Tim Hall | 79d07d2 | 2020-04-27 18:20:16 +0100 | [diff] [blame^] | 1 | # Copyright (C) 2020 Arm Limited or its affiliates. All rights reserved. |
| 2 | # |
| 3 | # SPDX-License-Identifier: Apache-2.0 |
| 4 | # |
| 5 | # Licensed under the Apache License, Version 2.0 (the License); you may |
| 6 | # not use this file except in compliance with the License. |
| 7 | # You may obtain a copy of the License at |
| 8 | # |
| 9 | # www.apache.org/licenses/LICENSE-2.0 |
| 10 | # |
| 11 | # Unless required by applicable law or agreed to in writing, software |
| 12 | # distributed under the License is distributed on an AS IS BASIS, WITHOUT |
| 13 | # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 14 | # See the License for the specific language governing permissions and |
| 15 | # limitations under the License. |
| 16 | |
| 17 | |
| 18 | # Description: |
| 19 | # Numerical utilities for various types of rounding etc. |
| 20 | |
| 21 | import math |
| 22 | import numpy as np |
| 23 | |
| 24 | |
| 25 | def round_up(a, b): |
| 26 | return ((a + b - 1) // b) * b |
| 27 | |
| 28 | |
| 29 | def round_up_divide(a, b): |
| 30 | return (a + b - 1) // b |
| 31 | |
| 32 | |
| 33 | def round_up_to_int(v): |
| 34 | return int(math.ceil(v)) |
| 35 | |
| 36 | |
| 37 | def round_down_to_power_of_two(v): |
| 38 | assert v > 0 |
| 39 | while v & (v - 1): |
| 40 | v &= v - 1 |
| 41 | |
| 42 | return v |
| 43 | |
| 44 | |
| 45 | def round_up_to_power_of_two(v): |
| 46 | return round_down_to_power_of_two(2 * v - 1) |
| 47 | |
| 48 | |
| 49 | def round_down_log2(v): |
| 50 | return int(math.floor(np.log2(v))) |
| 51 | |
| 52 | |
| 53 | def round_up_log2(v): |
| 54 | return int(math.ceil(np.log2(v))) |
| 55 | |
| 56 | |
| 57 | def round_to_int(v): |
| 58 | return np.rint(v).astype(np.int64) |
| 59 | |
| 60 | |
| 61 | # Performs rounding away from zero. |
| 62 | # n.b. This is identical to C++11 std::round() |
| 63 | def round_away_zero(f): |
| 64 | r = -0.5 if (f < 0) else 0.5 |
| 65 | return np.trunc(f + r) |
| 66 | |
| 67 | |
| 68 | def quantise_float32(f, scale=1.0, zero_point=0): |
| 69 | return zero_point + int(round_away_zero(np.float32(f) / np.float32(scale))) |
| 70 | |
| 71 | |
| 72 | def clamp_tanh(x): |
| 73 | if x <= -4: |
| 74 | y = -1.0 |
| 75 | elif x >= 4: |
| 76 | y = 1.0 |
| 77 | else: |
| 78 | y = math.tanh(x) |
| 79 | return y |
| 80 | |
| 81 | |
| 82 | def clamp_sigmoid(x): |
| 83 | if x <= -8: |
| 84 | y = 0.0 |
| 85 | elif x >= 8: |
| 86 | y = 1.0 |
| 87 | else: |
| 88 | y = 1 / (1 + math.exp(-x)) |
| 89 | return y |