When rebuilding the glibc RPM with --target=i686 gcc 2.96 core dumps (illegal instruction) during the compilation of the sun_rpc directory. It is very reproducible and it happens both with the original and the patched glibc you issued a few days ago. The distribution is vanilla RedHat 7 where everything has been installed, glibc was the original one. The RPM builds successfully when targetting 386 My box has a K6/2 processor
Details please, which file does it crash on, which options passed to it, preprocessed file (best run rpm -ba glibc.spec 2>&1 | tee glibc.log, then cut'n'paste the command which caused the gcc to crash, add -save-temps -v to it and send me its output and the .i file). I cannot reproduce this myself and I'm building glibc with these flags (both i386 and i686 targets) almost daily for a couple of months.
Actually, why are you building i686 glibc on K6/2? K6/2 AFAIK does not have conditional move instructions, so if the SIGILL comes when glibc tries to run rpcgen or similar program, it can crash on K6/2 if there are any cmoves generated (which gcc can legally use if -march=i686). During glibc bootstrap after the main library is compiled glibc executes binaries using the newly built dynamic linker and library.
It turned to be a mistake. Somewhere in the the building of glibc an auxilary program is byuilt and executed. Since that executable was generated with the PPro instruction set and I was on a K6/2 it core dumped and I thought it was the compiler who had core dumped.