1/* 2 * Copyright (c) 2014, 2015 Advanced Micro Devices, Inc. 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a copy 5 * of this software and associated documentation files (the "Software"), to deal 6 * in the Software without restriction, including without limitation the rights 7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 8 * copies of the Software, and to permit persons to whom the Software is 9 * furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice shall be included in 12 * all copies or substantial portions of the Software. 13 * 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 20 * THE SOFTWARE. 21 */ 22 23#include <clc/clc.h> 24 25#include "math.h" 26#include "tables.h" 27 28#ifdef cl_khr_fp64 29 30#pragma OPENCL EXTENSION cl_khr_fp64 : enable 31 32_CLC_DEF double __clc_exp_helper(double x, double x_min, double x_max, double r, int n) { 33 34 int j = n & 0x3f; 35 int m = n >> 6; 36 37 // 6 term tail of Taylor expansion of e^r 38 double z2 = r * fma(r, 39 fma(r, 40 fma(r, 41 fma(r, 42 fma(r, 0x1.6c16c16c16c17p-10, 0x1.1111111111111p-7), 43 0x1.5555555555555p-5), 44 0x1.5555555555555p-3), 45 0x1.0000000000000p-1), 46 1.0); 47 48 double2 tv = USE_TABLE(two_to_jby64_ep_tbl, j); 49 z2 = fma(tv.s0 + tv.s1, z2, tv.s1) + tv.s0; 50 51 int small_value = (m < -1022) || ((m == -1022) && (z2 < 1.0)); 52 53 int n1 = m >> 2; 54 int n2 = m-n1; 55 double z3= z2 * as_double(((long)n1 + 1023) << 52); 56 z3 *= as_double(((long)n2 + 1023) << 52); 57 58 z2 = ldexp(z2, m); 59 z2 = small_value ? z3: z2; 60 61 z2 = isnan(x) ? x : z2; 62 63 z2 = x > x_max ? as_double(PINFBITPATT_DP64) : z2; 64 z2 = x < x_min ? 0.0 : z2; 65 66 return z2; 67} 68 69#endif // cl_khr_fp64 70