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;
; jcsample.asm - downsampling (MMX)
;
; Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
; Copyright (C) 2016, 2024, 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) or Yasm.
%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