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1/*2 * Single-precision vector cos function.3 *4 * Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.5 * See https://llvm.org/LICENSE.txt for license information.6 * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception7 */8 9#include "mathlib.h"10#include "v_math.h"11#if V_SUPPORTED12 13static const float Poly[] = {14 /* 1.886 ulp error */15 0x1.5b2e76p-19f,16 -0x1.9f42eap-13f,17 0x1.110df4p-7f,18 -0x1.555548p-3f,19};20#define Pi1 v_f32 (0x1.921fb6p+1f)21#define Pi2 v_f32 (-0x1.777a5cp-24f)22#define Pi3 v_f32 (-0x1.ee59dap-49f)23#define A3 v_f32 (Poly[3])24#define A5 v_f32 (Poly[2])25#define A7 v_f32 (Poly[1])26#define A9 v_f32 (Poly[0])27#define RangeVal v_f32 (0x1p20f)28#define InvPi v_f32 (0x1.45f306p-2f)29#define Shift v_f32 (0x1.8p+23f)30#define AbsMask v_u32 (0x7fffffff)31#define HalfPi v_f32 (0x1.921fb6p0f)32 33VPCS_ATTR34static v_f32_t35specialcase (v_f32_t x, v_f32_t y, v_u32_t cmp)36{37 /* Fall back to scalar code. */38 return v_call_f32 (cosf, x, y, cmp);39}40 41VPCS_ATTR42v_f32_t43V_NAME(cosf) (v_f32_t x)44{45 v_f32_t n, r, r2, y;46 v_u32_t odd, cmp;47 48 r = v_as_f32_u32 (v_as_u32_f32 (x) & AbsMask);49 cmp = v_cond_u32 (v_as_u32_f32 (r) >= v_as_u32_f32 (RangeVal));50 51 /* n = rint((|x|+pi/2)/pi) - 0.5 */52 n = v_fma_f32 (InvPi, r + HalfPi, Shift);53 odd = v_as_u32_f32 (n) << 31;54 n -= Shift;55 n -= v_f32 (0.5f);56 57 /* r = |x| - n*pi (range reduction into -pi/2 .. pi/2) */58 r = v_fma_f32 (-Pi1, n, r);59 r = v_fma_f32 (-Pi2, n, r);60 r = v_fma_f32 (-Pi3, n, r);61 62 /* y = sin(r) */63 r2 = r * r;64 y = v_fma_f32 (A9, r2, A7);65 y = v_fma_f32 (y, r2, A5);66 y = v_fma_f32 (y, r2, A3);67 y = v_fma_f32 (y * r2, r, r);68 69 /* sign fix */70 y = v_as_f32_u32 (v_as_u32_f32 (y) ^ odd);71 72 if (unlikely (v_any_u32 (cmp)))73 return specialcase (x, y, cmp);74 return y;75}76VPCS_ALIAS77#endif78