glibc/sysdeps/aarch64/fpu/hypot_sve.c
Joe Ramsay 157f89fa3d aarch64/fpu: Add vector variants of hypot
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
2024-05-16 14:34:43 +01:00

55 lines
1.9 KiB
C

/* Double-precision vector (SVE) hypot function
Copyright (C) 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 "sv_math.h"
static const struct data
{
uint64_t tiny_bound, thres;
} data = {
.tiny_bound = 0x0c80000000000000, /* asuint (0x1p-102). */
.thres = 0x7300000000000000, /* asuint (inf) - tiny_bound. */
};
static svfloat64_t NOINLINE
special_case (svfloat64_t sqsum, svfloat64_t x, svfloat64_t y, svbool_t pg,
svbool_t special)
{
return sv_call2_f64 (hypot, x, y, svsqrt_x (pg, sqsum), special);
}
/* SVE implementation of double-precision hypot.
Maximum error observed is 1.21 ULP:
_ZGVsMxvv_hypot (-0x1.6a22d0412cdd3p+352, 0x1.d3d89bd66fb1ap+330)
got 0x1.6a22d0412cfp+352
want 0x1.6a22d0412cf01p+352. */
svfloat64_t SV_NAME_D2 (hypot) (svfloat64_t x, svfloat64_t y, svbool_t pg)
{
const struct data *d = ptr_barrier (&data);
svfloat64_t sqsum = svmla_x (pg, svmul_x (pg, x, x), y, y);
svbool_t special = svcmpge (
pg, svsub_x (pg, svreinterpret_u64 (sqsum), d->tiny_bound), d->thres);
if (__glibc_unlikely (svptest_any (pg, special)))
return special_case (sqsum, x, y, pg, special);
return svsqrt_x (pg, sqsum);
}