Richard Guenther <[EMAIL PROTECTED]> wrote: > I get a strange ICE if building (not bootstrapping) mainline with > current 3.4 branch with CFLAGS="-g": > > /tmp/gcc-obj-checking/gcc/xgcc -B/tmp/gcc-obj-checking/gcc/ > -B/i686-pc-linux-gnu/bin/ -B/i686-pc-linux-gnu/lib/ -isystem > /i686-pc-linux-gnu/include -isystem /i686-pc-linux-gnu/sys-include -c > -DHAVE_CONFIG_H -O2 -g -I. > -I/net/alwazn/home/rguenth/src/gcc/gcc/libiberty/../include -W -Wall > -Wtraditional -pedantic > /net/alwazn/home/rguenth/src/gcc/gcc/libiberty/sort.c -o sort.o > /net/alwazn/home/rguenth/src/gcc/gcc/libiberty/sort.c: In function > 'sort_pointers': > /net/alwazn/home/rguenth/src/gcc/gcc/libiberty/sort.c:51: internal > compiler error: in insert_aux, at tree-ssa-pre.c:1624 > Please submit a full bug report, > with preprocessed source if appropriate. > See <URL:http://gcc.gnu.org/bugs.html> for instructions. > > So, this is gcc 3.4.4 miscompiling HEAD with -g such that the built > compiler ICEs as above. > > gcc-3.4 (GCC) 3.4.4 20050112 (prerelease) > > Is this even worth entering into the bug database?
Yes, it is a miscompilation of GCC 3.4 which we should fix because we still maintain GCC. Moreover, it is possible that the same bug is latent in HEAD. > I guess nobody will do a build with just -g. That does not matter. The bug could trigger with different code. > What would be the appropriate > testcase? First, preprocess the sort.c above as a testcase for the miscompilation. Then you'd need to find out which file is miscompiled. It is possible that it is tree-ssa-pre so that would be the first thing to check (e.g. recompile only that file without -g, relink xgcc, and try running sort.i to see if it still ICEs). After that, you could try to find out which function is being miscompiled and compare the assembly / RTL dumps. A bug in Bugzilla would probably have a standalone (preprocessed) copy of the function being miscompiled and a diff of the assembly files showing the miscompilation. Others are surely more expert than me at analyzing this kind of issues, so maybe they have better solutions. -- Giovanni Bajo
