commit 3e5760fcb48528d48deeb60cb885a97bb731160c
Author: Joseph Myers <joseph@codesourcery.com>
Date:   Wed Sep 28 20:09:34 2022 +0000

    Update _FloatN header support for C++ in GCC 13
    
    GCC 13 adds support for _FloatN and _FloatNx types in C++, so breaking
    the installed glibc headers that assume such support is not present.
    GCC mostly works around this with fixincludes, but that doesn't help
    for building glibc and its tests (glibc doesn't itself contain C++
    code, but there's C++ code built for tests).  Update glibc's
    bits/floatn-common.h and bits/floatn.h headers to handle the GCC 13
    support directly.
    
    In general the changes match those made by fixincludes, though I think
    the ones in sysdeps/powerpc/bits/floatn.h, where the header tests
    __LDBL_MANT_DIG__ == 113 or uses #elif, wouldn't match the existing
    fixincludes patterns.
    
    Some places involving special C++ handling in relation to _FloatN
    support are not changed.  There's no need to change the
    __HAVE_FLOATN_NOT_TYPEDEF definition (also in a form that wouldn't be
    matched by the fixincludes fixes) because it's only used in relation
    to macro definitions using features not supported for C++
    (__builtin_types_compatible_p and _Generic).  And there's no need to
    change the inline function overloads for issignaling, iszero and
    iscanonical in C++ because cases where types have the same format but
    are no longer compatible types are handled automatically by the C++
    overload resolution rules.
    
    This patch also does not change the overload handling for iseqsig, and
    there I think changes *are* needed, beyond those in this patch or made
    by fixincludes.  The way that overload is defined, via a template
    parameter to a structure type, requires overloads whenever the types
    are incompatible, even if they have the same format.  So I think we
    need to add overloads with GCC 13 for every supported _FloatN and
    _FloatNx type, rather than just having one for _Float128 when it has a
    different ABI to long double as at present (but for older GCC, such
    overloads must not be defined for types that end up defined as
    typedefs for another type).
    
    Tested with build-many-glibcs.py: compilers build for
    aarch64-linux-gnu ia64-linux-gnu mips64-linux-gnu powerpc-linux-gnu
    powerpc64le-linux-gnu x86_64-linux-gnu; glibcs build for
    aarch64-linux-gnu ia64-linux-gnu i686-linux-gnu mips-linux-gnu
    mips64-linux-gnu-n32 powerpc-linux-gnu powerpc64le-linux-gnu
    x86_64-linux-gnu.

diff --git a/bits/floatn-common.h b/bits/floatn-common.h
index b43c9532d8b01cca..45d4555f48483fff 100644
--- a/bits/floatn-common.h
+++ b/bits/floatn-common.h
@@ -78,7 +78,7 @@
    or _FloatNx types, if __HAVE_<type> is 1.  The corresponding
    literal suffixes exist since GCC 7, for C only.  */
 # if __HAVE_FLOAT16
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 /* No corresponding suffix available for this type.  */
 #   define __f16(x) ((_Float16) x##f)
 #  else
@@ -87,7 +87,7 @@
 # endif
 
 # if __HAVE_FLOAT32
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 #   define __f32(x) x##f
 #  else
 #   define __f32(x) x##f32
@@ -95,7 +95,7 @@
 # endif
 
 # if __HAVE_FLOAT64
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 #   ifdef __NO_LONG_DOUBLE_MATH
 #    define __f64(x) x##l
 #   else
@@ -107,7 +107,7 @@
 # endif
 
 # if __HAVE_FLOAT32X
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 #   define __f32x(x) x
 #  else
 #   define __f32x(x) x##f32x
@@ -115,7 +115,7 @@
 # endif
 
 # if __HAVE_FLOAT64X
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 #   if __HAVE_FLOAT64X_LONG_DOUBLE
 #    define __f64x(x) x##l
 #   else
@@ -127,7 +127,7 @@
 # endif
 
 # if __HAVE_FLOAT128X
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 #   error "_Float128X supported but no constant suffix"
 #  else
 #   define __f128x(x) x##f128x
@@ -136,7 +136,7 @@
 
 /* Defined to a complex type if __HAVE_<type> is 1.  */
 # if __HAVE_FLOAT16
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 typedef _Complex float __cfloat16 __attribute__ ((__mode__ (__HC__)));
 #   define __CFLOAT16 __cfloat16
 #  else
@@ -145,7 +145,7 @@ typedef _Complex float __cfloat16 __attribute__ ((__mode__ (__HC__)));
 # endif
 
 # if __HAVE_FLOAT32
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 #   define __CFLOAT32 _Complex float
 #  else
 #   define __CFLOAT32 _Complex _Float32
@@ -153,7 +153,7 @@ typedef _Complex float __cfloat16 __attribute__ ((__mode__ (__HC__)));
 # endif
 
 # if __HAVE_FLOAT64
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 #   ifdef __NO_LONG_DOUBLE_MATH
 #    define __CFLOAT64 _Complex long double
 #   else
@@ -165,7 +165,7 @@ typedef _Complex float __cfloat16 __attribute__ ((__mode__ (__HC__)));
 # endif
 
 # if __HAVE_FLOAT32X
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 #   define __CFLOAT32X _Complex double
 #  else
 #   define __CFLOAT32X _Complex _Float32x
@@ -173,7 +173,7 @@ typedef _Complex float __cfloat16 __attribute__ ((__mode__ (__HC__)));
 # endif
 
 # if __HAVE_FLOAT64X
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 #   if __HAVE_FLOAT64X_LONG_DOUBLE
 #    define __CFLOAT64X _Complex long double
 #   else
@@ -185,7 +185,7 @@ typedef _Complex float __cfloat16 __attribute__ ((__mode__ (__HC__)));
 # endif
 
 # if __HAVE_FLOAT128X
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 #   error "_Float128X supported but no complex type"
 #  else
 #   define __CFLOAT128X _Complex _Float128x
@@ -195,7 +195,7 @@ typedef _Complex float __cfloat16 __attribute__ ((__mode__ (__HC__)));
 /* The remaining of this file provides support for older compilers.  */
 # if __HAVE_FLOAT16
 
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 typedef float _Float16 __attribute__ ((__mode__ (__HF__)));
 #  endif
 
@@ -210,7 +210,7 @@ typedef float _Float16 __attribute__ ((__mode__ (__HF__)));
 
 # if __HAVE_FLOAT32
 
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 typedef float _Float32;
 #  endif
 
@@ -234,7 +234,7 @@ typedef float _Float32;
 
 #  ifdef __NO_LONG_DOUBLE_MATH
 
-#   if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#   if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 typedef long double _Float64;
 #   endif
 
@@ -247,7 +247,7 @@ typedef long double _Float64;
 
 #  else
 
-#   if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#   if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 typedef double _Float64;
 #   endif
 
@@ -264,7 +264,7 @@ typedef double _Float64;
 
 # if __HAVE_FLOAT32X
 
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 typedef double _Float32x;
 #  endif
 
@@ -281,7 +281,7 @@ typedef double _Float32x;
 
 #  if __HAVE_FLOAT64X_LONG_DOUBLE
 
-#   if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#   if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 typedef long double _Float64x;
 #   endif
 
@@ -294,7 +294,7 @@ typedef long double _Float64x;
 
 #  else
 
-#   if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#   if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 typedef _Float128 _Float64x;
 #   endif
 
@@ -311,7 +311,7 @@ typedef _Float128 _Float64x;
 
 # if __HAVE_FLOAT128X
 
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 #   error "_Float128x supported but no type"
 #  endif
 
diff --git a/sysdeps/ia64/bits/floatn.h b/sysdeps/ia64/bits/floatn.h
index 60c5a130e12d88a1..3d493909aeebf81e 100644
--- a/sysdeps/ia64/bits/floatn.h
+++ b/sysdeps/ia64/bits/floatn.h
@@ -56,7 +56,7 @@
 /* Defined to concatenate the literal suffix to be used with _Float128
    types, if __HAVE_FLOAT128 is 1. */
 # if __HAVE_FLOAT128
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 /* The literal suffix f128 exists only since GCC 7.0.  */
 #   define __f128(x) x##q
 #  else
@@ -66,7 +66,7 @@
 
 /* Defined to a complex binary128 type if __HAVE_FLOAT128 is 1.  */
 # if __HAVE_FLOAT128
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 /* Add a typedef for older GCC compilers which don't natively support
    _Complex _Float128.  */
 typedef _Complex float __cfloat128 __attribute__ ((__mode__ (__TC__)));
@@ -80,7 +80,7 @@ typedef _Complex float __cfloat128 __attribute__ ((__mode__ (__TC__)));
 # if __HAVE_FLOAT128
 
 /* The type _Float128 exists only since GCC 7.0.  */
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 typedef __float128 _Float128;
 #  endif
 
diff --git a/sysdeps/ieee754/ldbl-128/bits/floatn.h b/sysdeps/ieee754/ldbl-128/bits/floatn.h
index da50ae796f681c60..d75a3d12e890c0be 100644
--- a/sysdeps/ieee754/ldbl-128/bits/floatn.h
+++ b/sysdeps/ieee754/ldbl-128/bits/floatn.h
@@ -55,7 +55,7 @@
 /* Defined to concatenate the literal suffix to be used with _Float128
    types, if __HAVE_FLOAT128 is 1. */
 # if __HAVE_FLOAT128
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 /* The literal suffix f128 exists only since GCC 7.0.  */
 #   define __f128(x) x##l
 #  else
@@ -65,7 +65,7 @@
 
 /* Defined to a complex binary128 type if __HAVE_FLOAT128 is 1.  */
 # if __HAVE_FLOAT128
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 #   define __CFLOAT128 _Complex long double
 #  else
 #   define __CFLOAT128 _Complex _Float128
@@ -76,7 +76,7 @@
 # if __HAVE_FLOAT128
 
 /* The type _Float128 exists only since GCC 7.0.  */
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 typedef long double _Float128;
 #  endif
 
diff --git a/sysdeps/mips/ieee754/bits/floatn.h b/sysdeps/mips/ieee754/bits/floatn.h
index b7720a2889e59e8f..fe7be983592e1e0e 100644
--- a/sysdeps/mips/ieee754/bits/floatn.h
+++ b/sysdeps/mips/ieee754/bits/floatn.h
@@ -55,7 +55,7 @@
 /* Defined to concatenate the literal suffix to be used with _Float128
    types, if __HAVE_FLOAT128 is 1. */
 # if __HAVE_FLOAT128
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 /* The literal suffix f128 exists only since GCC 7.0.  */
 #   define __f128(x) x##l
 #  else
@@ -65,7 +65,7 @@
 
 /* Defined to a complex binary128 type if __HAVE_FLOAT128 is 1.  */
 # if __HAVE_FLOAT128
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 #   define __CFLOAT128 _Complex long double
 #  else
 #   define __CFLOAT128 _Complex _Float128
@@ -76,7 +76,7 @@
 # if __HAVE_FLOAT128
 
 /* The type _Float128 exists only since GCC 7.0.  */
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 typedef long double _Float128;
 #  endif
 
diff --git a/sysdeps/powerpc/bits/floatn.h b/sysdeps/powerpc/bits/floatn.h
index fab164e0a2907668..a5a572f646dac2bf 100644
--- a/sysdeps/powerpc/bits/floatn.h
+++ b/sysdeps/powerpc/bits/floatn.h
@@ -57,7 +57,7 @@
 /* Defined to concatenate the literal suffix to be used with _Float128
    types, if __HAVE_FLOAT128 is 1. */
 # if __HAVE_FLOAT128
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 /* The literal suffix (f128) exist for powerpc only since GCC 7.0.  */
 #   if __LDBL_MANT_DIG__ == 113
 #    define __f128(x) x##l
@@ -71,10 +71,10 @@
 
 /* Defined to a complex binary128 type if __HAVE_FLOAT128 is 1.  */
 # if __HAVE_FLOAT128
-#  if __LDBL_MANT_DIG__ == 113 && defined __cplusplus
+#  if __LDBL_MANT_DIG__ == 113 && defined __cplusplus && !__GNUC_PREREQ (13, 0)
 typedef long double _Float128;
 #   define __CFLOAT128 _Complex long double
-#  elif !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  elif !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 /* The type _Float128 exist for powerpc only since GCC 7.0.  */
 typedef __float128 _Float128;
 /* Add a typedef for older GCC and C++ compilers which don't natively support
diff --git a/sysdeps/x86/bits/floatn.h b/sysdeps/x86/bits/floatn.h
index f0c51716a99c1886..8674273f46b87069 100644
--- a/sysdeps/x86/bits/floatn.h
+++ b/sysdeps/x86/bits/floatn.h
@@ -58,7 +58,7 @@
 /* Defined to concatenate the literal suffix to be used with _Float128
    types, if __HAVE_FLOAT128 is 1. */
 # if __HAVE_FLOAT128
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 /* The literal suffix f128 exists only since GCC 7.0.  */
 #   define __f128(x) x##q
 #  else
@@ -68,7 +68,7 @@
 
 /* Defined to a complex binary128 type if __HAVE_FLOAT128 is 1.  */
 # if __HAVE_FLOAT128
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 /* Add a typedef for older GCC compilers which don't natively support
    _Complex _Float128.  */
 typedef _Complex float __cfloat128 __attribute__ ((__mode__ (__TC__)));
@@ -82,7 +82,7 @@ typedef _Complex float __cfloat128 __attribute__ ((__mode__ (__TC__)));
 # if __HAVE_FLOAT128
 
 /* The type _Float128 exists only since GCC 7.0.  */
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || (defined __cplusplus && !__GNUC_PREREQ (13, 0))
 typedef __float128 _Float128;
 #  endif