4.2 misscompiles libavcodec/h264.o from FFmpeg project.
The likely cause of this problem is lies in the file cabac.h (in attachment)
gcc-4.0 and 4.1.0 compile this file correctly.
Here's the commandline:
/home/guillaume/Prgm/gcc/bin/gcc -DHAVE_AV_CONFIG_H -D_FILE_OFFSET_BITS=64
-D_LARGEFILE_SOURCE -D_ISOC9X_SOURCE -I.. -I.. -I../libavutil
-Wdeclaration-after-statement -fno-PIC -O4 -march=pentium-m -mtune=pentium-m
-pipe -ffast-math -fomit-frame-pointer -D_REENTRANT -D_LARGEFILE_SOURCE
-D_FILE_OFFSET_BITS=64 -D_LARGEFILE64_SOURCE -I/usr/include -I/usr/include/SDL
-D_REENTRANT -I/usr/include/kde/artsc -pthread -I/usr/include/glib-2.0
-I/usr/lib/glib-2.0/include -I/usr/include -I/usr/include/dvdnav
-I/usr/include/freetype2 -c -o h264.o h264.c -v -save-temps
gcc: warning: -pipe ignored because -save-temps specified
Using built-in specs.
Target: i686-pc-linux-gnu
Configured with: ../gcc-4.2-20061007/configure
--prefix=/home/guillaume/Prgm/gcc/
Thread model: posix
gcc version 4.2.0 20061007 (experimental)
/home/guillaume/Prgm/gcc/bin/../libexec/gcc/i686-pc-linux-gnu/4.2.0/cc1 -E
-quiet -v -I.. -I.. -I../libavutil -I/usr/include -I/usr/include/SDL
-I/usr/include/kde/artsc -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include
-I/usr/include -I/usr/include/dvdnav -I/usr/include/freetype2 -iprefix
/home/guillaume/Prgm/gcc/bin/../lib/gcc/i686-pc-linux-gnu/4.2.0/ -D_REENTRANT
-DHAVE_AV_CONFIG_H -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_ISOC9X_SOURCE
-D_REENTRANT -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE64_SOURCE
-D_REENTRANT h264.c -march=pentium-m -mtune=pentium-m
-Wdeclaration-after-statement -fno-PIC -ffast-math -fomit-frame-pointer -O4
-fpch-preprocess -o h264.i
ignoring nonexistent directory
"/home/guillaume/Prgm/gcc/bin/../lib/gcc/i686-pc-linux-gnu/4.2.0/../../../../i686-pc-linux-gnu/include"
ignoring duplicate directory
"/home/guillaume/Prgm/gcc//lib/gcc/i686-pc-linux-gnu/4.2.0/include"
ignoring nonexistent directory
"/home/guillaume/Prgm/gcc//lib/gcc/i686-pc-linux-gnu/4.2.0/../../../../i686-pc-linux-gnu/include"
ignoring duplicate directory ".."
ignoring duplicate directory "/usr/include"
as it is a non-system directory that duplicates a system directory
ignoring duplicate directory "/usr/include"
as it is a non-system directory that duplicates a system directory
#include "..." search starts here:
#include <...> search starts here:
..
../libavutil
/usr/include/SDL
/usr/include/kde/artsc
/usr/include/glib-2.0
/usr/lib/glib-2.0/include
/usr/include/dvdnav
/usr/include/freetype2
/home/guillaume/Prgm/gcc/bin/../lib/gcc/i686-pc-linux-gnu/4.2.0/include
/usr/local/include
/home/guillaume/Prgm/gcc//include
/usr/include
End of search list.
/home/guillaume/Prgm/gcc/bin/../libexec/gcc/i686-pc-linux-gnu/4.2.0/cc1
-fpreprocessed h264.i -quiet -dumpbase h264.c -march=pentium-m -mtune=pentium-m
-auxbase-strip h264.o -O4 -Wdeclaration-after-statement -version -fno-PIC
-ffast-math -fomit-frame-pointer -o h264.s
GNU C version 4.2.0 20061007 (experimental) (i686-pc-linux-gnu)
compiled by GNU C version 4.2.0 20061007 (experimental).
GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
Compiler executable checksum: 9d78c482f3158f545a4217a7c698d3a2
h264.c: In function 'decode_cabac_residual':
h264.c:6120: warning: initialization from incompatible pointer type
as -V -Qy -o h264.o h264.s
GNU assembler version 2.16.91 (i486-linux-gnu) using BFD version 2.16.91
20060118 Debian GNU/Linux
--
Summary: 4.2 20061007 experiemental misscompiles
libavcodec/h264.o
Product: gcc
Version: 4.2.0
Status: UNCONFIRMED
Severity: major
Priority: P3
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: poirierg at gmail dot com
GCC build triplet: (no options)
GCC host triplet: i686, Linux, debian
GCC target triplet: i686, Linux, debian
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29440
