simd/jcqnts2f.asm

;
; jcqnts2f.asm - sample data conversion and quantization (SSE & SSE2)
;
; Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
;
; Based on
; x86 SIMD extension for IJG JPEG library
; Copyright (C) 1999-2006, MIYASAKA Masaru.
; For conditions of distribution and use, see copyright notice in jsimdext.inc
;
; This file should be assembled with NASM (Netwide Assembler),
; can *not* be assembled with Microsoft's MASM or any compatible
; assembler (including Borland's Turbo Assembler).
; NASM is available from http://nasm.sourceforge.net/ or
; http://sourceforge.net/project/showfiles.php?group_id=6208
;
; [TAB8]

%include "jsimdext.inc"
%include "jdct.inc"

; --------------------------------------------------------------------------
        SECTION SEG_TEXT
        BITS    32
;
; Load data into workspace, applying unsigned->signed conversion
;
; GLOBAL(void)
; jsimd_convsamp_float_sse2 (JSAMPARRAY sample_data, JDIMENSION start_col,
;                            FAST_FLOAT * workspace);
;

%define sample_data     ebp+8           ; JSAMPARRAY sample_data
%define start_col       ebp+12          ; JDIMENSION start_col
%define workspace       ebp+16          ; FAST_FLOAT * workspace

        align   16
        global  EXTN(jsimd_convsamp_float_sse2)

EXTN(jsimd_convsamp_float_sse2):
        push    ebp
        mov     ebp,esp
        push    ebx
;       push    ecx             ; need not be preserved
;       push    edx             ; need not be preserved
        push    esi
        push    edi

        pcmpeqw  xmm7,xmm7
        psllw    xmm7,7
        packsswb xmm7,xmm7              ; xmm7 = PB_CENTERJSAMPLE (0x808080..)

        mov     esi, JSAMPARRAY [sample_data]   ; (JSAMPROW *)
        mov     eax, JDIMENSION [start_col]
        mov     edi, POINTER [workspace]        ; (DCTELEM *)
        mov     ecx, DCTSIZE/2
        alignx  16,7
.convloop:
        mov     ebx, JSAMPROW [esi+0*SIZEOF_JSAMPROW]   ; (JSAMPLE *)
        mov     edx, JSAMPROW [esi+1*SIZEOF_JSAMPROW]   ; (JSAMPLE *)

        movq    xmm0, XMM_MMWORD [ebx+eax*SIZEOF_JSAMPLE]
        movq    xmm1, XMM_MMWORD [edx+eax*SIZEOF_JSAMPLE]

        psubb   xmm0,xmm7                       ; xmm0=(01234567)
        psubb   xmm1,xmm7                       ; xmm1=(89ABCDEF)

        punpcklbw xmm0,xmm0                     ; xmm0=(*0*1*2*3*4*5*6*7)
        punpcklbw xmm1,xmm1                     ; xmm1=(*8*9*A*B*C*D*E*F)

        punpcklwd xmm2,xmm0                     ; xmm2=(***0***1***2***3)
        punpckhwd xmm0,xmm0                     ; xmm0=(***4***5***6***7)
        punpcklwd xmm3,xmm1                     ; xmm3=(***8***9***A***B)
        punpckhwd xmm1,xmm1                     ; xmm1=(***C***D***E***F)

        psrad     xmm2,(DWORD_BIT-BYTE_BIT)     ; xmm2=(0123)
        psrad     xmm0,(DWORD_BIT-BYTE_BIT)     ; xmm0=(4567)
        cvtdq2ps  xmm2,xmm2                     ; xmm2=(0123)
        cvtdq2ps  xmm0,xmm0                     ; xmm0=(4567)
        psrad     xmm3,(DWORD_BIT-BYTE_BIT)     ; xmm3=(89AB)
        psrad     xmm1,(DWORD_BIT-BYTE_BIT)     ; xmm1=(CDEF)
        cvtdq2ps  xmm3,xmm3                     ; xmm3=(89AB)
        cvtdq2ps  xmm1,xmm1                     ; xmm1=(CDEF)

        movaps  XMMWORD [XMMBLOCK(0,0,edi,SIZEOF_FAST_FLOAT)], xmm2
        movaps  XMMWORD [XMMBLOCK(0,1,edi,SIZEOF_FAST_FLOAT)], xmm0
        movaps  XMMWORD [XMMBLOCK(1,0,edi,SIZEOF_FAST_FLOAT)], xmm3
        movaps  XMMWORD [XMMBLOCK(1,1,edi,SIZEOF_FAST_FLOAT)], xmm1

        add     esi, byte 2*SIZEOF_JSAMPROW
        add     edi, byte 2*DCTSIZE*SIZEOF_FAST_FLOAT
        dec     ecx
        jnz     short .convloop

        pop     edi
        pop     esi
;       pop     edx             ; need not be preserved
;       pop     ecx             ; need not be preserved
        pop     ebx
        pop     ebp
        ret


; --------------------------------------------------------------------------
;
; Quantize/descale the coefficients, and store into coef_block
;
; GLOBAL(void)
; jsimd_quantize_float_sse2 (JCOEFPTR coef_block, FAST_FLOAT * divisors,
;                         FAST_FLOAT * workspace);
;

%define coef_block      ebp+8           ; JCOEFPTR coef_block
%define divisors        ebp+12          ; FAST_FLOAT * divisors
%define workspace       ebp+16          ; FAST_FLOAT * workspace

        align   16
        global  EXTN(jsimd_quantize_float_sse2)

EXTN(jsimd_quantize_float_sse2):
        push    ebp
        mov     ebp,esp
;       push    ebx             ; unused
;       push    ecx             ; unused
;       push    edx             ; need not be preserved
        push    esi
        push    edi

        mov     esi, POINTER [workspace]
        mov     edx, POINTER [divisors]
        mov     edi, JCOEFPTR [coef_block]
        mov     eax, DCTSIZE2/16
        alignx  16,7
.quantloop:
        movaps  xmm0, XMMWORD [XMMBLOCK(0,0,esi,SIZEOF_FAST_FLOAT)]
        movaps  xmm1, XMMWORD [XMMBLOCK(0,1,esi,SIZEOF_FAST_FLOAT)]
        mulps   xmm0, XMMWORD [XMMBLOCK(0,0,edx,SIZEOF_FAST_FLOAT)]
        mulps   xmm1, XMMWORD [XMMBLOCK(0,1,edx,SIZEOF_FAST_FLOAT)]
        movaps  xmm2, XMMWORD [XMMBLOCK(1,0,esi,SIZEOF_FAST_FLOAT)]
        movaps  xmm3, XMMWORD [XMMBLOCK(1,1,esi,SIZEOF_FAST_FLOAT)]
        mulps   xmm2, XMMWORD [XMMBLOCK(1,0,edx,SIZEOF_FAST_FLOAT)]
        mulps   xmm3, XMMWORD [XMMBLOCK(1,1,edx,SIZEOF_FAST_FLOAT)]

        cvtps2dq xmm0,xmm0
        cvtps2dq xmm1,xmm1
        cvtps2dq xmm2,xmm2
        cvtps2dq xmm3,xmm3

        packssdw xmm0,xmm1
        packssdw xmm2,xmm3

        movdqa  XMMWORD [XMMBLOCK(0,0,edi,SIZEOF_JCOEF)], xmm0
        movdqa  XMMWORD [XMMBLOCK(1,0,edi,SIZEOF_JCOEF)], xmm2

        add     esi, byte 16*SIZEOF_FAST_FLOAT
        add     edx, byte 16*SIZEOF_FAST_FLOAT
        add     edi, byte 16*SIZEOF_JCOEF
        dec     eax
        jnz     short .quantloop

        pop     edi
        pop     esi
;       pop     edx             ; need not be preserved
;       pop     ecx             ; unused
;       pop     ebx             ; unused
        pop     ebp
        ret

; For some reason, the OS X linker does not honor the request to align the
; segment unless we do this.
        align   16