sysdeps/generic/math-type-macros.h

   1 /* Helper macros for type generic function implementations within libm.
   2    Copyright (C) 2016-2017 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _MATH_TYPE_MACROS
  20 #define _MATH_TYPE_MACROS
  21
  22 /* Each type imports a header which is expected to
  23    define:
  24
  25    M_LIT(x)   - Paste the type specific suffix onto the constant x.
  26    M_MLIT(x)  - Paste the type specific suffix used by the macro
  27                 constants in math.h, i.e M_PI or M_PIl.
  28    M_PFX      - The prefixed used by float.h macros like FLT_MANT_DIG.
  29    M_SUF(x)   - Paste the the type specific suffix used by functions
  30                 i.e expf expl exp.
  31    FLOAT      - Resolves to the C typename of M_TYPE.
  32    CFLOAT     - Resolves to the complex typename of M_TYPE.
  33    M_STRTO_NAN - Resolves to the internal libc function which
  34                 converts a string into the appropriate FLOAT nan
  35                 value.
  36
  37   Optionally, these headers may inject a non-standard
  38   definition for the following:
  39
  40   declare_mgen_alias(from,to)
  41       This exposes the appropriate symbol(s) for a
  42       function f of type FLOAT.
  43
  44   declare_mgen_alias_2(from,to,to2)
  45       This exposes the appropriate symbol(s) for a
  46       function f of type FLOAT when it is aliased
  47       to two symbols.
  48
  49   M_LIBM_NEED_COMPAT(func)
  50       This is utilized in macro context to indicate
  51       whether func should declare compat symbols.
  52
  53   declare_mgen_libm_compat(from,to)
  54       This is used in conjunction with the above macro
  55       outside of macro context to paste whatever is
  56       required to generate a compat symbol. */
  57
  58 #ifndef M_PFX
  59 # error "M_PFX must be defined."
  60 #endif
  61 #ifndef M_LIT
  62 # error "M_LIT must be defined."
  63 #endif
  64 #ifndef M_MLIT
  65 # error "M_MLIT must be defined."
  66 #endif
  67 #ifndef M_SUF
  68 # error "M_SUF must be defined."
  69 #endif
  70 #ifndef FLOAT
  71 # error "FLOAT must be defined."
  72 #endif
  73 #ifndef CFLOAT
  74 # error "CFLOAT must be defined."
  75 #endif
  76
  77 #define __M_CONCAT(a,b) a ## b
  78 #define __M_CONCATX(a,b) __M_CONCAT(a,b)
  79
  80 #define M_NAN M_SUF (__builtin_nan) ("")
  81 #define M_MIN_EXP __M_CONCATX (M_PFX, _MIN_EXP)
  82 #define M_MAX_EXP __M_CONCATX (M_PFX, _MAX_EXP)
  83 #define M_MIN __M_CONCATX (M_PFX, _MIN)
  84 #define M_MAX __M_CONCATX (M_PFX, _MAX)
  85 #define M_MANT_DIG __M_CONCATX (M_PFX, _MANT_DIG)
  86 #define M_HUGE_VAL (M_SUF (__builtin_huge_val) ())
  87
  88 /* Helper macros for commonly used functions.  */
  89 #define M_COPYSIGN M_SUF (__copysign)
  90 #define M_FABS M_SUF (fabs)
  91 #define M_SINCOS M_SUF (__sincos)
  92 #define M_SCALBN M_SUF (__scalbn)
  93 #define M_LOG1P M_SUF (__log1p)
  94
  95 #define M_ATAN2 M_SUF (__ieee754_atan2)
  96 #define M_COSH M_SUF (__ieee754_cosh)
  97 #define M_EXP M_SUF (__ieee754_exp)
  98 #define M_HYPOT M_SUF (__ieee754_hypot)
  99 #define M_LOG M_SUF (__ieee754_log)
 100 #define M_SINH M_SUF (__ieee754_sinh)
 101 #define M_SQRT M_SUF (__ieee754_sqrt)
 102
 103 /* Needed to evaluate M_MANT_DIG below.  */
 104 #include <float.h>
 105
 106 /* Use a special epsilon value for IBM long double
 107    to avoid spurious overflows/underflows.  */
 108 #if M_MANT_DIG != 106
 109 # define M_EPSILON __M_CONCATX (M_PFX, _EPSILON)
 110 #else
 111 # define M_EPSILON M_LIT (0x1p-106)
 112 #endif
 113
 114 /* Enable overloading of function name to assist reuse.  */
 115 #ifndef M_DECL_FUNC
 116 # define M_DECL_FUNC(f) M_SUF (f)
 117 #endif
 118
 119 /* If the type does not declare special aliasing, use the default.  */
 120 #ifndef declare_mgen_alias
 121 # define declare_mgen_alias(from, to) weak_alias (M_SUF (from), M_SUF (to))
 122 #endif
 123
 124 /* Likewise, if two aliases are derived from the same symbol.  */
 125 #ifndef declare_mgen_alias_2
 126 # define declare_mgen_alias_2(from, to, to2)  \
 127  declare_mgen_alias (from, to)                \
 128  declare_mgen_alias (from, to2)
 129 #endif
 130
 131 /* Do not generate anything for compat symbols by default.  */
 132 #ifndef M_LIBM_NEED_COMPAT
 133 # define M_LIBM_NEED_COMPAT(func) 0
 134 # define declare_mgen_libm_compat(from, to)
 135 #endif
 136
 137 #endif /* _MATH_TYPE_MACROS */