;

; jquanti.asm - sample data conversion and quantization (SSE2)

;

; Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB</ossman@cendio.se>

; Copyright (C) 2016, D. R. Commander.

;

; Based on the 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

%include "jsimdext.inc"

%include "jdct.inc"

; --------------------------------------------------------------------------

    SECTION     SEG_TEXT

    BITS        32

;

; Load data into workspace, applying unsigned->signed conversion

;

; GLOBAL(void)

; jsimd_convsamp_sse2(JSAMPARRAY sample_data, JDIMENSION start_col,

;                     DCTELEM *workspace);

;

%define sample_data  ebp + 8            ; JSAMPARRAY sample_data

%define start_col    ebp + 12           ; JDIMENSION start_col

%define workspace    ebp + 16           ; DCTELEM *workspace

    align       32

    GLOBAL_FUNCTION(jsimd_convsamp_sse2)

EXTN(jsimd_convsamp_sse2):

    push        ebp

    mov         ebp, esp

    push        ebx

;   push        ecx                     ; need not be preserved

;   push        edx                     ; need not be preserved

    push        esi

    push        edi

    pxor        xmm6, xmm6              ; xmm6=(all 0's)

    pcmpeqw     xmm7, xmm7

    psllw       xmm7, 7                 ; xmm7={0xFF80 0xFF80 0xFF80 0xFF80 ..}

    mov         esi, JSAMPARRAY [sample_data]  ; (JSAMPROW *)

    mov         eax, JDIMENSION [start_col]

    mov         edi, POINTER [workspace]       ; (DCTELEM *)

    mov         ecx, DCTSIZE/4

    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]  ; xmm0=(01234567)

    movq        xmm1, XMM_MMWORD [edx+eax*SIZEOF_JSAMPLE]  ; xmm1=(89ABCDEF)

    mov         ebx, JSAMPROW [esi+2*SIZEOF_JSAMPROW]  ; (JSAMPLE *)

    mov         edx, JSAMPROW [esi+3*SIZEOF_JSAMPROW]  ; (JSAMPLE *)

    movq        xmm2, XMM_MMWORD [ebx+eax*SIZEOF_JSAMPLE]  ; xmm2=(GHIJKLMN)

    movq        xmm3, XMM_MMWORD [edx+eax*SIZEOF_JSAMPLE]  ; xmm3=(OPQRSTUV)

    punpcklbw   xmm0, xmm6              ; xmm0=(01234567)

    punpcklbw   xmm1, xmm6              ; xmm1=(89ABCDEF)

    paddw       xmm0, xmm7

    paddw       xmm1, xmm7

    punpcklbw   xmm2, xmm6              ; xmm2=(GHIJKLMN)

    punpcklbw   xmm3, xmm6              ; xmm3=(OPQRSTUV)

    paddw       xmm2, xmm7

    paddw       xmm3, xmm7

    movdqa      XMMWORD [XMMBLOCK(0,0,edi,SIZEOF_DCTELEM)], xmm0

    movdqa      XMMWORD [XMMBLOCK(1,0,edi,SIZEOF_DCTELEM)], xmm1

    movdqa      XMMWORD [XMMBLOCK(2,0,edi,SIZEOF_DCTELEM)], xmm2

    movdqa      XMMWORD [XMMBLOCK(3,0,edi,SIZEOF_DCTELEM)], xmm3

    add         esi, byte 4*SIZEOF_JSAMPROW

    add         edi, byte 4*DCTSIZE*SIZEOF_DCTELEM

    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

;

; This implementation is based on an algorithm described in

;   "How to optimize for the Pentium family of microprocessors"

;   (http://www.agner.org/assem/).

;

; GLOBAL(void)

; jsimd_quantize_sse2(JCOEFPTR coef_block, DCTELEM *divisors,

;                     DCTELEM *workspace);

;

%define RECIPROCAL(m, n, b) \

  XMMBLOCK(DCTSIZE * 0 + (m), (n), (b), SIZEOF_DCTELEM)

%define CORRECTION(m, n, b) \

  XMMBLOCK(DCTSIZE * 1 + (m), (n), (b), SIZEOF_DCTELEM)

%define SCALE(m, n, b) \

  XMMBLOCK(DCTSIZE * 2 + (m), (n), (b), SIZEOF_DCTELEM)

%define coef_block  ebp + 8             ; JCOEFPTR coef_block

%define divisors    ebp + 12            ; DCTELEM *divisors

%define workspace   ebp + 16            ; DCTELEM *workspace

    align       32

    GLOBAL_FUNCTION(jsimd_quantize_sse2)

EXTN(jsimd_quantize_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, DCTSIZE2/32

    alignx      16, 7

.quantloop:

    movdqa      xmm4, XMMWORD [XMMBLOCK(0,0,esi,SIZEOF_DCTELEM)]

    movdqa      xmm5, XMMWORD [XMMBLOCK(1,0,esi,SIZEOF_DCTELEM)]

    movdqa      xmm6, XMMWORD [XMMBLOCK(2,0,esi,SIZEOF_DCTELEM)]

    movdqa      xmm7, XMMWORD [XMMBLOCK(3,0,esi,SIZEOF_DCTELEM)]

    movdqa      xmm0, xmm4

    movdqa      xmm1, xmm5

    movdqa      xmm2, xmm6

    movdqa      xmm3, xmm7

    psraw       xmm4, (WORD_BIT-1)

    psraw       xmm5, (WORD_BIT-1)

    psraw       xmm6, (WORD_BIT-1)

    psraw       xmm7, (WORD_BIT-1)

    pxor        xmm0, xmm4

    pxor        xmm1, xmm5

    pxor        xmm2, xmm6

    pxor        xmm3, xmm7

    psubw       xmm0, xmm4              ; if (xmm0 < 0) xmm0 = -xmm0;

    psubw       xmm1, xmm5              ; if (xmm1 < 0) xmm1 = -xmm1;

    psubw       xmm2, xmm6              ; if (xmm2 < 0) xmm2 = -xmm2;

    psubw       xmm3, xmm7              ; if (xmm3 < 0) xmm3 = -xmm3;

    paddw       xmm0, XMMWORD [CORRECTION(0,0,edx)]  ; correction + roundfactor

    paddw       xmm1, XMMWORD [CORRECTION(1,0,edx)]

    paddw       xmm2, XMMWORD [CORRECTION(2,0,edx)]

    paddw       xmm3, XMMWORD [CORRECTION(3,0,edx)]

    pmulhuw     xmm0, XMMWORD [RECIPROCAL(0,0,edx)]  ; reciprocal

    pmulhuw     xmm1, XMMWORD [RECIPROCAL(1,0,edx)]

    pmulhuw     xmm2, XMMWORD [RECIPROCAL(2,0,edx)]

    pmulhuw     xmm3, XMMWORD [RECIPROCAL(3,0,edx)]

    pmulhuw     xmm0, XMMWORD [SCALE(0,0,edx)]       ; scale

    pmulhuw     xmm1, XMMWORD [SCALE(1,0,edx)]

    pmulhuw     xmm2, XMMWORD [SCALE(2,0,edx)]

    pmulhuw     xmm3, XMMWORD [SCALE(3,0,edx)]

    pxor        xmm0, xmm4

    pxor        xmm1, xmm5

    pxor        xmm2, xmm6

    pxor        xmm3, xmm7

    psubw       xmm0, xmm4

    psubw       xmm1, xmm5

    psubw       xmm2, xmm6

    psubw       xmm3, xmm7

    movdqa      XMMWORD [XMMBLOCK(0,0,edi,SIZEOF_DCTELEM)], xmm0

    movdqa      XMMWORD [XMMBLOCK(1,0,edi,SIZEOF_DCTELEM)], xmm1

    movdqa      XMMWORD [XMMBLOCK(2,0,edi,SIZEOF_DCTELEM)], xmm2

    movdqa      XMMWORD [XMMBLOCK(3,0,edi,SIZEOF_DCTELEM)], xmm3

    add         esi, byte 32*SIZEOF_DCTELEM

    add         edx, byte 32*SIZEOF_DCTELEM

    add         edi, byte 32*SIZEOF_JCOEF

    dec         eax

    jnz         near .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       32