glibc/sysdeps/arm/fesetmode.c

46 lines
1.4 KiB
C

/* Install given floating-point control modes. ARM version.
Copyright (C) 2016-2024 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 <arm-features.h>
/* NZCV flags, QC bit, IDC bit and bits for IEEE exception status. */
#define FPU_STATUS_BITS 0xf800009f
int
fesetmode (const femode_t *modep)
{
fpu_control_t fpscr, new_fpscr;
if (!ARM_HAVE_VFP)
/* Nothing to do. */
return 0;
_FPU_GETCW (fpscr);
if (modep == FE_DFL_MODE)
new_fpscr = (fpscr & (_FPU_RESERVED | FPU_STATUS_BITS)) | _FPU_DEFAULT;
else
new_fpscr = (fpscr & FPU_STATUS_BITS) | (*modep & ~FPU_STATUS_BITS);
if (((new_fpscr ^ fpscr) & ~_FPU_MASK_NZCV) != 0)
_FPU_SETCW (new_fpscr);
return 0;
}