1 /* ------------------------------------------------------------------ 2 * Copyright (C) 1998-2009 PacketVideo 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either 13 * express or implied. 14 * See the License for the specific language governing permissions 15 * and limitations under the License. 16 * ------------------------------------------------------------------- 17 */ 18 /**************************************************************************************** 19 Portions of this file are derived from the following 3GPP standard: 20 21 3GPP TS 26.073 22 ANSI-C code for the Adaptive Multi-Rate (AMR) speech codec 23 Available from http://www.3gpp.org 24 25 (C) 2004, 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TTA, TTC) 26 Permission to distribute, modify and use this file under the standard license 27 terms listed above has been obtained from the copyright holder. 28 ****************************************************************************************/ 29 /* 30 31 Pathname: ./gsm-amr/c/src/negate.c 32 33 ------------------------------------------------------------------------------ 34 REVISION HISTORY 35 36 Description: Created separate file for the negate function. Sync'ed up with 37 the current template and fixed tabs. 38 39 Description: Removed conditional code that updates WMOPS counter 40 41 Who: Date: 42 Description: 43 44 ------------------------------------------------------------------------------ 45 INPUT AND OUTPUT DEFINITIONS 46 47 Inputs: 48 var1 = 16 bit short signed integer (Word16) whose value falls in 49 the range : 0xffff 8000 <= var1 <= 0x0000 7fff. 50 51 Local Stores/Buffers/Pointers Needed: 52 None 53 54 Global Stores/Buffers/Pointers Needed: 55 None 56 57 Outputs: 58 var1 = negated value of input (Word16) 59 60 Pointers and Buffers Modified: 61 None 62 63 Local Stores Modified: 64 None 65 66 Global Stores Modified: 67 None 68 69 ------------------------------------------------------------------------------ 70 FUNCTION DESCRIPTION 71 72 This function negates var1 with saturation; saturate in the case where input 73 is -32768: negate(var1) = sub(0,var1). 74 75 ------------------------------------------------------------------------------ 76 REQUIREMENTS 77 78 None 79 80 ------------------------------------------------------------------------------ 81 REFERENCES 82 83 [1] basicop2.c, ETS Version 2.0.0, February 8, 1999 84 85 ------------------------------------------------------------------------------ 86 PSEUDO-CODE 87 88 Word16 negate (Word16 var1) 89 { 90 Word16 var_out; 91 92 var_out = (var1 == MIN_16) ? MAX_16 : -var1; 93 #if (WMOPS) 94 multiCounter[currCounter].negate++; 95 #endif 96 return (var_out); 97 } 98 99 ------------------------------------------------------------------------------ 100 RESOURCES USED 101 When the code is written for a specific target processor the 102 the resources used should be documented below. 103 104 STACK USAGE: [stack count for this module] + [variable to represent 105 stack usage for each subroutine called] 106 107 where: [stack usage variable] = stack usage for [subroutine 108 name] (see [filename].ext) 109 110 DATA MEMORY USED: x words 111 112 PROGRAM MEMORY USED: x words 113 114 CLOCK CYCLES: [cycle count equation for this module] + [variable 115 used to represent cycle count for each subroutine 116 called] 117 118 where: [cycle count variable] = cycle count for [subroutine 119 name] (see [filename].ext) 120 121 ------------------------------------------------------------------------------ 122 */ 123 124 125 /*---------------------------------------------------------------------------- 126 ; INCLUDES 127 ----------------------------------------------------------------------------*/ 128 #include "negate.h" 129 130 /*---------------------------------------------------------------------------- 131 ; MACROS 132 ; Define module specific macros here 133 ----------------------------------------------------------------------------*/ 134 135 /*---------------------------------------------------------------------------- 136 ; DEFINES 137 ; Include all pre-processor statements here. Include conditional 138 ; compile variables also. 139 ----------------------------------------------------------------------------*/ 140 141 /*---------------------------------------------------------------------------- 142 ; LOCAL FUNCTION DEFINITIONS 143 ; Function Prototype declaration 144 ----------------------------------------------------------------------------*/ 145 146 /*---------------------------------------------------------------------------- 147 ; LOCAL STORE/BUFFER/POINTER DEFINITIONS 148 ; Variable declaration - defined here and used outside this module 149 ----------------------------------------------------------------------------*/ 150 151 /*---------------------------------------------------------------------------- 152 ; EXTERNAL FUNCTION REFERENCES 153 ; Declare functions defined elsewhere and referenced in this module 154 ----------------------------------------------------------------------------*/ 155 156 /*---------------------------------------------------------------------------- 157 ; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES 158 ; Declare variables used in this module but defined elsewhere 159 ----------------------------------------------------------------------------*/ 160 161 /*---------------------------------------------------------------------------- 162 ; FUNCTION CODE 163 ----------------------------------------------------------------------------*/ 164 Word16 negate(register Word16 var1) 165 { 166 /*---------------------------------------------------------------------------- 167 ; Define all local variables 168 ----------------------------------------------------------------------------*/ 169 170 /*---------------------------------------------------------------------------- 171 ; Function body here 172 ----------------------------------------------------------------------------*/ 173 var1 = (var1 == MIN_16) ? MAX_16 : -var1; 174 175 /*---------------------------------------------------------------------------- 176 ; Return nothing or data or data pointer 177 ----------------------------------------------------------------------------*/ 178 return (var1); 179 } 180
