http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53266
Bug #: 53266 Summary: Error: Unrecognized opcode: `mulhwu' Classification: Unclassified Product: gcc Version: 4.7.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: bootstrap AssignedTo: unassig...@gcc.gnu.org ReportedBy: sk...@iskunk.org Host: powerpc-ibm-aix4.3.2.0 Target: powerpc-ibm-aix4.3.2.0 Build: powerpc-ibm-aix4.3.2.0 Bootstrapping GCC 4.7.0 on AIX 4.3 fails with [...] gmake[3]: Entering directory `/tmp/gcc-build/powerpc-ibm-aix4.3.2.0/libgcc' # If this is the top-level multilib, build all the other # multilibs. DEFINES='' HEADERS='' \ /home/src/gcc-4.7.0/libgcc/mkheader.sh > tmp-libgcc_tm.h /opt/freeware/bin/bash /home/src/gcc-4.7.0/libgcc/../move-if-change tmp-libgcc_tm.h libgcc_tm.h echo timestamp > libgcc_tm.stamp /tmp/gcc-build/./gcc/xgcc -B/tmp/gcc-build/./gcc/ -B/opt/tg/powerpc-ibm-aix4.3.2.0/bin/ -B/opt/tg/powerpc-ibm-aix4.3.2.0/lib/ -isystem /opt/tg/powerpc-ibm-aix4.3.2.0/include -isystem /opt/tg/powerpc-ibm-aix4.3.2.0/sys-include -g -O2 -O2 -g -O2 -DIN_GCC -W -Wall -Wwrite-strings -Wcast-qual -Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition -isystem ./include -mlong-double-128 -g -DIN_LIBGCC2 -fbuilding-libgcc -fno-stack-protector -mlong-double-128 -I. -I. -I../.././gcc -I/home/src/gcc-4.7.0/libgcc -I/home/src/gcc-4.7.0/libgcc/. -I/home/src/gcc-4.7.0/libgcc/../gcc -I/home/src/gcc-4.7.0/libgcc/../include -DHAVE_CC_TLS -DUSE_EMUTLS -o _muldi3.o -MT _muldi3.o -MD -MP -MF _muldi3.dep -DL_muldi3 -c /home/src/gcc-4.7.0/libgcc/libgcc2.c /tmp//cczJLmgC.s: Assembler messages: /tmp//cczJLmgC.s:379: Error: Unrecognized opcode: `mulhwu' gmake[3]: *** [_muldi3.o] Error 1 gmake[3]: Leaving directory `/tmp/gcc-build/powerpc-ibm-aix4.3.2.0/libgcc' gmake[2]: *** [all-stage1-target-libgcc] Error 2 gmake[2]: Leaving directory `/tmp/gcc-build' gmake[1]: *** [stage1-bubble] Error 2 gmake[1]: Leaving directory `/tmp/gcc-build' gmake: *** [bootstrap-lean] Error 2 It appears to be the same issue as reported in a comment long ago: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12691#c2 My error was obtained using --with-gnu-as and --disable-multilib. After some experimentation, I got rid of --disable-multilib, and configured the tree with --with-cpu=powerpc --disable-aix64 --disable-powercpu, which allowed the bootstrap to proceed without the above error. However, given that build=host=target, and that the system triplet explicitly denotes a 32-bit PowerPC processor, the configuration phase should have detected the need to avoid unsupported instructions on its own.