xref: /external/chromium_org/third_party/openmax_dl/dl/sp/src/arm/neon/armSP_FFT_CToC_SC32_Radix2_fs_unsafe_s.S

@//
@//  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_Radix2_fs_unsafe_s.s
@// OpenMAX DL: v1.0.2
@// Last Modified Revision:   5995
@// Last Modified Date:       Fri, 08 Jun 2007
@//
@// (c) Copyright 2007-2008 ARM Limited. All Rights Reserved.
@//
@//
@//
@// Description:
@// Compute the first stage of a Radix 2 DIT in-order out-of-place 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 pPingPongBuf	r5
#define subFFTNum	r6
#define subFFTSize	r7


@//Output Registers


@//Local Scratch Registers

#define pointStep	r3
#define outPointStep	r3
#define grpSize		r4
#define setCount	r4
#define step		r8
#define dstStep		r8

@// Neon Registers

#define dX0	D0.S32
#define dX1	D1.S32
#define dY0	D2.S32
#define dY1	D3.S32


        .macro FFTSTAGE scaled, inverse, name

        @// Define stack arguments


        @// update subFFTSize and subFFTNum into RN6 and RN7 for the next stage


        MOV        subFFTSize,#2
        LSR        grpSize,subFFTNum,#1
        MOV        subFFTNum,grpSize


        @// pT0+1 increments pT0 by 8 bytes
        @// pT0+pointStep = increment of 8*pointStep bytes = 4*grpSize bytes
        @// Note: outPointStep = pointStep for firststage
        @// Note: setCount = grpSize/2 (reuse the updated grpSize for setCount)

        MOV        pointStep,grpSize,LSL #3
        RSB        step,pointStep,#8


        @// Loop on the sets for grp zero

grpZeroSetLoop\name :

        VLD1    dX0,[pSrc],pointStep
        VLD1    dX1,[pSrc],step                   @// step = -pointStep + 8
        SUBS    setCount,setCount,#1              @// decrement the loop counter

        .ifeqs "\scaled", "TRUE"

            VHADD    dY0,dX0,dX1
            VHSUB    dY1,dX0,dX1

        .else

            VADD    dY0,dX0,dX1
            VSUB    dY1,dX0,dX1


        .endif

        VST1    dY0,[pDst],outPointStep
        VST1    dY1,[pDst],dstStep                  @// dstStep =  step = -pointStep + 8

        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_Radix2_fs_OutOfPlace_unsafe,r4
        FFTSTAGE "FALSE","FALSE",fwd
        M_END



        M_START armSP_FFTInv_CToC_SC32_Radix2_fs_OutOfPlace_unsafe,r4
        FFTSTAGE "FALSE","TRUE",inv
        M_END



        M_START armSP_FFTFwd_CToC_SC32_Sfs_Radix2_fs_OutOfPlace_unsafe,r4
        FFTSTAGE "TRUE","FALSE",fwdsfs
        M_END



        M_START armSP_FFTInv_CToC_SC32_Sfs_Radix2_fs_OutOfPlace_unsafe,r4
        FFTSTAGE "TRUE","TRUE",invsfs
        M_END

	.end