrintf(__x); }
 
   constexpr long long
   llround(__gnu_cxx::__bfloat16_t __x)
-  { return __gnu_cxx::__bfloat16_t(__builtin_llroundf(__x)); }
+  { return __builtin_llroundf(__x); }
 
   constexpr __gnu_cxx::__bfloat16_t
   log1p(__gnu_cxx::__bfloat16_t __x)
@@ -3589,11 +3589,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
   constexpr long
   lrint(__gnu_cxx::__bfloat16_t __x)
-  { return __gnu_cxx::__bfloat16_t(__builtin_lrintf(__x)); }
+  { return __builtin_lrintf(__x); }
 
   constexpr long
   lround(__gnu_cxx::__bfloat16_t __x)
-  { return __gnu_cxx::__bfloat16_t(__builtin_lroundf(__x)); }
+  { return __builtin_lroundf(__x); }
 
   constexpr __gnu_cxx::__bfloat16_t
   nearbyint(__gnu_cxx::__bfloat16_t __x)
--- libstdc++-v3/testsuite/26_numerics/headers/cmath/117406.cc.jj	2024-11-02 07:55:07.555121231 +0100
+++ libstdc++-v3/testsuite/26_numerics/headers/cmath/117406.cc	2024-11-02 08:00:14.150679537 +0100
@@ -0,0 +1,59 @@
+// Copyright (C) 2024 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-do run { target c++23 } }
+// { dg-require-cmath "" }
+
+#include <stdfloat>
+#include <cmath>
+#include <limits>
+#include <testsuite_hooks.h>
+
+template <typename T>
+void
+test ()
+{
+  using lim = std::numeric_limits<T>;
+  int t0 = std::ilogb(T(4.0));
+  VERIFY( t0 == 2 );
+  int t1 = std::ilogb(lim::infinity());
+  VERIFY( t1 == INT_MAX );
+  int t2 = std::ilogb(-lim::infinity());
+  VERIFY( t2 == INT_MAX );
+}
+
+int
+main ()
+{
+#if defined(__STDCPP_FLOAT16_T__) && defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32)
+  test <std::float16_t>();
+#endif
+#if defined(__STDCPP_FLOAT32_T__) && defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32)
+  test <std::float32_t>();
+#endif
+#if defined(__STDCPP_FLOAT64_T__) && defined(_GLIBCXX_DOUBLE_IS_IEEE_BINARY64)
+  test <std::float64_t>();
+#endif
+#if defined(__STDCPP_FLOAT128_T__) \
+    && (defined(_GLIBCXX_LDOUBLE_IS_IEEE_BINARY128) \
+	|| defined(_GLIBCXX_HAVE_FLOAT128_MATH))
+  test <std::float128_t>();
+#endif
+#if defined(__STDCPP_BFLOAT16_T__) && defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32)
+  test <std::bfloat16_t>();
+#endif
+}
