WebSVN - shark - Rev 96 - /shark/trunk/ports/png/pngvcrd.c

/* pngvcrd.c - mixed C/assembler version of utilities to read a PNG file
*
* For Intel x86 CPU and Microsoft Visual C++ compiler
*
* libpng version 1.2.5 - October 3, 2002
* For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1998-2002 Glenn Randers-Pehrson
* Copyright (c) 1998, Intel Corporation
*
* Contributed by Nirav Chhatrapati, Intel Corporation, 1998
* Interface to libpng contributed by Gilles Vollant, 1999
*
*
* In png_do_read_interlace() in libpng versions 1.0.3a through 1.0.4d,
* a sign error in the post-MMX cleanup code for each pixel_depth resulted
* in bad pixels at the beginning of some rows of some images, and also
* (due to out-of-range memory reads and writes) caused heap corruption
* when compiled with MSVC 6.0. The error was fixed in version 1.0.4e.
*
* [png_read_filter_row_mmx_avg() bpp == 2 bugfix, GRR 20000916]
*
* [runtime MMX configuration, GRR 20010102]
*
*/

#define PNG_INTERNAL
#include "png.h"

#if defined(PNG_ASSEMBLER_CODE_SUPPORTED) && defined(PNG_USE_PNGVCRD)

static int mmx_supported=2;

int PNGAPI
png_mmx_support(void)
{
int mmx_supported_local = 0;
_asm {
push ebx //CPUID will trash these
push ecx
push edx

pushfd //Save Eflag to stack
pop eax //Get Eflag from stack into eax
mov ecx, eax //Make another copy of Eflag in ecx
xor eax, 0x200000 //Toggle ID bit in Eflag [i.e. bit(21)]
push eax //Save modified Eflag back to stack

popfd //Restored modified value back to Eflag reg
pushfd //Save Eflag to stack
pop eax //Get Eflag from stack
push ecx // save original Eflag to stack
popfd // restore original Eflag
xor eax, ecx //Compare the new Eflag with the original Eflag
jz NOT_SUPPORTED //If the same, CPUID instruction is not supported,
//skip following instructions and jump to
//NOT_SUPPORTED label

xor eax, eax //Set eax to zero

_asm _emit 0x0f //CPUID instruction (two bytes opcode)
_asm _emit 0xa2

cmp eax, 1 //make sure eax return non-zero value
jl NOT_SUPPORTED //If eax is zero, mmx not supported

xor eax, eax //set eax to zero
inc eax //Now increment eax to 1. This instruction is
//faster than the instruction "mov eax, 1"

_asm _emit 0x0f //CPUID instruction
_asm _emit 0xa2

and edx, 0x00800000 //mask out all bits but mmx bit(24)
cmp edx, 0 // 0 = mmx not supported
jz NOT_SUPPORTED // non-zero = Yes, mmx IS supported

mov mmx_supported_local, 1 //set return value to 1

NOT_SUPPORTED:
mov eax, mmx_supported_local //move return value to eax
pop edx //CPUID trashed these
pop ecx
pop ebx
}

//mmx_supported_local=0; // test code for force don't support MMX
//printf("MMX : %u (1=MMX supported)\n",mmx_supported_local);

mmx_supported = mmx_supported_local;
return mmx_supported_local;
}

/* Combines the row recently read in with the previous row.
This routine takes care of alpha and transparency if requested.
This routine also handles the two methods of progressive display
of interlaced images, depending on the mask value.
The mask value describes which pixels are to be combined with
the row. The pattern always repeats every 8 pixels, so just 8
bits are needed. A one indicates the pixel is to be combined; a
zero indicates the pixel is to be skipped. This is in addition
to any alpha or transparency value associated with the pixel. If
you want all pixels to be combined, pass 0xff (255) in mask. */

/* Use this routine for x86 platform - uses faster MMX routine if machine
supports MMX */

void /* PRIVATE */
png_combine_row(png_structp png_ptr, png_bytep row, int mask)
{
#ifdef PNG_USE_LOCAL_ARRAYS
const int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
#endif

png_debug(1,"in png_combine_row_asm\n");

if (mmx_supported == 2) {
/* this should have happened in png_init_mmx_flags() already */
png_warning(png_ptr, "asm_flags may not have been initialized");
png_mmx_support();
}

if (mask == 0xff)
{
png_memcpy(row, png_ptr->row_buf + 1,
(png_size_t)((png_ptr->width * png_ptr->row_info.pixel_depth + 7) >> 3));
}
/* GRR: add "else if (mask == 0)" case?
* or does png_combine_row() not even get called in that case? */
else
{
switch (png_ptr->row_info.pixel_depth)
{
case 1:
{
png_bytep sp;
png_bytep dp;
int s_inc, s_start, s_end;
int m;
int shift;
png_uint_32 i;

sp = png_ptr->row_buf + 1;
dp = row;
m = 0x80;
#if defined(PNG_READ_PACKSWAP_SUPPORTED)
if (png_ptr->transformations & PNG_PACKSWAP)
{
s_start = 0;
s_end = 7;
s_inc = 1;
}
else
#endif
{
s_start = 7;
s_end = 0;
s_inc = -1;
}

shift = s_start;

for (i = 0; i < png_ptr->width; i++)
{
if (m & mask)
{
int value;

value = (*sp >> shift) & 0x1;
*dp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff);
*dp |= (png_byte)(value << shift);
}

if (shift == s_end)
{
shift = s_start;
sp++;
dp++;
}
else
shift += s_inc;

if (m == 1)
m = 0x80;
else
m >>= 1;
}
break;
}

case 2:
{
png_bytep sp;
png_bytep dp;
int s_start, s_end, s_inc;
int m;
int shift;
png_uint_32 i;
int value;

sp = png_ptr->row_buf + 1;
dp = row;
m = 0x80;
#if defined(PNG_READ_PACKSWAP_SUPPORTED)
if (png_ptr->transformations & PNG_PACKSWAP)
{
s_start = 0;
s_end = 6;
s_inc = 2;
}
else
#endif
{
s_start = 6;
s_end = 0;
s_inc = -2;
}

shift = s_start;

for (i = 0; i < png_ptr->width; i++)
{
if (m & mask)
{
value = (*sp >> shift) & 0x3;
*dp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
*dp |= (png_byte)(value << shift);
}

if (shift == s_end)
{
shift = s_start;
sp++;
dp++;
}
else
shift += s_inc;
if (m == 1)
m = 0x80;
else
m >>= 1;
}
break;
}

case 4:
{
png_bytep sp;
png_bytep dp;
int s_start, s_end, s_inc;
int m;
int shift;
png_uint_32 i;
int value;

sp = png_ptr->row_buf + 1;
dp = row;
m = 0x80;
#if defined(PNG_READ_PACKSWAP_SUPPORTED)
if (png_ptr->transformations & PNG_PACKSWAP)
{
s_start = 0;
s_end = 4;
s_inc = 4;
}
else
#endif
{
s_start = 4;
s_end = 0;
s_inc = -4;
}
shift = s_start;

for (i = 0; i < png_ptr->width; i++)
{
if (m & mask)
{
value = (*sp >> shift) & 0xf;
*dp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
*dp |= (png_byte)(value << shift);
}

if (shift == s_end)
{
shift = s_start;
sp++;
dp++;
}
else
shift += s_inc;
if (m == 1)
m = 0x80;
else
m >>= 1;
}
break;
}

case 8:
{
png_bytep srcptr;
png_bytep dstptr;
png_uint_32 len;
int m;
int diff, unmask;

__int64 mask0=0x0102040810204080;

if ((png_ptr->asm_flags & PNG_ASM_FLAG_MMX_READ_COMBINE_ROW)
/* && mmx_supported */ )
{
srcptr = png_ptr->row_buf + 1;
dstptr = row;
m = 0x80;
unmask = ~mask;
len = png_ptr->width &~7; //reduce to multiple of 8
diff = png_ptr->width & 7; //amount lost

_asm
{
movd mm7, unmask //load bit pattern
psubb mm6,mm6 //zero mm6
punpcklbw mm7,mm7
punpcklwd mm7,mm7
punpckldq mm7,mm7 //fill register with 8 masks

movq mm0,mask0

pand mm0,mm7 //nonzero if keep byte
pcmpeqb mm0,mm6 //zeros->1s, v versa

mov ecx,len //load length of line (pixels)
mov esi,srcptr //load source
mov ebx,dstptr //load dest
cmp ecx,0 //lcr
je mainloop8end

mainloop8:
movq mm4,[esi]
pand mm4,mm0
movq mm6,mm0
pandn mm6,[ebx]
por mm4,mm6
movq [ebx],mm4

add esi,8 //inc by 8 bytes processed
add ebx,8
sub ecx,8 //dec by 8 pixels processed

ja mainloop8
mainloop8end:

mov ecx,diff
cmp ecx,0
jz end8

mov edx,mask
sal edx,24 //make low byte the high byte

secondloop8:
sal edx,1 //move high bit to CF
jnc skip8 //if CF = 0
mov al,[esi]
mov [ebx],al
skip8:
inc esi
inc ebx

dec ecx
jnz secondloop8
end8:
emms
}
}
else /* mmx not supported - use modified C routine */
{
register unsigned int incr1, initial_val, final_val;
png_size_t pixel_bytes;
png_uint_32 i;
register int disp = png_pass_inc[png_ptr->pass];
int offset_table[7] = {0, 4, 0, 2, 0, 1, 0};

pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
srcptr = png_ptr->row_buf + 1 + offset_table[png_ptr->pass]*
pixel_bytes;
dstptr = row + offset_table[png_ptr->pass]*pixel_bytes;
initial_val = offset_table[png_ptr->pass]*pixel_bytes;
final_val = png_ptr->width*pixel_bytes;
incr1 = (disp)*pixel_bytes;
for (i = initial_val; i < final_val; i += incr1)
{
png_memcpy(dstptr, srcptr, pixel_bytes);
srcptr += incr1;
dstptr += incr1;
}
} /* end of else */

break;
} // end 8 bpp

case 16:
{
png_bytep srcptr;
png_bytep dstptr;
png_uint_32 len;
int unmask, diff;
__int64 mask1=0x0101020204040808,
mask0=0x1010202040408080;

if ((png_ptr->asm_flags & PNG_ASM_FLAG_MMX_READ_COMBINE_ROW)
/* && mmx_supported */ )
{
srcptr = png_ptr->row_buf + 1;
dstptr = row;

unmask = ~mask;
len = (png_ptr->width)&~7;
diff = (png_ptr->width)&7;
_asm
{
movd mm7, unmask //load bit pattern
psubb mm6,mm6 //zero mm6
punpcklbw mm7,mm7
punpcklwd mm7,mm7
punpckldq mm7,mm7 //fill register with 8 masks

movq mm0,mask0
movq mm1,mask1

pand mm0,mm7
pand mm1,mm7

pcmpeqb mm0,mm6
pcmpeqb mm1,mm6

mov ecx,len //load length of line
mov esi,srcptr //load source
mov ebx,dstptr //load dest
cmp ecx,0 //lcr
jz mainloop16end

mainloop16:
movq mm4,[esi]
pand mm4,mm0
movq mm6,mm0
movq mm7,[ebx]
pandn mm6,mm7
por mm4,mm6
movq [ebx],mm4

movq mm5,[esi+8]
pand mm5,mm1
movq mm7,mm1
movq mm6,[ebx+8]
pandn mm7,mm6
por mm5,mm7
movq [ebx+8],mm5

add esi,16 //inc by 16 bytes processed
add ebx,16
sub ecx,8 //dec by 8 pixels processed

ja mainloop16

mainloop16end:
mov ecx,diff
cmp ecx,0
jz end16

mov edx,mask
sal edx,24 //make low byte the high byte
secondloop16:
sal edx,1 //move high bit to CF
jnc skip16 //if CF = 0
mov ax,[esi]
mov [ebx],ax
skip16:
add esi,2
add ebx,2

dec ecx
jnz secondloop16
end16:
emms
}
}
else /* mmx not supported - use modified C routine */
{
register unsigned int incr1, initial_val, final_val;
png_size_t pixel_bytes;
png_uint_32 i;
register int disp = png_pass_inc[png_ptr->pass];
int offset_table[7] = {0, 4, 0, 2, 0, 1, 0};

pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
srcptr = png_ptr->row_buf + 1 + offset_table[png_ptr->pass]*
pixel_bytes;
dstptr = row + offset_table[png_ptr->pass]*pixel_bytes;
initial_val = offset_table[png_ptr->pass]*pixel_bytes;
final_val = png_ptr->width*pixel_bytes;
incr1 = (disp)*pixel_bytes;
for (i = initial_val; i < final_val; i += incr1)
{
png_memcpy(dstptr, srcptr, pixel_bytes);
srcptr += incr1;
dstptr += incr1;
}
} /* end of else */

break;
} // end 16 bpp

case 24:
{
png_bytep srcptr;
png_bytep dstptr;
png_uint_32 len;
int unmask, diff;

__int64 mask2=0x0101010202020404, //24bpp
mask1=0x0408080810101020,
mask0=0x2020404040808080;

srcptr = png_ptr->row_buf + 1;
dstptr = row;

unmask = ~mask;
len = (png_ptr->width)&~7;
diff = (png_ptr->width)&7;

if ((png_ptr->asm_flags & PNG_ASM_FLAG_MMX_READ_COMBINE_ROW)
/* && mmx_supported */ )
{
_asm
{
movd mm7, unmask //load bit pattern
psubb mm6,mm6 //zero mm6
punpcklbw mm7,mm7
punpcklwd mm7,mm7
punpckldq mm7,mm7 //fill register with 8 masks

movq mm0,mask0
movq mm1,mask1
movq mm2,mask2

pand mm0,mm7
pand mm1,mm7
pand mm2,mm7

pcmpeqb mm0,mm6
pcmpeqb mm1,mm6
pcmpeqb mm2,mm6

mov ecx,len //load length of line
mov esi,srcptr //load source
mov ebx,dstptr //load dest
cmp ecx,0
jz mainloop24end

mainloop24:
movq mm4,[esi]
pand mm4,mm0
movq mm6,mm0
movq mm7,[ebx]
pandn mm6,mm7
por mm4,mm6
movq [ebx],mm4

movq mm5,[esi+8]
pand mm5,mm1
movq mm7,mm1
movq mm6,[ebx+8]
pandn mm7,mm6
por mm5,mm7
movq [ebx+8],mm5

movq mm6,[esi+16]
pand mm6,mm2
movq mm4,mm2
movq mm7,[ebx+16]
pandn mm4,mm7
por mm6,mm4
movq [ebx+16],mm6

add esi,24 //inc by 24 bytes processed
add ebx,24
sub ecx,8 //dec by 8 pixels processed

ja mainloop24

mainloop24end:
mov ecx,diff
cmp ecx,0
jz end24

mov edx,mask
sal edx,24 //make low byte the high byte
secondloop24:
sal edx,1 //move high bit to CF
jnc skip24 //if CF = 0
mov ax,[esi]
mov [ebx],ax
xor eax,eax
mov al,[esi+2]
mov [ebx+2],al
skip24:
add esi,3
add ebx,3

dec ecx
jnz secondloop24

end24:
emms
}
}
else /* mmx not supported - use modified C routine */
{
register unsigned int incr1, initial_val, final_val;
png_size_t pixel_bytes;
png_uint_32 i;
register int disp = png_pass_inc[png_ptr->pass];
int offset_table[7] = {0, 4, 0, 2, 0, 1, 0};

pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
srcptr = png_ptr->row_buf + 1 + offset_table[png_ptr->pass]*
pixel_bytes;
dstptr = row + offset_table[png_ptr->pass]*pixel_bytes;
initial_val = offset_table[png_ptr->pass]*pixel_bytes;
final_val = png_ptr->width*pixel_bytes;
incr1 = (disp)*pixel_bytes;
for (i = initial_val; i < final_val; i += incr1)
{
png_memcpy(dstptr, srcptr, pixel_bytes);
srcptr += incr1;
dstptr += incr1;
}
} /* end of else */

break;
} // end 24 bpp

case 32:
{
png_bytep srcptr;
png_bytep dstptr;
png_uint_32 len;
int unmask, diff;

__int64 mask3=0x0101010102020202, //32bpp
mask2=0x0404040408080808,
mask1=0x1010101020202020,
mask0=0x4040404080808080;

srcptr = png_ptr->row_buf + 1;
dstptr = row;

unmask = ~mask;
len = (png_ptr->width)&~7;
diff = (png_ptr->width)&7;

if ((png_ptr->asm_flags & PNG_ASM_FLAG_MMX_READ_COMBINE_ROW)
/* && mmx_supported */ )
{
_asm
{
movd mm7, unmask //load bit pattern
psubb mm6,mm6 //zero mm6
punpcklbw mm7,mm7
punpcklwd mm7,mm7
punpckldq mm7,mm7 //fill register with 8 masks

movq mm0,mask0
movq mm1,mask1
movq mm2,mask2
movq mm3,mask3

pand mm0,mm7
pand mm1,mm7
pand mm2,mm7
pand mm3,mm7

pcmpeqb mm0,mm6
pcmpeqb mm1,mm6
pcmpeqb mm2,mm6
pcmpeqb mm3,mm6

mov ecx,len //load length of line
mov esi,srcptr //load source
mov ebx,dstptr //load dest

cmp ecx,0 //lcr
jz mainloop32end

mainloop32:
movq mm4,[esi]
pand mm4,mm0
movq mm6,mm0
movq mm7,[ebx]
pandn mm6,mm7
por mm4,mm6
movq [ebx],mm4

movq mm5,[esi+8]
pand mm5,mm1
movq mm7,mm1
movq mm6,[ebx+8]
pandn mm7,mm6
por mm5,mm7
movq [ebx+8],mm5

movq mm6,[esi+16]
pand mm6,mm2
movq mm4,mm2
movq mm7,[ebx+16]
pandn mm4,mm7
por mm6,mm4
movq [ebx+16],mm6

movq mm7,[esi+24]
pand mm7,mm3
movq mm5,mm3
movq mm4,[ebx+24]
pandn mm5,mm4
por mm7,mm5
movq [ebx+24],mm7

add esi,32 //inc by 32 bytes processed
add ebx,32
sub ecx,8 //dec by 8 pixels processed

ja mainloop32

mainloop32end:
mov ecx,diff
cmp ecx,0
jz end32

mov edx,mask
sal edx,24 //make low byte the high byte
secondloop32:
sal edx,1 //move high bit to CF
jnc skip32 //if CF = 0
mov eax,[esi]
mov [ebx],eax
skip32:
add esi,4
add ebx,4

dec ecx
jnz secondloop32

end32:
emms
}
}
else /* mmx _not supported - Use modified C routine */
{
register unsigned int incr1, initial_val, final_val;
png_size_t pixel_bytes;
png_uint_32 i;
register int disp = png_pass_inc[png_ptr->pass];
int offset_table[7] = {0, 4, 0, 2, 0, 1, 0};

pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
srcptr = png_ptr->row_buf + 1 + offset_table[png_ptr->pass]*
pixel_bytes;
dstptr = row + offset_table[png_ptr->pass]*pixel_bytes;
initial_val = offset_table[png_ptr->pass]*pixel_bytes;
final_val = png_ptr->width*pixel_bytes;
incr1 = (disp)*pixel_bytes;
for (i = initial_val; i < final_val; i += incr1)
{
png_memcpy(dstptr, srcptr, pixel_bytes);
srcptr += incr1;
dstptr += incr1;
}
} /* end of else */

break;
} // end 32 bpp

case 48:
{
png_bytep srcptr;
png_bytep dstptr;
png_uint_32 len;
int unmask, diff;

__int64 mask5=0x0101010101010202,
mask4=0x0202020204040404,
mask3=0x0404080808080808,
mask2=0x1010101010102020,
mask1=0x2020202040404040,
mask0=0x4040808080808080;

if ((png_ptr->asm_flags & PNG_ASM_FLAG_MMX_READ_COMBINE_ROW)
/* && mmx_supported */ )
{
srcptr = png_ptr->row_buf + 1;
dstptr = row;

unmask = ~mask;
len = (png_ptr->width)&~7;
diff = (png_ptr->width)&7;
_asm
{
movd mm7, unmask //load bit pattern
psubb mm6,mm6 //zero mm6
punpcklbw mm7,mm7
punpcklwd mm7,mm7
punpckldq mm7,mm7 //fill register with 8 masks

movq mm0,mask0
movq mm1,mask1
movq mm2,mask2
movq mm3,mask3
movq mm4,mask4
movq mm5,mask5

pand mm0,mm7
pand mm1,mm7
pand mm2,mm7
pand mm3,mm7
pand mm4,mm7
pand mm5,mm7

pcmpeqb mm0,mm6
pcmpeqb mm1,mm6
pcmpeqb mm2,mm6
pcmpeqb mm3,mm6
pcmpeqb mm4,mm6
pcmpeqb mm5,mm6

mov ecx,len //load length of line
mov esi,srcptr //load source
mov ebx,dstptr //load dest

cmp ecx,0
jz mainloop48end

mainloop48:
movq mm7,[esi]
pand mm7,mm0
movq mm6,mm0
pandn mm6,[ebx]
por mm7,mm6
movq [ebx],mm7

movq mm6,[esi+8]
pand mm6,mm1
movq mm7,mm1
pandn mm7,[ebx+8]
por mm6,mm7
movq [ebx+8],mm6

movq mm6,[esi+16]
pand mm6,mm2
movq mm7,mm2
pandn mm7,[ebx+16]
por mm6,mm7
movq [ebx+16],mm6

movq mm7,[esi+24]
pand mm7,mm3
movq mm6,mm3
pandn mm6,[ebx+24]
por mm7,mm6
movq [ebx+24],mm7

movq mm6,[esi+32]
pand mm6,mm4
movq mm7,mm4
pandn mm7,[ebx+32]
por mm6,mm7
movq [ebx+32],mm6

movq mm7,[esi+40]
pand mm7,mm5
movq mm6,mm5
pandn mm6,[ebx+40]
por mm7,mm6
movq [ebx+40],mm7

add esi,48 //inc by 32 bytes processed
add ebx,48
sub ecx,8 //dec by 8 pixels processed

ja mainloop48
mainloop48end:

mov ecx,diff
cmp ecx,0
jz end48

mov edx,mask
sal edx,24 //make low byte the high byte

secondloop48:
sal edx,1 //move high bit to CF
jnc skip48 //if CF = 0
mov eax,[esi]
mov [ebx],eax
skip48:
add esi,4
add ebx,4

dec ecx
jnz secondloop48

end48:
emms
}
}
else /* mmx _not supported - Use modified C routine */
{
register unsigned int incr1, initial_val, final_val;
png_size_t pixel_bytes;
png_uint_32 i;
register int disp = png_pass_inc[png_ptr->pass];
int offset_table[7] = {0, 4, 0, 2, 0, 1, 0};

pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
srcptr = png_ptr->row_buf + 1 + offset_table[png_ptr->pass]*
pixel_bytes;
dstptr = row + offset_table[png_ptr->pass]*pixel_bytes;
initial_val = offset_table[png_ptr->pass]*pixel_bytes;
final_val = png_ptr->width*pixel_bytes;
incr1 = (disp)*pixel_bytes;
for (i = initial_val; i < final_val; i += incr1)
{
png_memcpy(dstptr, srcptr, pixel_bytes);
srcptr += incr1;
dstptr += incr1;
}
} /* end of else */

break;
} // end 48 bpp

default:
{
png_bytep sptr;
png_bytep dp;
png_size_t pixel_bytes;
int offset_table[7] = {0, 4, 0, 2, 0, 1, 0};
unsigned int i;
register int disp = png_pass_inc[png_ptr->pass]; // get the offset
register unsigned int incr1, initial_val, final_val;

pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
sptr = png_ptr->row_buf + 1 + offset_table[png_ptr->pass]*
pixel_bytes;
dp = row + offset_table[png_ptr->pass]*pixel_bytes;
initial_val = offset_table[png_ptr->pass]*pixel_bytes;
final_val = png_ptr->width*pixel_bytes;
incr1 = (disp)*pixel_bytes;
for (i = initial_val; i < final_val; i += incr1)
{
png_memcpy(dp, sptr, pixel_bytes);
sptr += incr1;
dp += incr1;
}
break;
}
} /* end switch (png_ptr->row_info.pixel_depth) */
} /* end if (non-trivial mask) */

} /* end png_combine_row() */

#if defined(PNG_READ_INTERLACING_SUPPORTED)

void /* PRIVATE */
png_do_read_interlace(png_structp png_ptr)
{
png_row_infop row_info = &(png_ptr->row_info);
png_bytep row = png_ptr->row_buf + 1;
int pass = png_ptr->pass;
png_uint_32 transformations = png_ptr->transformations;
#ifdef PNG_USE_LOCAL_ARRAYS
const int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
#endif

png_debug(1,"in png_do_read_interlace\n");

if (mmx_supported == 2) {
/* this should have happened in png_init_mmx_flags() already */
png_warning(png_ptr, "asm_flags may not have been initialized");
png_mmx_support();
}

if (row != NULL && row_info != NULL)
{
png_uint_32 final_width;

final_width = row_info->width * png_pass_inc[pass];

switch (row_info->pixel_depth)
{
case 1:
{
png_bytep sp, dp;
int sshift, dshift;
int s_start, s_end, s_inc;
png_byte v;
png_uint_32 i;
int j;

sp = row + (png_size_t)((row_info->width - 1) >> 3);
dp = row + (png_size_t)((final_width - 1) >> 3);
#if defined(PNG_READ_PACKSWAP_SUPPORTED)
if (transformations & PNG_PACKSWAP)
{
sshift = (int)((row_info->width + 7) & 7);
dshift = (int)((final_width + 7) & 7);
s_start = 7;
s_end = 0;
s_inc = -1;
}
else
#endif
{
sshift = 7 - (int)((row_info->width + 7) & 7);
dshift = 7 - (int)((final_width + 7) & 7);
s_start = 0;
s_end = 7;
s_inc = 1;
}

for (i = row_info->width; i; i--)
{
v = (png_byte)((*sp >> sshift) & 0x1);
for (j = 0; j < png_pass_inc[pass]; j++)
{
*dp &= (png_byte)((0x7f7f >> (7 - dshift)) & 0xff);
*dp |= (png_byte)(v << dshift);
if (dshift == s_end)
{
dshift = s_start;
dp--;
}
else
dshift += s_inc;
}
if (sshift == s_end)
{
sshift = s_start;
sp--;
}
else
sshift += s_inc;
}
break;
}

case 2:
{
png_bytep sp, dp;
int sshift, dshift;
int s_start, s_end, s_inc;
png_uint_32 i;

sp = row + (png_size_t)((row_info->width - 1) >> 2);
dp = row + (png_size_t)((final_width - 1) >> 2);
#if defined(PNG_READ_PACKSWAP_SUPPORTED)
if (transformations & PNG_PACKSWAP)
{
sshift = (png_size_t)(((row_info->width + 3) & 3) << 1);
dshift = (png_size_t)(((final_width + 3) & 3) << 1);
s_start = 6;
s_end = 0;
s_inc = -2;
}
else
#endif
{
sshift = (png_size_t)((3 - ((row_info->width + 3) & 3)) << 1);
dshift = (png_size_t)((3 - ((final_width + 3) & 3)) << 1);
s_start = 0;
s_end = 6;
s_inc = 2;
}

for (i = row_info->width; i; i--)
{
png_byte v;
int j;

v = (png_byte)((*sp >> sshift) & 0x3);
for (j = 0; j < png_pass_inc[pass]; j++)
{
*dp &= (png_byte)((0x3f3f >> (6 - dshift)) & 0xff);
*dp |= (png_byte)(v << dshift);
if (dshift == s_end)
{
dshift = s_start;
dp--;
}
else
dshift += s_inc;
}
if (sshift == s_end)
{
sshift = s_start;
sp--;
}
else
sshift += s_inc;
}
break;
}

case 4:
{
png_bytep sp, dp;
int sshift, dshift;
int s_start, s_end, s_inc;
png_uint_32 i;

sp = row + (png_size_t)((row_info->width - 1) >> 1);
dp = row + (png_size_t)((final_width - 1) >> 1);
#if defined(PNG_READ_PACKSWAP_SUPPORTED)
if (transformations & PNG_PACKSWAP)
{
sshift = (png_size_t)(((row_info->width + 1) & 1) << 2);
dshift = (png_size_t)(((final_width + 1) & 1) << 2);
s_start = 4;
s_end = 0;
s_inc = -4;
}
else
#endif
{
sshift = (png_size_t)((1 - ((row_info->width + 1) & 1)) << 2);
dshift = (png_size_t)((1 - ((final_width + 1) & 1)) << 2);
s_start = 0;
s_end = 4;
s_inc = 4;
}

for (i = row_info->width; i; i--)
{
png_byte v;
int j;

v = (png_byte)((*sp >> sshift) & 0xf);
for (j = 0; j < png_pass_inc[pass]; j++)
{
*dp &= (png_byte)((0xf0f >> (4 - dshift)) & 0xff);
*dp |= (png_byte)(v << dshift);
if (dshift == s_end)
{
dshift = s_start;
dp--;
}
else
dshift += s_inc;
}
if (sshift == s_end)
{
sshift = s_start;
sp--;
}
else
sshift += s_inc;
}
break;
}

default: // This is the place where the routine is modified
{
__int64 const4 = 0x0000000000FFFFFF;
// __int64 const5 = 0x000000FFFFFF0000; // unused...
__int64 const6 = 0x00000000000000FF;
png_bytep sptr, dp;
png_uint_32 i;
png_size_t pixel_bytes;
int width = row_info->width;

pixel_bytes = (row_info->pixel_depth >> 3);

sptr = row + (width - 1) * pixel_bytes;
dp = row + (final_width - 1) * pixel_bytes;
// New code by Nirav Chhatrapati - Intel Corporation
// sign fix by GRR
// NOTE: there is NO MMX code for 48-bit and 64-bit images

// use MMX routine if machine supports it
if ((png_ptr->asm_flags & PNG_ASM_FLAG_MMX_READ_INTERLACE)
/* && mmx_supported */ )
{
if (pixel_bytes == 3)
{
if (((pass == 0) || (pass == 1)) && width)
{
_asm
{
mov esi, sptr
mov edi, dp
mov ecx, width
sub edi, 21 // (png_pass_inc[pass] - 1)*pixel_bytes
loop_pass0:
movd mm0, [esi] ; X X X X X v2 v1 v0
pand mm0, const4 ; 0 0 0 0 0 v2 v1 v0
movq mm1, mm0 ; 0 0 0 0 0 v2 v1 v0
psllq mm0, 16 ; 0 0 0 v2 v1 v0 0 0
movq mm2, mm0 ; 0 0 0 v2 v1 v0 0 0
psllq mm0, 24 ; v2 v1 v0 0 0 0 0 0
psrlq mm1, 8 ; 0 0 0 0 0 0 v2 v1
por mm0, mm2 ; v2 v1 v0 v2 v1 v0 0 0
por mm0, mm1 ; v2 v1 v0 v2 v1 v0 v2 v1
movq mm3, mm0 ; v2 v1 v0 v2 v1 v0 v2 v1
psllq mm0, 16 ; v0 v2 v1 v0 v2 v1 0 0
movq mm4, mm3 ; v2 v1 v0 v2 v1 v0 v2 v1
punpckhdq mm3, mm0 ; v0 v2 v1 v0 v2 v1 v0 v2
movq [edi+16] , mm4
psrlq mm0, 32 ; 0 0 0 0 v0 v2 v1 v0
movq [edi+8] , mm3
punpckldq mm0, mm4 ; v1 v0 v2 v1 v0 v2 v1 v0
sub esi, 3
movq [edi], mm0
sub edi, 24
//sub esi, 3
dec ecx
jnz loop_pass0
EMMS
}
}
else if (((pass == 2) || (pass == 3)) && width)
{
_asm
{
mov esi, sptr
mov edi, dp
mov ecx, width
sub edi, 9 // (png_pass_inc[pass] - 1)*pixel_bytes
loop_pass2:
movd mm0, [esi] ; X X X X X v2 v1 v0
pand mm0, const4 ; 0 0 0 0 0 v2 v1 v0
movq mm1, mm0 ; 0 0 0 0 0 v2 v1 v0
psllq mm0, 16 ; 0 0 0 v2 v1 v0 0 0
movq mm2, mm0 ; 0 0 0 v2 v1 v0 0 0
psllq mm0, 24 ; v2 v1 v0 0 0 0 0 0
psrlq mm1, 8 ; 0 0 0 0 0 0 v2 v1
por mm0, mm2 ; v2 v1 v0 v2 v1 v0 0 0
por mm0, mm1 ; v2 v1 v0 v2 v1 v0 v2 v1
movq [edi+4], mm0 ; move to memory
psrlq mm0, 16 ; 0 0 v2 v1 v0 v2 v1 v0
movd [edi], mm0 ; move to memory
sub esi, 3
sub edi, 12
dec ecx
jnz loop_pass2
EMMS
}
}
else if (width) /* && ((pass == 4) || (pass == 5)) */
{
int width_mmx = ((width >> 1) << 1) - 8;
if (width_mmx < 0)
width_mmx = 0;
width -= width_mmx; // 8 or 9 pix, 24 or 27 bytes
if (width_mmx)
{
_asm
{
mov esi, sptr
mov edi, dp
mov ecx, width_mmx
sub esi, 3
sub edi, 9
loop_pass4:
movq mm0, [esi] ; X X v2 v1 v0 v5 v4 v3
movq mm7, mm0 ; X X v2 v1 v0 v5 v4 v3
movq mm6, mm0 ; X X v2 v1 v0 v5 v4 v3
psllq mm0, 24 ; v1 v0 v5 v4 v3 0 0 0
pand mm7, const4 ; 0 0 0 0 0 v5 v4 v3
psrlq mm6, 24 ; 0 0 0 X X v2 v1 v0
por mm0, mm7 ; v1 v0 v5 v4 v3 v5 v4 v3
movq mm5, mm6 ; 0 0 0 X X v2 v1 v0
psllq mm6, 8 ; 0 0 X X v2 v1 v0 0
movq [edi], mm0 ; move quad to memory
psrlq mm5, 16 ; 0 0 0 0 0 X X v2
pand mm5, const6 ; 0 0 0 0 0 0 0 v2
por mm6, mm5 ; 0 0 X X v2 v1 v0 v2
movd [edi+8], mm6 ; move double to memory
sub esi, 6
sub edi, 12
sub ecx, 2
jnz loop_pass4
EMMS
}
}

sptr -= width_mmx*3;
dp -= width_mmx*6;
for (i = width; i; i--)
{
png_byte v[8];
int j;

png_memcpy(v, sptr, 3);
for (j = 0; j < png_pass_inc[pass]; j++)
{
png_memcpy(dp, v, 3);
dp -= 3;
}
sptr -= 3;
}
}
} /* end of pixel_bytes == 3 */

else if (pixel_bytes == 1)
{
if (((pass == 0) || (pass == 1)) && width)
{
int width_mmx = ((width >> 2) << 2);
width -= width_mmx;
if (width_mmx)
{
_asm
{
mov esi, sptr
mov edi, dp
mov ecx, width_mmx
sub edi, 31
sub esi, 3
loop1_pass0:
movd mm0, [esi] ; X X X X v0 v1 v2 v3
movq mm1, mm0 ; X X X X v0 v1 v2 v3
punpcklbw mm0, mm0 ; v0 v0 v1 v1 v2 v2 v3 v3
movq mm2, mm0 ; v0 v0 v1 v1 v2 v2 v3 v3
punpcklwd mm0, mm0 ; v2 v2 v2 v2 v3 v3 v3 v3
movq mm3, mm0 ; v2 v2 v2 v2 v3 v3 v3 v3
punpckldq mm0, mm0 ; v3 v3 v3 v3 v3 v3 v3 v3
punpckhdq mm3, mm3 ; v2 v2 v2 v2 v2 v2 v2 v2
movq [edi], mm0 ; move to memory v3
punpckhwd mm2, mm2 ; v0 v0 v0 v0 v1 v1 v1 v1
movq [edi+8], mm3 ; move to memory v2
movq mm4, mm2 ; v0 v0 v0 v0 v1 v1 v1 v1
punpckldq mm2, mm2 ; v1 v1 v1 v1 v1 v1 v1 v1
punpckhdq mm4, mm4 ; v0 v0 v0 v0 v0 v0 v0 v0
movq [edi+16], mm2 ; move to memory v1
movq [edi+24], mm4 ; move to memory v0
sub esi, 4
sub edi, 32
sub ecx, 4
jnz loop1_pass0
EMMS
}
}

sptr -= width_mmx;
dp -= width_mmx*8;
for (i = width; i; i--)
{
int j;

/* I simplified this part in version 1.0.4e
* here and in several other instances where
* pixel_bytes == 1 -- GR-P
*
* Original code:
*
* png_byte v[8];
* png_memcpy(v, sptr, pixel_bytes);
* for (j = 0; j < png_pass_inc[pass]; j++)
* {
* png_memcpy(dp, v, pixel_bytes);
* dp -= pixel_bytes;
* }
* sptr -= pixel_bytes;
*
* Replacement code is in the next three lines:
*/

for (j = 0; j < png_pass_inc[pass]; j++)
*dp-- = *sptr;
sptr--;
}
}
else if (((pass == 2) || (pass == 3)) && width)
{
int width_mmx = ((width >> 2) << 2);
width -= width_mmx;
if (width_mmx)
{
_asm
{
mov esi, sptr
mov edi, dp
mov ecx, width_mmx
sub edi, 15
sub esi, 3
loop1_pass2:
movd mm0, [esi] ; X X X X v0 v1 v2 v3
punpcklbw mm0, mm0 ; v0 v0 v1 v1 v2 v2 v3 v3
movq mm1, mm0 ; v0 v0 v1 v1 v2 v2 v3 v3
punpcklwd mm0, mm0 ; v2 v2 v2 v2 v3 v3 v3 v3
punpckhwd mm1, mm1 ; v0 v0 v0 v0 v1 v1 v1 v1
movq [edi], mm0 ; move to memory v2 and v3
sub esi, 4
movq [edi+8], mm1 ; move to memory v1 and v0
sub edi, 16
sub ecx, 4
jnz loop1_pass2
EMMS
}
}

sptr -= width_mmx;
dp -= width_mmx*4;
for (i = width; i; i--)
{
int j;

for (j = 0; j < png_pass_inc[pass]; j++)
{
*dp-- = *sptr;
}
sptr --;
}
}
else if (width) /* && ((pass == 4) || (pass == 5))) */
{
int width_mmx = ((width >> 3) << 3);
width -= width_mmx;
if (width_mmx)
{
_asm
{
mov esi, sptr
mov edi, dp
mov ecx, width_mmx
sub edi, 15
sub esi, 7
loop1_pass4:
movq mm0, [esi] ; v0 v1 v2 v3 v4 v5 v6 v7
movq mm1, mm0 ; v0 v1 v2 v3 v4 v5 v6 v7
punpcklbw mm0, mm0 ; v4 v4 v5 v5 v6 v6 v7 v7
//movq mm1, mm0 ; v0 v0 v1 v1 v2 v2 v3 v3
punpckhbw mm1, mm1 ;v0 v0 v1 v1 v2 v2 v3 v3
movq [edi+8], mm1 ; move to memory v0 v1 v2 and v3
sub esi, 8
movq [edi], mm0 ; move to memory v4 v5 v6 and v7
//sub esi, 4
sub edi, 16
sub ecx, 8
jnz loop1_pass4
EMMS
}
}

sptr -= width_mmx;
dp -= width_mmx*2;
for (i = width; i; i--)
{
int j;

for (j = 0; j < png_pass_inc[pass]; j++)
{
*dp-- = *sptr;
}
sptr --;
}
}
} /* end of pixel_bytes == 1 */

else if (pixel_bytes == 2)
{
if (((pass == 0) || (pass == 1)) && width)
{
int width_mmx = ((width >> 1) << 1);
width -= width_mmx;
if (width_mmx)
{
_asm
{
mov esi, sptr
mov edi, dp
mov ecx, width_mmx
sub esi, 2
sub edi, 30
loop2_pass0:
movd mm0, [esi] ; X X X X v1 v0 v3 v2
punpcklwd mm0, mm0 ; v1 v0 v1 v0 v3 v2 v3 v2
movq mm1, mm0 ; v1 v0 v1 v0 v3 v2 v3 v2
punpckldq mm0, mm0 ; v3 v2 v3 v2 v3 v2 v3 v2
punpckhdq mm1, mm1 ; v1 v0 v1 v0 v1 v0 v1 v0
movq [edi], mm0
movq [edi + 8], mm0
movq [edi + 16], mm1
movq [edi + 24], mm1
sub esi, 4
sub edi, 32
sub ecx, 2
jnz loop2_pass0
EMMS
}
}

sptr -= (width_mmx*2 - 2); // sign fixed
dp -= (width_mmx*16 - 2); // sign fixed
for (i = width; i; i--)
{
png_byte v[8];
int j;
sptr -= 2;
png_memcpy(v, sptr, 2);
for (j = 0; j < png_pass_inc[pass]; j++)
{
dp -= 2;
png_memcpy(dp, v, 2);
}
}
}
else if (((pass == 2) || (pass == 3)) && width)
{
int width_mmx = ((width >> 1) << 1) ;
width -= width_mmx;
if (width_mmx)
{
_asm
{
mov esi, sptr
mov edi, dp
mov ecx, width_mmx
sub esi, 2
sub edi, 14
loop2_pass2:
movd mm0, [esi] ; X X X X v1 v0 v3 v2
punpcklwd mm0, mm0 ; v1 v0 v1 v0 v3 v2 v3 v2
movq mm1, mm0 ; v1 v0 v1 v0 v3 v2 v3 v2
punpckldq mm0, mm0 ; v3 v2 v3 v2 v3 v2 v3 v2
punpckhdq mm1, mm1 ; v1 v0 v1 v0 v1 v0 v1 v0
movq [edi], mm0
sub esi, 4
movq [edi + 8], mm1
//sub esi, 4
sub edi, 16
sub ecx, 2
jnz loop2_pass2
EMMS
}
}

sptr -= (width_mmx*2 - 2); // sign fixed
dp -= (width_mmx*8 - 2); // sign fixed
for (i = width; i; i--)
{
png_byte v[8];
int j;
sptr -= 2;
png_memcpy(v, sptr, 2);
for (j = 0; j < png_pass_inc[pass]; j++)
{
dp -= 2;
png_memcpy(dp, v, 2);
}
}
}
else if (width) // pass == 4 or 5
{
int width_mmx = ((width >> 1) << 1) ;
width -= width_mmx;
if (width_mmx)
{
_asm
{
mov esi, sptr
mov edi, dp
mov ecx, width_mmx
sub esi, 2
sub edi, 6
loop2_pass4:
movd mm0, [esi] ; X X X X v1 v0 v3 v2
punpcklwd mm0, mm0 ; v1 v0 v1 v0 v3 v2 v3 v2
sub esi, 4
movq [edi], mm0
sub edi, 8
sub ecx, 2
jnz loop2_pass4
EMMS
}
}

sptr -= (width_mmx*2 - 2); // sign fixed
dp -= (width_mmx*4 - 2); // sign fixed
for (i = width; i; i--)
{
png_byte v[8];
int j;
sptr -= 2;
png_memcpy(v, sptr, 2);
for (j = 0; j < png_pass_inc[pass]; j++)
{
dp -= 2;
png_memcpy(dp, v, 2);
}
}
}
} /* end of pixel_bytes == 2 */

else if (pixel_bytes == 4)
{
if (((pass == 0) || (pass == 1)) && width)
{
int width_mmx = ((width >> 1) << 1) ;
width -= width_mmx;
if (width_mmx)
{
_asm
{
mov esi, sptr
mov edi, dp
mov ecx, width_mmx
sub esi, 4
sub edi, 60
loop4_pass0:
movq mm0, [esi] ; v3 v2 v1 v0 v7 v6 v5 v4
movq mm1, mm0 ; v3 v2 v1 v0 v7 v6 v5 v4
punpckldq mm0, mm0 ; v7 v6 v5 v4 v7 v6 v5 v4
punpckhdq mm1, mm1 ; v3 v2 v1 v0 v3 v2 v1 v0
movq [edi], mm0
movq [edi + 8], mm0
movq [edi + 16], mm0
movq [edi + 24], mm0
movq [edi+32], mm1
movq [edi + 40], mm1
movq [edi+ 48], mm1
sub esi, 8
movq [edi + 56], mm1
sub edi, 64
sub ecx, 2
jnz loop4_pass0
EMMS
}
}

sptr -= (width_mmx*4 - 4); // sign fixed
dp -= (width_mmx*32 - 4); // sign fixed
for (i = width; i; i--)
{
png_byte v[8];
int j;
sptr -= 4;
png_memcpy(v, sptr, 4);
for (j = 0; j < png_pass_inc[pass]; j++)
{
dp -= 4;
png_memcpy(dp, v, 4);
}
}
}
else if (((pass == 2) || (pass == 3)) && width)
{
int width_mmx = ((width >> 1) << 1) ;
width -= width_mmx;
if (width_mmx)
{
_asm
{
mov esi, sptr
mov edi, dp
mov ecx, width_mmx
sub esi, 4
sub edi, 28
loop4_pass2:
movq mm0, [esi] ; v3 v2 v1 v0 v7 v6 v5 v4
movq mm1, mm0 ; v3 v2 v1 v0 v7 v6 v5 v4
punpckldq mm0, mm0 ; v7 v6 v5 v4 v7 v6 v5 v4
punpckhdq mm1, mm1 ; v3 v2 v1 v0 v3 v2 v1 v0
movq [edi], mm0
movq [edi + 8], mm0
movq [edi+16], mm1
movq [edi + 24], mm1
sub esi, 8
sub edi, 32
sub ecx, 2
jnz loop4_pass2
EMMS
}
}

sptr -= (width_mmx*4 - 4); // sign fixed
dp -= (width_mmx*16 - 4); // sign fixed
for (i = width; i; i--)
{
png_byte v[8];
int j;
sptr -= 4;
png_memcpy(v, sptr, 4);
for (j = 0; j < png_pass_inc[pass]; j++)
{
dp -= 4;
png_memcpy(dp, v, 4);
}
}
}
else if (width) // pass == 4 or 5
{
int width_mmx = ((width >> 1) << 1) ;
width -= width_mmx;
if (width_mmx)
{
_asm
{
mov esi, sptr
mov edi, dp
mov ecx, width_mmx
sub esi, 4
sub edi, 12
loop4_pass4:
movq mm0, [esi] ; v3 v2 v1 v0 v7 v6 v5 v4
movq mm1, mm0 ; v3 v2 v1 v0 v7 v6 v5 v4
punpckldq mm0, mm0 ; v7 v6 v5 v4 v7 v6 v5 v4
punpckhdq mm1, mm1 ; v3 v2 v1 v0 v3 v2 v1 v0
movq [edi], mm0
sub esi, 8
movq [edi + 8], mm1
sub edi, 16
sub ecx, 2
jnz loop4_pass4
EMMS
}
}

sptr -= (width_mmx*4 - 4); // sign fixed
dp -= (width_mmx*8 - 4); // sign fixed
for (i = width; i; i--)
{
png_byte v[8];
int j;
sptr -= 4;
png_memcpy(v, sptr, 4);
for (j = 0; j < png_pass_inc[pass]; j++)
{
dp -= 4;
png_memcpy(dp, v, 4);
}
}
}

} /* end of pixel_bytes == 4 */

else if (pixel_bytes == 6)
{
for (i = width; i; i--)
{
png_byte v[8];
int j;
png_memcpy(v, sptr, 6);
for (j = 0; j < png_pass_inc[pass]; j++)
{
png_memcpy(dp, v, 6);
dp -= 6;
}
sptr -= 6;
}
} /* end of pixel_bytes == 6 */

else
{
for (i = width; i; i--)
{
png_byte v[8];
int j;
png_memcpy(v, sptr, pixel_bytes);
for (j = 0; j < png_pass_inc[pass]; j++)
{
png_memcpy(dp, v, pixel_bytes);
dp -= pixel_bytes;
}
sptr-= pixel_bytes;
}
}
} /* end of mmx_supported */

else /* MMX not supported: use modified C code - takes advantage
* of inlining of memcpy for a constant */
{
if (pixel_bytes == 1)
{
for (i = width; i; i--)
{
int j;
for (j = 0; j < png_pass_inc[pass]; j++)
*dp-- = *sptr;
sptr--;
}
}
else if (pixel_bytes == 3)
{
for (i = width; i; i--)
{
png_byte v[8];
int j;
png_memcpy(v, sptr, pixel_bytes);
for (j = 0; j < png_pass_inc[pass]; j++)
{
png_memcpy(dp, v, pixel_bytes);
dp -= pixel_bytes;
}
sptr -= pixel_bytes;
}
}
else if (pixel_bytes == 2)
{
for (i = width; i; i--)
{
png_byte v[8];
int j;
png_memcpy(v, sptr, pixel_bytes);
for (j = 0; j < png_pass_inc[pass]; j++)
{
png_memcpy(dp, v, pixel_bytes);
dp -= pixel_bytes;
}
sptr -= pixel_bytes;
}
}
else if (pixel_bytes == 4)
{
for (i = width; i; i--)
{
png_byte v[8];
int j;
png_memcpy(v, sptr, pixel_bytes);
for (j = 0; j < png_pass_inc[pass]; j++)
{
png_memcpy(dp, v, pixel_bytes);
dp -= pixel_bytes;
}
sptr -= pixel_bytes;
}
}
else if (pixel_bytes == 6)
{
for (i = width; i; i--)
{
png_byte v[8];
int j;
png_memcpy(v, sptr, pixel_bytes);
for (j = 0; j < png_pass_inc[pass]; j++)
{
png_memcpy(dp, v, pixel_bytes);
dp -= pixel_bytes;
}
sptr -= pixel_bytes;
}
}
else
{
for (i = width; i; i--)
{
png_byte v[8];
int j;
png_memcpy(v, sptr, pixel_bytes);
for (j = 0; j < png_pass_inc[pass]; j++)
{
png_memcpy(dp, v, pixel_bytes);
dp -= pixel_bytes;
}
sptr -= pixel_bytes;
}
}

} /* end of MMX not supported */
break;
}
} /* end switch (row_info->pixel_depth) */

row_info->width = final_width;
row_info->rowbytes = ((final_width *
(png_uint_32)row_info->pixel_depth + 7) >> 3);
}

}

#endif /* PNG_READ_INTERLACING_SUPPORTED */

// These variables are utilized in the functions below. They are declared
// globally here to ensure alignment on 8-byte boundaries.

union uAll {
__int64 use;
double align;
} LBCarryMask = {0x0101010101010101},
HBClearMask = {0x7f7f7f7f7f7f7f7f},
ActiveMask, ActiveMask2, ActiveMaskEnd, ShiftBpp, ShiftRem;

// Optimized code for PNG Average filter decoder
void /* PRIVATE */
png_read_filter_row_mmx_avg(png_row_infop row_info, png_bytep row
, png_bytep prev_row)
{
int bpp;
png_uint_32 FullLength;
png_uint_32 MMXLength;
//png_uint_32 len;
int diff;

bpp = (row_info->pixel_depth + 7) >> 3; // Get # bytes per pixel
FullLength = row_info->rowbytes; // # of bytes to filter
_asm {
// Init address pointers and offset
mov edi, row // edi ==> Avg(x)
xor ebx, ebx // ebx ==> x
mov edx, edi
mov esi, prev_row // esi ==> Prior(x)
sub edx, bpp // edx ==> Raw(x-bpp)

xor eax, eax
// Compute the Raw value for the first bpp bytes
// Raw(x) = Avg(x) + (Prior(x)/2)
davgrlp:
mov al, [esi + ebx] // Load al with Prior(x)
inc ebx
shr al, 1 // divide by 2
add al, [edi+ebx-1] // Add Avg(x); -1 to offset inc ebx
cmp ebx, bpp
mov [edi+ebx-1], al // Write back Raw(x);
// mov does not affect flags; -1 to offset inc ebx
jb davgrlp
// get # of bytes to alignment
mov diff, edi // take start of row
add diff, ebx // add bpp
add diff, 0xf // add 7 + 8 to incr past alignment boundary
and diff, 0xfffffff8 // mask to alignment boundary
sub diff, edi // subtract from start ==> value ebx at alignment
jz davggo
// fix alignment
// Compute the Raw value for the bytes upto the alignment boundary
// Raw(x) = Avg(x) + ((Raw(x-bpp) + Prior(x))/2)
xor ecx, ecx
davglp1:
xor eax, eax
mov cl, [esi + ebx] // load cl with Prior(x)
mov al, [edx + ebx] // load al with Raw(x-bpp)
add ax, cx
inc ebx
shr ax, 1 // divide by 2
add al, [edi+ebx-1] // Add Avg(x); -1 to offset inc ebx
cmp ebx, diff // Check if at alignment boundary
mov [edi+ebx-1], al // Write back Raw(x);
// mov does not affect flags; -1 to offset inc ebx
jb davglp1 // Repeat until at alignment boundary
davggo:
mov eax, FullLength
mov ecx, eax
sub eax, ebx // subtract alignment fix
and eax, 0x00000007 // calc bytes over mult of 8
sub ecx, eax // drop over bytes from original length
mov MMXLength, ecx
} // end _asm block
// Now do the math for the rest of the row
switch ( bpp )
{
case 3:
{
ActiveMask.use = 0x0000000000ffffff;
ShiftBpp.use = 24; // == 3 * 8
ShiftRem.use = 40; // == 64 - 24
_asm {
// Re-init address pointers and offset
movq mm7, ActiveMask
mov ebx, diff // ebx ==> x = offset to alignment boundary
movq mm5, LBCarryMask
mov edi, row // edi ==> Avg(x)
movq mm4, HBClearMask
mov esi, prev_row // esi ==> Prior(x)
// PRIME the pump (load the first Raw(x-bpp) data set
movq mm2, [edi + ebx - 8] // Load previous aligned 8 bytes
// (we correct position in loop below)
davg3lp:
movq mm0, [edi + ebx] // Load mm0 with Avg(x)
// Add (Prev_row/2) to Average
movq mm3, mm5
psrlq mm2, ShiftRem // Correct position Raw(x-bpp) data
movq mm1, [esi + ebx] // Load mm1 with Prior(x)
movq mm6, mm7
pand mm3, mm1 // get lsb for each prev_row byte
psrlq mm1, 1 // divide prev_row bytes by 2
pand mm1, mm4 // clear invalid bit 7 of each byte
paddb mm0, mm1 // add (Prev_row/2) to Avg for each byte
// Add 1st active group (Raw(x-bpp)/2) to Average with LBCarry
movq mm1, mm3 // now use mm1 for getting LBCarrys
pand mm1, mm2 // get LBCarrys for each byte where both
// lsb's were == 1 (Only valid for active group)
psrlq mm2, 1 // divide raw bytes by 2
pand mm2, mm4 // clear invalid bit 7 of each byte
paddb mm2, mm1 // add LBCarrys to (Raw(x-bpp)/2) for each byte
pand mm2, mm6 // Leave only Active Group 1 bytes to add to Avg
paddb mm0, mm2 // add (Raw/2) + LBCarrys to Avg for each Active
// byte
// Add 2nd active group (Raw(x-bpp)/2) to Average with LBCarry
psllq mm6, ShiftBpp // shift the mm6 mask to cover bytes 3-5
movq mm2, mm0 // mov updated Raws to mm2
psllq mm2, ShiftBpp // shift data to position correctly
movq mm1, mm3 // now use mm1 for getting LBCarrys
pand mm1, mm2 // get LBCarrys for each byte where both
// lsb's were == 1 (Only valid for active group)
psrlq mm2, 1 // divide raw bytes by 2
pand mm2, mm4 // clear invalid bit 7 of each byte
paddb mm2, mm1 // add LBCarrys to (Raw(x-bpp)/2) for each byte
pand mm2, mm6 // Leave only Active Group 2 bytes to add to Avg
paddb mm0, mm2 // add (Raw/2) + LBCarrys to Avg for each Active
// byte

// Add 3rd active group (Raw(x-bpp)/2) to Average with LBCarry
psllq mm6, ShiftBpp // shift the mm6 mask to cover the last two
// bytes
movq mm2, mm0 // mov updated Raws to mm2
psllq mm2, ShiftBpp // shift data to position correctly
// Data only needs to be shifted once here to
// get the correct x-bpp offset.
movq mm1, mm3 // now use mm1 for getting LBCarrys
pand mm1, mm2 // get LBCarrys for each byte where both
// lsb's were == 1 (Only valid for active group)
psrlq mm2, 1 // divide raw bytes by 2
pand mm2, mm4 // clear invalid bit 7 of each byte
paddb mm2, mm1 // add LBCarrys to (Raw(x-bpp)/2) for each byte
pand mm2, mm6 // Leave only Active Group 2 bytes to add to Avg
add ebx, 8
paddb mm0, mm2 // add (Raw/2) + LBCarrys to Avg for each Active
// byte

// Now ready to write back to memory
movq [edi + ebx - 8], mm0
// Move updated Raw(x) to use as Raw(x-bpp) for next loop
cmp ebx, MMXLength
movq mm2, mm0 // mov updated Raw(x) to mm2
jb davg3lp
} // end _asm block
}
break;

case 6:
case 4:
case 7:
case 5:
{
ActiveMask.use = 0xffffffffffffffff; // use shift below to clear
// appropriate inactive bytes
ShiftBpp.use = bpp << 3;
ShiftRem.use = 64 - ShiftBpp.use;
_asm {
movq mm4, HBClearMask
// Re-init address pointers and offset
mov ebx, diff // ebx ==> x = offset to alignment boundary
// Load ActiveMask and clear all bytes except for 1st active group
movq mm7, ActiveMask
mov edi, row // edi ==> Avg(x)
psrlq mm7, ShiftRem
mov esi, prev_row // esi ==> Prior(x)
movq mm6, mm7
movq mm5, LBCarryMask
psllq mm6, ShiftBpp // Create mask for 2nd active group
// PRIME the pump (load the first Raw(x-bpp) data set
movq mm2, [edi + ebx - 8] // Load previous aligned 8 bytes
// (we correct position in loop below)
davg4lp:
movq mm0, [edi + ebx]
psrlq mm2, ShiftRem // shift data to position correctly
movq mm1, [esi + ebx]
// Add (Prev_row/2) to Average
movq mm3, mm5
pand mm3, mm1 // get lsb for each prev_row byte
psrlq mm1, 1 // divide prev_row bytes by 2
pand mm1, mm4 // clear invalid bit 7 of each byte
paddb mm0, mm1 // add (Prev_row/2) to Avg for each byte
// Add 1st active group (Raw(x-bpp)/2) to Average with LBCarry
movq mm1, mm3 // now use mm1 for getting LBCarrys
pand mm1, mm2 // get LBCarrys for each byte where both
// lsb's were == 1 (Only valid for active group)
psrlq mm2, 1 // divide raw bytes by 2
pand mm2, mm4 // clear invalid bit 7 of each byte
paddb mm2, mm1 // add LBCarrys to (Raw(x-bpp)/2) for each byte
pand mm2, mm7 // Leave only Active Group 1 bytes to add to Avg
paddb mm0, mm2 // add (Raw/2) + LBCarrys to Avg for each Active
// byte
// Add 2nd active group (Raw(x-bpp)/2) to Average with LBCarry
movq mm2, mm0 // mov updated Raws to mm2
psllq mm2, ShiftBpp // shift data to position correctly
add ebx, 8
movq mm1, mm3 // now use mm1 for getting LBCarrys
pand mm1, mm2 // get LBCarrys for each byte where both
// lsb's were == 1 (Only valid for active group)
psrlq mm2, 1 // divide raw bytes by 2
pand mm2, mm4 // clear invalid bit 7 of each byte
paddb mm2, mm1 // add LBCarrys to (Raw(x-bpp)/2) for each byte
pand mm2, mm6 // Leave only Active Group 2 bytes to add to Avg
paddb mm0, mm2 // add (Raw/2) + LBCarrys to Avg for each Active
// byte
cmp ebx, MMXLength
// Now ready to write back to memory
movq [edi + ebx - 8], mm0
// Prep Raw(x-bpp) for next loop
movq mm2, mm0 // mov updated Raws to mm2
jb davg4lp
} // end _asm block
}
break;
case 2:
{
ActiveMask.use = 0x000000000000ffff;
ShiftBpp.use = 16; // == 2 * 8 [BUGFIX]
ShiftRem.use = 48; // == 64 - 16 [BUGFIX]
_asm {
// Load ActiveMask
movq mm7, ActiveMask
// Re-init address pointers and offset
mov ebx, diff // ebx ==> x = offset to alignment boundary
movq mm5, LBCarryMask
mov edi, row // edi ==> Avg(x)
movq mm4, HBClearMask
mov esi, prev_row // esi ==> Prior(x)
// PRIME the pump (load the first Raw(x-bpp) data set
movq mm2, [edi + ebx - 8] // Load previous aligned 8 bytes
// (we correct position in loop below)
davg2lp:
movq mm0, [edi + ebx]
psrlq mm2, ShiftRem // shift data to position correctly [BUGFIX]
movq mm1, [esi + ebx]
// Add (Prev_row/2) to Average
movq mm3, mm5
pand mm3, mm1 // get lsb for each prev_row byte
psrlq mm1, 1 // divide prev_row bytes by 2
pand mm1, mm4 // clear invalid bit 7 of each byte
movq mm6, mm7
paddb mm0, mm1 // add (Prev_row/2) to Avg for each byte
// Add 1st active group (Raw(x-bpp)/2) to Average with LBCarry
movq mm1, mm3 // now use mm1 for getting LBCarrys
pand mm1, mm2 // get LBCarrys for each byte where both
// lsb's were == 1 (Only valid for active group)
psrlq mm2, 1 // divide raw bytes by 2
pand mm2, mm4 // clear invalid bit 7 of each byte
paddb mm2, mm1 // add LBCarrys to (Raw(x-bpp)/2) for each byte
pand mm2, mm6 // Leave only Active Group 1 bytes to add to Avg
paddb mm0, mm2 // add (Raw/2) + LBCarrys to Avg for each Active byte
// Add 2nd active group (Raw(x-bpp)/2) to Average with LBCarry
psllq mm6, ShiftBpp // shift the mm6 mask to cover bytes 2 & 3
movq mm2, mm0 // mov updated Raws to mm2
psllq mm2, ShiftBpp // shift data to position correctly
movq mm1, mm3 // now use mm1 for getting LBCarrys
pand mm1, mm2 // get LBCarrys for each byte where both
// lsb's were == 1 (Only valid for active group)
psrlq mm2, 1 // divide raw bytes by 2
pand mm2, mm4 // clear invalid bit 7 of each byte
paddb mm2, mm1 // add LBCarrys to (Raw(x-bpp)/2) for each byte
pand mm2, mm6 // Leave only Active Group 2 bytes to add to Avg
paddb mm0, mm2 // add (Raw/2) + LBCarrys to Avg for each Active byte

// Add rdd active group (Raw(x-bpp)/2) to Average with LBCarry
psllq mm6, ShiftBpp // shift the mm6 mask to cover bytes 4 & 5
movq mm2, mm0 // mov updated Raws to mm2
psllq mm2, ShiftBpp // shift data to position correctly
// Data only needs to be shifted once here to
// get the correct x-bpp offset.
movq mm1, mm3 // now use mm1 for getting LBCarrys
pand mm1, mm2 // get LBCarrys for each byte where both
// lsb's were == 1 (Only valid for active group)
psrlq mm2, 1 // divide raw bytes by 2
pand mm2, mm4 // clear invalid bit 7 of each byte
paddb mm2, mm1 // add LBCarrys to (Raw(x-bpp)/2) for each byte
pand mm2, mm6 // Leave only Active Group 2 bytes to add to Avg
paddb mm0, mm2 // add (Raw/2) + LBCarrys to Avg for each Active byte

// Add 4th active group (Raw(x-bpp)/2) to Average with LBCarry
psllq mm6, ShiftBpp // shift the mm6 mask to cover bytes 6 & 7
movq mm2, mm0 // mov updated Raws to mm2
psllq mm2, ShiftBpp // shift data to position correctly
// Data only needs to be shifted once here to
// get the correct x-bpp offset.
add ebx, 8
movq mm1, mm3 // now use mm1 for getting LBCarrys
pand mm1, mm2 // get LBCarrys for each byte where both
// lsb's were == 1 (Only valid for active group)
psrlq mm2, 1 // divide raw bytes by 2
pand mm2, mm4 // clear invalid bit 7 of each byte
paddb mm2, mm1 // add LBCarrys to (Raw(x-bpp)/2) for each byte
pand mm2, mm6 // Leave only Active Group 2 bytes to add to Avg
paddb mm0, mm2 // add (Raw/2) + LBCarrys to Avg for each Active byte

cmp ebx, MMXLength
// Now ready to write back to memory
movq [edi + ebx - 8], mm0
// Prep Raw(x-bpp) for next loop
movq mm2, mm0 // mov updated Raws to mm2
jb davg2lp
} // end _asm block
}
break;

case 1: // bpp == 1
{
_asm {
// Re-init address pointers and offset
mov ebx, diff // ebx ==> x = offset to alignment boundary
mov edi, row // edi ==> Avg(x)
cmp ebx, FullLength // Test if offset at end of array
jnb davg1end
// Do Paeth decode for remaining bytes
mov esi, prev_row // esi ==> Prior(x)
mov edx, edi
xor ecx, ecx // zero ecx before using cl & cx in loop below
sub edx, bpp // edx ==> Raw(x-bpp)
davg1lp:
// Raw(x) = Avg(x) + ((Raw(x-bpp) + Prior(x))/2)
xor eax, eax
mov cl, [esi + ebx] // load cl with Prior(x)
mov al, [edx + ebx] // load al with Raw(x-bpp)
add ax, cx
inc ebx
shr ax, 1 // divide by 2
add al, [edi+ebx-1] // Add Avg(x); -1 to offset inc ebx
cmp ebx, FullLength // Check if at end of array
mov [edi+ebx-1], al // Write back Raw(x);
// mov does not affect flags; -1 to offset inc ebx
jb davg1lp
davg1end:
} // end _asm block
}
return;

case 8: // bpp == 8
{
_asm {
// Re-init address pointers and offset
mov ebx, diff // ebx ==> x = offset to alignment boundary
movq mm5, LBCarryMask
mov edi, row // edi ==> Avg(x)
movq mm4, HBClearMask
mov esi, prev_row // esi ==> Prior(x)
// PRIME the pump (load the first Raw(x-bpp) data set
movq mm2, [edi + ebx - 8] // Load previous aligned 8 bytes
// (NO NEED to correct position in loop below)
davg8lp:
movq mm0, [edi + ebx]
movq mm3, mm5
movq mm1, [esi + ebx]
add ebx, 8
pand mm3, mm1 // get lsb for each prev_row byte
psrlq mm1, 1 // divide prev_row bytes by 2
pand mm3, mm2 // get LBCarrys for each byte where both
// lsb's were == 1
psrlq mm2, 1 // divide raw bytes by 2
pand mm1, mm4 // clear invalid bit 7 of each byte
paddb mm0, mm3 // add LBCarrys to Avg for each byte
pand mm2, mm4 // clear invalid bit 7 of each byte
paddb mm0, mm1 // add (Prev_row/2) to Avg for each byte
paddb mm0, mm2 // add (Raw/2) to Avg for each byte
cmp ebx, MMXLength
movq [edi + ebx - 8], mm0
movq mm2, mm0 // reuse as Raw(x-bpp)
jb davg8lp
} // end _asm block
}
break;
default: // bpp greater than 8
{
_asm {
movq mm5, LBCarryMask
// Re-init address pointers and offset
mov ebx, diff // ebx ==> x = offset to alignment boundary
mov edi, row // edi ==> Avg(x)
movq mm4, HBClearMask
mov edx, edi
mov esi, prev_row // esi ==> Prior(x)
sub edx, bpp // edx ==> Raw(x-bpp)
davgAlp:
movq mm0, [edi + ebx]
movq mm3, mm5
movq mm1, [esi + ebx]
pand mm3, mm1 // get lsb for each prev_row byte
movq mm2, [edx + ebx]
psrlq mm1, 1 // divide prev_row bytes by 2
pand mm3, mm2 // get LBCarrys for each byte where both
// lsb's were == 1
psrlq mm2, 1 // divide raw bytes by 2
pand mm1, mm4 // clear invalid bit 7 of each byte
paddb mm0, mm3 // add LBCarrys to Avg for each byte
pand mm2, mm4 // clear invalid bit 7 of each byte
paddb mm0, mm1 // add (Prev_row/2) to Avg for each byte
add ebx, 8
paddb mm0, mm2 // add (Raw/2) to Avg for each byte
cmp ebx, MMXLength
movq [edi + ebx - 8], mm0
jb davgAlp
} // end _asm block
}
break;
} // end switch ( bpp )

_asm {
// MMX acceleration complete now do clean-up
// Check if any remaining bytes left to decode
mov ebx, MMXLength // ebx ==> x = offset bytes remaining after MMX
mov edi, row // edi ==> Avg(x)
cmp ebx, FullLength // Test if offset at end of array
jnb davgend
// Do Paeth decode for remaining bytes
mov esi, prev_row // esi ==> Prior(x)
mov edx, edi
xor ecx, ecx // zero ecx before using cl & cx in loop below
sub edx, bpp // edx ==> Raw(x-bpp)
davglp2:
// Raw(x) = Avg(x) + ((Raw(x-bpp) + Prior(x))/2)
xor eax, eax
mov cl, [esi + ebx] // load cl with Prior(x)
mov al, [edx + ebx] // load al with Raw(x-bpp)
add ax, cx
inc ebx
shr ax, 1 // divide by 2
add al, [edi+ebx-1] // Add Avg(x); -1 to offset inc ebx
cmp ebx, FullLength // Check if at end of array
mov [edi+ebx-1], al // Write back Raw(x);
// mov does not affect flags; -1 to offset inc ebx
jb davglp2
davgend:
emms // End MMX instructions; prep for possible FP instrs.
} // end _asm block
}

// Optimized code for PNG Paeth filter decoder
void /* PRIVATE */
png_read_filter_row_mmx_paeth(png_row_infop row_info, png_bytep row,
png_bytep prev_row)
{
png_uint_32 FullLength;
png_uint_32 MMXLength;
//png_uint_32 len;
int bpp;
int diff;
//int ptemp;
int patemp, pbtemp, pctemp;

bpp = (row_info->pixel_depth + 7) >> 3; // Get # bytes per pixel
FullLength = row_info->rowbytes; // # of bytes to filter
_asm
{
xor ebx, ebx // ebx ==> x offset
mov edi, row
xor edx, edx // edx ==> x-bpp offset
mov esi, prev_row
xor eax, eax

// Compute the Raw value for the first bpp bytes
// Note: the formula works out to be always
// Paeth(x) = Raw(x) + Prior(x) where x < bpp
dpthrlp:
mov al, [edi + ebx]
add al, [esi + ebx]
inc ebx
cmp ebx, bpp
mov [edi + ebx - 1], al
jb dpthrlp
// get # of bytes to alignment
mov diff, edi // take start of row
add diff, ebx // add bpp
xor ecx, ecx
add diff, 0xf // add 7 + 8 to incr past alignment boundary
and diff, 0xfffffff8 // mask to alignment boundary
sub diff, edi // subtract from start ==> value ebx at alignment
jz dpthgo
// fix alignment
dpthlp1:
xor eax, eax
// pav = p - a = (a + b - c) - a = b - c
mov al, [esi + ebx] // load Prior(x) into al
mov cl, [esi + edx] // load Prior(x-bpp) into cl
sub eax, ecx // subtract Prior(x-bpp)
mov patemp, eax // Save pav for later use
xor eax, eax
// pbv = p - b = (a + b - c) - b = a - c
mov al, [edi + edx] // load Raw(x-bpp) into al
sub eax, ecx // subtract Prior(x-bpp)
mov ecx, eax
// pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
add eax, patemp // pcv = pav + pbv
// pc = abs(pcv)
test eax, 0x80000000
jz dpthpca
neg eax // reverse sign of neg values
dpthpca:
mov pctemp, eax // save pc for later use
// pb = abs(pbv)
test ecx, 0x80000000
jz dpthpba
neg ecx // reverse sign of neg values
dpthpba:
mov pbtemp, ecx // save pb for later use
// pa = abs(pav)
mov eax, patemp
test eax, 0x80000000
jz dpthpaa
neg eax // reverse sign of neg values
dpthpaa:
mov patemp, eax // save pa for later use
// test if pa <= pb
cmp eax, ecx
jna dpthabb
// pa > pb; now test if pb <= pc
cmp ecx, pctemp
jna dpthbbc
// pb > pc; Raw(x) = Paeth(x) + Prior(x-bpp)
mov cl, [esi + edx] // load Prior(x-bpp) into cl
jmp dpthpaeth
dpthbbc:
// pb <= pc; Raw(x) = Paeth(x) + Prior(x)
mov cl, [esi + ebx] // load Prior(x) into cl
jmp dpthpaeth
dpthabb:
// pa <= pb; now test if pa <= pc
cmp eax, pctemp
jna dpthabc
// pa > pc; Raw(x) = Paeth(x) + Prior(x-bpp)
mov cl, [esi + edx] // load Prior(x-bpp) into cl
jmp dpthpaeth
dpthabc:
// pa <= pc; Raw(x) = Paeth(x) + Raw(x-bpp)
mov cl, [edi + edx] // load Raw(x-bpp) into cl
dpthpaeth:
inc ebx
inc edx
// Raw(x) = (Paeth(x) + Paeth_Predictor( a, b, c )) mod 256
add [edi + ebx - 1], cl
cmp ebx, diff
jb dpthlp1
dpthgo:
mov ecx, FullLength
mov eax, ecx
sub eax, ebx // subtract alignment fix
and eax, 0x00000007 // calc bytes over mult of 8
sub ecx, eax // drop over bytes from original length
mov MMXLength, ecx
} // end _asm block
// Now do the math for the rest of the row
switch ( bpp )
{
case 3:
{
ActiveMask.use = 0x0000000000ffffff;
ActiveMaskEnd.use = 0xffff000000000000;
ShiftBpp.use = 24; // == bpp(3) * 8
ShiftRem.use = 40; // == 64 - 24
_asm
{
mov ebx, diff
mov edi, row
mov esi, prev_row
pxor mm0, mm0
// PRIME the pump (load the first Raw(x-bpp) data set
movq mm1, [edi+ebx-8]
dpth3lp:
psrlq mm1, ShiftRem // shift last 3 bytes to 1st 3 bytes
movq mm2, [esi + ebx] // load b=Prior(x)
punpcklbw mm1, mm0 // Unpack High bytes of a
movq mm3, [esi+ebx-8] // Prep c=Prior(x-bpp) bytes
punpcklbw mm2, mm0 // Unpack High bytes of b
psrlq mm3, ShiftRem // shift last 3 bytes to 1st 3 bytes
// pav = p - a = (a + b - c) - a = b - c
movq mm4, mm2
punpcklbw mm3, mm0 // Unpack High bytes of c
// pbv = p - b = (a + b - c) - b = a - c
movq mm5, mm1
psubw mm4, mm3
pxor mm7, mm7
// pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
movq mm6, mm4
psubw mm5, mm3

// pa = abs(p-a) = abs(pav)
// pb = abs(p-b) = abs(pbv)
// pc = abs(p-c) = abs(pcv)
pcmpgtw mm0, mm4 // Create mask pav bytes < 0
paddw mm6, mm5
pand mm0, mm4 // Only pav bytes < 0 in mm7
pcmpgtw mm7, mm5 // Create mask pbv bytes < 0
psubw mm4, mm0
pand mm7, mm5 // Only pbv bytes < 0 in mm0
psubw mm4, mm0
psubw mm5, mm7
pxor mm0, mm0
pcmpgtw mm0, mm6 // Create mask pcv bytes < 0
pand mm0, mm6 // Only pav bytes < 0 in mm7
psubw mm5, mm7
psubw mm6, mm0
// test pa <= pb
movq mm7, mm4
psubw mm6, mm0
pcmpgtw mm7, mm5 // pa > pb?
movq mm0, mm7
// use mm7 mask to merge pa & pb
pand mm5, mm7
// use mm0 mask copy to merge a & b
pand mm2, mm0
pandn mm7, mm4
pandn mm0, mm1
paddw mm7, mm5
paddw mm0, mm2
// test ((pa <= pb)? pa:pb) <= pc
pcmpgtw mm7, mm6 // pab > pc?
pxor mm1, mm1
pand mm3, mm7
pandn mm7, mm0
paddw mm7, mm3
pxor mm0, mm0
packuswb mm7, mm1
movq mm3, [esi + ebx] // load c=Prior(x-bpp)
pand mm7, ActiveMask
movq mm2, mm3 // load b=Prior(x) step 1
paddb mm7, [edi + ebx] // add Paeth predictor with Raw(x)
punpcklbw mm3, mm0 // Unpack High bytes of c
movq [edi + ebx], mm7 // write back updated value
movq mm1, mm7 // Now mm1 will be used as Raw(x-bpp)
// Now do Paeth for 2nd set of bytes (3-5)
psrlq mm2, ShiftBpp // load b=Prior(x) step 2
punpcklbw mm1, mm0 // Unpack High bytes of a
pxor mm7, mm7
punpcklbw mm2, mm0 // Unpack High bytes of b
// pbv = p - b = (a + b - c) - b = a - c
movq mm5, mm1
// pav = p - a = (a + b - c) - a = b - c
movq mm4, mm2
psubw mm5, mm3
psubw mm4, mm3
// pcv = p - c = (a + b - c) -c = (a - c) + (b - c) =
// pav + pbv = pbv + pav
movq mm6, mm5
paddw mm6, mm4

// pa = abs(p-a) = abs(pav)
// pb = abs(p-b) = abs(pbv)
// pc = abs(p-c) = abs(pcv)
pcmpgtw mm0, mm5 // Create mask pbv bytes < 0
pcmpgtw mm7, mm4 // Create mask pav bytes < 0
pand mm0, mm5 // Only pbv bytes < 0 in mm0
pand mm7, mm4 // Only pav bytes < 0 in mm7
psubw mm5, mm0
psubw mm4, mm7
psubw mm5, mm0
psubw mm4, mm7
pxor mm0, mm0
pcmpgtw mm0, mm6 // Create mask pcv bytes < 0
pand mm0, mm6 // Only pav bytes < 0 in mm7
psubw mm6, mm0
// test pa <= pb
movq mm7, mm4
psubw mm6, mm0
pcmpgtw mm7, mm5 // pa > pb?
movq mm0, mm7
// use mm7 mask to merge pa & pb
pand mm5, mm7
// use mm0 mask copy to merge a & b
pand mm2, mm0
pandn mm7, mm4
pandn mm0, mm1
paddw mm7, mm5
paddw mm0, mm2
// test ((pa <= pb)? pa:pb) <= pc
pcmpgtw mm7, mm6 // pab > pc?
movq mm2, [esi + ebx] // load b=Prior(x)
pand mm3, mm7
pandn mm7, mm0
pxor mm1, mm1
paddw mm7, mm3
pxor mm0, mm0
packuswb mm7, mm1
movq mm3, mm2 // load c=Prior(x-bpp) step 1
pand mm7, ActiveMask
punpckhbw mm2, mm0 // Unpack High bytes of b
psllq mm7, ShiftBpp // Shift bytes to 2nd group of 3 bytes
// pav = p - a = (a + b - c) - a = b - c
movq mm4, mm2
paddb mm7, [edi + ebx] // add Paeth predictor with Raw(x)
psllq mm3, ShiftBpp // load c=Prior(x-bpp) step 2
movq [edi + ebx], mm7 // write back updated value
movq mm1, mm7
punpckhbw mm3, mm0 // Unpack High bytes of c
psllq mm1, ShiftBpp // Shift bytes
// Now mm1 will be used as Raw(x-bpp)
// Now do Paeth for 3rd, and final, set of bytes (6-7)
pxor mm7, mm7
punpckhbw mm1, mm0 // Unpack High bytes of a
psubw mm4, mm3
// pbv = p - b = (a + b - c) - b = a - c
movq mm5, mm1
// pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
movq mm6, mm4
psubw mm5, mm3
pxor mm0, mm0
paddw mm6, mm5

// pa = abs(p-a) = abs(pav)
// pb = abs(p-b) = abs(pbv)
// pc = abs(p-c) = abs(pcv)
pcmpgtw mm0, mm4 // Create mask pav bytes < 0
pcmpgtw mm7, mm5 // Create mask pbv bytes < 0
pand mm0, mm4 // Only pav bytes < 0 in mm7
pand mm7, mm5 // Only pbv bytes < 0 in mm0
psubw mm4, mm0
psubw mm5, mm7
psubw mm4, mm0
psubw mm5, mm7
pxor mm0, mm0
pcmpgtw mm0, mm6 // Create mask pcv bytes < 0
pand mm0, mm6 // Only pav bytes < 0 in mm7
psubw mm6, mm0
// test pa <= pb
movq mm7, mm4
psubw mm6, mm0
pcmpgtw mm7, mm5 // pa > pb?
movq mm0, mm7
// use mm0 mask copy to merge a & b
pand mm2, mm0
// use mm7 mask to merge pa & pb
pand mm5, mm7
pandn mm0, mm1
pandn mm7, mm4
paddw mm0, mm2
paddw mm7, mm5
// test ((pa <= pb)? pa:pb) <= pc
pcmpgtw mm7, mm6 // pab > pc?
pand mm3, mm7
pandn mm7, mm0
paddw mm7, mm3
pxor mm1, mm1
packuswb mm1, mm7
// Step ebx to next set of 8 bytes and repeat loop til done
add ebx, 8
pand mm1, ActiveMaskEnd
paddb mm1, [edi + ebx - 8] // add Paeth predictor with Raw(x)

cmp ebx, MMXLength
pxor mm0, mm0 // pxor does not affect flags
movq [edi + ebx - 8], mm1 // write back updated value
// mm1 will be used as Raw(x-bpp) next loop
// mm3 ready to be used as Prior(x-bpp) next loop
jb dpth3lp
} // end _asm block
}
break;

case 6:
case 7:
case 5:
{
ActiveMask.use = 0x00000000ffffffff;
ActiveMask2.use = 0xffffffff00000000;
ShiftBpp.use = bpp << 3; // == bpp * 8
ShiftRem.use = 64 - ShiftBpp.use;
_asm
{
mov ebx, diff
mov edi, row
mov esi, prev_row
// PRIME the pump (load the first Raw(x-bpp) data set
movq mm1, [edi+ebx-8]
pxor mm0, mm0
dpth6lp:
// Must shift to position Raw(x-bpp) data
psrlq mm1, ShiftRem
// Do first set of 4 bytes
movq mm3, [esi+ebx-8] // read c=Prior(x-bpp) bytes
punpcklbw mm1, mm0 // Unpack Low bytes of a
movq mm2, [esi + ebx] // load b=Prior(x)
punpcklbw mm2, mm0 // Unpack Low bytes of b
// Must shift to position Prior(x-bpp) data
psrlq mm3, ShiftRem
// pav = p - a = (a + b - c) - a = b - c
movq mm4, mm2
punpcklbw mm3, mm0 // Unpack Low bytes of c
// pbv = p - b = (a + b - c) - b = a - c
movq mm5, mm1
psubw mm4, mm3
pxor mm7, mm7
// pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
movq mm6, mm4
psubw mm5, mm3
// pa = abs(p-a) = abs(pav)
// pb = abs(p-b) = abs(pbv)
// pc = abs(p-c) = abs(pcv)
pcmpgtw mm0, mm4 // Create mask pav bytes < 0
paddw mm6, mm5
pand mm0, mm4 // Only pav bytes < 0 in mm7
pcmpgtw mm7, mm5 // Create mask pbv bytes < 0
psubw mm4, mm0
pand mm7, mm5 // Only pbv bytes < 0 in mm0
psubw mm4, mm0
psubw mm5, mm7
pxor mm0, mm0
pcmpgtw mm0, mm6 // Create mask pcv bytes < 0
pand mm0, mm6 // Only pav bytes < 0 in mm7
psubw mm5, mm7
psubw mm6, mm0
// test pa <= pb
movq mm7, mm4
psubw mm6, mm0
pcmpgtw mm7, mm5 // pa > pb?
movq mm0, mm7
// use mm7 mask to merge pa & pb
pand mm5, mm7
// use mm0 mask copy to merge a & b
pand mm2, mm0
pandn mm7, mm4
pandn mm0, mm1
paddw mm7, mm5
paddw mm0, mm2
// test ((pa <= pb)? pa:pb) <= pc
pcmpgtw mm7, mm6 // pab > pc?
pxor mm1, mm1
pand mm3, mm7
pandn mm7, mm0
paddw mm7, mm3
pxor mm0, mm0
packuswb mm7, mm1
movq mm3, [esi + ebx - 8] // load c=Prior(x-bpp)
pand mm7, ActiveMask
psrlq mm3, ShiftRem
movq mm2, [esi + ebx] // load b=Prior(x) step 1
paddb mm7, [edi + ebx] // add Paeth predictor with Raw(x)
movq mm6, mm2
movq [edi + ebx], mm7 // write back updated value
movq mm1, [edi+ebx-8]
psllq mm6, ShiftBpp
movq mm5, mm7
psrlq mm1, ShiftRem
por mm3, mm6
psllq mm5, ShiftBpp
punpckhbw mm3, mm0 // Unpack High bytes of c
por mm1, mm5
// Do second set of 4 bytes
punpckhbw mm2, mm0 // Unpack High bytes of b
punpckhbw mm1, mm0 // Unpack High bytes of a
// pav = p - a = (a + b - c) - a = b - c
movq mm4, mm2
// pbv = p - b = (a + b - c) - b = a - c
movq mm5, mm1
psubw mm4, mm3
pxor mm7, mm7
// pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
movq mm6, mm4
psubw mm5, mm3
// pa = abs(p-a) = abs(pav)
// pb = abs(p-b) = abs(pbv)
// pc = abs(p-c) = abs(pcv)
pcmpgtw mm0, mm4 // Create mask pav bytes < 0
paddw mm6, mm5
pand mm0, mm4 // Only pav bytes < 0 in mm7
pcmpgtw mm7, mm5 // Create mask pbv bytes < 0
psubw mm4, mm0
pand mm7, mm5 // Only pbv bytes < 0 in mm0
psubw mm4, mm0
psubw mm5, mm7
pxor mm0, mm0
pcmpgtw mm0, mm6 // Create mask pcv bytes < 0
pand mm0, mm6 // Only pav bytes < 0 in mm7
psubw mm5, mm7
psubw mm6, mm0
// test pa <= pb
movq mm7, mm4
psubw mm6, mm0
pcmpgtw mm7, mm5 // pa > pb?
movq mm0, mm7
// use mm7 mask to merge pa & pb
pand mm5, mm7
// use mm0 mask copy to merge a & b
pand mm2, mm0
pandn mm7, mm4
pandn mm0, mm1
paddw mm7, mm5
paddw mm0, mm2
// test ((pa <= pb)? pa:pb) <= pc
pcmpgtw mm7, mm6 // pab > pc?
pxor mm1, mm1
pand mm3, mm7
pandn mm7, mm0
pxor mm1, mm1
paddw mm7, mm3
pxor mm0, mm0
// Step ex to next set of 8 bytes and repeat loop til done
add ebx, 8
packuswb mm1, mm7
paddb mm1, [edi + ebx - 8] // add Paeth predictor with Raw(x)
cmp ebx, MMXLength
movq [edi + ebx - 8], mm1 // write back updated value
// mm1 will be used as Raw(x-bpp) next loop
jb dpth6lp
} // end _asm block
}
break;

case 4:
{
ActiveMask.use = 0x00000000ffffffff;
_asm {
mov ebx, diff
mov edi, row
mov esi, prev_row
pxor mm0, mm0
// PRIME the pump (load the first Raw(x-bpp) data set
movq mm1, [edi+ebx-8] // Only time should need to read
// a=Raw(x-bpp) bytes
dpth4lp:
// Do first set of 4 bytes
movq mm3, [esi+ebx-8] // read c=Prior(x-bpp) bytes
punpckhbw mm1, mm0 // Unpack Low bytes of a
movq mm2, [esi + ebx] // load b=Prior(x)
punpcklbw mm2, mm0 // Unpack High bytes of b
// pav = p - a = (a + b - c) - a = b - c
movq mm4, mm2
punpckhbw mm3, mm0 // Unpack High bytes of c
// pbv = p - b = (a + b - c) - b = a - c
movq mm5, mm1
psubw mm4, mm3
pxor mm7, mm7
// pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
movq mm6, mm4
psubw mm5, mm3
// pa = abs(p-a) = abs(pav)
// pb = abs(p-b) = abs(pbv)
// pc = abs(p-c) = abs(pcv)
pcmpgtw mm0, mm4 // Create mask pav bytes < 0
paddw mm6, mm5
pand mm0, mm4 // Only pav bytes < 0 in mm7
pcmpgtw mm7, mm5 // Create mask pbv bytes < 0
psubw mm4, mm0
pand mm7, mm5 // Only pbv bytes < 0 in mm0
psubw mm4, mm0
psubw mm5, mm7
pxor mm0, mm0
pcmpgtw mm0, mm6 // Create mask pcv bytes < 0
pand mm0, mm6 // Only pav bytes < 0 in mm7
psubw mm5, mm7
psubw mm6, mm0
// test pa <= pb
movq mm7, mm4
psubw mm6, mm0
pcmpgtw mm7, mm5 // pa > pb?
movq mm0, mm7
// use mm7 mask to merge pa & pb
pand mm5, mm7
// use mm0 mask copy to merge a & b
pand mm2, mm0
pandn mm7, mm4
pandn mm0, mm1
paddw mm7, mm5
paddw mm0, mm2
// test ((pa <= pb)? pa:pb) <= pc
pcmpgtw mm7, mm6 // pab > pc?
pxor mm1, mm1
pand mm3, mm7
pandn mm7, mm0
paddw mm7, mm3
pxor mm0, mm0
packuswb mm7, mm1
movq mm3, [esi + ebx] // load c=Prior(x-bpp)
pand mm7, ActiveMask
movq mm2, mm3 // load b=Prior(x) step 1
paddb mm7, [edi + ebx] // add Paeth predictor with Raw(x)
punpcklbw mm3, mm0 // Unpack High bytes of c
movq [edi + ebx], mm7 // write back updated value
movq mm1, mm7 // Now mm1 will be used as Raw(x-bpp)
// Do second set of 4 bytes
punpckhbw mm2, mm0 // Unpack Low bytes of b
punpcklbw mm1, mm0 // Unpack Low bytes of a
// pav = p - a = (a + b - c) - a = b - c
movq mm4, mm2
// pbv = p - b = (a + b - c) - b = a - c
movq mm5, mm1
psubw mm4, mm3
pxor mm7, mm7
// pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
movq mm6, mm4
psubw mm5, mm3
// pa = abs(p-a) = abs(pav)
// pb = abs(p-b) = abs(pbv)
// pc = abs(p-c) = abs(pcv)
pcmpgtw mm0, mm4 // Create mask pav bytes < 0
paddw mm6, mm5
pand mm0, mm4 // Only pav bytes < 0 in mm7
pcmpgtw mm7, mm5 // Create mask pbv bytes < 0
psubw mm4, mm0
pand mm7, mm5 // Only pbv bytes < 0 in mm0
psubw mm4, mm0
psubw mm5, mm7
pxor mm0, mm0
pcmpgtw mm0, mm6 // Create mask pcv bytes < 0
pand mm0, mm6 // Only pav bytes < 0 in mm7
psubw mm5, mm7
psubw mm6, mm0
// test pa <= pb
movq mm7, mm4
psubw mm6, mm0
pcmpgtw mm7, mm5 // pa > pb?
movq mm0, mm7
// use mm7 mask to merge pa & pb
pand mm5, mm7
// use mm0 mask copy to merge a & b
pand mm2, mm0
pandn mm7, mm4
pandn mm0, mm1
paddw mm7, mm5
paddw mm0, mm2
// test ((pa <= pb)? pa:pb) <= pc
pcmpgtw mm7, mm6 // pab > pc?
pxor mm1, mm1
pand mm3, mm7
pandn mm7, mm0
pxor mm1, mm1
paddw mm7, mm3
pxor mm0, mm0
// Step ex to next set of 8 bytes and repeat loop til done
add ebx, 8
packuswb mm1, mm7
paddb mm1, [edi + ebx - 8] // add Paeth predictor with Raw(x)
cmp ebx, MMXLength
movq [edi + ebx - 8], mm1 // write back updated value
// mm1 will be used as Raw(x-bpp) next loop
jb dpth4lp
} // end _asm block
}
break;
case 8: // bpp == 8
{
ActiveMask.use = 0x00000000ffffffff;
_asm {
mov ebx, diff
mov edi, row
mov esi, prev_row
pxor mm0, mm0
// PRIME the pump (load the first Raw(x-bpp) data set
movq mm1, [edi+ebx-8] // Only time should need to read
// a=Raw(x-bpp) bytes
dpth8lp:
// Do first set of 4 bytes
movq mm3, [esi+ebx-8] // read c=Prior(x-bpp) bytes
punpcklbw mm1, mm0 // Unpack Low bytes of a
movq mm2, [esi + ebx] // load b=Prior(x)
punpcklbw mm2, mm0 // Unpack Low bytes of b
// pav = p - a = (a + b - c) - a = b - c
movq mm4, mm2
punpcklbw mm3, mm0 // Unpack Low bytes of c
// pbv = p - b = (a + b - c) - b = a - c
movq mm5, mm1
psubw mm4, mm3
pxor mm7, mm7
// pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
movq mm6, mm4
psubw mm5, mm3
// pa = abs(p-a) = abs(pav)
// pb = abs(p-b) = abs(pbv)
// pc = abs(p-c) = abs(pcv)
pcmpgtw mm0, mm4 // Create mask pav bytes < 0
paddw mm6, mm5
pand mm0, mm4 // Only pav bytes < 0 in mm7
pcmpgtw mm7, mm5 // Create mask pbv bytes < 0
psubw mm4, mm0
pand mm7, mm5 // Only pbv bytes < 0 in mm0
psubw mm4, mm0
psubw mm5, mm7
pxor mm0, mm0
pcmpgtw mm0, mm6 // Create mask pcv bytes < 0
pand mm0, mm6 // Only pav bytes < 0 in mm7
psubw mm5, mm7
psubw mm6, mm0
// test pa <= pb
movq mm7, mm4
psubw mm6, mm0
pcmpgtw mm7, mm5 // pa > pb?
movq mm0, mm7
// use mm7 mask to merge pa & pb
pand mm5, mm7
// use mm0 mask copy to merge a & b
pand mm2, mm0
pandn mm7, mm4
pandn mm0, mm1
paddw mm7, mm5
paddw mm0, mm2
// test ((pa <= pb)? pa:pb) <= pc
pcmpgtw mm7, mm6 // pab > pc?
pxor mm1, mm1
pand mm3, mm7
pandn mm7, mm0
paddw mm7, mm3
pxor mm0, mm0
packuswb mm7, mm1
movq mm3, [esi+ebx-8] // read c=Prior(x-bpp) bytes
pand mm7, ActiveMask
movq mm2, [esi + ebx] // load b=Prior(x)
paddb mm7, [edi + ebx] // add Paeth predictor with Raw(x)
punpckhbw mm3, mm0 // Unpack High bytes of c
movq [edi + ebx], mm7 // write back updated value
movq mm1, [edi+ebx-8] // read a=Raw(x-bpp) bytes

// Do second set of 4 bytes
punpckhbw mm2, mm0 // Unpack High bytes of b
punpckhbw mm1, mm0 // Unpack High bytes of a
// pav = p - a = (a + b - c) - a = b - c
movq mm4, mm2
// pbv = p - b = (a + b - c) - b = a - c
movq mm5, mm1
psubw mm4, mm3
pxor mm7, mm7
// pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
movq mm6, mm4
psubw mm5, mm3
// pa = abs(p-a) = abs(pav)
// pb = abs(p-b) = abs(pbv)
// pc = abs(p-c) = abs(pcv)
pcmpgtw mm0, mm4 // Create mask pav bytes < 0
paddw mm6, mm5
pand mm0, mm4 // Only pav bytes < 0 in mm7
pcmpgtw mm7, mm5 // Create mask pbv bytes < 0
psubw mm4, mm0
pand mm7, mm5 // Only pbv bytes < 0 in mm0
psubw mm4, mm0
psubw mm5, mm7
pxor mm0, mm0
pcmpgtw mm0, mm6 // Create mask pcv bytes < 0
pand mm0, mm6 // Only pav bytes < 0 in mm7
psubw mm5, mm7
psubw mm6, mm0
// test pa <= pb
movq mm7, mm4
psubw mm6, mm0
pcmpgtw mm7, mm5 // pa > pb?
movq mm0, mm7
// use mm7 mask to merge pa & pb
pand mm5, mm7
// use mm0 mask copy to merge a & b
pand mm2, mm0
pandn mm7, mm4
pandn mm0, mm1
paddw mm7, mm5
paddw mm0, mm2
// test ((pa <= pb)? pa:pb) <= pc
pcmpgtw mm7, mm6 // pab > pc?
pxor mm1, mm1
pand mm3, mm7
pandn mm7, mm0
pxor mm1, mm1
paddw mm7, mm3
pxor mm0, mm0
// Step ex to next set of 8 bytes and repeat loop til done
add ebx, 8
packuswb mm1, mm7
paddb mm1, [edi + ebx - 8] // add Paeth predictor with Raw(x)
cmp ebx, MMXLength
movq [edi + ebx - 8], mm1 // write back updated value
// mm1 will be used as Raw(x-bpp) next loop
jb dpth8lp
} // end _asm block
}
break;

case 1: // bpp = 1
case 2: // bpp = 2
default: // bpp > 8
{
_asm {
mov ebx, diff
cmp ebx, FullLength
jnb dpthdend
mov edi, row
mov esi, prev_row
// Do Paeth decode for remaining bytes
mov edx, ebx
xor ecx, ecx // zero ecx before using cl & cx in loop below
sub edx, bpp // Set edx = ebx - bpp
dpthdlp:
xor eax, eax
// pav = p - a = (a + b - c) - a = b - c
mov al, [esi + ebx] // load Prior(x) into al
mov cl, [esi + edx] // load Prior(x-bpp) into cl
sub eax, ecx // subtract Prior(x-bpp)
mov patemp, eax // Save pav for later use
xor eax, eax
// pbv = p - b = (a + b - c) - b = a - c
mov al, [edi + edx] // load Raw(x-bpp) into al
sub eax, ecx // subtract Prior(x-bpp)
mov ecx, eax
// pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
add eax, patemp // pcv = pav + pbv
// pc = abs(pcv)
test eax, 0x80000000
jz dpthdpca
neg eax // reverse sign of neg values
dpthdpca:
mov pctemp, eax // save pc for later use
// pb = abs(pbv)
test ecx, 0x80000000
jz dpthdpba
neg ecx // reverse sign of neg values
dpthdpba:
mov pbtemp, ecx // save pb for later use
// pa = abs(pav)
mov eax, patemp
test eax, 0x80000000
jz dpthdpaa
neg eax // reverse sign of neg values
dpthdpaa:
mov patemp, eax // save pa for later use
// test if pa <= pb
cmp eax, ecx
jna dpthdabb
// pa > pb; now test if pb <= pc
cmp ecx, pctemp
jna dpthdbbc
// pb > pc; Raw(x) = Paeth(x) + Prior(x-bpp)
mov cl, [esi + edx] // load Prior(x-bpp) into cl
jmp dpthdpaeth
dpthdbbc:
// pb <= pc; Raw(x) = Paeth(x) + Prior(x)
mov cl, [esi + ebx] // load Prior(x) into cl
jmp dpthdpaeth
dpthdabb:
// pa <= pb; now test if pa <= pc
cmp eax, pctemp
jna dpthdabc
// pa > pc; Raw(x) = Paeth(x) + Prior(x-bpp)
mov cl, [esi + edx] // load Prior(x-bpp) into cl
jmp dpthdpaeth
dpthdabc:
// pa <= pc; Raw(x) = Paeth(x) + Raw(x-bpp)
mov cl, [edi + edx] // load Raw(x-bpp) into cl
dpthdpaeth:
inc ebx
inc edx
// Raw(x) = (Paeth(x) + Paeth_Predictor( a, b, c )) mod 256
add [edi + ebx - 1], cl
cmp ebx, FullLength
jb dpthdlp
dpthdend:
} // end _asm block
}
return; // No need to go further with this one
} // end switch ( bpp )
_asm
{
// MMX acceleration complete now do clean-up
// Check if any remaining bytes left to decode
mov ebx, MMXLength
cmp ebx, FullLength
jnb dpthend
mov edi, row
mov esi, prev_row
// Do Paeth decode for remaining bytes
mov edx, ebx
xor ecx, ecx // zero ecx before using cl & cx in loop below
sub edx, bpp // Set edx = ebx - bpp
dpthlp2:
xor eax, eax
// pav = p - a = (a + b - c) - a = b - c
mov al, [esi + ebx] // load Prior(x) into al
mov cl, [esi + edx] // load Prior(x-bpp) into cl
sub eax, ecx // subtract Prior(x-bpp)
mov patemp, eax // Save pav for later use
xor eax, eax
// pbv = p - b = (a + b - c) - b = a - c
mov al, [edi + edx] // load Raw(x-bpp) into al
sub eax, ecx // subtract Prior(x-bpp)
mov ecx, eax
// pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
add eax, patemp // pcv = pav + pbv
// pc = abs(pcv)
test eax, 0x80000000
jz dpthpca2
neg eax // reverse sign of neg values
dpthpca2:
mov pctemp, eax // save pc for later use
// pb = abs(pbv)
test ecx, 0x80000000
jz dpthpba2
neg ecx // reverse sign of neg values
dpthpba2:
mov pbtemp, ecx // save pb for later use
// pa = abs(pav)
mov eax, patemp
test eax, 0x80000000
jz dpthpaa2
neg eax // reverse sign of neg values
dpthpaa2:
mov patemp, eax // save pa for later use
// test if pa <= pb
cmp eax, ecx
jna dpthabb2
// pa > pb; now test if pb <= pc
cmp ecx, pctemp
jna dpthbbc2
// pb > pc; Raw(x) = Paeth(x) + Prior(x-bpp)
mov cl, [esi + edx] // load Prior(x-bpp) into cl
jmp dpthpaeth2
dpthbbc2:
// pb <= pc; Raw(x) = Paeth(x) + Prior(x)
mov cl, [esi + ebx] // load Prior(x) into cl
jmp dpthpaeth2
dpthabb2:
// pa <= pb; now test if pa <= pc
cmp eax, pctemp
jna dpthabc2
// pa > pc; Raw(x) = Paeth(x) + Prior(x-bpp)
mov cl, [esi + edx] // load Prior(x-bpp) into cl
jmp dpthpaeth2
dpthabc2:
// pa <= pc; Raw(x) = Paeth(x) + Raw(x-bpp)
mov cl, [edi + edx] // load Raw(x-bpp) into cl
dpthpaeth2:
inc ebx
inc edx
// Raw(x) = (Paeth(x) + Paeth_Predictor( a, b, c )) mod 256
add [edi + ebx - 1], cl
cmp ebx, FullLength
jb dpthlp2
dpthend:
emms // End MMX instructions; prep for possible FP instrs.
} // end _asm block
}

// Optimized code for PNG Sub filter decoder
void /* PRIVATE */
png_read_filter_row_mmx_sub(png_row_infop row_info, png_bytep row)
{
//int test;
int bpp;
png_uint_32 FullLength;
png_uint_32 MMXLength;
int diff;

bpp = (row_info->pixel_depth + 7) >> 3; // Get # bytes per pixel
FullLength = row_info->rowbytes - bpp; // # of bytes to filter
_asm {
mov edi, row
mov esi, edi // lp = row
add edi, bpp // rp = row + bpp
xor eax, eax
// get # of bytes to alignment
mov diff, edi // take start of row
add diff, 0xf // add 7 + 8 to incr past
// alignment boundary
xor ebx, ebx
and diff, 0xfffffff8 // mask to alignment boundary
sub diff, edi // subtract from start ==> value
// ebx at alignment
jz dsubgo
// fix alignment
dsublp1:
mov al, [esi+ebx]
add [edi+ebx], al
inc ebx
cmp ebx, diff
jb dsublp1
dsubgo:
mov ecx, FullLength
mov edx, ecx
sub edx, ebx // subtract alignment fix
and edx, 0x00000007 // calc bytes over mult of 8
sub ecx, edx // drop over bytes from length
mov MMXLength, ecx
} // end _asm block

// Now do the math for the rest of the row
switch ( bpp )
{
case 3:
{
ActiveMask.use = 0x0000ffffff000000;
ShiftBpp.use = 24; // == 3 * 8
ShiftRem.use = 40; // == 64 - 24
_asm {
mov edi, row
movq mm7, ActiveMask // Load ActiveMask for 2nd active byte group
mov esi, edi // lp = row
add edi, bpp // rp = row + bpp
movq mm6, mm7
mov ebx, diff
psllq mm6, ShiftBpp // Move mask in mm6 to cover 3rd active
// byte group
// PRIME the pump (load the first Raw(x-bpp) data set
movq mm1, [edi+ebx-8]
dsub3lp:
psrlq mm1, ShiftRem // Shift data for adding 1st bpp bytes
// no need for mask; shift clears inactive bytes
// Add 1st active group
movq mm0, [edi+ebx]
paddb mm0, mm1
// Add 2nd active group
movq mm1, mm0 // mov updated Raws to mm1
psllq mm1, ShiftBpp // shift data to position correctly
pand mm1, mm7 // mask to use only 2nd active group
paddb mm0, mm1
// Add 3rd active group
movq mm1, mm0 // mov updated Raws to mm1
psllq mm1, ShiftBpp // shift data to position correctly
pand mm1, mm6 // mask to use only 3rd active group
add ebx, 8
paddb mm0, mm1
cmp ebx, MMXLength
movq [edi+ebx-8], mm0 // Write updated Raws back to array
// Prep for doing 1st add at top of loop
movq mm1, mm0
jb dsub3lp
} // end _asm block
}
break;

case 1:
{
// Placed here just in case this is a duplicate of the
// non-MMX code for the SUB filter in png_read_filter_row below
//
// png_bytep rp;
// png_bytep lp;
// png_uint_32 i;
// bpp = (row_info->pixel_depth + 7) >> 3;
// for (i = (png_uint_32)bpp, rp = row + bpp, lp = row;
// i < row_info->rowbytes; i++, rp++, lp++)
// {
// *rp = (png_byte)(((int)(*rp) + (int)(*lp)) & 0xff);
// }
_asm {
mov ebx, diff
mov edi, row
cmp ebx, FullLength
jnb dsub1end
mov esi, edi // lp = row
xor eax, eax
add edi, bpp // rp = row + bpp
dsub1lp:
mov al, [esi+ebx]
add [edi+ebx], al
inc ebx
cmp ebx, FullLength
jb dsub1lp
dsub1end:
} // end _asm block
}
return;

case 6:
case 7:
case 4:
case 5:
{
ShiftBpp.use = bpp << 3;
ShiftRem.use = 64 - ShiftBpp.use;
_asm {
mov edi, row
mov ebx, diff
mov esi, edi // lp = row
add edi, bpp // rp = row + bpp
// PRIME the pump (load the first Raw(x-bpp) data set
movq mm1, [edi+ebx-8]
dsub4lp:
psrlq mm1, ShiftRem // Shift data for adding 1st bpp bytes
// no need for mask; shift clears inactive bytes
movq mm0, [edi+ebx]
paddb mm0, mm1
// Add 2nd active group
movq mm1, mm0 // mov updated Raws to mm1
psllq mm1, ShiftBpp // shift data to position correctly
// there is no need for any mask
// since shift clears inactive bits/bytes
add ebx, 8
paddb mm0, mm1
cmp ebx, MMXLength
movq [edi+ebx-8], mm0
movq mm1, mm0 // Prep for doing 1st add at top of loop
jb dsub4lp
} // end _asm block
}
break;

case 2:
{
ActiveMask.use = 0x00000000ffff0000;
ShiftBpp.use = 16; // == 2 * 8
ShiftRem.use = 48; // == 64 - 16
_asm {
movq mm7, ActiveMask // Load ActiveMask for 2nd active byte group
mov ebx, diff
movq mm6, mm7
mov edi, row
psllq mm6, ShiftBpp // Move mask in mm6 to cover 3rd active
// byte group
mov esi, edi // lp = row
movq mm5, mm6
add edi, bpp // rp = row + bpp
psllq mm5, ShiftBpp // Move mask in mm5 to cover 4th active
// byte group
// PRIME the pump (load the first Raw(x-bpp) data set
movq mm1, [edi+ebx-8]
dsub2lp:
// Add 1st active group
psrlq mm1, ShiftRem // Shift data for adding 1st bpp bytes
// no need for mask; shift clears inactive
// bytes
movq mm0, [edi+ebx]
paddb mm0, mm1
// Add 2nd active group
movq mm1, mm0 // mov updated Raws to mm1
psllq mm1, ShiftBpp // shift data to position correctly
pand mm1, mm7 // mask to use only 2nd active group
paddb mm0, mm1
// Add 3rd active group
movq mm1, mm0 // mov updated Raws to mm1
psllq mm1, ShiftBpp // shift data to position correctly
pand mm1, mm6 // mask to use only 3rd active group
paddb mm0, mm1
// Add 4th active group
movq mm1, mm0 // mov updated Raws to mm1
psllq mm1, ShiftBpp // shift data to position correctly
pand mm1, mm5 // mask to use only 4th active group
add ebx, 8
paddb mm0, mm1
cmp ebx, MMXLength
movq [edi+ebx-8], mm0 // Write updated Raws back to array
movq mm1, mm0 // Prep for doing 1st add at top of loop
jb dsub2lp
} // end _asm block
}
break;
case 8:
{
_asm {
mov edi, row
mov ebx, diff
mov esi, edi // lp = row
add edi, bpp // rp = row + bpp
mov ecx, MMXLength
movq mm7, [edi+ebx-8] // PRIME the pump (load the first
// Raw(x-bpp) data set
and ecx, 0x0000003f // calc bytes over mult of 64
dsub8lp:
movq mm0, [edi+ebx] // Load Sub(x) for 1st 8 bytes
paddb mm0, mm7
movq mm1, [edi+ebx+8] // Load Sub(x) for 2nd 8 bytes
movq [edi+ebx], mm0 // Write Raw(x) for 1st 8 bytes
// Now mm0 will be used as Raw(x-bpp) for
// the 2nd group of 8 bytes. This will be
// repeated for each group of 8 bytes with
// the 8th group being used as the Raw(x-bpp)
// for the 1st group of the next loop.
paddb mm1, mm0
movq mm2, [edi+ebx+16] // Load Sub(x) for 3rd 8 bytes
movq [edi+ebx+8], mm1 // Write Raw(x) for 2nd 8 bytes
paddb mm2, mm1
movq mm3, [edi+ebx+24] // Load Sub(x) for 4th 8 bytes
movq [edi+ebx+16], mm2 // Write Raw(x) for 3rd 8 bytes
paddb mm3, mm2
movq mm4, [edi+ebx+32] // Load Sub(x) for 5th 8 bytes
movq [edi+ebx+24], mm3 // Write Raw(x) for 4th 8 bytes
paddb mm4, mm3
movq mm5, [edi+ebx+40] // Load Sub(x) for 6th 8 bytes
movq [edi+ebx+32], mm4 // Write Raw(x) for 5th 8 bytes
paddb mm5, mm4
movq mm6, [edi+ebx+48] // Load Sub(x) for 7th 8 bytes
movq [edi+ebx+40], mm5 // Write Raw(x) for 6th 8 bytes
paddb mm6, mm5
movq mm7, [edi+ebx+56] // Load Sub(x) for 8th 8 bytes
movq [edi+ebx+48], mm6 // Write Raw(x) for 7th 8 bytes
add ebx, 64
paddb mm7, mm6
cmp ebx, ecx
movq [edi+ebx-8], mm7 // Write Raw(x) for 8th 8 bytes
jb dsub8lp
cmp ebx, MMXLength
jnb dsub8lt8
dsub8lpA:
movq mm0, [edi+ebx]
add ebx, 8
paddb mm0, mm7
cmp ebx, MMXLength
movq [edi+ebx-8], mm0 // use -8 to offset early add to ebx
movq mm7, mm0 // Move calculated Raw(x) data to mm1 to
// be the new Raw(x-bpp) for the next loop
jb dsub8lpA
dsub8lt8:
} // end _asm block
}
break;

default: // bpp greater than 8 bytes
{
_asm {
mov ebx, diff
mov edi, row
mov esi, edi // lp = row
add edi, bpp // rp = row + bpp
dsubAlp:
movq mm0, [edi+ebx]
movq mm1, [esi+ebx]
add ebx, 8
paddb mm0, mm1
cmp ebx, MMXLength
movq [edi+ebx-8], mm0 // mov does not affect flags; -8 to offset
// add ebx
jb dsubAlp
} // end _asm block
}
break;

} // end switch ( bpp )

_asm {
mov ebx, MMXLength
mov edi, row
cmp ebx, FullLength
jnb dsubend
mov esi, edi // lp = row
xor eax, eax
add edi, bpp // rp = row + bpp
dsublp2:
mov al, [esi+ebx]
add [edi+ebx], al
inc ebx
cmp ebx, FullLength
jb dsublp2
dsubend:
emms // End MMX instructions; prep for possible FP instrs.
} // end _asm block
}

// Optimized code for PNG Up filter decoder
void /* PRIVATE */
png_read_filter_row_mmx_up(png_row_infop row_info, png_bytep row,
png_bytep prev_row)
{
png_uint_32 len;
len = row_info->rowbytes; // # of bytes to filter
_asm {
mov edi, row
// get # of bytes to alignment
mov ecx, edi
xor ebx, ebx
add ecx, 0x7
xor eax, eax
and ecx, 0xfffffff8
mov esi, prev_row
sub ecx, edi
jz dupgo
// fix alignment
duplp1:
mov al, [edi+ebx]
add al, [esi+ebx]
inc ebx
cmp ebx, ecx
mov [edi + ebx-1], al // mov does not affect flags; -1 to offset inc ebx
jb duplp1
dupgo:
mov ecx, len
mov edx, ecx
sub edx, ebx // subtract alignment fix
and edx, 0x0000003f // calc bytes over mult of 64
sub ecx, edx // drop over bytes from length
// Unrolled loop - use all MMX registers and interleave to reduce
// number of branch instructions (loops) and reduce partial stalls
duploop:
movq mm1, [esi+ebx]
movq mm0, [edi+ebx]
movq mm3, [esi+ebx+8]
paddb mm0, mm1
movq mm2, [edi+ebx+8]
movq [edi+ebx], mm0
paddb mm2, mm3
movq mm5, [esi+ebx+16]
movq [edi+ebx+8], mm2
movq mm4, [edi+ebx+16]
movq mm7, [esi+ebx+24]
paddb mm4, mm5
movq mm6, [edi+ebx+24]
movq [edi+ebx+16], mm4
paddb mm6, mm7
movq mm1, [esi+ebx+32]
movq [edi+ebx+24], mm6
movq mm0, [edi+ebx+32]
movq mm3, [esi+ebx+40]
paddb mm0, mm1
movq mm2, [edi+ebx+40]
movq [edi+ebx+32], mm0
paddb mm2, mm3
movq mm5, [esi+ebx+48]
movq [edi+ebx+40], mm2
movq mm4, [edi+ebx+48]
movq mm7, [esi+ebx+56]
paddb mm4, mm5
movq mm6, [edi+ebx+56]
movq [edi+ebx+48], mm4
add ebx, 64
paddb mm6, mm7
cmp ebx, ecx
movq [edi+ebx-8], mm6 // (+56)movq does not affect flags;
// -8 to offset add ebx
jb duploop

cmp edx, 0 // Test for bytes over mult of 64
jz dupend

// 2 lines added by lcreeve@netins.net
// (mail 11 Jul 98 in png-implement list)
cmp edx, 8 //test for less than 8 bytes
jb duplt8

add ecx, edx
and edx, 0x00000007 // calc bytes over mult of 8
sub ecx, edx // drop over bytes from length
jz duplt8
// Loop using MMX registers mm0 & mm1 to update 8 bytes simultaneously
duplpA:
movq mm1, [esi+ebx]
movq mm0, [edi+ebx]
add ebx, 8
paddb mm0, mm1
cmp ebx, ecx
movq [edi+ebx-8], mm0 // movq does not affect flags; -8 to offset add ebx
jb duplpA
cmp edx, 0 // Test for bytes over mult of 8
jz dupend
duplt8:
xor eax, eax
add ecx, edx // move over byte count into counter
// Loop using x86 registers to update remaining bytes
duplp2:
mov al, [edi + ebx]
add al, [esi + ebx]
inc ebx
cmp ebx, ecx
mov [edi + ebx-1], al // mov does not affect flags; -1 to offset inc ebx
jb duplp2
dupend:
// Conversion of filtered row completed
emms // End MMX instructions; prep for possible FP instrs.
} // end _asm block
}

// Optimized png_read_filter_row routines
void /* PRIVATE */
png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep
row, png_bytep prev_row, int filter)
{
#ifdef PNG_DEBUG
char filnm[10];
#endif

if (mmx_supported == 2) {
/* this should have happened in png_init_mmx_flags() already */
png_warning(png_ptr, "asm_flags may not have been initialized");
png_mmx_support();
}

#ifdef PNG_DEBUG
png_debug(1, "in png_read_filter_row\n");
switch (filter)
{
case 0: sprintf(filnm, "none");
break;
case 1: sprintf(filnm, "sub-%s",
(png_ptr->asm_flags & PNG_ASM_FLAG_MMX_READ_FILTER_SUB)? "MMX" : "x86");
break;
case 2: sprintf(filnm, "up-%s",
(png_ptr->asm_flags & PNG_ASM_FLAG_MMX_READ_FILTER_UP)? "MMX" : "x86");
break;
case 3: sprintf(filnm, "avg-%s",
(png_ptr->asm_flags & PNG_ASM_FLAG_MMX_READ_FILTER_AVG)? "MMX" : "x86");
break;
case 4: sprintf(filnm, "Paeth-%s",
(png_ptr->asm_flags & PNG_ASM_FLAG_MMX_READ_FILTER_PAETH)? "MMX":"x86");
break;
default: sprintf(filnm, "unknw");
break;
}
png_debug2(0,"row=%5d, %s, ", png_ptr->row_number, filnm);
png_debug2(0, "pd=%2d, b=%d, ", (int)row_info->pixel_depth,
(int)((row_info->pixel_depth + 7) >> 3));
png_debug1(0,"len=%8d, ", row_info->rowbytes);
#endif /* PNG_DEBUG */

switch (filter)
{
case PNG_FILTER_VALUE_NONE:
break;

case PNG_FILTER_VALUE_SUB:
{
if ((png_ptr->asm_flags & PNG_ASM_FLAG_MMX_READ_FILTER_SUB) &&
(row_info->pixel_depth >= png_ptr->mmx_bitdepth_threshold) &&
(row_info->rowbytes >= png_ptr->mmx_rowbytes_threshold))
{
png_read_filter_row_mmx_sub(row_info, row);
}
else
{
png_uint_32 i;
png_uint_32 istop = row_info->rowbytes;
png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3;
png_bytep rp = row + bpp;
png_bytep lp = row;

for (i = bpp; i < istop; i++)
{
*rp = (png_byte)(((int)(*rp) + (int)(*lp++)) & 0xff);
rp++;
}
}
break;
}

case PNG_FILTER_VALUE_UP:
{
if ((png_ptr->asm_flags & PNG_ASM_FLAG_MMX_READ_FILTER_UP) &&
(row_info->pixel_depth >= png_ptr->mmx_bitdepth_threshold) &&
(row_info->rowbytes >= png_ptr->mmx_rowbytes_threshold))
{
png_read_filter_row_mmx_up(row_info, row, prev_row);
}
else
{
png_uint_32 i;
png_uint_32 istop = row_info->rowbytes;
png_bytep rp = row;
png_bytep pp = prev_row;

for (i = 0; i < istop; ++i)
{
*rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
rp++;
}
}
break;
}

case PNG_FILTER_VALUE_AVG:
{
if ((png_ptr->asm_flags & PNG_ASM_FLAG_MMX_READ_FILTER_AVG) &&
(row_info->pixel_depth >= png_ptr->mmx_bitdepth_threshold) &&
(row_info->rowbytes >= png_ptr->mmx_rowbytes_threshold))
{
png_read_filter_row_mmx_avg(row_info, row, prev_row);
}
else
{
png_uint_32 i;
png_bytep rp = row;
png_bytep pp = prev_row;
png_bytep lp = row;
png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3;
png_uint_32 istop = row_info->rowbytes - bpp;

for (i = 0; i < bpp; i++)
{
*rp = (png_byte)(((int)(*rp) +
((int)(*pp++) >> 1)) & 0xff);
rp++;
}

for (i = 0; i < istop; i++)
{
*rp = (png_byte)(((int)(*rp) +
((int)(*pp++ + *lp++) >> 1)) & 0xff);
rp++;
}
}
break;
}

case PNG_FILTER_VALUE_PAETH:
{
if ((png_ptr->asm_flags & PNG_ASM_FLAG_MMX_READ_FILTER_PAETH) &&
(row_info->pixel_depth >= png_ptr->mmx_bitdepth_threshold) &&
(row_info->rowbytes >= png_ptr->mmx_rowbytes_threshold))
{
png_read_filter_row_mmx_paeth(row_info, row, prev_row);
}
else
{
png_uint_32 i;
png_bytep rp = row;
png_bytep pp = prev_row;
png_bytep lp = row;
png_bytep cp = prev_row;
png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3;
png_uint_32 istop=row_info->rowbytes - bpp;

for (i = 0; i < bpp; i++)
{
*rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
rp++;
}

for (i = 0; i < istop; i++) // use leftover rp,pp
{
int a, b, c, pa, pb, pc, p;

a = *lp++;
b = *pp++;
c = *cp++;

p = b - c;
pc = a - c;

#ifdef PNG_USE_ABS
pa = abs(p);
pb = abs(pc);
pc = abs(p + pc);
#else
pa = p < 0 ? -p : p;
pb = pc < 0 ? -pc : pc;
pc = (p + pc) < 0 ? -(p + pc) : p + pc;
#endif

/*
if (pa <= pb && pa <= pc)
p = a;
else if (pb <= pc)
p = b;
else
p = c;
*/

p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;

*rp = (png_byte)(((int)(*rp) + p) & 0xff);
rp++;
}
}
break;
}

default:
png_warning(png_ptr, "Ignoring bad row filter type");
*row=0;
break;
}
}

#endif /* PNG_ASSEMBLER_CODE_SUPPORTED && PNG_USE_PNGVCRD */

Subversion Repositories shark

(root)/shark/trunk/ports/png/pngvcrd.c @ 956 - Rev 96