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Imported from libpng-1.0.4d2.tar

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This commit is contained in:
Glenn Randers-Pehrson 1999-10-06 20:28:28 -05:00
parent ab1e583c44
commit 310faa8ec9
2 changed files with 3840 additions and 3844 deletions
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24
KNOWNBUG
View File

@ -38,13 +38,21 @@ Known bugs and suggested enhancements in libpng-1.0.4
for the png_set_gAMA(), png_set_cHRM(), and corresponding png_get_()
functions will be needed.
4. September 1999 -- BUG --
4. September 1999 -- BUG [FIXED] --
Portions of the new MMX code in pngvcrd.c are defined out because the
did not work properly. When PNGVCRD_INTERLACE_BUG_IS_FIXED is defined,
to enable the code, pngtest pngtest.png pngout.png results in a
"Debug error! Damage before normal block # 57 at 0x007e19f0" on
a Pentium II with MMX system. This seems to be caused by the heap
being trashed before a free() in png_read_destroy().
Portions of the new MMX code in pngvcrd.c were ifdef'd out because they
didn't work properly, but the bug appears to have been found and fixed.
As a result, all parts of the code are once again enabled. If you think
there's still a problem, you can recompile with one of the following two
macros defined and see if the problem goes away:
When PNGVCRD_COMBINE_BUG_IS_FIXED is defined (what?)
DISABLE_PNGVCRD_COMBINE
DISABLE_PNGVCRD_INTERLACE
The second one is in the function where the bug was; as far as we are
aware, there was never any bug in the other function. Please notify us
if you find any problems in libpng, regardless of whether the two macros
make any difference: png-implement@ccrc.wustl.edu
Again, we believe the MMX code in pngvcrd.c is 100% correct, but it has
not yet been tested extensively.

80
pngvcrd.c
View File

@ -961,24 +961,25 @@ void
png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
png_uint_32 transformations)
{
#ifndef ENABLE_PNGVCRD_INTERLACE
#ifdef DISABLE_PNGVCRD_INTERLACE
int save_mmx_supported = mmx_supported;
#endif
png_debug(1,"in png_do_read_interlace\n");
#ifndef ENABLE_PNGVCRD_INTERLACE
/* passes 0 and 2 affect rpng2-win + stefan_full_rgba.png
* symptom: first pixel in every 4th or 8th row is wrong color
* pass < 6 affects pngtest + any interlaced png
* symptom: corruption of heap, crash in png_destroy_read
#ifdef DISABLE_PNGVCRD_INTERLACE
/* 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 is now fixed, and the code
* appears to work completely correctly, so it is enabled by default.
*/
if(pass < 6)
if (1) /* all passes caused a heap problem in the old code */
mmx_supported = 0;
#else
else
#endif
if (mmx_supported == 2)
mmx_supported = mmxsupport();
#endif
if (row != NULL && row_info != NULL)
{
@ -1163,19 +1164,18 @@ png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
__int64 const4 = 0x0000000000FFFFFF;
__int64 const5 = 0x000000FFFFFF0000;
__int64 const6 = 0x00000000000000FF;
//int mmx_supported = 1;
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 + (row_info->width - 1) * pixel_bytes;
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
if (mmx_supported) // use MMX routine if machine supports it
{
@ -1480,8 +1480,8 @@ loop2_pass0:
}
}
sptr -= (width_mmx*2 + 2);
dp -= (width_mmx*16 + 2);
sptr -= (width_mmx*2 - 2); // sign fixed
dp -= (width_mmx*16 - 2); // sign fixed
for (i = width; i; i--)
{
png_byte v[8];
@ -1492,9 +1492,7 @@ loop2_pass0:
{
dp -= pixel_bytes;
png_memcpy(dp, v, pixel_bytes);
//dp -= pixel_bytes;
}
//sptr -= pixel_bytes;
}
}
@ -1528,8 +1526,8 @@ loop2_pass2:
}
}
sptr -= (width_mmx*2 + 2);
dp -= (width_mmx*8 + 2);
sptr -= (width_mmx*2 - 2); // sign fixed
dp -= (width_mmx*8 - 2); // sign fixed
for (i = width; i; i--)
{
png_byte v[8];
@ -1540,9 +1538,7 @@ loop2_pass2:
{
dp -= pixel_bytes;
png_memcpy(dp, v, pixel_bytes);
//dp -= pixel_bytes;
}
//sptr -= pixel_bytes;
}
}
@ -1571,8 +1567,8 @@ loop2_pass4:
}
}
sptr -= (width_mmx*2 + 2);
dp -= (width_mmx*4 + 2);
sptr -= (width_mmx*2 - 2); // sign fixed
dp -= (width_mmx*4 - 2); // sign fixed
for (i = width; i; i--)
{
png_byte v[8];
@ -1583,9 +1579,7 @@ loop2_pass4:
{
dp -= pixel_bytes;
png_memcpy(dp, v, pixel_bytes);
//dp -= pixel_bytes;
}
//sptr -= pixel_bytes;
}
}
} /* end of pixel_bytes == 2 */
@ -1626,8 +1620,8 @@ loop4_pass0:
}
}
sptr -= (width_mmx*4 + 4);
dp -= (width_mmx*32 + 4);
sptr -= (width_mmx*4 - 4); // sign fixed
dp -= (width_mmx*32 - 4); // sign fixed
for (i = width; i; i--)
{
png_byte v[8];
@ -1638,9 +1632,7 @@ loop4_pass0:
{
dp -= pixel_bytes;
png_memcpy(dp, v, pixel_bytes);
//dp -= pixel_bytes;
}
//sptr -= pixel_bytes;
}
}
@ -1674,8 +1666,8 @@ loop4_pass2:
}
}
sptr -= (width_mmx*4 + 4);
dp -= (width_mmx*16 + 4);
sptr -= (width_mmx*4 - 4); // sign fixed
dp -= (width_mmx*16 - 4); // sign fixed
for (i = width; i; i--)
{
png_byte v[8];
@ -1686,9 +1678,7 @@ loop4_pass2:
{
dp -= pixel_bytes;
png_memcpy(dp, v, pixel_bytes);
//dp -= pixel_bytes;
}
//sptr -= pixel_bytes;
}
}
@ -1720,8 +1710,8 @@ loop4_pass4:
}
}
sptr -= (width_mmx*4 + 4);
dp -= (width_mmx*8 + 4);
sptr -= (width_mmx*4 - 4); // sign fixed
dp -= (width_mmx*8 - 4); // sign fixed
for (i = width; i; i--)
{
png_byte v[8];
@ -1732,9 +1722,7 @@ loop4_pass4:
{
dp -= pixel_bytes;
png_memcpy(dp, v, pixel_bytes);
//dp -= pixel_bytes;
}
//sptr -= pixel_bytes;
}
}
@ -1742,7 +1730,7 @@ loop4_pass4:
else if (pixel_bytes == 6)
{
for (i = row_info->width; i; i--)
for (i = width; i; i--)
{
png_byte v[8];
int j;
@ -1758,7 +1746,7 @@ loop4_pass4:
else
{
for (i = row_info->width; i; i--)
for (i = width; i; i--)
{
png_byte v[8];
int j;
@ -1778,7 +1766,7 @@ loop4_pass4:
{
if (pixel_bytes == 1)
{
for (i = row_info->width; i; i--)
for (i = width; i; i--)
{
png_byte v[8];
int j;
@ -1794,7 +1782,7 @@ loop4_pass4:
}
else if (pixel_bytes == 3)
{
for (i = row_info->width; i; i--)
for (i = width; i; i--)
{
png_byte v[8];
int j;
@ -1809,7 +1797,7 @@ loop4_pass4:
}
else if (pixel_bytes == 2)
{
for (i = row_info->width; i; i--)
for (i = width; i; i--)
{
png_byte v[8];
int j;
@ -1824,7 +1812,7 @@ loop4_pass4:
}
else if (pixel_bytes == 4)
{
for (i = row_info->width; i; i--)
for (i = width; i; i--)
{
png_byte v[8];
int j;
@ -1839,7 +1827,7 @@ loop4_pass4:
}
else if (pixel_bytes == 6)
{
for (i = row_info->width; i; i--)
for (i = width; i; i--)
{
png_byte v[8];
int j;
@ -1854,7 +1842,7 @@ loop4_pass4:
}
else
{
for (i = row_info->width; i; i--)
for (i = width; i; i--)
{
png_byte v[8];
int j;
@ -1878,7 +1866,7 @@ loop4_pass4:
(png_uint_32)row_info->pixel_depth + 7) >> 3);
}
#ifndef ENABLE_PNGVCRD_INTERLACE
#ifdef DISABLE_PNGVCRD_INTERLACE
mmx_supported = save_mmx_supported;
#endif
}