ARC: hardware floating point support

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>

sysdeps/arc/fpu/fclrexcpt.c

@@ -0,0 +1,36 @@
+/* Clear given exceptions in current floating-point environment.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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/>.  */
+
+#include <fenv.h>
+#include <fpu_control.h>
+
+int
+feclearexcept (int excepts)
+{
+  unsigned int fpsr;
+
+  _FPU_GETS (fpsr);
+
+  /* Clear the relevant bits, FWE is preserved.  */
+  fpsr &= ~excepts;
+
+  _FPU_SETS (fpsr);
+
+  return 0;
+}
+libm_hidden_def (feclearexcept)

sysdeps/arc/fpu/fegetenv.c

@@ -0,0 +1,37 @@
+/* Store current floating-point environment.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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/>.  */
+
+#include <fenv.h>
+#include <fpu_control.h>
+
+int
+__fegetenv (fenv_t *envp)
+{
+  unsigned int fpcr;
+  unsigned int fpsr;
+
+  _FPU_GETCW (fpcr);
+  _FPU_GETS (fpsr);
+  envp->__fpcr = fpcr;
+  envp->__fpsr = fpsr;
+
+  return 0;
+}
+libm_hidden_def (__fegetenv)
+weak_alias (__fegetenv, fegetenv)
+libm_hidden_weak (fegetenv)

sysdeps/arc/fpu/fegetmode.c

@@ -0,0 +1,31 @@
+/* Store current floating-point control modes.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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/>.  */
+
+#include <fenv.h>
+#include <fpu_control.h>
+
+int
+fegetmode (femode_t *modep)
+{
+  unsigned int fpcr;
+
+  _FPU_GETCW (fpcr);
+  *modep = fpcr;
+
+  return 0;
+}

sysdeps/arc/fpu/fegetround.c

@@ -0,0 +1,32 @@
+/* Return current rounding direction.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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/>.  */
+
+#include <fenv.h>
+#include <fenv_private.h>
+
+int
+__fegetround (void)
+{
+  unsigned int fpcr;
+  _FPU_GETCW (fpcr);
+
+  return (fpcr >> __FPU_RND_SHIFT) & __FPU_RND_MASK;
+}
+libm_hidden_def (__fegetround)
+weak_alias (__fegetround, fegetround)
+libm_hidden_weak (fegetround)

sysdeps/arc/fpu/feholdexcpt.c

@@ -0,0 +1,43 @@
+/* Store current floating-point environment and clear exceptions.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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/>.  */
+
+#include <fenv.h>
+#include <fenv_private.h>
+
+int
+__feholdexcept (fenv_t *envp)
+{
+  unsigned int fpcr;
+  unsigned int fpsr;
+
+  _FPU_GETCW (fpcr);
+  _FPU_GETS (fpsr);
+
+  envp->__fpcr = fpcr;
+  envp->__fpsr = fpsr;
+
+  fpsr &= ~FE_ALL_EXCEPT;
+
+  _FPU_SETCW (fpcr);
+  _FPU_SETS (fpsr);
+
+  return 0;
+}
+libm_hidden_def (__feholdexcept)
+weak_alias (__feholdexcept, feholdexcept)
+libm_hidden_weak (feholdexcept)

sysdeps/arc/fpu/fesetenv.c

@@ -0,0 +1,48 @@
+/* Install given floating-point environment (doesnot raise exceptions).
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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/>.  */
+
+#include <fenv.h>
+#include <fpu_control.h>
+
+int
+__fesetenv (const fenv_t *envp)
+{
+  unsigned int fpcr;
+  unsigned int fpsr;
+
+  if (envp == FE_DFL_ENV)
+    {
+      fpcr = _FPU_DEFAULT;
+      fpsr = _FPU_FPSR_DEFAULT;
+    }
+  else
+    {
+      /* No need to mask out reserved bits as they are IoW.  */
+      fpcr = envp->__fpcr;
+      fpsr = envp->__fpsr;
+    }
+
+  _FPU_SETCW (fpcr);
+  _FPU_SETS (fpsr);
+
+  /* Success.  */
+  return 0;
+}
+libm_hidden_def (__fesetenv)
+weak_alias (__fesetenv, fesetenv)
+libm_hidden_weak (fesetenv)

sysdeps/arc/fpu/fesetexcept.c

@@ -0,0 +1,32 @@
+/* Set given exception flags.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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/>.  */
+
+#include <fenv.h>
+#include <fpu_control.h>
+
+int
+fesetexcept (int excepts)
+{
+  unsigned int fpsr;
+
+  _FPU_GETS (fpsr);
+  fpsr |= excepts;
+  _FPU_SETS (fpsr);
+
+  return 0;
+}

sysdeps/arc/fpu/fesetmode.c

@@ -0,0 +1,40 @@
+/* Install given floating-point control modes.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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/>.  */
+
+#include <fenv.h>
+#include <fpu_control.h>
+
+int
+fesetmode (const femode_t *modep)
+{
+  unsigned int fpcr;
+
+  if (modep == FE_DFL_MODE)
+    {
+      fpcr = _FPU_DEFAULT;
+    }
+  else
+    {
+      /* No need to mask out reserved bits as they are IoW.  */
+      fpcr = *modep;
+    }
+
+  _FPU_SETCW (fpcr);
+
+  return 0;
+}

sysdeps/arc/fpu/fesetround.c

@@ -0,0 +1,40 @@
+/* Set current rounding direction.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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/>.  */
+
+#include <fenv.h>
+#include <fenv_private.h>
+
+int
+__fesetround (int round)
+{
+  unsigned int fpcr;
+
+  _FPU_GETCW (fpcr);
+
+  if (((fpcr >> __FPU_RND_SHIFT) & __FPU_RND_MASK) != round)
+    {
+      fpcr &= ~(__FPU_RND_MASK << __FPU_RND_SHIFT);
+      fpcr |= (round & __FPU_RND_MASK) << __FPU_RND_SHIFT;
+      _FPU_SETCW (fpcr);
+    }
+
+  return 0;
+}
+libm_hidden_def (__fesetround)
+weak_alias (__fesetround, fesetround)
+libm_hidden_weak (fesetround)

sysdeps/arc/fpu/feupdateenv.c

@@ -0,0 +1,51 @@
+/* Install given floating-point environment and raise exceptions,
+   without clearing currently raised exceptions.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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/>.  */
+
+#include <fenv.h>
+#include <fpu_control.h>
+
+int
+__feupdateenv (const fenv_t *envp)
+{
+  unsigned int fpcr;
+  unsigned int fpsr;
+
+  _FPU_GETS (fpsr);
+
+  if (envp == FE_DFL_ENV)
+    {
+      fpcr = _FPU_DEFAULT;
+    }
+  else
+    {
+      fpcr = envp->__fpcr;
+
+      /* currently raised exceptions need to be preserved.  */
+      fpsr |= envp->__fpsr;
+    }
+
+  _FPU_SETCW (fpcr);
+  _FPU_SETS (fpsr);
+
+  /* Success.  */
+  return 0;
+}
+libm_hidden_def (__feupdateenv)
+weak_alias (__feupdateenv, feupdateenv)
+libm_hidden_weak (feupdateenv)

sysdeps/arc/fpu/fgetexcptflg.c

@@ -0,0 +1,31 @@
+/* Store current representation for exceptions, ARC version.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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/>.  */
+
+#include <fenv.h>
+#include <fenv_private.h>
+
+int
+fegetexceptflag (fexcept_t *flagp, int excepts)
+{
+  unsigned int fpsr;
+
+  _FPU_GETS (fpsr);
+  *flagp = fpsr & excepts;
+
+  return 0;
+}

sysdeps/arc/fpu/fraiseexcpt.c

@@ -0,0 +1,39 @@
+/* Raise given exceptions.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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/>.  */
+
+#include <fenv.h>
+#include <fpu_control.h>
+#include <float.h>
+#include <math.h>
+
+int
+__feraiseexcept (int excepts)
+{
+  unsigned int fpsr;
+
+  /* currently raised exceptions are not cleared.  */
+  _FPU_GETS (fpsr);
+  fpsr |= excepts;
+
+  _FPU_SETS (fpsr);
+
+  return 0;
+}
+libm_hidden_def (__feraiseexcept)
+weak_alias (__feraiseexcept, feraiseexcept)
+libm_hidden_weak (feraiseexcept)

sysdeps/arc/fpu/fsetexcptflg.c

@@ -0,0 +1,38 @@
+/* Set floating-point environment exception handling, ARC version.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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/>.  */
+
+#include <fenv.h>
+#include <fpu_control.h>
+
+int
+fesetexceptflag (const fexcept_t *flagp, int excepts)
+{
+  unsigned int fpsr;
+
+  _FPU_GETS (fpsr);
+
+  /* Clear the bits first.  */
+  fpsr &= ~excepts;
+
+  /* Now set those bits, copying them over from @flagp.  */
+  fpsr |= *flagp & excepts;
+
+  _FPU_SETS (fpsr);
+
+  return 0;
+}

sysdeps/arc/fpu/ftestexcept.c

@@ -0,0 +1,33 @@
+/* Test exception in current environment.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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/>.  */
+
+#include <fenv.h>
+#include <fpu_control.h>
+#include <fenv_private.h>
+#include <stdio.h>
+
+int
+fetestexcept (int excepts)
+{
+  unsigned int fpsr;
+
+  _FPU_GETS (fpsr);
+
+  return fpsr & excepts;
+}
+libm_hidden_def (fetestexcept)

sysdeps/arc/fpu/math-use-builtins-fma.h

@@ -0,0 +1,4 @@
+#define USE_FMA_BUILTIN 1
+#define USE_FMAF_BUILTIN 1
+#define USE_FMAL_BUILTIN 0
+#define USE_FMAF128_BUILTIN 0

sysdeps/arc/fpu/math-use-builtins-sqrt.h

@@ -0,0 +1,4 @@
+#define USE_SQRT_BUILTIN 1
+#define USE_SQRTF_BUILTIN 1
+#define USE_SQRTL_BUILTIN 0
+#define USE_SQRTF128_BUILTIN 0

sysdeps/arc/fpu_control.h

@@ -0,0 +1,106 @@
+/* FPU control word bits.  ARC version.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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 _FPU_CONTROL_H
+#define _FPU_CONTROL_H
+
+/* ARC FPU control register bits.
+
+  [  0] -> IVE: Enable invalid operation exception.
+           if 0, soft exception: status register IV flag set.
+           if 1, hardware exception trap (not supported in Linux yet).
+  [  1] -> DZE: Enable division by zero exception.
+           if 0, soft exception: status register IV flag set.
+           if 1, hardware exception: (not supported in Linux yet).
+  [9:8] -> RM: Rounding Mode:
+           00 - Rounding toward zero.
+           01 - Rounding to nearest (default).
+           10 - Rounding (up) toward plus infinity.
+           11 - Rounding (down)toward minus infinity.
+
+   ARC FPU status register bits.
+
+   [ 0] -> IV: flag invalid operation.
+   [ 1] -> DZ: flag division by zero.
+   [ 2] -> OV: flag Overflow operation.
+   [ 3] -> UV: flag Underflow operation.
+   [ 4] -> IX: flag Inexact operation.
+   [31] -> FWE: Flag Write Enable.
+           If 1, above flags writable explicitly (clearing),
+           else IoW and only writable indirectly via bits [12:7].  */
+
+#include <features.h>
+
+#if !defined(__ARC_FPU_SP__) &&  !defined(__ARC_FPU_DP__)
+
+# define _FPU_RESERVED 0xffffffff
+# define _FPU_DEFAULT  0x00000000
+typedef unsigned int fpu_control_t;
+# define _FPU_GETCW(cw) (cw) = 0
+# define _FPU_SETCW(cw) (void) (cw)
+# define _FPU_GETS(cw) (cw) = 0
+# define _FPU_SETS(cw) (void) (cw)
+extern fpu_control_t __fpu_control;
+
+#else
+
+#define _FPU_RESERVED		0
+
+/* The fdlibm code requires strict IEEE double precision arithmetic,
+   and no interrupts for exceptions, rounding to nearest.
+   So only RM set to b'01.  */
+# define _FPU_DEFAULT		0x00000100
+
+/* Actually default needs to have FWE bit as 1 but that is already
+   ingrained into _FPU_SETS macro below.  */
+#define  _FPU_FPSR_DEFAULT	0x00000000
+
+#define __FPU_RND_SHIFT		8
+#define __FPU_RND_MASK		0x3
+
+/* Type of the control word.  */
+typedef unsigned int fpu_control_t;
+
+/* Macros for accessing the hardware control word.  */
+#  define _FPU_GETCW(cw) __asm__ volatile ("lr %0, [0x300]" : "=r" (cw))
+#  define _FPU_SETCW(cw) __asm__ volatile ("sr %0, [0x300]" : : "r" (cw))
+
+/*  Macros for accessing the hardware status word.
+    FWE bit is special as it controls if actual status bits could be wrritten
+    explicitly (other than FPU instructions). We handle it here to keep the
+    callers agnostic of it:
+      - clear it out when reporting status bits
+      - always set it when changing status bits.  */
+#  define _FPU_GETS(cw)				\
+    __asm__ volatile ("lr   %0, [0x301]	\r\n" 	\
+                      "bclr %0, %0, 31	\r\n" 	\
+                      : "=r" (cw))
+
+#  define _FPU_SETS(cw)				\
+    do {					\
+      unsigned int __tmp = 0x80000000 | (cw);	\
+      __asm__ volatile ("sr  %0, [0x301] \r\n" 	\
+                        : : "r" (__tmp));	\
+    } while (0)
+
+/* Default control word set at startup.  */
+extern fpu_control_t __fpu_control;
+
+#endif
+
+#endif /* fpu_control.h */

sysdeps/arc/get-rounding-mode.h

@@ -0,0 +1,38 @@
+/* Determine floating-point rounding mode within libc.  ARC version.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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 _ARC_GET_ROUNDING_MODE_H
+#define _ARC_GET_ROUNDING_MODE_H	1
+
+#include <fenv.h>
+#include <fpu_control.h>
+
+static inline int
+get_rounding_mode (void)
+{
+#if defined(__ARC_FPU_SP__) ||  defined(__ARC_FPU_DP__)
+  unsigned int fpcr;
+  _FPU_GETCW (fpcr);
+
+  return (fpcr >> __FPU_RND_SHIFT) & __FPU_RND_MASK;
+#else
+  return FE_TONEAREST;
+#endif
+}
+
+#endif /* get-rounding-mode.h */

sysdeps/arc/math-tests-trap.h

@@ -0,0 +1,27 @@
+/* Configuration for math tests: support for enabling exception traps.
+   ARC version.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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 ARC_MATH_TESTS_TRAP_H
+#define ARC_MATH_TESTS_TRAP_H 1
+
+/* Trapping exceptions are optional on ARC
+   and not supported in Linux kernel just yet.  */
+#define EXCEPTION_ENABLE_SUPPORTED(EXCEPT)	((EXCEPT) == 0)
+
+#endif /* math-tests-trap.h.  */

sysdeps/arc/tininess.h

@@ -0,0 +1 @@
+#define TININESS_AFTER_ROUNDING	1