; ; jcsample.asm - downsampling (MMX) ; ; Copyright 2009 Pierre Ossman 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 %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