1 files changed, 27 insertions, 64 deletions

diff --git a/gl/float.in.h b/gl/float.in.h
index d75a06e7..9f735cb9 100644
--- a/gl/float.in.h
+++ b/gl/float.in.h
@@ -1,6 +1,6 @@
 /* A correct <float.h>.
 
-   Copyright (C) 2007-2025 Free Software Foundation, Inc.
+   Copyright (C) 2007-2026 Free Software Foundation, Inc.
 
    This file is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as
@@ -113,69 +113,31 @@ extern const union gl_long_double_union gl_LDBL_MAX;
 # define LDBL_MAX_10_EXP 4932
 #endif
 
-/* On PowerPC with gcc 15 when using __ibm128 long double, the value of
-   LDBL_MIN_EXP, LDBL_MIN, LDBL_MAX, and LDBL_NORM_MAX are wrong.  */
+/* On AIX 7.1 with gcc 4.2, the values of LDBL_MIN_EXP, LDBL_MIN, LDBL_MAX are
+   wrong.
+   On Linux/PowerPC with gcc 8.3, the values of LDBL_MAX and LDBL_EPSILON are
+   wrong.
+   Assume these bugs are fixed in any GCC new enough
+   to define __LDBL_NORM_MAX__.  */
 #if (defined _ARCH_PPC && LDBL_MANT_DIG == 106 \
-     && defined __GNUC__)
+     && defined __GNUC__ && !defined __LDBL_NORM_MAX__)
 # undef LDBL_MIN_EXP
-# define LDBL_MIN_EXP DBL_MIN_EXP
+# define LDBL_MIN_EXP (-968)
 # undef LDBL_MIN_10_EXP
-# define LDBL_MIN_10_EXP DBL_MIN_10_EXP
+# define LDBL_MIN_10_EXP (-291)
 # undef LDBL_MIN
-# define LDBL_MIN 2.22507385850720138309023271733240406422e-308L /* DBL_MIN = 2^-1022 */
+# define LDBL_MIN 0x1p-969L
+
+/* IBM long double is tricky: it is represented as the sum of two doubles,
+   and the high double must equal the sum of the two parts rounded to nearest.
+   The maximum finite value for which this is true is
+   { 0x1.fffffffffffffp+1023, 0x1.ffffffffffffep+969 },
+   which represents 0x1.fffffffffffff7ffffffffffff8p+1023L.
+   Although computations can yield representations of numbers larger than this,
+   these computations are considered to have overflowed and behavior is undefined.
+   See <https://gcc.gnu.org/PR120993>.  */
 # undef LDBL_MAX
-/* LDBL_MAX is 2**1024 - 2**918, represented as: { 0x7FEFFFFF, 0xFFFFFFFF,
-                                                   0x7C9FFFFF, 0xFFFFFFFF }.
-
-   Do not write it as a constant expression, as GCC would likely treat
-   that as infinity due to the vagaries of this platform's funky arithmetic.
-   Instead, define it through a reference to an external variable.
-   Like the following, but using a union to avoid type mismatches:
-
-     const double LDBL_MAX[2] = { DBL_MAX, DBL_MAX / 0x1p53 };
-     extern const long double LDBL_MAX;
-
-   The following alternative would not work as well when GCC is optimizing:
-
-     #define LDBL_MAX (*(long double const *) (double[])
-                       { DBL_MAX, DBL_MAX / 0x1p53 })
-
-   The following alternative would require GCC 6 or later:
-
-     #define LDBL_MAX __builtin_pack_longdouble (DBL_MAX, DBL_MAX / 0x1p53)
-
-   Unfortunately none of the alternatives are constant expressions.  */
-# if !GNULIB_defined_long_double_union
-union gl_long_double_union
-  {
-    struct { double hi; double lo; } dd;
-    long double ld;
-  };
-#  define GNULIB_defined_long_double_union 1
-# endif
-extern const union gl_long_double_union gl_LDBL_MAX;
-# define LDBL_MAX (gl_LDBL_MAX.ld)
-# undef LDBL_NORM_MAX
-# define LDBL_NORM_MAX LDBL_MAX
-#endif
-
-/* On IRIX 6.5, with cc, the value of LDBL_MANT_DIG is wrong.
-   On IRIX 6.5, with gcc 4.2, the values of LDBL_MIN_EXP, LDBL_MIN, LDBL_EPSILON
-   are wrong.  */
-#if defined __sgi && (LDBL_MANT_DIG >= 106)
-# undef LDBL_MANT_DIG
-# define LDBL_MANT_DIG 106
-# if defined __GNUC__
-#  undef LDBL_MIN_EXP
-#  define LDBL_MIN_EXP DBL_MIN_EXP
-#  undef LDBL_MIN_10_EXP
-#  define LDBL_MIN_10_EXP DBL_MIN_10_EXP
-#  undef LDBL_MIN
-#  define LDBL_MIN 2.22507385850720138309023271733240406422e-308L /* DBL_MIN = 2^-1022 */
-#  undef LDBL_EPSILON
-#  define LDBL_EPSILON 2.46519032881566189191165176650870696773e-32L /* 2^-105 */
-# endif
-#endif
+# define LDBL_MAX 0x1.fffffffffffff7ffffffffffff8p+1023L
 
 /* On PowerPC platforms, 'long double' has a double-double representation.
    Up to ISO C 17, this was outside the scope of ISO C because it can represent
@@ -187,9 +149,8 @@ extern const union gl_long_double_union gl_LDBL_MAX;
    numbers with mantissas of the form 1.<52 bits><many zeroes><52 bits> are
    called "unnormalized".  And since LDBL_EPSILON must be normalized (per
    ISO C 23 § 5.2.5.3.3.(33)), it must be 2^-105.  */
-#if defined __powerpc__ && LDBL_MANT_DIG == 106
 # undef LDBL_EPSILON
-# define LDBL_EPSILON 2.46519032881566189191165176650870696773e-32L /* 2^-105 */
+# define LDBL_EPSILON 0x1p-105L
 #endif
 
 /* ============================ ISO C11 support ============================ */
@@ -273,7 +234,7 @@ extern const union gl_long_double_union gl_LDBL_TRUE_MIN;
 # define FLT_NORM_MAX FLT_MAX
 #endif
 #ifndef FLT_SNAN
-/* For sh, beware of <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111814>.  */
+/* For sh, beware of <https://gcc.gnu.org/PR111814>.  */
 # if ((__GNUC__ + (__GNUC_MINOR__ >= 3) > 3) || defined __clang__) && !defined __sh__
 #  define FLT_SNAN __builtin_nansf ("")
 # else
@@ -297,7 +258,7 @@ extern gl_FLT_SNAN_t gl_FLT_SNAN;
 # define DBL_NORM_MAX DBL_MAX
 #endif
 #ifndef DBL_SNAN
-/* For sh, beware of <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111814>.  */
+/* For sh, beware of <https://gcc.gnu.org/PR111814>.  */
 # if ((__GNUC__ + (__GNUC_MINOR__ >= 3) > 3) || defined __clang__) && !defined __sh__
 #  define DBL_SNAN __builtin_nans ("")
 # else
@@ -322,12 +283,14 @@ extern gl_DBL_SNAN_t gl_DBL_SNAN;
 #ifndef LDBL_NORM_MAX
 # ifdef __LDBL_NORM_MAX__
 #  define LDBL_NORM_MAX __LDBL_NORM_MAX__
+# elif FLT_RADIX == 2 && LDBL_MAX_EXP == 1024 && LDBL_MANT_DIG == 106
+#  define LDBL_NORM_MAX 0x1.ffffffffffffffffffffffffff8p+1022L
 # else
 #  define LDBL_NORM_MAX LDBL_MAX
 # endif
 #endif
 #ifndef LDBL_SNAN
-/* For sh, beware of <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111814>.  */
+/* For sh, beware of <https://gcc.gnu.org/PR111814>.  */
 # if ((__GNUC__ + (__GNUC_MINOR__ >= 3) > 3) || defined __clang__) && !defined __sh__
 #  define LDBL_SNAN __builtin_nansl ("")
 # else