1 @/****************************************************************************** 2 @ * 3 @ * Copyright (C) 2015 The Android Open Source Project 4 @ * 5 @ * Licensed under the Apache License, Version 2.0 (the "License"); 6 @ * you may not use this file except in compliance with the License. 7 @ * You may obtain a copy of the License at: 8 @ * 9 @ * http://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, 13 @ * WITHOUT 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 @ * Originally developed and contributed by Ittiam Systems Pvt. Ltd, Bangalore 19 @*/ 20 21 22 @****************************************************************************** 23 @* 24 @* 25 @* @brief 26 @* This file contains definitions of routines for variance caclulation 27 @* 28 @* @author 29 @* Ittiam 30 @* 31 @* @par List of Functions: 32 @* - icv_variance_8x4_a9() 33 @* 34 @* @remarks 35 @* None 36 @* 37 @******************************************************************************* 38 39 40 @****************************************************************************** 41 @* 42 @* @brief computes variance of a 8x4 block 43 @* 44 @* 45 @* @par Description 46 @* This functions computes variance of a 8x4 block 47 @* 48 @* @param[in] pu1_src 49 @* UWORD8 pointer to the source 50 @* 51 @* @param[in] src_strd 52 @* integer source stride 53 @* 54 @* @param[in] wd 55 @* Width (assumed to be 8) 56 @* 57 @* @param[in] ht 58 @* Height (assumed to be 4) 59 @* 60 @* @returns 61 @* variance value in r0 62 @* 63 @* @remarks 64 @* 65 @****************************************************************************** 66 67 .global icv_variance_8x4_a9 68 69 icv_variance_8x4_a9: 70 71 push {lr} 72 73 @ Load 8x4 source 74 vld1.8 d0, [r0], r1 75 vld1.8 d1, [r0], r1 76 vld1.8 d2, [r0], r1 77 vld1.8 d3, [r0], r1 78 79 @ Calculate Sum(values) 80 vaddl.u8 q2, d0, d1 81 vaddl.u8 q3, d2, d3 82 vadd.u16 q2, q2, q3 83 84 vadd.u16 d4, d4, d5 85 vpadd.u16 d4, d4, d4 86 vpadd.u16 d4, d4, d4 87 88 @ Calculate SumOfSquares 89 vmull.u8 q10, d0, d0 90 vmull.u8 q11, d1, d1 91 vmull.u8 q12, d2, d2 92 vmull.u8 q13, d3, d3 93 94 vaddl.u16 q10, d20, d21 95 vaddl.u16 q11, d22, d23 96 vaddl.u16 q12, d24, d25 97 vaddl.u16 q13, d26, d27 98 99 vadd.u32 q10, q10, q11 100 vadd.u32 q11, q12, q13 101 vadd.u32 q10, q10, q11 102 vadd.u32 d20, d20, d21 103 vpadd.u32 d20, d20, d20 104 105 @ Sum(values) 106 vmov.u16 r0, d4[0] 107 108 @ SumOfSquares 109 vmov.u32 r1, d20[0] 110 111 @ SquareOfSums 112 mul r3, r0, r0 113 114 @ SumOfSquares * 8 * 4 - SquareOfSums 115 rsb r0, r3, r1, LSL #5 116 117 @ Divide by 32 * 32 118 119 mov r0, r0, ASR #10 120 pop {pc} 121
