diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4
index 0ce3b8b5b31d8aa2aacabed691ea382bc98d0793..84b12adbc248baa89ee4878cd6b0bb75173ea1b5 100644
--- a/libstdc++-v3/acinclude.m4
+++ b/libstdc++-v3/acinclude.m4
@@ -1200,6 +1200,43 @@ AC_DEFUN([GLIBCXX_ENABLE_C99], [
requires corresponding C99 library functions to be present.])
fi
+ # Check for the existence of <complex.h> complex inverse trigonometric
+ # math functions used by <complex> for C++11 and later.
+ ac_c99_complex_arc=no;
+ if test x"$ac_has_complex_h" = x"yes"; then
+ AC_MSG_CHECKING([for ISO C99 support for inverse trig functions in <complex.h>])
+ AC_TRY_COMPILE([#include <complex.h>],
+ [typedef __complex__ float float_type; float_type tmpf;
+ cacosf(tmpf);
+ casinf(tmpf);
+ catanf(tmpf);
+ cacoshf(tmpf);
+ casinhf(tmpf);
+ catanhf(tmpf);
+ typedef __complex__ double double_type; double_type tmpd;
+ cacos(tmpd);
+ casin(tmpd);
+ catan(tmpd);
+ cacosh(tmpd);
+ casinh(tmpd);
+ catanh(tmpd);
+ typedef __complex__ long double ld_type; ld_type tmpld;
+ cacosl(tmpld);
+ casinl(tmpld);
+ catanl(tmpld);
+ cacoshl(tmpld);
+ casinhl(tmpld);
+ catanhl(tmpld);
+ ],[ac_c99_complex_arc=yes], [ac_c99_complex_arc=no])
+ fi
+ AC_MSG_RESULT($ac_c99_complex_arc)
+ if test x"$ac_c99_complex_arc" = x"yes"; then
+ AC_DEFINE(_GLIBCXX_USE_C99_COMPLEX_ARC, 1,
+ [Define if C99 inverse trig functions in <complex.h> should be
+ used in <complex>. Using compiler builtins for these functions
+ requires corresponding C99 library functions to be present.])
+ fi
+
# Check for the existence in <stdio.h> of vscanf, et. al.
AC_CACHE_CHECK([for ISO C99 support in <stdio.h> for C++11],
glibcxx_cv_c99_stdio_cxx11, [
diff --git a/libstdc++-v3/config.h.in b/libstdc++-v3/config.h.in
index a336daf23030e450f7f496f306e5310d7b2547a6..8e037fb13fd76462d59a8de44267e4fb9e62949b 100644
--- a/libstdc++-v3/config.h.in
+++ b/libstdc++-v3/config.h.in
@@ -892,6 +892,11 @@
<stdio.h>, and <stdlib.h> can be used or exposed. */
#undef _GLIBCXX_USE_C99
+/* Define if C99 inverse trig functions in <complex.h> should be used in
+ <complex>. Using compiler builtins for these functions requires
+ corresponding C99 library functions to be present. */
+#undef _GLIBCXX_USE_C99_COMPLEX_ARC
+
/* Define if C99 functions in <complex.h> should be used in <tr1/complex>.
Using compiler builtins for these functions requires corresponding C99
library functions to be present. */
diff --git a/libstdc++-v3/configure b/libstdc++-v3/configure
index c1faebd54f2f648bd707dfc5ddeee2783d83be1c..04fe6f9ad1cb5d6cdcbcb2134b69bdbf39a501dc 100755
--- a/libstdc++-v3/configure
+++ b/libstdc++-v3/configure
@@ -18266,6 +18266,59 @@ $as_echo "#define _GLIBCXX11_USE_C99_COMPLEX 1" >>confdefs.h
fi
+ # Check for the existence of <complex.h> complex inverse trigonometric
+ # math functions used by <complex> for C++11 and later.
+ ac_c99_complex_arc=no;
+ if test x"$ac_has_complex_h" = x"yes"; then
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking for ISO C99 support for inverse trig functions in <complex.h>" >&5
+$as_echo_n "checking for ISO C99 support for inverse trig functions in <complex.h>... " >&6; }
+ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+#include <complex.h>
+int
+main ()
+{
+typedef __complex__ float float_type; float_type tmpf;
+ cacosf(tmpf);
+ casinf(tmpf);
+ catanf(tmpf);
+ cacoshf(tmpf);
+ casinhf(tmpf);
+ catanhf(tmpf);
+ typedef __complex__ double double_type; double_type tmpd;
+ cacos(tmpd);
+ casin(tmpd);
+ catan(tmpd);
+ cacosh(tmpd);
+ casinh(tmpd);
+ catanh(tmpd);
+ typedef __complex__ long double ld_type; ld_type tmpld;
+ cacosl(tmpld);
+ casinl(tmpld);
+ catanl(tmpld);
+ cacoshl(tmpld);
+ casinhl(tmpld);
+ catanhl(tmpld);
+
+ ;
+ return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+ ac_c99_complex_arc=yes
+else
+ ac_c99_complex_arc=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ fi
+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_c99_complex_arc" >&5
+$as_echo "$ac_c99_complex_arc" >&6; }
+ if test x"$ac_c99_complex_arc" = x"yes"; then
+
+$as_echo "#define _GLIBCXX_USE_C99_COMPLEX_ARC 1" >>confdefs.h
+
+ fi
+
# Check for the existence in <stdio.h> of vscanf, et. al.
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for ISO C99 support in <stdio.h> for C++11" >&5
$as_echo_n "checking for ISO C99 support in <stdio.h> for C++11... " >&6; }
diff --git a/libstdc++-v3/doc/doxygen/user.cfg.in b/libstdc++-v3/doc/doxygen/user.cfg.in
index 14981c96f9517c98554b263b35c771d110ead78a..210e13400b98f12f833fee9ab0bf083cc6394510 100644
--- a/libstdc++-v3/doc/doxygen/user.cfg.in
+++ b/libstdc++-v3/doc/doxygen/user.cfg.in
@@ -2352,6 +2352,7 @@ PREDEFINED = __cplusplus=202002L \
_GLIBCXX_USE_NOEXCEPT=noexcept \
_GLIBCXX_USE_WCHAR_T \
_GLIBCXX_USE_LONG_LONG \
+ _GLIBCXX_USE_C99_COMPLEX_ARC \
_GLIBCXX_USE_C99_STDINT_TR1 \
_GLIBCXX_USE_SCHED_YIELD \
_GLIBCXX_USE_NANOSLEEP \
diff --git a/libstdc++-v3/include/std/complex b/libstdc++-v3/include/std/complex
index 0f5f14c3ddb750546abdd8ab33817c6de8267d8f..40fc062e53db87baa887545fdbf1b163b304178f 100644
--- a/libstdc++-v3/include/std/complex
+++ b/libstdc++-v3/include/std/complex
@@ -2021,7 +2021,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
return std::complex<_Tp>(__pi_2 - __t.real(), -__t.imag());
}
-#if _GLIBCXX_USE_C99_COMPLEX_TR1
+#if _GLIBCXX_USE_C99_COMPLEX_ARC
#if defined(__STDCPP_FLOAT16_T__) && defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32)
inline __complex__ _Float16
__complex_acos(__complex__ _Float16 __z)
@@ -2177,7 +2177,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
#endif
#endif
-#if _GLIBCXX_USE_C99_COMPLEX_TR1
+#if _GLIBCXX_USE_C99_COMPLEX_ARC
inline __complex__ float
__complex_acos(__complex__ float __z)
{ return __builtin_cacosf(__z); }
@@ -2213,7 +2213,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
return std::complex<_Tp>(__t.imag(), -__t.real());
}
-#if _GLIBCXX_USE_C99_COMPLEX_TR1
+#if _GLIBCXX_USE_C99_COMPLEX_ARC
inline __complex__ float
__complex_asin(__complex__ float __z)
{ return __builtin_casinf(__z); }
@@ -2257,7 +2257,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_Tp(0.25) * log(__num / __den));
}
-#if _GLIBCXX_USE_C99_COMPLEX_TR1
+#if _GLIBCXX_USE_C99_COMPLEX_ARC
inline __complex__ float
__complex_atan(__complex__ float __z)
{ return __builtin_catanf(__z); }
@@ -2293,7 +2293,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
+ std::sqrt(_Tp(0.5) * (__z - _Tp(1.0))));
}
-#if _GLIBCXX_USE_C99_COMPLEX_TR1
+#if _GLIBCXX_USE_C99_COMPLEX_ARC
inline __complex__ float
__complex_acosh(__complex__ float __z)
{ return __builtin_cacoshf(__z); }
@@ -2332,7 +2332,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
return std::log(__t + __z);
}
-#if _GLIBCXX_USE_C99_COMPLEX_TR1
+#if _GLIBCXX_USE_C99_COMPLEX_ARC
inline __complex__ float
__complex_asinh(__complex__ float __z)
{ return __builtin_casinhf(__z); }
@@ -2376,7 +2376,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_Tp(0.5) * atan2(_Tp(2.0) * __z.imag(), __x));
}
-#if _GLIBCXX_USE_C99_COMPLEX_TR1
+#if _GLIBCXX_USE_C99_COMPLEX_ARC
inline __complex__ float
__complex_atanh(__complex__ float __z)
{ return __builtin_catanhf(__z); }