[PATCH v7.1 06/13] ARC: hardware floating point support

Adhemerval Zanella adhemerval.zanella@linaro.org
Thu Jul 2 18:55:44 GMT 2020



On 30/06/2020 21:08, Vineet Gupta via Libc-alpha wrote:
> ---
>    Changes since v7:
>      - Disintegrated math-use-builtins.h (deleted) and added
>        math-use-builtins-{fma,sqrt}.h

LGTM with some clarification below.

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

> ---
>  sysdeps/arc/fpu/fclrexcpt.c              |  36 ++++++++
>  sysdeps/arc/fpu/fegetenv.c               |  37 ++++++++
>  sysdeps/arc/fpu/fegetmode.c              |  31 +++++++
>  sysdeps/arc/fpu/fegetround.c             |  32 +++++++
>  sysdeps/arc/fpu/feholdexcpt.c            |  43 +++++++++
>  sysdeps/arc/fpu/fesetenv.c               |  48 ++++++++++
>  sysdeps/arc/fpu/fesetexcept.c            |  32 +++++++
>  sysdeps/arc/fpu/fesetmode.c              |  40 +++++++++
>  sysdeps/arc/fpu/fesetround.c             |  40 +++++++++
>  sysdeps/arc/fpu/feupdateenv.c            |  51 +++++++++++
>  sysdeps/arc/fpu/fgetexcptflg.c           |  31 +++++++
>  sysdeps/arc/fpu/fraiseexcpt.c            |  39 +++++++++
>  sysdeps/arc/fpu/fsetexcptflg.c           |  38 ++++++++
>  sysdeps/arc/fpu/ftestexcept.c            |  33 +++++++
>  sysdeps/arc/fpu/math-use-builtins-fma.h  |   4 +
>  sysdeps/arc/fpu/math-use-builtins-sqrt.h |   4 +
>  sysdeps/arc/fpu_control.h                | 106 +++++++++++++++++++++++
>  sysdeps/arc/get-rounding-mode.h          |  38 ++++++++
>  sysdeps/arc/math-tests-trap.h            |  27 ++++++
>  sysdeps/arc/tininess.h                   |   1 +
>  20 files changed, 711 insertions(+)
>  create mode 100644 sysdeps/arc/fpu/fclrexcpt.c
>  create mode 100644 sysdeps/arc/fpu/fegetenv.c
>  create mode 100644 sysdeps/arc/fpu/fegetmode.c
>  create mode 100644 sysdeps/arc/fpu/fegetround.c
>  create mode 100644 sysdeps/arc/fpu/feholdexcpt.c
>  create mode 100644 sysdeps/arc/fpu/fesetenv.c
>  create mode 100644 sysdeps/arc/fpu/fesetexcept.c
>  create mode 100644 sysdeps/arc/fpu/fesetmode.c
>  create mode 100644 sysdeps/arc/fpu/fesetround.c
>  create mode 100644 sysdeps/arc/fpu/feupdateenv.c
>  create mode 100644 sysdeps/arc/fpu/fgetexcptflg.c
>  create mode 100644 sysdeps/arc/fpu/fraiseexcpt.c
>  create mode 100644 sysdeps/arc/fpu/fsetexcptflg.c
>  create mode 100644 sysdeps/arc/fpu/ftestexcept.c
>  create mode 100644 sysdeps/arc/fpu/math-use-builtins-fma.h
>  create mode 100644 sysdeps/arc/fpu/math-use-builtins-sqrt.h
>  create mode 100644 sysdeps/arc/fpu_control.h
>  create mode 100644 sysdeps/arc/get-rounding-mode.h
>  create mode 100644 sysdeps/arc/math-tests-trap.h
>  create mode 100644 sysdeps/arc/tininess.h
> 
> diff --git a/sysdeps/arc/fpu/fclrexcpt.c b/sysdeps/arc/fpu/fclrexcpt.c
> new file mode 100644
> index 000000000000..7653d99a008c
> --- /dev/null
> +++ b/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)

Ok.

> diff --git a/sysdeps/arc/fpu/fegetenv.c b/sysdeps/arc/fpu/fegetenv.c
> new file mode 100644
> index 000000000000..bbb3b477b423
> --- /dev/null
> +++ b/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)


Ok.

> diff --git a/sysdeps/arc/fpu/fegetmode.c b/sysdeps/arc/fpu/fegetmode.c
> new file mode 100644
> index 000000000000..f02c9119f222
> --- /dev/null
> +++ b/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;
> +}

OK.

> diff --git a/sysdeps/arc/fpu/fegetround.c b/sysdeps/arc/fpu/fegetround.c
> new file mode 100644
> index 000000000000..c5496bcbf7b4
> --- /dev/null
> +++ b/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)

Ok.

> diff --git a/sysdeps/arc/fpu/feholdexcpt.c b/sysdeps/arc/fpu/feholdexcpt.c
> new file mode 100644
> index 000000000000..59527ee25a66
> --- /dev/null
> +++ b/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)

Ok.

> diff --git a/sysdeps/arc/fpu/fesetenv.c b/sysdeps/arc/fpu/fesetenv.c
> new file mode 100644
> index 000000000000..4ef858fc10a9
> --- /dev/null
> +++ b/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)

Ok.

> diff --git a/sysdeps/arc/fpu/fesetexcept.c b/sysdeps/arc/fpu/fesetexcept.c
> new file mode 100644
> index 000000000000..77517d0b25ab
> --- /dev/null
> +++ b/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;
> +}

Ok.

> diff --git a/sysdeps/arc/fpu/fesetmode.c b/sysdeps/arc/fpu/fesetmode.c
> new file mode 100644
> index 000000000000..c4ea02d8d15b
> --- /dev/null
> +++ b/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;
> +}

Ok.

> diff --git a/sysdeps/arc/fpu/fesetround.c b/sysdeps/arc/fpu/fesetround.c
> new file mode 100644
> index 000000000000..701c0b2dcb42
> --- /dev/null
> +++ b/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)

Ok.

> diff --git a/sysdeps/arc/fpu/feupdateenv.c b/sysdeps/arc/fpu/feupdateenv.c
> new file mode 100644
> index 000000000000..c63aefb25463
> --- /dev/null
> +++ b/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)

Ok.

> diff --git a/sysdeps/arc/fpu/fgetexcptflg.c b/sysdeps/arc/fpu/fgetexcptflg.c
> new file mode 100644
> index 000000000000..a816121fd9b7
> --- /dev/null
> +++ b/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;
> +}

Ok.

> diff --git a/sysdeps/arc/fpu/fraiseexcpt.c b/sysdeps/arc/fpu/fraiseexcpt.c
> new file mode 100644
> index 000000000000..067c0607784f
> --- /dev/null
> +++ b/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.  */

Capitalize 'currently'.

> +  _FPU_GETS (fpsr);
> +  fpsr |= excepts;
> +
> +  _FPU_SETS (fpsr);
> +
> +  return 0;
> +}
> +libm_hidden_def (__feraiseexcept)
> +weak_alias (__feraiseexcept, feraiseexcept)
> +libm_hidden_weak (feraiseexcept)

Ok.

> diff --git a/sysdeps/arc/fpu/fsetexcptflg.c b/sysdeps/arc/fpu/fsetexcptflg.c
> new file mode 100644
> index 000000000000..f9e08d504418
> --- /dev/null
> +++ b/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;
> +}

Ok.

> diff --git a/sysdeps/arc/fpu/ftestexcept.c b/sysdeps/arc/fpu/ftestexcept.c
> new file mode 100644
> index 000000000000..bb8ed27ab22b
> --- /dev/null
> +++ b/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)

Ok.

> diff --git a/sysdeps/arc/fpu/math-use-builtins-fma.h b/sysdeps/arc/fpu/math-use-builtins-fma.h
> new file mode 100644
> index 000000000000..eede75aa41be
> --- /dev/null
> +++ b/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

Ok.

> diff --git a/sysdeps/arc/fpu/math-use-builtins-sqrt.h b/sysdeps/arc/fpu/math-use-builtins-sqrt.h
> new file mode 100644
> index 000000000000..e94c915ba66a
> --- /dev/null
> +++ b/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

Ok.

> diff --git a/sysdeps/arc/fpu_control.h b/sysdeps/arc/fpu_control.h
> new file mode 100644
> index 000000000000..64457972d637
> --- /dev/null
> +++ b/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].  */

Good description.

> +
> +#include <features.h>
> +
> +#if !defined(__ARC_FPU_SP__) &&  !defined(__ARC_FPU_DP__)

My guess is __ARC_FPU_SP__ indicates single floating point and
__ARC_FPU_DP__ a double precision support.  Is there a possibility
to compiler define just one of them? If so how should we handle it
on glibc?

> +
> +# 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 */

Ok.

> diff --git a/sysdeps/arc/get-rounding-mode.h b/sysdeps/arc/get-rounding-mode.h
> new file mode 100644
> index 000000000000..15173e37aa4f
> --- /dev/null
> +++ b/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 */

Ok.

> diff --git a/sysdeps/arc/math-tests-trap.h b/sysdeps/arc/math-tests-trap.h
> new file mode 100644
> index 000000000000..08b16f57976a
> --- /dev/null
> +++ b/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.  */

Ok.

> diff --git a/sysdeps/arc/tininess.h b/sysdeps/arc/tininess.h
> new file mode 100644
> index 000000000000..1db37790f881
> --- /dev/null
> +++ b/sysdeps/arc/tininess.h
> @@ -0,0 +1 @@
> +#define TININESS_AFTER_ROUNDING	1
> 

Ok.


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