sysdeps/riscv/rvf/fenv_private.h

   1 /* Private floating point rounding and exceptions handling.  RISC-V version.
   2    Copyright (C) 2014-2024 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    <https://www.gnu.org/licenses/>.  */
  18
  19 #ifndef RISCV_FENV_PRIVATE_H
  20 #define RISCV_FENV_PRIVATE_H 1
  21
  22 #include <fenv.h>
  23 #include <fpu_control.h>
  24 #include <get-rounding-mode.h>
  25
  26 static __always_inline int
  27 riscv_getround (void)
  28 {
  29   return get_rounding_mode ();
  30 }
  31
  32 static __always_inline void
  33 riscv_setround (int rm)
  34 {
  35   asm volatile ("fsrm %z0" : : "rJ" (rm));
  36 }
  37
  38 static __always_inline int
  39 riscv_getflags (void)
  40 {
  41   int flags;
  42   asm volatile ("frflags %0" : "=r" (flags));
  43   return flags;
  44 }
  45
  46 static __always_inline void
  47 riscv_setflags (int flags)
  48 {
  49   asm volatile ("fsflags %z0" : : "rJ" (flags));
  50 }
  51
  52 static __always_inline void
  53 libc_feholdexcept_riscv (fenv_t *envp)
  54 {
  55   asm volatile ("csrrc %0, fcsr, %1" : "=r" (*envp) : "i" (FE_ALL_EXCEPT));
  56 }
  57
  58 #define libc_feholdexcept  libc_feholdexcept_riscv
  59 #define libc_feholdexceptf libc_feholdexcept_riscv
  60 #define libc_feholdexceptl libc_feholdexcept_riscv
  61
  62 static __always_inline void
  63 libc_fesetround_riscv (int round)
  64 {
  65   riscv_setround (round);
  66 }
  67
  68 #define libc_fesetround  libc_fesetround_riscv
  69 #define libc_fesetroundf libc_fesetround_riscv
  70 #define libc_fesetroundl libc_fesetround_riscv
  71
  72 static __always_inline void
  73 libc_feholdexcept_setround_riscv (fenv_t *envp, int round)
  74 {
  75   libc_feholdexcept_riscv (envp);
  76   libc_fesetround_riscv (round);
  77 }
  78
  79 #define libc_feholdexcept_setround  libc_feholdexcept_setround_riscv
  80 #define libc_feholdexcept_setroundf libc_feholdexcept_setround_riscv
  81 #define libc_feholdexcept_setroundl libc_feholdexcept_setround_riscv
  82
  83 static __always_inline int
  84 libc_fetestexcept_riscv (int ex)
  85 {
  86   return riscv_getflags () & ex;
  87 }
  88
  89 #define libc_fetestexcept  libc_fetestexcept_riscv
  90 #define libc_fetestexceptf libc_fetestexcept_riscv
  91 #define libc_fetestexceptl libc_fetestexcept_riscv
  92
  93 static __always_inline void
  94 libc_fesetenv_riscv (const fenv_t *envp)
  95 {
  96   long int env = (envp != FE_DFL_ENV ? *envp : 0);
  97   _FPU_SETCW (env);
  98 }
  99
 100 #define libc_fesetenv  libc_fesetenv_riscv
 101 #define libc_fesetenvf libc_fesetenv_riscv
 102 #define libc_fesetenvl libc_fesetenv_riscv
 103 #define libc_feresetround_noex  libc_fesetenv_riscv
 104 #define libc_feresetround_noexf libc_fesetenv_riscv
 105 #define libc_feresetround_noexl libc_fesetenv_riscv
 106
 107 static __always_inline int
 108 libc_feupdateenv_test_riscv (const fenv_t *envp, int ex)
 109 {
 110   fenv_t env = *envp;
 111   int flags = riscv_getflags ();
 112   asm volatile ("csrw fcsr, %z0" : : "rJ" (env | flags));
 113   return flags & ex;
 114 }
 115
 116 #define libc_feupdateenv_test  libc_feupdateenv_test_riscv
 117 #define libc_feupdateenv_testf libc_feupdateenv_test_riscv
 118 #define libc_feupdateenv_testl libc_feupdateenv_test_riscv
 119
 120 static __always_inline void
 121 libc_feupdateenv_riscv (const fenv_t *envp)
 122 {
 123   long int env = (envp != FE_DFL_ENV ? *envp : 0);
 124   _FPU_SETCW (env | riscv_getflags ());
 125 }
 126
 127 #define libc_feupdateenv  libc_feupdateenv_riscv
 128 #define libc_feupdateenvf libc_feupdateenv_riscv
 129 #define libc_feupdateenvl libc_feupdateenv_riscv
 130
 131 static __always_inline void
 132 libc_feholdsetround_riscv (fenv_t *envp, int round)
 133 {
 134   /* Note this implementation makes an improperly-formatted fenv_t and
 135      so should only be used in conjunction with libc_feresetround.  */
 136   int old_round;
 137   asm volatile ("csrrw %0, frm, %z1" : "=r" (old_round) : "rJ" (round));
 138   *envp = old_round;
 139 }
 140
 141 #define libc_feholdsetround  libc_feholdsetround_riscv
 142 #define libc_feholdsetroundf libc_feholdsetround_riscv
 143 #define libc_feholdsetroundl libc_feholdsetround_riscv
 144
 145 static __always_inline void
 146 libc_feresetround_riscv (fenv_t *envp)
 147 {
 148   /* Note this implementation takes an improperly-formatted fenv_t and
 149      so should only be used in conjunction with libc_feholdsetround.  */
 150   riscv_setround (*envp);
 151 }
 152
 153 #define libc_feresetround  libc_feresetround_riscv
 154 #define libc_feresetroundf libc_feresetround_riscv
 155 #define libc_feresetroundl libc_feresetround_riscv
 156
 157 #include_next <fenv_private.h>
 158
 159 #endif