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/*
* Copyright (C) 2004-2010 NXP Software
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/************************************************************************/
/* */
/* Project:: */
/* $Author: beq07716 $*/
/* $Revision: 1000 $*/
/* $Date: 2010-06-28 13:08:20 +0200 (Mon, 28 Jun 2010) $*/
/* */
/************************************************************************/
#include "LVM_Types.h"
#include "LVM_Macros.h"
#include "ScalarArithmetic.h"
/*-------------------------------------------------------------------------*/
/* FUNCTION: */
/* LVM_Polynomial */
/* */
/* DESCRIPTION: */
/* This function performs polynomial expansion */
/* Y = (A0 + A1*X + A2*X2 + A3*X3 + ….. + AN*xN) << AN+1 */
/* */
/* LVM_INT32 LVM_Polynomial(LVM_UINT16 N, */
/* LVM_INT32 *pCoefficients, */
/* LVM_INT32 X) */
/* */
/* PARAMETERS: */
/* */
/* N is the polynomial order */
/* pCoefficients is the ptr to polynomial coefficients A0,A1.. in Q.31 */
/* X is the input variable */
/* */
/* RETURNS: */
/* The result of the polynomial expansion in Q1.31 format */
/*-------------------------------------------------------------------------*/
LVM_INT32 LVM_Polynomial(LVM_UINT16 N,
LVM_INT32 *pCoefficients,
LVM_INT32 X)
{
LVM_INT32 i;
LVM_INT32 Y,A,XTemp,Temp,sign;
Y=*pCoefficients; /* Y=A0*/
pCoefficients++;
if((LVM_UINT32)X==0x80000000)
{
Temp=-1;
sign=Temp;
for(i=1;i<=N;i++)
{
Y+=((*pCoefficients)*sign);
pCoefficients++;
sign*=Temp;
}
}
else
{
XTemp=X;
for(i=N-1;i>=0;i--)
{
A=*pCoefficients;
pCoefficients++;
MUL32x32INTO32(A,XTemp,Temp,31)
Y+=Temp;
MUL32x32INTO32(XTemp,X,Temp,31)
XTemp=Temp;
}
}
A=*pCoefficients;
pCoefficients++;
if(A<0)
{
A=Abs_32(A);
Y=Y>>A;
}
else
{
Y = Y<<A;
}
return Y;
}
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