glibc/sysdeps/riscv/rvf/s_roundevenf.c
H.J. Lu 3213ed770c Update math: redirect roundeven function
Redirect target specific roundeven functions for aarch64, ldbl-128ibm
and riscv.
2021-06-27 07:56:57 -07:00

54 lines
1.5 KiB
C

/* Round to nearest integer value, rounding halfway cases to even.
Copyright (C) 2017-2021 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/>. */
#define NO_MATH_REDIRECT
#include <math.h>
#include <fenv_private.h>
#include <libm-alias-float.h>
#include <stdint.h>
float
__roundevenf (float x)
{
int flags = riscv_getflags ();
bool nan = isnan (x);
float mag = fabsf (x);
if (nan)
return x + x;
if (mag < (1 << __FLT_MANT_DIG__))
{
int32_t i;
float new_x;
asm volatile ("fcvt.w.s %0, %1, rne" : "=r" (i) : "f" (x));
asm volatile ("fcvt.s.w %0, %1, rne" : "=f" (new_x) : "r" (i));
/* roundeven(-0) == -0, and in general we'll always have the same
sign as our input. */
x = copysignf (new_x, x);
riscv_setflags (flags);
}
return x;
}
libm_alias_float (__roundeven, roundeven)