Sync with Gnulib stable-202507 code (a8ac9f9ce5)

1 files changed, 194 insertions, 27 deletions

diff --git a/gl/float.in.h b/gl/float.in.h
index 73e8d406..d75a06e7 100644
--- a/gl/float.in.h
+++ b/gl/float.in.h
@@ -1,6 +1,6 @@
 /* A correct <float.h>.
 
-   Copyright (C) 2007-2024 Free Software Foundation, Inc.
+   Copyright (C) 2007-2025 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
@@ -28,6 +28,8 @@
 #ifndef _@GUARD_PREFIX@_FLOAT_H
 #define _@GUARD_PREFIX@_FLOAT_H
 
+/* ============================ ISO C99 support ============================ */
+
 /* 'long double' properties.  */
 
 #if defined __i386__ && (defined __BEOS__ || defined __OpenBSD__)
@@ -111,44 +113,38 @@ extern const union gl_long_double_union gl_LDBL_MAX;
 # define LDBL_MAX_10_EXP 4932
 #endif
 
-/* 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 4.4, the value of LDBL_MAX is wrong.  */
-#if (defined _ARCH_PPC || defined _POWER) && defined _AIX && (LDBL_MANT_DIG == 106) && defined __GNUC__
+/* 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.  */
+#if (defined _ARCH_PPC && LDBL_MANT_DIG == 106 \
+     && 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 */
-#endif
-#if (defined _ARCH_PPC || defined _POWER) && (defined _AIX || defined __linux__) && (LDBL_MANT_DIG == 106) && defined __GNUC__
 # undef LDBL_MAX
-/* LDBL_MAX is represented as { 0x7FEFFFFF, 0xFFFFFFFF, 0x7C8FFFFF, 0xFFFFFFFF }.
-   It is not easy to define:
-     #define LDBL_MAX 1.79769313486231580793728971405302307166e308L
-   is too small, whereas
-     #define LDBL_MAX 1.79769313486231580793728971405302307167e308L
-   is too large.  Apparently a bug in GCC decimal-to-binary conversion.
-   Also, I can't get values larger than
-     #define LDBL63 ((long double) (1ULL << 63))
-     #define LDBL882 (LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63)
-     #define LDBL945 (LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63)
-     #define LDBL1008 (LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63)
-     #define LDBL_MAX (LDBL1008 * 65535.0L + LDBL945 * (long double) 9223372036821221375ULL + LDBL882 * (long double) 4611686018427387904ULL)
-   which is represented as { 0x7FEFFFFF, 0xFFFFFFFF, 0x7C8FFFFF, 0xF8000000 }.
-   So, define it like this through a reference to an external variable
+/* 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 / (double)134217728UL / (double)134217728UL };
+     const double LDBL_MAX[2] = { DBL_MAX, DBL_MAX / 0x1p53 };
      extern const long double LDBL_MAX;
 
-   or through a pointer cast
+   The following alternative would not work as well when GCC is optimizing:
 
-     #define LDBL_MAX \
-       (*(const long double *) (double[]) { DBL_MAX, DBL_MAX / (double)134217728UL / (double)134217728UL })
+     #define LDBL_MAX (*(long double const *) (double[])
+                       { DBL_MAX, DBL_MAX / 0x1p53 })
 
-   Unfortunately, this is not a constant expression, and the latter expression
-   does not work well when GCC is optimizing..  */
+   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
   {
@@ -159,6 +155,8 @@ union gl_long_double_union
 # 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.
@@ -179,6 +177,175 @@ extern const union gl_long_double_union gl_LDBL_MAX;
 # endif
 #endif
 
+/* 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
+   numbers with mantissas of the form 1.<52 bits><many zeroes><52 bits>, such as
+   1.0L + 4.94065645841246544176568792868221e-324L = 1 + 2^-1074; see
+   ISO C 17 § 5.2.4.2.2.(3).
+   In ISO C 23, wording has been included that makes this 'long double'
+   representation compliant; see ISO C 23 § 5.2.5.3.3.(8)-(9).  In this setting,
+   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 */
+#endif
+
+/* ============================ ISO C11 support ============================ */
+
+/* 'float' properties */
+
+#ifndef FLT_HAS_SUBNORM
+# define FLT_HAS_SUBNORM 1
+#endif
+#ifndef FLT_DECIMAL_DIG
+/* FLT_MANT_DIG = 24 => FLT_DECIMAL_DIG = 9 */
+# define FLT_DECIMAL_DIG ((int)(FLT_MANT_DIG * 0.3010299956639812 + 2))
+#endif
+#if defined _AIX && !defined __GNUC__
+/* On AIX, the value of FLT_TRUE_MIN in /usr/include/float.h is a 'double',
+   not a 'float'.  */
+# undef FLT_TRUE_MIN
+#endif
+#ifndef FLT_TRUE_MIN
+/* FLT_MIN / 2^(FLT_MANT_DIG-1) */
+# define FLT_TRUE_MIN (FLT_MIN / 8388608.0f)
+#endif
+
+/* 'double' properties */
+
+#ifndef DBL_HAS_SUBNORM
+# define DBL_HAS_SUBNORM 1
+#endif
+#ifndef DBL_DECIMAL_DIG
+/* DBL_MANT_DIG = 53 => DBL_DECIMAL_DIG = 17 */
+# define DBL_DECIMAL_DIG ((int)(DBL_MANT_DIG * 0.3010299956639812 + 2))
+#endif
+#ifndef DBL_TRUE_MIN
+/* DBL_MIN / 2^(DBL_MANT_DIG-1) */
+# define DBL_TRUE_MIN (DBL_MIN / 4503599627370496.0)
+#endif
+
+/* 'long double' properties */
+
+#ifndef LDBL_HAS_SUBNORM
+# define LDBL_HAS_SUBNORM 1
+#endif
+#ifndef LDBL_DECIMAL_DIG
+/* LDBL_MANT_DIG = 53 => LDBL_DECIMAL_DIG = 17 */
+/* LDBL_MANT_DIG = 64 => LDBL_DECIMAL_DIG = 21 */
+/* LDBL_MANT_DIG = 106 => LDBL_DECIMAL_DIG = 33 */
+/* LDBL_MANT_DIG = 113 => LDBL_DECIMAL_DIG = 36 */
+# define LDBL_DECIMAL_DIG ((int)(LDBL_MANT_DIG * 0.3010299956639812 + 2))
+#endif
+#ifndef LDBL_TRUE_MIN
+/* LDBL_MIN / 2^(LDBL_MANT_DIG-1) */
+# if LDBL_MANT_DIG == 53
+#  define LDBL_TRUE_MIN (LDBL_MIN / 4503599627370496.0L)
+# elif LDBL_MANT_DIG == 64
+#  if defined __i386__ && (defined __FreeBSD__ || defined __DragonFly__)
+/* Work around FreeBSD/x86 problem mentioned above.  */
+extern const union gl_long_double_union gl_LDBL_TRUE_MIN;
+#   define LDBL_TRUE_MIN (gl_LDBL_TRUE_MIN.ld)
+#  else
+#   define LDBL_TRUE_MIN (LDBL_MIN / 9223372036854775808.0L)
+#  endif
+# elif LDBL_MANT_DIG == 106
+#  define LDBL_TRUE_MIN (LDBL_MIN / 40564819207303340847894502572032.0L)
+# elif LDBL_MANT_DIG == 113
+#  define LDBL_TRUE_MIN (LDBL_MIN / 5192296858534827628530496329220096.0L)
+# endif
+#endif
+
+/* ============================ ISO C23 support ============================ */
+
+/* 'float' properties */
+
+#ifndef FLT_IS_IEC_60559
+# if defined __m68k__
+#  define FLT_IS_IEC_60559 0
+# else
+#  define FLT_IS_IEC_60559 1
+# endif
+#endif
+#ifndef FLT_NORM_MAX
+# define FLT_NORM_MAX FLT_MAX
+#endif
+#ifndef FLT_SNAN
+/* For sh, beware of <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111814>.  */
+# if ((__GNUC__ + (__GNUC_MINOR__ >= 3) > 3) || defined __clang__) && !defined __sh__
+#  define FLT_SNAN __builtin_nansf ("")
+# else
+typedef union { unsigned int word[1]; float value; } gl_FLT_SNAN_t;
+extern gl_FLT_SNAN_t gl_FLT_SNAN;
+#  define FLT_SNAN (gl_FLT_SNAN.value)
+#  define GNULIB_defined_FLT_SNAN 1
+# endif
+#endif
+
+/* 'double' properties */
+
+#ifndef DBL_IS_IEC_60559
+# if defined __m68k__
+#  define DBL_IS_IEC_60559 0
+# else
+#  define DBL_IS_IEC_60559 1
+# endif
+#endif
+#ifndef DBL_NORM_MAX
+# define DBL_NORM_MAX DBL_MAX
+#endif
+#ifndef DBL_SNAN
+/* For sh, beware of <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111814>.  */
+# if ((__GNUC__ + (__GNUC_MINOR__ >= 3) > 3) || defined __clang__) && !defined __sh__
+#  define DBL_SNAN __builtin_nans ("")
+# else
+typedef union { unsigned long long word[1]; double value; } gl_DBL_SNAN_t;
+extern gl_DBL_SNAN_t gl_DBL_SNAN;
+#  define DBL_SNAN (gl_DBL_SNAN.value)
+#  define GNULIB_defined_DBL_SNAN 1
+# endif
+#endif
+
+/* 'long double' properties */
+
+#ifndef LDBL_IS_IEC_60559
+# if defined __m68k__
+#  define LDBL_IS_IEC_60559 0
+# elif LDBL_MANT_DIG == 53 || LDBL_MANT_DIG == 113
+#  define LDBL_IS_IEC_60559 1
+# else
+#  define LDBL_IS_IEC_60559 0
+# endif
+#endif
+#ifndef LDBL_NORM_MAX
+# ifdef __LDBL_NORM_MAX__
+#  define LDBL_NORM_MAX __LDBL_NORM_MAX__
+# 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>.  */
+# if ((__GNUC__ + (__GNUC_MINOR__ >= 3) > 3) || defined __clang__) && !defined __sh__
+#  define LDBL_SNAN __builtin_nansl ("")
+# else
+#  if LDBL_MANT_DIG == 53
+typedef union { unsigned long long word[1]; long double value; } gl_LDBL_SNAN_t;
+#  elif defined __m68k__
+typedef union { unsigned int word[3]; long double value; } gl_LDBL_SNAN_t;
+#  else
+typedef union { unsigned long long word[2]; long double value; } gl_LDBL_SNAN_t;
+#  endif
+extern gl_LDBL_SNAN_t gl_LDBL_SNAN;
+#  define LDBL_SNAN (gl_LDBL_SNAN.value)
+#  define GNULIB_defined_LDBL_SNAN 1
+# endif
+#endif
+
+/* ================================= Other ================================= */
+
 #if @REPLACE_ITOLD@
 /* Pull in a function that fixes the 'int' to 'long double' conversion
    of glibc 2.7.  */