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19c791cdac6df84418c66eb9d67cfa9703bc2461
mozjpeg/simd/i386/jcsample-mmx.asm
DRC 19c791cdac 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.
2018-03-16 02:14:34 -05:00

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;
; jcsample.asm - downsampling (MMX)
;
; 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"
; --------------------------------------------------------------------------
SECTION SEG_TEXT
BITS 32
;
; Downsample pixel values of a single component.
; This version handles the common case of 2:1 horizontal and 1:1 vertical,
; without smoothing.
;
; GLOBAL(void)
; jsimd_h2v1_downsample_mmx(JDIMENSION image_width, int max_v_samp_factor,
; JDIMENSION v_samp_factor,
; JDIMENSION width_in_blocks, JSAMPARRAY input_data,
; JSAMPARRAY output_data);
;
%define img_width(b) (b) + 8 ; JDIMENSION image_width
%define max_v_samp(b) (b) + 12 ; int max_v_samp_factor
%define v_samp(b) (b) + 16 ; JDIMENSION v_samp_factor
%define width_blks(b) (b) + 20 ; JDIMENSION width_in_blocks
%define input_data(b) (b) + 24 ; JSAMPARRAY input_data
%define output_data(b) (b) + 28 ; JSAMPARRAY output_data
align 32
GLOBAL_FUNCTION(jsimd_h2v1_downsample_mmx)
EXTN(jsimd_h2v1_downsample_mmx):
push ebp
mov ebp, esp
; push ebx ; unused
; push ecx ; need not be preserved
; push edx ; need not be preserved
push esi
push edi
mov ecx, JDIMENSION [width_blks(ebp)]
shl ecx, 3 ; imul ecx,DCTSIZE (ecx = output_cols)
jz near .return
mov edx, JDIMENSION [img_width(ebp)]
; -- expand_right_edge
push ecx
shl ecx, 1 ; output_cols * 2
sub ecx, edx
jle short .expand_end
mov eax, INT [max_v_samp(ebp)]
test eax, eax
jle short .expand_end
cld
mov esi, JSAMPARRAY [input_data(ebp)] ; input_data
alignx 16, 7
.expandloop:
push eax
push ecx
mov edi, JSAMPROW [esi]
add edi, edx
mov al, JSAMPLE [edi-1]
rep stosb
pop ecx
pop eax
add esi, byte SIZEOF_JSAMPROW
dec eax
jg short .expandloop
.expand_end:
pop ecx ; output_cols
; -- h2v1_downsample
mov eax, JDIMENSION [v_samp(ebp)] ; rowctr
test eax, eax
jle near .return
mov edx, 0x00010000 ; bias pattern
movd mm7, edx
pcmpeqw mm6, mm6
punpckldq mm7, mm7 ; mm7={0, 1, 0, 1}
psrlw mm6, BYTE_BIT ; mm6={0xFF 0x00 0xFF 0x00 ..}
mov esi, JSAMPARRAY [input_data(ebp)] ; input_data
mov edi, JSAMPARRAY [output_data(ebp)] ; output_data
alignx 16, 7
.rowloop:
push ecx
push edi
push esi
mov esi, JSAMPROW [esi] ; inptr
mov edi, JSAMPROW [edi] ; outptr
alignx 16, 7
.columnloop:
movq mm0, MMWORD [esi+0*SIZEOF_MMWORD]
movq mm1, MMWORD [esi+1*SIZEOF_MMWORD]
movq mm2, mm0
movq mm3, mm1
pand mm0, mm6
psrlw mm2, BYTE_BIT
pand mm1, mm6
psrlw mm3, BYTE_BIT
paddw mm0, mm2
paddw mm1, mm3
paddw mm0, mm7
paddw mm1, mm7
psrlw mm0, 1
psrlw mm1, 1
packuswb mm0, mm1
movq MMWORD [edi+0*SIZEOF_MMWORD], mm0
add esi, byte 2*SIZEOF_MMWORD ; inptr
add edi, byte 1*SIZEOF_MMWORD ; outptr
sub ecx, byte SIZEOF_MMWORD ; outcol
jnz short .columnloop
pop esi
pop edi
pop ecx
add esi, byte SIZEOF_JSAMPROW ; input_data
add edi, byte SIZEOF_JSAMPROW ; output_data
dec eax ; rowctr
jg short .rowloop
emms ; empty MMX state
.return:
pop edi
pop esi
; pop edx ; need not be preserved
; pop ecx ; need not be preserved
; pop ebx ; unused
pop ebp
ret
; --------------------------------------------------------------------------
;
; Downsample pixel values of a single component.
; This version handles the standard case of 2:1 horizontal and 2:1 vertical,
; without smoothing.
;
; GLOBAL(void)
; jsimd_h2v2_downsample_mmx(JDIMENSION image_width, int max_v_samp_factor,
; JDIMENSION v_samp_factor,
; JDIMENSION width_in_blocks, JSAMPARRAY input_data,
; JSAMPARRAY output_data);
;
%define img_width(b) (b) + 8 ; JDIMENSION image_width
%define max_v_samp(b) (b) + 12 ; int max_v_samp_factor
%define v_samp(b) (b) + 16 ; JDIMENSION v_samp_factor
%define width_blks(b) (b) + 20 ; JDIMENSION width_in_blocks
%define input_data(b) (b) + 24 ; JSAMPARRAY input_data
%define output_data(b) (b) + 28 ; JSAMPARRAY output_data
align 32
GLOBAL_FUNCTION(jsimd_h2v2_downsample_mmx)
EXTN(jsimd_h2v2_downsample_mmx):
push ebp
mov ebp, esp
; push ebx ; unused
; push ecx ; need not be preserved
; push edx ; need not be preserved
push esi
push edi
mov ecx, JDIMENSION [width_blks(ebp)]
shl ecx, 3 ; imul ecx,DCTSIZE (ecx = output_cols)
jz near .return
mov edx, JDIMENSION [img_width(ebp)]
; -- expand_right_edge
push ecx
shl ecx, 1 ; output_cols * 2
sub ecx, edx
jle short .expand_end
mov eax, INT [max_v_samp(ebp)]
test eax, eax
jle short .expand_end
cld
mov esi, JSAMPARRAY [input_data(ebp)] ; input_data
alignx 16, 7
.expandloop:
push eax
push ecx
mov edi, JSAMPROW [esi]
add edi, edx
mov al, JSAMPLE [edi-1]
rep stosb
pop ecx
pop eax
add esi, byte SIZEOF_JSAMPROW
dec eax
jg short .expandloop
.expand_end:
pop ecx ; output_cols
; -- h2v2_downsample
mov eax, JDIMENSION [v_samp(ebp)] ; rowctr
test eax, eax
jle near .return
mov edx, 0x00020001 ; bias pattern
movd mm7, edx
pcmpeqw mm6, mm6
punpckldq mm7, mm7 ; mm7={1, 2, 1, 2}
psrlw mm6, BYTE_BIT ; mm6={0xFF 0x00 0xFF 0x00 ..}
mov esi, JSAMPARRAY [input_data(ebp)] ; input_data
mov edi, JSAMPARRAY [output_data(ebp)] ; output_data
alignx 16, 7
.rowloop:
push ecx
push edi
push esi
mov edx, JSAMPROW [esi+0*SIZEOF_JSAMPROW] ; inptr0
mov esi, JSAMPROW [esi+1*SIZEOF_JSAMPROW] ; inptr1
mov edi, JSAMPROW [edi] ; outptr
alignx 16, 7
.columnloop:
movq mm0, MMWORD [edx+0*SIZEOF_MMWORD]
movq mm1, MMWORD [esi+0*SIZEOF_MMWORD]
movq mm2, MMWORD [edx+1*SIZEOF_MMWORD]
movq mm3, MMWORD [esi+1*SIZEOF_MMWORD]
movq mm4, mm0
movq mm5, mm1
pand mm0, mm6
psrlw mm4, BYTE_BIT
pand mm1, mm6
psrlw mm5, BYTE_BIT
paddw mm0, mm4
paddw mm1, mm5
movq mm4, mm2
movq mm5, mm3
pand mm2, mm6
psrlw mm4, BYTE_BIT
pand mm3, mm6
psrlw mm5, BYTE_BIT
paddw mm2, mm4
paddw mm3, mm5
paddw mm0, mm1
paddw mm2, mm3
paddw mm0, mm7
paddw mm2, mm7
psrlw mm0, 2
psrlw mm2, 2
packuswb mm0, mm2
movq MMWORD [edi+0*SIZEOF_MMWORD], mm0
add edx, byte 2*SIZEOF_MMWORD ; inptr0
add esi, byte 2*SIZEOF_MMWORD ; inptr1
add edi, byte 1*SIZEOF_MMWORD ; outptr
sub ecx, byte SIZEOF_MMWORD ; outcol
jnz near .columnloop
pop esi
pop edi
pop ecx
add esi, byte 2*SIZEOF_JSAMPROW ; input_data
add edi, byte 1*SIZEOF_JSAMPROW ; output_data
dec eax ; rowctr
jg near .rowloop
emms ; empty MMX state
.return:
pop edi
pop esi
; pop edx ; need not be preserved
; pop ecx ; need not be preserved
; 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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