| George Lander | da55ef9 | 2015-11-19 12:05:06 +0000 | [diff] [blame] | 1 | /* |
| Szabolcs Nagy | 1b94597 | 2018-05-14 14:46:40 +0100 | [diff] [blame] | 2 | * poly.c |
| George Lander | da55ef9 | 2015-11-19 12:05:06 +0000 | [diff] [blame] | 3 | * |
| Szabolcs Nagy | 11253b0 | 2018-11-12 11:10:57 +0000 | [diff] [blame] | 4 | * Copyright (c) 1998-2018, Arm Limited. |
| 5 | * SPDX-License-Identifier: MIT |
| George Lander | da55ef9 | 2015-11-19 12:05:06 +0000 | [diff] [blame] | 6 | */ |
| 7 | |
| Szabolcs Nagy | 0d51c04 | 2018-04-25 13:26:22 +0100 | [diff] [blame] | 8 | double __kernel_poly(const double *coeffs, int n, double x) |
| George Lander | da55ef9 | 2015-11-19 12:05:06 +0000 | [diff] [blame] | 9 | { |
| 10 | double result = coeffs[--n]; |
| 11 | |
| 12 | while ((n & ~0x6) != 0) /* Loop until n even and < 8 */ |
| 13 | result = (result * x) + coeffs[--n]; |
| 14 | |
| 15 | switch (n) |
| 16 | { |
| 17 | case 6: result = (result * x) + coeffs[5]; |
| 18 | result = (result * x) + coeffs[4]; |
| 19 | case 4: result = (result * x) + coeffs[3]; |
| 20 | result = (result * x) + coeffs[2]; |
| 21 | case 2: result = (result * x) + coeffs[1]; |
| 22 | result = (result * x) + coeffs[0]; |
| 23 | } |
| 24 | return result; |
| 25 | } |