sysdeps/s390/fpu/fenv_private.h

   1 /* Private floating point rounding and exceptions handling.  390/s390x version.
   2    Copyright (C) 2019-2023 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 S390_FENV_PRIVATE_H
  20 #define S390_FENV_PRIVATE_H 1
  21
  22 #include <fenv.h>
  23 #include <fenv_libc.h>
  24 #include <fpu_control.h>
  25
  26 static __always_inline void
  27 libc_feholdexcept_s390 (fenv_t *envp)
  28 {
  29   fpu_control_t fpc, fpc_new;
  30
  31   /* Store the environment.  */
  32   _FPU_GETCW (fpc);
  33   envp->__fpc = fpc;
  34
  35   /* Clear the current exception flags and dxc field.
  36      Hold from generating fpu exceptions temporarily.  */
  37   fpc_new = fpc & ~(FPC_FLAGS_MASK | FPC_DXC_MASK | FPC_EXCEPTION_MASK);
  38
  39   /* Only set new environment if it has changed.  */
  40   if (fpc_new != fpc)
  41     _FPU_SETCW (fpc_new);
  42 }
  43
  44 #define libc_feholdexcept  libc_feholdexcept_s390
  45 #define libc_feholdexceptf libc_feholdexcept_s390
  46 #define libc_feholdexceptl libc_feholdexcept_s390
  47
  48 static __always_inline void
  49 libc_fesetround_s390 (int round)
  50 {
  51   __asm__ __volatile__ ("srnm 0(%0)" : : "a" (round));
  52 }
  53
  54 #define libc_fesetround  libc_fesetround_s390
  55 #define libc_fesetroundf libc_fesetround_s390
  56 #define libc_fesetroundl libc_fesetround_s390
  57
  58 static __always_inline void
  59 libc_feholdexcept_setround_s390 (fenv_t *envp, int r)
  60 {
  61   fpu_control_t fpc, fpc_new;
  62
  63   _FPU_GETCW (fpc);
  64   envp->__fpc = fpc;
  65
  66   /* Clear the current exception flags and dxc field.
  67      Hold from generating fpu exceptions temporarily.
  68      Reset rounding mode bits.  */
  69   fpc_new = fpc & ~(FPC_FLAGS_MASK | FPC_DXC_MASK | FPC_EXCEPTION_MASK
  70                     | FPC_RM_MASK);
  71
  72   /* Set new rounding mode.  */
  73   fpc_new |= (r & FPC_RM_MASK);
  74
  75   /* Only set new environment if it has changed.  */
  76   if (fpc_new != fpc)
  77     _FPU_SETCW (fpc_new);
  78 }
  79
  80 #define libc_feholdexcept_setround  libc_feholdexcept_setround_s390
  81 #define libc_feholdexcept_setroundf libc_feholdexcept_setround_s390
  82 #define libc_feholdexcept_setroundl libc_feholdexcept_setround_s390
  83
  84 static __always_inline int
  85 libc_fetestexcept_s390 (int excepts)
  86 {
  87   int res;
  88   fexcept_t fpc;
  89
  90   _FPU_GETCW (fpc);
  91
  92   /* Get current exceptions.  */
  93   res = (fpc >> FPC_FLAGS_SHIFT) & FE_ALL_EXCEPT;
  94   if ((fpc & FPC_NOT_FPU_EXCEPTION) == 0)
  95     /* Bits 6, 7 of dxc-byte are zero,
  96        thus bits 0-5 of dxc-byte correspond to the flag-bits.
  97        Evaluate flags and last dxc-exception-code.  */
  98     res |= (fpc >> FPC_DXC_SHIFT) & FE_ALL_EXCEPT;
  99
 100   return res & excepts;
 101 }
 102
 103 #define libc_fetestexcept  libc_fetestexcept_s390
 104 #define libc_fetestexceptf libc_fetestexcept_s390
 105 #define libc_fetestexceptl libc_fetestexcept_s390
 106
 107 static __always_inline void
 108 libc_fesetenv_s390 (const fenv_t *envp)
 109 {
 110   _FPU_SETCW (envp->__fpc);
 111 }
 112
 113 #define libc_fesetenv  libc_fesetenv_s390
 114 #define libc_fesetenvf libc_fesetenv_s390
 115 #define libc_fesetenvl libc_fesetenv_s390
 116
 117 static __always_inline int
 118 libc_feupdateenv_test_s390 (const fenv_t *envp, int ex)
 119 {
 120   /* Get the currently raised exceptions.  */
 121   int excepts;
 122   fexcept_t fpc_old;
 123
 124   _FPU_GETCW (fpc_old);
 125
 126   /* Get current exceptions.  */
 127   excepts = (fpc_old >> FPC_FLAGS_SHIFT) & FE_ALL_EXCEPT;
 128   if ((fpc_old & FPC_NOT_FPU_EXCEPTION) == 0)
 129     /* Bits 6, 7 of dxc-byte are zero,
 130        thus bits 0-5 of dxc-byte correspond to the flag-bits.
 131        Evaluate flags and last dxc-exception-code.  */
 132     excepts |= (fpc_old >> FPC_DXC_SHIFT) & FE_ALL_EXCEPT;
 133
 134   /* Merge the currently raised exceptions with those in envp.  */
 135   fpu_control_t fpc_new = envp->__fpc;
 136   fpc_new |= excepts << FPC_FLAGS_SHIFT;
 137
 138   /* Install the new fpc from envp.  */
 139   if (fpc_new != fpc_old)
 140     _FPU_SETCW (fpc_new);
 141
 142   /* Raise the exceptions if enabled in new fpc.  */
 143   if (__glibc_unlikely ((fpc_new >> FPC_EXCEPTION_MASK_SHIFT) & excepts))
 144     __feraiseexcept (excepts);
 145
 146   return excepts & ex;
 147 }
 148
 149 #define libc_feupdateenv_test  libc_feupdateenv_test_s390
 150 #define libc_feupdateenv_testf libc_feupdateenv_test_s390
 151 #define libc_feupdateenv_testl libc_feupdateenv_test_s390
 152
 153 static __always_inline void
 154 libc_feupdateenv_s390 (const fenv_t *envp)
 155 {
 156   libc_feupdateenv_test_s390 (envp, 0);
 157 }
 158
 159 #define libc_feupdateenv  libc_feupdateenv_s390
 160 #define libc_feupdateenvf libc_feupdateenv_s390
 161 #define libc_feupdateenvl libc_feupdateenv_s390
 162
 163 static __always_inline fenv_t
 164 libc_handle_user_fenv_s390 (const fenv_t *envp)
 165 {
 166   fenv_t env;
 167   if (envp == FE_DFL_ENV)
 168     {
 169       env.__fpc = _FPU_DEFAULT;
 170     }
 171   else if (envp == FE_NOMASK_ENV)
 172     {
 173       env.__fpc = FPC_EXCEPTION_MASK;
 174     }
 175   else
 176     env = (*envp);
 177
 178   return env;
 179 }
 180
 181 /* We have support for rounding mode context.  */
 182 #define HAVE_RM_CTX 1
 183
 184 static __always_inline void
 185 libc_feholdsetround_s390_ctx (struct rm_ctx *ctx, int r)
 186 {
 187   fpu_control_t fpc;
 188   int round;
 189
 190   _FPU_GETCW (fpc);
 191   ctx->env.__fpc = fpc;
 192
 193   /* Check whether rounding modes are different.  */
 194   round = fpc & FPC_RM_MASK;
 195
 196   /* Set the rounding mode if changed.  */
 197   if (__glibc_unlikely (round != r))
 198     {
 199       ctx->updated_status = true;
 200       libc_fesetround_s390 (r);
 201     }
 202   else
 203     ctx->updated_status = false;
 204 }
 205
 206 #define libc_feholdsetround_ctx         libc_feholdsetround_s390_ctx
 207 #define libc_feholdsetroundf_ctx        libc_feholdsetround_s390_ctx
 208 #define libc_feholdsetroundl_ctx        libc_feholdsetround_s390_ctx
 209
 210 static __always_inline void
 211 libc_feresetround_s390_ctx (struct rm_ctx *ctx)
 212 {
 213   /* Restore the rounding mode if updated.  */
 214   if (__glibc_unlikely (ctx->updated_status))
 215     {
 216       fpu_control_t fpc;
 217       _FPU_GETCW (fpc);
 218       fpc = ctx->env.__fpc | (fpc & FPC_FLAGS_MASK);
 219       _FPU_SETCW (fpc);
 220     }
 221 }
 222
 223 #define libc_feresetround_ctx           libc_feresetround_s390_ctx
 224 #define libc_feresetroundf_ctx          libc_feresetround_s390_ctx
 225 #define libc_feresetroundl_ctx          libc_feresetround_s390_ctx
 226
 227 static __always_inline void
 228 libc_feholdsetround_noex_s390_ctx (struct rm_ctx *ctx, int r)
 229 {
 230   libc_feholdexcept_setround_s390 (&ctx->env, r);
 231 }
 232
 233 #define libc_feholdsetround_noex_ctx    libc_feholdsetround_noex_s390_ctx
 234 #define libc_feholdsetround_noexf_ctx   libc_feholdsetround_noex_s390_ctx
 235 #define libc_feholdsetround_noexl_ctx   libc_feholdsetround_noex_s390_ctx
 236
 237 static __always_inline void
 238 libc_feresetround_noex_s390_ctx (struct rm_ctx *ctx)
 239 {
 240   /* Restore exception flags and rounding mode.  */
 241   libc_fesetenv_s390 (&ctx->env);
 242 }
 243
 244 #define libc_feresetround_noex_ctx      libc_feresetround_noex_s390_ctx
 245 #define libc_feresetround_noexf_ctx     libc_feresetround_noex_s390_ctx
 246 #define libc_feresetround_noexl_ctx     libc_feresetround_noex_s390_ctx
 247
 248 #include_next <fenv_private.h>
 249
 250 #endif