wegt_az.asm

TI C54写的G729代码,视线8kbps高质量语音编码,汇编优化

;=======================================================================
;  File Name
;  ----------
;  WEGT_AZ.ASM
;
;  Brief Description of the Code:
;  ------------------------------
;  Compute weighted LPC coefficients.
;
;  Ref
;  ------
;  LPCFUNC.C (Weight_Az)
;=======================================================================
;
;-----------------------------------------------------------------------
;   Weight_Az
;-----------------------------------------------------------------------
;
;   Weighting of LPC coefficients.
;    ap[i]  =  a[i] * (gamma ** i)
;-----------------------------------------------------------------------
;  void Weight_Az(
;    Word16 a[],      /* (i) Q12 : a[m+1]  LPC coefficients           */
;    Word16 gamma,    /* (i) Q15 : Spectral expansion factor.         */
;    Word16 m,        /* (i)     : LPC order.                         */
;    Word16 ap[]      /* (o) Q12 : Spectral expanded LPC coefficients */
;  )
;-----------------------------------------------------------------------
;   Input Registers : Ah = gamma
;                     BRC = m - 1
;                     AR4 -> a[]
;                     AR5 -> ap[]
;
;-----------------------------------------------------------------------

        .mmregs

        .include  ../include/const.h
        .include  ../include/tab_ld8a.h
        .include  ../include/ld8amem.h

        .text
        .def      Weight_Az

        .asg    "AR3", pGamma
        .asg    "AR4", pLPC
        .asg    "AR5", pWLPC

Weight_Az:

        LD      #0, DP
        STM     #Addr_local_buf1, pGamma
        STL     A, -16, *pGamma               
	
        RPTB    EndWeight_Az - 1

        STL     A, -16, T            ; T = factor
        MPYR    *pLPC+, A
        STL     A, -16, *pWLPC+
        MPYR    *pGamma, A      ; A = factor * gamma

EndWeight_Az:

        RET