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Diffstat (limited to 'libclc/generic/lib/math/exp_helper.cl')
-rw-r--r-- | libclc/generic/lib/math/exp_helper.cl | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/libclc/generic/lib/math/exp_helper.cl b/libclc/generic/lib/math/exp_helper.cl new file mode 100644 index 0000000..046f306 --- /dev/null +++ b/libclc/generic/lib/math/exp_helper.cl @@ -0,0 +1,69 @@ +/* + * Copyright (c) 2014, 2015 Advanced Micro Devices, Inc. + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +#include <clc/clc.h> + +#include "math.h" +#include "tables.h" + +#ifdef cl_khr_fp64 + +#pragma OPENCL EXTENSION cl_khr_fp64 : enable + +_CLC_DEF double __clc_exp_helper(double x, double x_min, double x_max, double r, int n) { + + int j = n & 0x3f; + int m = n >> 6; + + // 6 term tail of Taylor expansion of e^r + double z2 = r * fma(r, + fma(r, + fma(r, + fma(r, + fma(r, 0x1.6c16c16c16c17p-10, 0x1.1111111111111p-7), + 0x1.5555555555555p-5), + 0x1.5555555555555p-3), + 0x1.0000000000000p-1), + 1.0); + + double2 tv = USE_TABLE(two_to_jby64_ep_tbl, j); + z2 = fma(tv.s0 + tv.s1, z2, tv.s1) + tv.s0; + + int small_value = (m < -1022) || ((m == -1022) && (z2 < 1.0)); + + int n1 = m >> 2; + int n2 = m-n1; + double z3= z2 * as_double(((long)n1 + 1023) << 52); + z3 *= as_double(((long)n2 + 1023) << 52); + + z2 = ldexp(z2, m); + z2 = small_value ? z3: z2; + + z2 = isnan(x) ? x : z2; + + z2 = x > x_max ? as_double(PINFBITPATT_DP64) : z2; + z2 = x < x_min ? 0.0 : z2; + + return z2; +} + +#endif // cl_khr_fp64 |