@//
@//  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_SC16_Radix8_fs_unsafe_s.s
@// OpenMAX DL: v1.0.2
@// Last Modified Revision:   7766
@// Last Modified Date:       Thu, 27 Sep 2007
@//
@// (c) Copyright 2007-2008 ARM Limited. All Rights Reserved.
@//
@//
@//
@// Description:
@// Compute a first stage Radix 8 FFT stage for a N point complex signal
@//
@//


@// Include standard headers

#include "dl/api/arm/armCOMM_s.h"
#include "dl/api/arm/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 subFFTNum                       r6
#define subFFTSize                      r7
@// dest buffer for the next stage (not pSrc for first stage)
#define pPingPongBuf                    r5


@//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 step2                           r10
#define t0                              r11


@// Neon Registers

#define dXr0                            D14.S16
#define dXi0                            D15.S16
#define dXr1                            D2.S16
#define dXi1                            D3.S16
#define dXr2                            D4.S16
#define dXi2                            D5.S16
#define dXr3                            D6.S16
#define dXi3                            D7.S16
#define dXr4                            D8.S16
#define dXi4                            D9.S16
#define dXr5                            D10.S16
#define dXi5                            D11.S16
#define dXr6                            D12.S16
#define dXi6                            D13.S16
#define dXr7                            D0.S16
#define dXi7                            D1.S16
#define qX0                             Q7.S16
#define qX1                             Q1.S16
#define qX2                             Q2.S16
#define qX3                             Q3.S16
#define qX4                             Q4.S16
#define qX5                             Q5.S16
#define qX6                             Q6.S16
#define qX7                             Q0.S16

#define dUr0                            D16.S16
#define dUi0                            D17.S16
#define dUr2                            D18.S16
#define dUi2                            D19.S16
#define dUr4                            D20.S16
#define dUi4                            D21.S16
#define dUr6                            D22.S16
#define dUi6                            D23.S16
#define dUr1                            D24.S16
#define dUi1                            D25.S16
#define dUr3                            D26.S16
#define dUi3                            D27.S16
#define dUr5                            D28.S16
#define dUi5                            D29.S16
@// reuse dXr7 and dXi7
#define dUr7                            D30.S16
#define dUi7                            D31.S16
#define qU0                             Q8.S16
#define qU1                             Q12.S16
#define qU2                             Q9.S16
#define qU3                             Q13.S16
#define qU4                             Q10.S16
#define qU5                             Q14.S16
#define qU6                             Q11.S16
#define qU7                             Q15.S16


#define dVr0                            D24.S16
#define dVi0                            D25.S16
#define dVr2                            D26.S16
#define dVi2                            D27.S16
#define dVr4                            D28.S16
#define dVi4                            D29.S16
#define dVr6                            D30.S16
#define dVi6                            D31.S16
#define dVr1                            D16.S16
#define dVi1                            D17.S16
#define dVr3                            D18.S16
#define dVi3                            D19.S16
#define dVr5                            D20.S16
#define dVi5                            D21.S16
@// reuse dUi7
#define dVr7                            D22.S16
@// reuse dUr7
#define dVi7                            D23.S16
#define qV0                             Q12.S16
#define qV1                             Q8.S16
#define qV2                             Q13.S16
#define qV3                             Q9.S16
#define qV4                             Q14.S16
#define qV5                             Q10.S16
#define qV6                             Q15.S16
#define qV7                             Q11.S16


#define dYr0                            D16.S16
#define dYi0                            D17.S16
#define dYr2                            D18.S16
#define dYi2                            D19.S16
#define dYr4                            D20.S16
#define dYi4                            D21.S16
#define dYr6                            D22.S16
#define dYi6                            D23.S16
#define dYr1                            D24.S16
#define dYi1                            D25.S16
#define dYr3                            D26.S16
#define dYi3                            D27.S16
#define dYr5                            D28.S16
#define dYi5                            D29.S16
@// reuse dYr4 and dYi4
#define dYr7                            D30.S16
#define dYi7                            D31.S16
#define qY0                             Q8.S16
#define qY1                             Q12.S16
#define qY2                             Q9.S16
#define qY3                             Q13.S16
#define qY4                             Q10.S16
#define qY5                             Q14.S16
#define qY6                             Q11.S16
#define qY7                             Q15.S16


#define dT0                             D0.S16
#define dT1                             D1.S16


@// Define constants
        .set   ONEBYSQRT2, 0x00005A82        @// Q15 format


        .macro FFTSTAGE scaled, inverse , name

        @// Define stack arguments

        @// Update pSubFFTSize and pSubFFTNum regs
        MOV     subFFTSize,#8                               @// subFFTSize = 1 for the first stage
        LDR     t0,=ONEBYSQRT2                              @// t0=(1/sqrt(2)) as Q15 format

        @// Note: setCount = subFFTNum/8 (reuse the grpSize reg for setCount)
        LSR     grpSize,subFFTNum,#3
        MOV     subFFTNum,grpSize


        @// pT0+1 increments pT0 by 4 bytes
        @// pT0+pointStep = increment of 4*pointStep bytes = grpSize/2 bytes
        @// Note: outPointStep = pointStep for firststage

        MOV     pointStep,grpSize,LSL #2


        @// Calculate the step of input data for the next set
        @//MOV     step1,pointStep,LSL #1                      @// step1 = 2*pointStep
        VLD2    {dXr0,dXi0},[pSrc :128],pointStep          @//  data[0]
        MOV     step1,grpSize,LSL #3

        MOV     step2,pointStep,LSL #3
        VLD2    {dXr1,dXi1},[pSrc :128],pointStep          @//  data[1]
        SUB     step2,step2,pointStep                          @// step2 = 7*pointStep
        RSB     setStep,step2,#16                              @// setStep = - 7*pointStep+16


        VLD2    {dXr2,dXi2},[pSrc :128],pointStep          @//  data[2]
        VLD2    {dXr3,dXi3},[pSrc :128],pointStep          @//  data[3]
        VLD2    {dXr4,dXi4},[pSrc :128],pointStep          @//  data[4]
        VLD2    {dXr5,dXi5},[pSrc :128],pointStep          @//  data[5]
        VLD2    {dXr6,dXi6},[pSrc :128],pointStep          @//  data[6]
        @// grp = 0 a special case since all the twiddle factors are 1
        @// Loop on the sets : 4 sets at a time

grpZeroSetLoop\name:
        VLD2    {dXr7,dXi7},[pSrc :128],setStep            @//  data[7] & update pSrc for the next set
                                                           @//  setStep = -7*pointStep + 16

        @// Decrement setcount
        SUBS    setCount,setCount,#4                    @// decrement the set loop counter


        .ifeqs "\scaled", "TRUE"
            @// finish first stage of 8 point FFT

            VHADD    qU0,qX0,qX4
            VHADD    qU2,qX1,qX5
            VHADD    qU4,qX2,qX6
            VHADD    qU6,qX3,qX7

            @// finish second stage of 8 point FFT

            VHADD    qV0,qU0,qU4
            VHSUB    qV2,qU0,qU4
            VHADD    qV4,qU2,qU6
            VHSUB    qV6,qU2,qU6

            @// finish third stage of 8 point FFT

            VHADD    qY0,qV0,qV4
            VHSUB    qY4,qV0,qV4
            VST2    {dYr0,dYi0},[pDst :128],step1                    @// store y0

            .ifeqs  "\inverse", "TRUE"

                VHSUB    dYr2,dVr2,dVi6
                VHADD    dYi2,dVi2,dVr6

                VHADD    dYr6,dVr2,dVi6
                VST2    {dYr2,dYi2},[pDst :128],step1                    @// store y2
                VHSUB    dYi6,dVi2,dVr6

                VHSUB    qU1,qX0,qX4
                VST2    {dYr4,dYi4},[pDst :128],step1                    @// store y4

                VHSUB    qU3,qX1,qX5
                VHSUB    qU5,qX2,qX6
                VST2    {dYr6,dYi6},[pDst :128],step1                    @// store y6

            .else

                VHADD    dYr6,dVr2,dVi6
                VHSUB    dYi6,dVi2,dVr6

                VHSUB    dYr2,dVr2,dVi6
                VST2    {dYr6,dYi6},[pDst :128],step1                    @// store y2
                VHADD    dYi2,dVi2,dVr6


                VHSUB    qU1,qX0,qX4
                VST2    {dYr4,dYi4},[pDst :128],step1                    @// store y4
                VHSUB    qU3,qX1,qX5
                VHSUB    qU5,qX2,qX6
                VST2    {dYr2,dYi2},[pDst :128],step1                    @// store y6


            .endif

            @// finish first stage of 8 point FFT

            VHSUB    qU7,qX3,qX7
            VMOV    dT0[0],t0

            @// finish second stage of 8 point FFT

            VHSUB    dVr1,dUr1,dUi5
            VLD2    {dXr0,dXi0},[pSrc :128],pointStep          @//  data[0] for next iteration
            VHADD    dVi1,dUi1,dUr5
            VHADD    dVr3,dUr1,dUi5
            VLD2    {dXr1,dXi1},[pSrc :128],pointStep          @//  data[1]
            VHSUB    dVi3,dUi1,dUr5

            VHSUB    dVr5,dUr3,dUi7
            VLD2    {dXr2,dXi2},[pSrc :128],pointStep          @//  data[2]
            VHADD    dVi5,dUi3,dUr7
            VHADD    dVr7,dUr3,dUi7
            VLD2    {dXr3,dXi3},[pSrc :128],pointStep          @//  data[3]
            VHSUB    dVi7,dUi3,dUr7

            @// finish third stage of 8 point FFT

            .ifeqs  "\inverse", "TRUE"

                @// calculate a*v5
                VQRDMULH    dT1,dVr5,dT0[0]                         @// use dVi0 for dT1
                VLD2    {dXr4,dXi4},[pSrc :128],pointStep          @//  data[4]
                VQRDMULH    dVi5,dVi5,dT0[0]

                VLD2    {dXr5,dXi5},[pSrc :128],pointStep          @//  data[5]
                VSUB    dVr5,dT1,dVi5                               @// a * V5
                VADD    dVi5,dT1,dVi5

                VLD2    {dXr6,dXi6},[pSrc :128],pointStep          @//  data[6]

                @// calculate  b*v7
                VQRDMULH    dT1,dVr7,dT0[0]
                VQRDMULH    dVi7,dVi7,dT0[0]

                VHADD    qY1,qV1,qV5
                VHSUB    qY5,qV1,qV5


                VADD    dVr7,dT1,dVi7                               @// b * V7
                VSUB    dVi7,dVi7,dT1
                SUB     pDst, pDst, step2                           @// set pDst to y1

                VHSUB    dYr3,dVr3,dVr7
                VHSUB    dYi3,dVi3,dVi7
                VST2    {dYr1,dYi1},[pDst :128],step1                    @// store y1
                VHADD    dYr7,dVr3,dVr7
                VHADD    dYi7,dVi3,dVi7


                VST2    {dYr3,dYi3},[pDst :128],step1                    @// store y3
                VST2    {dYr5,dYi5},[pDst :128],step1                    @// store y5
#if 0
                VST2    {dYr7,dYi7},[pDst :128],#16                      @// store y7
#else
                VST2    {dYr7,dYi7},[pDst :128]!                      @// store y7
#endif
            .else

                @// calculate  b*v7
                VQRDMULH    dT1,dVr7,dT0[0]
                VLD2    {dXr4,dXi4},[pSrc :128],pointStep          @//  data[4]
                VQRDMULH    dVi7,dVi7,dT0[0]

                VLD2    {dXr5,dXi5},[pSrc :128],pointStep          @//  data[5]
                VADD    dVr7,dT1,dVi7                               @// b * V7
                VSUB    dVi7,dVi7,dT1

                VLD2    {dXr6,dXi6},[pSrc :128],pointStep          @//  data[6]

                @// calculate a*v5
                VQRDMULH    dT1,dVr5,dT0[0]                         @// use dVi0 for dT1
                VQRDMULH    dVi5,dVi5,dT0[0]

                VHADD    dYr7,dVr3,dVr7
                VHADD    dYi7,dVi3,dVi7
                SUB     pDst, pDst, step2                           @// set pDst to y1

                VSUB    dVr5,dT1,dVi5                               @// a * V5
                VADD    dVi5,dT1,dVi5

                VHSUB    qY5,qV1,qV5

                VHSUB    dYr3,dVr3,dVr7
                VST2    {dYr7,dYi7},[pDst :128],step1                    @// store y1
                VHSUB    dYi3,dVi3,dVi7
                VHADD    qY1,qV1,qV5


                VST2    {dYr5,dYi5},[pDst :128],step1                    @// store y3
                VST2    {dYr3,dYi3},[pDst :128],step1                    @// store y5
#if 0
                VST2    {dYr1,dYi1},[pDst :128],#16                      @// store y7
#else
                VST2    {dYr1,dYi1},[pDst :128]!                      @// store y7
#endif

            .endif


        .else
            @// finish first stage of 8 point FFT

            VADD    qU0,qX0,qX4
            VADD    qU2,qX1,qX5
            VADD    qU4,qX2,qX6
            VADD    qU6,qX3,qX7

            @// finish second stage of 8 point FFT

            VADD    qV0,qU0,qU4
            VSUB    qV2,qU0,qU4
            VADD    qV4,qU2,qU6
            VSUB    qV6,qU2,qU6

            @// finish third stage of 8 point FFT

            VADD    qY0,qV0,qV4
            VSUB    qY4,qV0,qV4
            VST2    {dYr0,dYi0},[pDst :128],step1                    @// store y0

            .ifeqs  "\inverse", "TRUE"

                VSUB    dYr2,dVr2,dVi6
                VADD    dYi2,dVi2,dVr6

                VADD    dYr6,dVr2,dVi6
                VST2    {dYr2,dYi2},[pDst :128],step1                    @// store y2
                VSUB    dYi6,dVi2,dVr6

                VSUB    qU1,qX0,qX4
                VST2    {dYr4,dYi4},[pDst :128],step1                    @// store y4

                VSUB    qU3,qX1,qX5
                VSUB    qU5,qX2,qX6
                VST2    {dYr6,dYi6},[pDst :128],step1                    @// store y6

            .else

                VADD    dYr6,dVr2,dVi6
                VSUB    dYi6,dVi2,dVr6

                VSUB    dYr2,dVr2,dVi6
                VST2    {dYr6,dYi6},[pDst :128],step1                    @// store y2
                VADD    dYi2,dVi2,dVr6


                VSUB    qU1,qX0,qX4
                VST2    {dYr4,dYi4},[pDst :128],step1                    @// store y4
                VSUB    qU3,qX1,qX5
                VSUB    qU5,qX2,qX6
                VST2    {dYr2,dYi2},[pDst :128],step1                    @// store y6


            .endif

            @// finish first stage of 8 point FFT

            VSUB    qU7,qX3,qX7
            VMOV    dT0[0],t0

            @// finish second stage of 8 point FFT

            VSUB    dVr1,dUr1,dUi5
            VLD2    {dXr0,dXi0},[pSrc :128],pointStep          @//  data[0] for next iteration
            VADD    dVi1,dUi1,dUr5
            VADD    dVr3,dUr1,dUi5
            VLD2    {dXr1,dXi1},[pSrc :128],pointStep          @//  data[1]
            VSUB    dVi3,dUi1,dUr5

            VSUB    dVr5,dUr3,dUi7
            VLD2    {dXr2,dXi2},[pSrc :128],pointStep          @//  data[2]
            VADD    dVi5,dUi3,dUr7
            VADD    dVr7,dUr3,dUi7
            VLD2    {dXr3,dXi3},[pSrc :128],pointStep          @//  data[3]
            VSUB    dVi7,dUi3,dUr7

            @// finish third stage of 8 point FFT

            .ifeqs  "\inverse", "TRUE"

                @// calculate a*v5
                VQRDMULH    dT1,dVr5,dT0[0]                         @// use dVi0 for dT1
                VLD2    {dXr4,dXi4},[pSrc :128],pointStep          @//  data[4]
                VQRDMULH    dVi5,dVi5,dT0[0]

                VLD2    {dXr5,dXi5},[pSrc :128],pointStep          @//  data[5]
                VSUB    dVr5,dT1,dVi5                               @// a * V5
                VADD    dVi5,dT1,dVi5

                VLD2    {dXr6,dXi6},[pSrc :128],pointStep          @//  data[6]

                @// calculate  b*v7
                VQRDMULH    dT1,dVr7,dT0[0]
                VQRDMULH    dVi7,dVi7,dT0[0]

                VADD    qY1,qV1,qV5
                VSUB    qY5,qV1,qV5


                VADD    dVr7,dT1,dVi7                               @// b * V7
                VSUB    dVi7,dVi7,dT1
                SUB     pDst, pDst, step2                           @// set pDst to y1

                VSUB    dYr3,dVr3,dVr7
                VSUB    dYi3,dVi3,dVi7
                VST2    {dYr1,dYi1},[pDst :128],step1                    @// store y1
                VADD    dYr7,dVr3,dVr7
                VADD    dYi7,dVi3,dVi7


                VST2    {dYr3,dYi3},[pDst :128],step1                    @// store y3
                VST2    {dYr5,dYi5},[pDst :128],step1                    @// store y5
#if 0
                VST2    {dYr7,dYi7},[pDst :128],#16                      @// store y7
#else
                VST2    {dYr7,dYi7},[pDst :128]!                      @// store y7
#endif
            .else

                @// calculate  b*v7
                VQRDMULH    dT1,dVr7,dT0[0]
                VLD2    {dXr4,dXi4},[pSrc :128],pointStep          @//  data[4]
                VQRDMULH    dVi7,dVi7,dT0[0]

                VLD2    {dXr5,dXi5},[pSrc :128],pointStep          @//  data[5]
                VADD    dVr7,dT1,dVi7                               @// b * V7
                VSUB    dVi7,dVi7,dT1

                VLD2    {dXr6,dXi6},[pSrc :128],pointStep          @//  data[6]

                @// calculate a*v5
                VQRDMULH    dT1,dVr5,dT0[0]                         @// use dVi0 for dT1
                VQRDMULH    dVi5,dVi5,dT0[0]

                VADD    dYr7,dVr3,dVr7
                VADD    dYi7,dVi3,dVi7
                SUB     pDst, pDst, step2                           @// set pDst to y1

                VSUB    dVr5,dT1,dVi5                               @// a * V5
                VADD    dVi5,dT1,dVi5

                VSUB    qY5,qV1,qV5

                VSUB    dYr3,dVr3,dVr7
                VST2    {dYr7,dYi7},[pDst :128],step1                    @// store y1
                VSUB    dYi3,dVi3,dVi7
                VADD    qY1,qV1,qV5


                VST2    {dYr5,dYi5},[pDst :128],step1                    @// store y3
                VST2    {dYr3,dYi3},[pDst :128],step1                    @// store y5
#if 0
                VST2    {dYr1,dYi1},[pDst :128],#16                      @// store y7
#else
                VST2    {dYr1,dYi1},[pDst :128]!                      @// store y7
#endif

            .endif


        .endif

        SUB     pDst, pDst, step2                               @// update pDst for the next set
        BGT     grpZeroSetLoop\name


        @// reset pSrc to pDst for the next stage
        SUB     pSrc,pDst,pointStep                             @// pDst -= 2*grpSize
        MOV     pDst,pPingPongBuf


        .endm


        @// Allocate stack memory required by the function


        M_START armSP_FFTFwd_CToC_SC16_Radix8_fs_OutOfPlace_unsafe,r4
            FFTSTAGE "FALSE","FALSE",FWD
        M_END


        M_START armSP_FFTInv_CToC_SC16_Radix8_fs_OutOfPlace_unsafe,r4
            FFTSTAGE "FALSE","TRUE",INV
        M_END


        M_START armSP_FFTFwd_CToC_SC16_Sfs_Radix8_fs_OutOfPlace_unsafe,r4
            FFTSTAGE "TRUE","FALSE",FWDSFS
        M_END


        M_START armSP_FFTInv_CToC_SC16_Sfs_Radix8_fs_OutOfPlace_unsafe,r4
            FFTSTAGE "TRUE","TRUE",INVSFS
        M_END


    .end