Files
llvm-project/libc/AOR_v20.02/math/v_sinf.c
Kristof Beyls 0928368f62 [libc] Provide Arm Optimized Routines for the LLVM libc project.
This adds the Arm Optimized Routines (see
https://github.com/ARM-software/optimized-routines) source code under the
the LLVM license. The version of the code provided in this patch is v20.02
of the Arm Optimized Routines project.

This entire contribution is being committed as is even though it does
not currently fit the LLVM libc model and does not follow the LLVM
coding style. In the near future, implementations from this patch will be
moved over to their right place in the LLVM-libc tree. This will be done
over many small patches, all of which will go through the normal LLVM code
review process. See this libc-dev post for the plan:
http://lists.llvm.org/pipermail/libc-dev/2020-March/000044.html

Differential revision of the original upload: https://reviews.llvm.org/D75355
2020-03-16 12:19:31 -07:00

77 lines
1.7 KiB
C

/*
* Single-precision vector sin function.
*
* Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
* See https://llvm.org/LICENSE.txt for license information.
* SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
*/
#include "mathlib.h"
#include "v_math.h"
#if V_SUPPORTED
static const float Poly[] = {
/* 1.886 ulp error */
0x1.5b2e76p-19f,
-0x1.9f42eap-13f,
0x1.110df4p-7f,
-0x1.555548p-3f,
};
#define Pi1 v_f32 (0x1.921fb6p+1f)
#define Pi2 v_f32 (-0x1.777a5cp-24f)
#define Pi3 v_f32 (-0x1.ee59dap-49f)
#define A3 v_f32 (Poly[3])
#define A5 v_f32 (Poly[2])
#define A7 v_f32 (Poly[1])
#define A9 v_f32 (Poly[0])
#define RangeVal v_f32 (0x1p20f)
#define InvPi v_f32 (0x1.45f306p-2f)
#define Shift v_f32 (0x1.8p+23f)
#define AbsMask v_u32 (0x7fffffff)
VPCS_ATTR
static v_f32_t
specialcase (v_f32_t x, v_f32_t y, v_u32_t cmp)
{
/* Fall back to scalar code. */
return v_call_f32 (sinf, x, y, cmp);
}
VPCS_ATTR
v_f32_t
V_NAME(sinf) (v_f32_t x)
{
v_f32_t n, r, r2, y;
v_u32_t sign, odd, cmp;
r = v_as_f32_u32 (v_as_u32_f32 (x) & AbsMask);
sign = v_as_u32_f32 (x) & ~AbsMask;
cmp = v_cond_u32 (v_as_u32_f32 (r) >= v_as_u32_f32 (RangeVal));
/* n = rint(|x|/pi) */
n = v_fma_f32 (InvPi, r, Shift);
odd = v_as_u32_f32 (n) << 31;
n -= Shift;
/* r = |x| - n*pi (range reduction into -pi/2 .. pi/2) */
r = v_fma_f32 (-Pi1, n, r);
r = v_fma_f32 (-Pi2, n, r);
r = v_fma_f32 (-Pi3, n, r);
/* y = sin(r) */
r2 = r * r;
y = v_fma_f32 (A9, r2, A7);
y = v_fma_f32 (y, r2, A5);
y = v_fma_f32 (y, r2, A3);
y = v_fma_f32 (y * r2, r, r);
/* sign fix */
y = v_as_f32_u32 (v_as_u32_f32 (y) ^ sign ^ odd);
if (unlikely (v_any_u32 (cmp)))
return specialcase (x, y, cmp);
return y;
}
VPCS_ALIAS
#endif