14f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber/* ------------------------------------------------------------------ 24f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber * Copyright (C) 1998-2009 PacketVideo 34f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber * 44f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber * Licensed under the Apache License, Version 2.0 (the "License"); 54f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber * you may not use this file except in compliance with the License. 64f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber * You may obtain a copy of the License at 74f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber * 84f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber * http://www.apache.org/licenses/LICENSE-2.0 94f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber * 104f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber * Unless required by applicable law or agreed to in writing, software 114f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber * distributed under the License is distributed on an "AS IS" BASIS, 124f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either 134f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber * express or implied. 144f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber * See the License for the specific language governing permissions 154f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber * and limitations under the License. 164f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber * ------------------------------------------------------------------- 174f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber */ 184f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber/**************************************************************************************** 194f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas HuberPortions of this file are derived from the following 3GPP standard: 204f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 214f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 3GPP TS 26.073 224f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber ANSI-C code for the Adaptive Multi-Rate (AMR) speech codec 234f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber Available from http://www.3gpp.org 244f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 254f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber(C) 2004, 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TTA, TTC) 264f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas HuberPermission to distribute, modify and use this file under the standard license 274f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huberterms listed above has been obtained from the copyright holder. 284f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber****************************************************************************************/ 294f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber/* 304f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 314f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber Filename: /audio/gsm_amr/c/src/div_32.c 324f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 334f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber------------------------------------------------------------------------------ 344f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber REVISION HISTORY 354f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 364f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber Description: Updated template. Changed function interface to pass in a 374f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber pointer to overflow flag into the function instead of using a 384f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber global flag. Removed inclusion of unwanted header files. Changed 394f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber the name of input and output variables for clarity. 404f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 414f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber Description: 424f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1. Eliminated unused include files. 434f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 2. Replaced l_extract functionality, code size and speed 444f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber do not justify calling this function 454f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 3. Eliminated sub() function call, replace by (-), this knowing 464f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber that the result will not saturate. 474f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 484f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber Description: Added casting to eliminate warnings 494f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 504f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber Who: Date: 514f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber Description: 524f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 534f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 544f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber------------------------------------------------------------------------------ 554f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber*/ 564f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 574f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber/*---------------------------------------------------------------------------- 584f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber; INCLUDES 594f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber----------------------------------------------------------------------------*/ 604f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber#include "basic_op.h" 614f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 624f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber/*---------------------------------------------------------------------------- 634f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber; MACROS 644f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber; [Define module specific macros here] 654f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber----------------------------------------------------------------------------*/ 664f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 674f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber/*---------------------------------------------------------------------------- 684f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber; DEFINES 694f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber; [Include all pre-processor statements here. Include conditional 704f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber; compile variables also.] 714f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber----------------------------------------------------------------------------*/ 724f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 734f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber/*---------------------------------------------------------------------------- 744f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber; LOCAL FUNCTION DEFINITIONS 754f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber; [List function prototypes here] 764f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber----------------------------------------------------------------------------*/ 774f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 784f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber/*---------------------------------------------------------------------------- 794f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber; LOCAL VARIABLE DEFINITIONS 804f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber; [Variable declaration - defined here and used outside this module] 814f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber----------------------------------------------------------------------------*/ 824f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 834f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 844f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber/* 854f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber------------------------------------------------------------------------------ 864f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber FUNCTION NAME: div_32 874f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber------------------------------------------------------------------------------ 884f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber INPUT AND OUTPUT DEFINITIONS 894f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 904f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber Inputs: 914f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber L_num = 32 bit signed integer (Word32) whose value falls in the 924f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber range : 0x0000 0000 < L_num < L_denom 934f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber L_denom_hi = 16 bit positive normalized integer whose value falls in 944f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber the range : 0x4000 < hi < 0x7fff 954f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber L_denom_lo = 16 bit positive integer whose value falls in the range : 964f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 0 < lo < 0x7fff 974f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 984f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber pOverflow = pointer to overflow (Flag) 994f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1004f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber Outputs: 1014f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber pOverflow -> 1 if the 32 bit divide operation resulted in overflow 1024f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1034f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber Returns: 1044f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber result = 32-bit quotient of of the division of two 32 bit integers 1054f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber L_num / L_denom (Word32) 1064f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1074f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber Global Variables Used: 1084f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber None 1094f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1104f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber Local Variables Needed: 1114f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber None 1124f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1134f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber------------------------------------------------------------------------------ 1144f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber FUNCTION DESCRIPTION 1154f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1164f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber This function is a fractional integer division of two 32 bit numbers, the 1174f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber numerator L_num and the denominator L_denom. The denominator is formed by 1184f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber combining denom_hi and denom_lo. Note that denom_hi is a normalized numbers. 1194f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber The numerator and denominator must be positive and the numerator must be 1204f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber less than the denominator. 1214f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1224f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber The division is done as follows: 1234f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1. Find 1/L_denom by first approximating: approx = 1 / denom_hi. 1244f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 2. 1/L_denom = approx * (2.0 - L_denom * approx ). 1254f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 3. result = L_num * (1/L_denom). 1264f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1274f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber------------------------------------------------------------------------------ 1284f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber REQUIREMENTS 1294f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1304f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber None 1314f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1324f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber------------------------------------------------------------------------------ 1334f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber REFERENCES 1344f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1354f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber [1] div_32() function in oper_32b.c, UMTS GSM AMR speech codec, R99 - 1364f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber Version 3.2.0, March 2, 2001 1374f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1384f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber------------------------------------------------------------------------------ 1394f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber PSEUDO-CODE 1404f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1414f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1424f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber------------------------------------------------------------------------------ 1434f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber RESOURCES USED [optional] 1444f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1454f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber When the code is written for a specific target processor the 1464f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber the resources used should be documented below. 1474f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1484f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber HEAP MEMORY USED: x bytes 1494f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1504f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber STACK MEMORY USED: x bytes 1514f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1524f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber CLOCK CYCLES: (cycle count equation for this function) + (variable 1534f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber used to represent cycle count for each subroutine 1544f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber called) 1554f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber where: (cycle count variable) = cycle count for [subroutine 1564f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber name] 1574f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1584f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber------------------------------------------------------------------------------ 1594f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber CAUTION [optional] 1604f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber [State any special notes, constraints or cautions for users of this function] 1614f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1624f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber------------------------------------------------------------------------------ 1634f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber*/ 1644f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1654f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber/*---------------------------------------------------------------------------- 1664f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber; FUNCTION CODE 1674f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber----------------------------------------------------------------------------*/ 1684f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas HuberWord32 Div_32(Word32 L_num, 1694f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber Word16 L_denom_hi, 1704f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber Word16 L_denom_lo, 1714f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber Flag *pOverflow) 1724f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber{ 1734f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1744f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber Word16 approx; 1754f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber Word16 hi; 1764f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber Word16 lo; 1774f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber Word16 n_hi; 1784f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber Word16 n_lo; 1794f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber Word32 result; 1804f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1814f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber /* First approximation: 1 / L_denom = 1/L_denom_hi */ 1824f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1834f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber approx = div_s((Word16) 0x3fff, L_denom_hi); 1844f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1854f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber /* 1/L_denom = approx * (2.0 - L_denom * approx) */ 1864f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1874f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber result = Mpy_32_16(L_denom_hi, L_denom_lo, approx, pOverflow); 1884f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber /* result is > 0 , and less than 1.0 */ 1894f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber result = 0x7fffffffL - result; 1904f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1914f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber hi = (Word16)(result >> 16); 1924f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber lo = (result >> 1) - (hi << 15); 1934f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1944f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber result = Mpy_32_16(hi, lo, approx, pOverflow); 1954f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1964f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber /* L_num * (1/L_denom) */ 1974f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 1984f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber hi = (Word16)(result >> 16); 1994f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber lo = (result >> 1) - (hi << 15); 2004f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 2014f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber n_hi = (Word16)(L_num >> 16); 2024f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber n_lo = (L_num >> 1) - (n_hi << 15); 2034f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 2044f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber result = Mpy_32(n_hi, n_lo, hi, lo, pOverflow); 2054f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber result = L_shl(result, 2, pOverflow); 2064f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 2074f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber return (result); 2084f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber} 2094f1efc098cb5791c3e9f483f2af84aef70d2d0a0Andreas Huber 210