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Replace INT32 with a new internal datatype (JLONG)

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These days, INT32 is a commonly-defined datatype in system headers.  We
cannot eliminate the definition of that datatype from jmorecfg.h, since
the INT32 typedef has technically been part of the libjpeg API since
version 5 (1994.)  However, using INT32 internally is risky, because the
inclusion of a particular header (Xmd.h, for instance) could change the
definition of INT32 from long to int on 64-bit platforms and thus change
the internal behavior of libjpeg-turbo in unexpected ways (for instance,
failing to correctly set __INT32_IS_ACTUALLY_LONG to match the INT32
typedef-- perhaps as a result of including the wrong version of
jpeglib.h-- could cause libjpeg-turbo to produce incorrect results.)

The library has always been built in environments in which INT32 is
effectively long (on Windows, long is always 32-bit, so effectively it's
the same as int), so it makes sense to turn INT32 into an explicitly
long datatype.  This ensures that libjpeg-turbo will always behave
consistently, regardless of the headers included at compile time.

Addresses a concern expressed in #26.
This commit is contained in:
DRC
2015-10-14 17:32:39 -05:00
parent 250c887763
commit 1e32fe3113
38 changed files with 478 additions and 447 deletions
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9
jcsample.c
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@@ -6,6 +6,7 @@
* libjpeg-turbo Modifications:
* Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
* Copyright (C) 2014, MIPS Technologies, Inc., California
* Copyright (C) 2015, D. R. Commander.
* For conditions of distribution and use, see the accompanying README.ijg
* file.
*
@@ -150,7 +151,7 @@ int_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr,
JDIMENSION outcol, outcol_h; /* outcol_h == outcol*h_expand */
JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE;
JSAMPROW inptr, outptr;
INT32 outvalue;
JLONG outvalue;
h_expand = cinfo->max_h_samp_factor / compptr->h_samp_factor;
v_expand = cinfo->max_v_samp_factor / compptr->v_samp_factor;
@@ -173,7 +174,7 @@ int_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr,
for (v = 0; v < v_expand; v++) {
inptr = input_data[inrow+v] + outcol_h;
for (h = 0; h < h_expand; h++) {
outvalue += (INT32) GETJSAMPLE(*inptr++);
outvalue += (JLONG) GETJSAMPLE(*inptr++);
}
}
*outptr++ = (JSAMPLE) ((outvalue + numpix2) / numpix);
@@ -302,7 +303,7 @@ h2v2_smooth_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr,
JDIMENSION colctr;
JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE;
register JSAMPROW inptr0, inptr1, above_ptr, below_ptr, outptr;
INT32 membersum, neighsum, memberscale, neighscale;
JLONG membersum, neighsum, memberscale, neighscale;
/* Expand input data enough to let all the output samples be generated
* by the standard loop. Special-casing padded output would be more
@@ -402,7 +403,7 @@ fullsize_smooth_downsample (j_compress_ptr cinfo, jpeg_component_info *compptr,
JDIMENSION colctr;
JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE;
register JSAMPROW inptr, above_ptr, below_ptr, outptr;
INT32 membersum, neighsum, memberscale, neighscale;
JLONG membersum, neighsum, memberscale, neighscale;
int colsum, lastcolsum, nextcolsum;
/* Expand input data enough to let all the output samples be generated