@//
@//  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
@//
@//  Use of this source code is governed by a BSD-style license
@//  that can be found in the LICENSE file in the root of the source
@//  tree. An additional intellectual property rights grant can be found
@//  in the file PATENTS.  All contributing project authors may
@//  be found in the AUTHORS file in the root of the source tree.
@//
@//  This file was originally licensed as follows. It has been
@//  relicensed with permission from the copyright holders.
@//

@// 
@// File Name:  armSP_FFT_CToC_SC32_Radix4_fs_unsafe_s.s
@// OpenMAX DL: v1.0.2
@// Last Modified Revision:   7767
@// Last Modified Date:       Thu, 27 Sep 2007
@// 
@// (c) Copyright 2007-2008 ARM Limited. All Rights Reserved.
@// 
@// 
@//
@// Description:
@// Compute a first stage Radix 4 FFT stage for a N point complex signal
@// 


@// Include standard headers

#include "dl/api/armCOMM_s.h"
#include "dl/api/omxtypes_s.h"
        
@// Import symbols required from other files
@// (For example tables)
    
        
@// Set debugging level        
@//DEBUG_ON    SETL {TRUE}


@// Guarding implementation by the processor name
    
    
@// Guarding implementation by the processor name
    
    
@//Input Registers

#define pSrc		r0
#define pDst		r2
#define pTwiddle	r1
#define pPingPongBuf	r5
#define subFFTNum	r6
#define subFFTSize	r7


@//Output Registers


@//Local Scratch Registers

#define grpSize		r3
@// Reuse grpSize as setCount
#define setCount	r3
#define pointStep	r4
#define outPointStep	r4
#define setStep		r8
#define step1		r9
#define step3		r10

@// Neon Registers

#define dXr0	D0.S32
#define dXi0	D1.S32
#define dXr1	D2.S32
#define dXi1	D3.S32
#define dXr2	D4.S32
#define dXi2	D5.S32
#define dXr3	D6.S32
#define dXi3	D7.S32
#define dYr0	D8.S32
#define dYi0	D9.S32
#define dYr1	D10.S32
#define dYi1	D11.S32
#define dYr2	D12.S32
#define dYi2	D13.S32
#define dYr3	D14.S32
#define dYi3	D15.S32
#define qX0	Q0.S32
#define qX1	Q1.S32
#define qX2	Q2.S32
#define qX3	Q3.S32
#define qY0	Q4.S32
#define qY1	Q5.S32
#define qY2	Q6.S32
#define qY3	Q7.S32
#define dZr0	D16.S32
#define dZi0	D17.S32
#define dZr1	D18.S32
#define dZi1	D19.S32
#define dZr2	D20.S32
#define dZi2	D21.S32
#define dZr3	D22.S32
#define dZi3	D23.S32
#define qZ0	Q8.S32
#define qZ1	Q9.S32
#define qZ2	Q10.S32
#define qZ3	Q11.S32

    
        .MACRO FFTSTAGE scaled, inverse, name
        
        @// Define stack arguments
        
        @// pT0+1 increments pT0 by 8 bytes
        @// pT0+pointStep = increment of 8*pointStep bytes = 2*grpSize bytes
        @// Note: outPointStep = pointStep for firststage
        
        MOV     pointStep,subFFTNum,LSL #1
        
        
        @// Update pSubFFTSize and pSubFFTNum regs
        VLD2    {dXr0,dXi0},[pSrc :128],pointStep          @//  data[0]
        MOV     subFFTSize,#4                                 @// subFFTSize = 1 for the first stage
        
        @// Note: setCount = subFFTNum/4 (reuse the grpSize reg for setCount)
        LSR     grpSize,subFFTNum,#2
        VLD2    {dXr1,dXi1},[pSrc :128],pointStep          @//  data[1]  
        MOV     subFFTNum,grpSize
        
                                       
        @// Calculate the step of input data for the next set
        @//MOV     setStep,pointStep,LSL #1
        MOV     setStep,grpSize,LSL #4
        VLD2    {dXr2,dXi2},[pSrc :128],pointStep          @//  data[2]
        ADD     setStep,setStep,pointStep                   @// setStep = 3*pointStep
        RSB     setStep,setStep,#16                         @// setStep = - 3*pointStep+16
        
        VLD2    {dXr3,dXi3},[pSrc :128],setStep            @//  data[3] & update pSrc for the next set
        MOV     step1,pointStep,LSL #1                      @// step1 = 2*pointStep
        
        .ifeqs "\scaled", "TRUE"
            VHADD    qY0,qX0,qX2
        .else
            VADD    qY0,qX0,qX2
        .endif
            
        RSB     step3,pointStep,#0                          @// step3 = -pointStep                          
        
        @// grp = 0 a special case since all the twiddle factors are 1
        @// Loop on the sets : 2 sets at a time

grpZeroSetLoop\name :	
        
        
        @// Decrement setcount
        SUBS    setCount,setCount,#2                    @// decrement the set loop counter           
        
        .ifeqs "\scaled", "TRUE" 
        
            @// finish first stage of 4 point FFT 
                        
            VHSUB    qY2,qX0,qX2
            
            VLD2    {dXr0,dXi0},[pSrc :128],step1          @//  data[0]
            VHADD    qY1,qX1,qX3
            VLD2    {dXr2,dXi2},[pSrc :128],step3          @//  data[2]
            VHSUB    qY3,qX1,qX3
            
                       
            @// finish second stage of 4 point FFT 
                                                
            .ifeqs "\inverse", "TRUE"
                   
                VLD2    {dXr1,dXi1},[pSrc :128],step1          @//  data[1]
                VHADD    qZ0,qY0,qY1
            
                VLD2    {dXr3,dXi3},[pSrc :128],setStep            @//  data[3] & update pSrc for the next set    
                VHSUB    dZr3,dYr2,dYi3
                
                VST2    {dZr0,dZi0},[pDst :128],outPointStep
                VHADD    dZi3,dYi2,dYr3
                
                VHSUB    qZ1,qY0,qY1
                VST2    {dZr3,dZi3},[pDst :128],outPointStep
                
                VHADD    dZr2,dYr2,dYi3
                VST2    {dZr1,dZi1},[pDst :128],outPointStep
                VHSUB    dZi2,dYi2,dYr3
                
                VHADD    qY0,qX0,qX2                     @// u0 for next iteration
                VST2    {dZr2,dZi2},[pDst :128],setStep
                
                
            .else
                
                VLD2    {dXr1,dXi1},[pSrc :128],step1          @//  data[1]
                VHADD    qZ0,qY0,qY1
            
                VLD2    {dXr3,dXi3},[pSrc :128],setStep            @//  data[3] & update pSrc for the next set
                VHADD    dZr2,dYr2,dYi3
            
                VST2    {dZr0,dZi0},[pDst :128],outPointStep
                VHSUB    dZi2,dYi2,dYr3
            
                VHSUB    qZ1,qY0,qY1
                VST2    {dZr2,dZi2},[pDst :128],outPointStep
            
                VHSUB    dZr3,dYr2,dYi3
                VST2    {dZr1,dZi1},[pDst :128],outPointStep
                VHADD    dZi3,dYi2,dYr3
            
                VHADD    qY0,qX0,qX2                     @// u0 for next iteration
                VST2    {dZr3,dZi3},[pDst :128],setStep
            
            .endif
            
        
        .else
        
            @// finish first stage of 4 point FFT 
            
            
            VSUB    qY2,qX0,qX2
            
            VLD2    {dXr0,dXi0},[pSrc :128],step1          @//  data[0]
            VADD    qY1,qX1,qX3
            VLD2    {dXr2,dXi2},[pSrc :128],step3          @//  data[2]
            VSUB    qY3,qX1,qX3
            
                       
            @// finish second stage of 4 point FFT 
                                                
            .ifeqs "\inverse", "TRUE" 
                   
                VLD2    {dXr1,dXi1},[pSrc :128],step1          @//  data[1]
                VADD    qZ0,qY0,qY1
            
                VLD2    {dXr3,dXi3},[pSrc :128],setStep            @//  data[3] & update pSrc for the next set    
                VSUB    dZr3,dYr2,dYi3
                
                VST2    {dZr0,dZi0},[pDst :128],outPointStep
                VADD    dZi3,dYi2,dYr3
                
                VSUB    qZ1,qY0,qY1
                VST2    {dZr3,dZi3},[pDst :128],outPointStep
                
                VADD    dZr2,dYr2,dYi3
                VST2    {dZr1,dZi1},[pDst :128],outPointStep
                VSUB    dZi2,dYi2,dYr3
                
                VADD    qY0,qX0,qX2                     @// u0 for next iteration
                VST2    {dZr2,dZi2},[pDst :128],setStep
                
                
            .else
                
                VLD2    {dXr1,dXi1},[pSrc :128],step1          @//  data[1]
                VADD    qZ0,qY0,qY1
            
                VLD2    {dXr3,dXi3},[pSrc :128],setStep            @//  data[3] & update pSrc for the next set
                VADD    dZr2,dYr2,dYi3
            
                VST2    {dZr0,dZi0},[pDst :128],outPointStep
                VSUB    dZi2,dYi2,dYr3
            
                VSUB    qZ1,qY0,qY1
                VST2    {dZr2,dZi2},[pDst :128],outPointStep
            
                VSUB    dZr3,dYr2,dYi3
                VST2    {dZr1,dZi1},[pDst :128],outPointStep
                VADD    dZi3,dYi2,dYr3
            
                VADD    qY0,qX0,qX2                     @// u0 for next iteration
                VST2    {dZr3,dZi3},[pDst :128],setStep
            
            .endif
            
        .endif
        
        BGT     grpZeroSetLoop\name
        
        @// reset pSrc to pDst for the next stage
        SUB     pSrc,pDst,pointStep                     @// pDst -= 2*grpSize  
        MOV     pDst,pPingPongBuf
        
        
        .endm

                
        M_START armSP_FFTFwd_CToC_SC32_Radix4_fs_OutOfPlace_unsafe,r4
        FFTSTAGE "FALSE","FALSE",fwd
        M_END

        
        M_START armSP_FFTInv_CToC_SC32_Radix4_fs_OutOfPlace_unsafe,r4
        FFTSTAGE "FALSE","TRUE",inv
        M_END
 
                
        M_START armSP_FFTFwd_CToC_SC32_Sfs_Radix4_fs_OutOfPlace_unsafe,r4
        FFTSTAGE "TRUE","FALSE",fwdsfs
        M_END

                
        M_START armSP_FFTInv_CToC_SC32_Sfs_Radix4_fs_OutOfPlace_unsafe,r4
        FFTSTAGE "TRUE","TRUE",invsfs
        M_END
    
	.end