glibc/sysdeps/powerpc/fpu/fegetmode.c
Paul A. Clarke 3db85a9814 powerpc: Use faster means to access FPSCR when possible in some cases
Using 'mffs' instruction to read the Floating Point Status Control Register
(FPSCR) can force a processor flush in some cases, with undesirable
performance impact.  If the values of the bits in the FPSCR which force the
flush are not needed, an instruction that is new to POWER9 (ISA version 3.0),
'mffsl' can be used instead.

Cases included:  get_rounding_mode, fegetround, fegetmode, fegetexcept.

	* sysdeps/powerpc/bits/fenvinline.h (__fegetround): Use
	__fegetround_ISA300() or __fegetround_ISA2() as appropriate.
	(__fegetround_ISA300) New.
	(__fegetround_ISA2) New.
	* sysdeps/powerpc/fpu_control.h (IS_ISA300): New.
	(_FPU_MFFS): Move implementation...
	(_FPU_GETCW): Here.
	(_FPU_MFFSL): Move implementation....
	(_FPU_GET_RC_ISA300): Here. New.
	(_FPU_GET_RC): Use _FPU_GET_RC_ISA300() or _FPU_GETCW() as appropriate.
	* sysdeps/powerpc/fpu/fenv_libc.h (fegetenv_status_ISA300): New.
	(fegetenv_status): New.
	* sysdeps/powerpc/fpu/fegetmode.c (fegetmode): Use fegetenv_status()
	instead of fegetenv_register().
	* sysdeps/powerpc/fpu/fegetexcept.c (__fegetexcept): Likewise.

Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
2019-06-30 08:40:44 -03:00

27 lines
957 B
C

/* Store current floating-point control modes. PowerPC version.
Copyright (C) 2016-2019 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
<http://www.gnu.org/licenses/>. */
#include <fenv_libc.h>
int
fegetmode (femode_t *modep)
{
*modep = fegetenv_status ();
return 0;
}