1 files changed, 156 insertions, 0 deletions
diff --git a/libm/riscv64/fenv_private.h b/libm/riscv64/fenv_private.h
new file mode 100644
index 000000000..9eed4b614
--- /dev/null
+++ b/libm/riscv64/fenv_private.h
@@ -0,0 +1,156 @@
+/* Private floating point rounding and exceptions handling.  RISC-V version.
+   Copyright (C) 2014-2025 Free Software Foundation, Inc.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef RISCV_FENV_PRIVATE_H
+#define RISCV_FENV_PRIVATE_H 1
+
+#include <fenv.h>
+#include <fpu_control.h>
+#include "get-rounding-mode.h"
+
+static __always_inline int
+riscv_getround (void)
+{
+  return get_rounding_mode ();
+}
+
+static __always_inline void
+riscv_setround (int rm)
+{
+  __asm__ volatile ("fsrm %z0" : : "rJ" (rm));
+}
+
+static __always_inline int
+riscv_getflags (void)
+{
+  int flags;
+  __asm__ volatile ("frflags %0" : "=r" (flags));
+  return flags;
+}
+
+static __always_inline void
+riscv_setflags (int flags)
+{
+  __asm__ volatile ("fsflags %z0" : : "rJ" (flags));
+}
+
+static __always_inline void
+libc_feholdexcept_riscv (fenv_t *envp)
+{
+  __asm__ volatile ("csrrc %0, fcsr, %1" : "=r" (*envp) : "i" (FE_ALL_EXCEPT));
+}
+
+#define libc_feholdexcept  libc_feholdexcept_riscv
+#define libc_feholdexceptf libc_feholdexcept_riscv
+#define libc_feholdexceptl libc_feholdexcept_riscv
+
+static __always_inline void
+libc_fesetround_riscv (int round)
+{
+  riscv_setround (round);
+}
+
+#define libc_fesetround  libc_fesetround_riscv
+#define libc_fesetroundf libc_fesetround_riscv
+#define libc_fesetroundl libc_fesetround_riscv
+
+static __always_inline void
+libc_feholdexcept_setround_riscv (fenv_t *envp, int round)
+{
+  libc_feholdexcept_riscv (envp);
+  libc_fesetround_riscv (round);
+}
+
+#define libc_feholdexcept_setround  libc_feholdexcept_setround_riscv
+#define libc_feholdexcept_setroundf libc_feholdexcept_setround_riscv
+#define libc_feholdexcept_setroundl libc_feholdexcept_setround_riscv
+
+static __always_inline int
+libc_fetestexcept_riscv (int ex)
+{
+  return riscv_getflags () & ex;
+}
+
+#define libc_fetestexcept  libc_fetestexcept_riscv
+#define libc_fetestexceptf libc_fetestexcept_riscv
+#define libc_fetestexceptl libc_fetestexcept_riscv
+
+static __always_inline void
+libc_fesetenv_riscv (const fenv_t *envp)
+{
+  long int env = (envp != FE_DFL_ENV ? *envp : 0);
+  _FPU_SETCW (env);
+}
+
+#define libc_fesetenv  libc_fesetenv_riscv
+#define libc_fesetenvf libc_fesetenv_riscv
+#define libc_fesetenvl libc_fesetenv_riscv
+#define libc_feresetround_noex  libc_fesetenv_riscv
+#define libc_feresetround_noexf libc_fesetenv_riscv
+#define libc_feresetround_noexl libc_fesetenv_riscv
+
+static __always_inline int
+libc_feupdateenv_test_riscv (const fenv_t *envp, int ex)
+{
+  fenv_t env = *envp;
+  int flags = riscv_getflags ();
+  __asm__ volatile ("csrw fcsr, %z0" : : "rJ" (env | flags));
+  return flags & ex;
+}
+
+#define libc_feupdateenv_test  libc_feupdateenv_test_riscv
+#define libc_feupdateenv_testf libc_feupdateenv_test_riscv
+#define libc_feupdateenv_testl libc_feupdateenv_test_riscv
+
+static __always_inline void
+libc_feupdateenv_riscv (const fenv_t *envp)
+{
+  long int env = (envp != FE_DFL_ENV ? *envp : 0);
+  _FPU_SETCW (env | riscv_getflags ());
+}
+
+#define libc_feupdateenv  libc_feupdateenv_riscv
+#define libc_feupdateenvf libc_feupdateenv_riscv
+#define libc_feupdateenvl libc_feupdateenv_riscv
+
+static __always_inline void
+libc_feholdsetround_riscv (fenv_t *envp, int round)
+{
+  /* Note this implementation makes an improperly-formatted fenv_t and
+     so should only be used in conjunction with libc_feresetround.  */
+  int old_round;
+  __asm__ volatile ("csrrw %0, frm, %z1" : "=r" (old_round) : "rJ" (round));
+  *envp = old_round;
+}
+
+#define libc_feholdsetround  libc_feholdsetround_riscv
+#define libc_feholdsetroundf libc_feholdsetround_riscv
+#define libc_feholdsetroundl libc_feholdsetround_riscv
+
+static __always_inline void
+libc_feresetround_riscv (fenv_t *envp)
+{
+  /* Note this implementation takes an improperly-formatted fenv_t and
+     so should only be used in conjunction with libc_feholdsetround.  */
+  riscv_setround (*envp);
+}
+
+#define libc_feresetround  libc_feresetround_riscv
+#define libc_feresetroundf libc_feresetround_riscv
+#define libc_feresetroundl libc_feresetround_riscv
+
+#endif