msisasm.asm

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;/*
; * DCT functions, Assembler version
; *	MP3 decoding
; *
; * Original Copyright (c) 1999, Jean-Michel HERVE
; * Re-programmed by ULTiMaTuM
; * Copyright (c) 2000
; *
; * Code : TuO / StG
; * Date : 08/04/99
; *
; * WARNING : only _fdct32_* has been tested. The other ones are made from
; *           this function, but hasn't been tested at all. Should check it.
; * NOTE : I don't think that forward_bf and back_bf macros can be more
; *        optimized (except maybe in changing algo)
; */

  BITS 32

SECTION .data USE32

GLOBAL _antialias_asm

EXTERN _csa

SECTION .text USE32

;/*
; * Antialias ASM Version
; */
_antialias_asm: ;// PROC x, n :  DWORD
                ;//      ebp ebp+4
        push   ebp
        lea    ebp,[esp+8]
        pushad

;//   for (k = 0; k < n; k++)
;//   {
        mov    ecx,[ebp+4]

        cmp    ecx,0
        je     near .Skip

        mov    ebp,[ebp]
      .Loop:
;//      for (i = 0; i < 8; i++)
;//      {
%assign i 0
%rep 8
;//        a = x[17 - i];
        fld    dword [ebp+(17-i)*4]    ;/* a */
;//        b = x[18 + i];
        fld    dword [ebp+(18+i)*4]    ;/* b a */
;//        x[17 - i] = a * csa[i][0] - b * csa[i][1];
        fld    st1                     ;/* a b a */
        fmul   dword [_csa+i*8]        ;/* a*csa[i][0] b a */
        fld    st1                     ;/* b a*csa[i][0] b a */
        fmul   dword [_csa+i*8+4]      ;/* b*csa[i][1] a*csa[i][0] b a */
        fsubp  st1,st0                 ;/* x[17-i] b a */
        fstp   dword [ebp+(17-i)*4]    ;/* b a */
;//        x[18 + i] = b * csa[i][0] + a * csa[i][1];
        fmul   dword [_csa+i*8]        ;/* b*csa[i][0] a */
        fxch   st1                     ;/* a b*csa[i][0] */
        fmul   dword [_csa+i*8+4]      ;/* a*csa[i][1] b*csa[i][0] */
        faddp  st1,st0                 ;/* x[18+i] */
        fstp   dword [ebp+(18+i)*4]    ;/* - */
;//      }
%assign i i+1
%endrep
;//      x += 18;
        add    ebp,18*4
;//   }
        dec    ecx
        jnz    near .Loop

      .Skip:

        popad
        pop    ebp
        ret

end