jquanti-sse2.asm

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Hash : 19c791cd
Author :
Date : 2018-03-08T10:55:20

Improve code formatting consistency

With rare exceptions ...
- Always separate line continuation characters by one space from
  preceding code.
- Always use two-space indentation.  Never use tabs.
- Always use K&R-style conditional blocks.
- Always surround operators with spaces, except in raw assembly code.
- Always put a space after, but not before, a comma.
- Never put a space between type casts and variables/function calls.
- Never put a space between the function name and the argument list in
  function declarations and prototypes.
- Always surround braces ('{' and '}') with spaces.
- Always surround statements (if, for, else, catch, while, do, switch)
  with spaces.
- Always attach pointer symbols ('*' and '**') to the variable or
  function name.
- Always precede pointer symbols ('*' and '**') by a space in type
  casts.
- Use the MIN() macro from jpegint.h within the libjpeg and TurboJPEG
  API libraries (using min() from tjutil.h is still necessary for
  TJBench.)
- Where it makes sense (particularly in the TurboJPEG code), put a blank
  line after variable declaration blocks.
- Always separate statements in one-liners by two spaces.

The purpose of this was to ease maintenance on my part and also to make
it easier for contributors to figure out how to format patch
submissions.  This was admittedly confusing (even to me sometimes) when
we had 3 or 4 different style conventions in the same source tree.  The
new convention is more consistent with the formatting of other OSS code
bases.

This commit corrects deviations from the chosen formatting style in the
libjpeg API code and reformats the TurboJPEG API code such that it
conforms to the same standard.

NOTES:
- Although it is no longer necessary for the function name in function
  declarations to begin in Column 1 (this was historically necessary
  because of the ansi2knr utility, which allowed libjpeg to be built
  with non-ANSI compilers), we retain that formatting for the libjpeg
  code because it improves readability when using libjpeg's function
  attribute macros (GLOBAL(), etc.)
- This reformatting project was accomplished with the help of AStyle and
  Uncrustify, although neither was completely up to the task, and thus
  a great deal of manual tweaking was required.  Note to developers of
  code formatting utilities:  the libjpeg-turbo code base is an
  excellent test bed, because AFAICT, it breaks every single one of the
  utilities that are currently available.
- The legacy (MMX, SSE, 3DNow!) assembly code for i386 has been
  formatted to match the SSE2 code (refer to
  ff5685d5344273df321eb63a005eaae19d2496e3.)  I hadn't intended to
  bother with this, but the Loongson MMI implementation demonstrated
  that there is still academic value to the MMX implementation, as an
  algorithmic model for other 64-bit vector implementations.  Thus, it
  is desirable to improve its readability in the same manner as that of
  the SSE2 implementation.

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simd/i386/jquanti-sse2.asm

;
; jquanti.asm - sample data conversion and quantization (SSE2)
;
; Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
; 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
;
; [TAB8]

%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

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kc3-lang/libjpeg-turbo/simd/i386/jquanti-sse2.asm

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simd/i386/jquanti-sse2.asm