[Bug regression/49285] New: [4.7 Regression]: build fails on mmix in libgcc2.c:__powisf2: ICE in emit_unop_insn

["hp at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49285

           Summary: [4.7 Regression]: build fails on mmix in
                    libgcc2.c:__powisf2: ICE in emit_unop_insn
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Keywords: build, ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: regression
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: hp@gcc.gnu.org
              Host: x86_64-unknown-linux-gnu
            Target: mmix


Build fails on trunk (r174648) for mmix, last worked r171197:
/tmp/pr48542bl47/gccobj/./gcc/xgcc -B/tmp/pr48542bl47/gccobj/./gcc/ -nostdinc
-B/tmp/pr48542bl47/gccobj/mmix/newlib/ -i\
system /tmp/pr48542bl47/gccobj/mmix/newlib/targ-include -isystem
/tmp/pr48542bl47/gcc/newlib/libc/include -B/tmp/pr4854\
2bl47/gccobj/mmix/libgloss/mmix
-L/tmp/pr48542bl47/gccobj/mmix/libgloss/libnosys
-L/tmp/pr48542bl47/gcc/libgloss/mmix -\
B/tmp/pr48542bl47/pre/mmix/bin/ -B/tmp/pr48542bl47/pre/mmix/lib/ -isystem
/tmp/pr48542bl47/pre/mmix/include -isystem /t\
mp/pr48542bl47/pre/mmix/sys-include    -g -O2 -mabi=gnu -O2  -g -O2 -DIN_GCC
-DCROSS_DIRECTORY_STRUCTURE  -W -Wall -Wwr\
ite-strings -Wcast-qual -Wstrict-prototypes -Wmissing-prototypes
-Wold-style-definition  -isystem ./include  -mlibfuncs\
 -O2 -g  -DIN_LIBGCC2 -D__GCC_FLOAT_NOT_NEEDED -fno-stack-protector
-Dinhibit_libc  -I. -I. -I../../.././gcc -I/tmp/pr4\
8542bl47/gcc/libgcc -I/tmp/pr48542bl47/gcc/libgcc/.
-I/tmp/pr48542bl47/gcc/libgcc/../gcc -I/tmp/pr48542bl47/gcc/libgcc/\
../include  -DHAVE_CC_TLS -DUSE_EMUTLS -o _powisf2.o -MT _powisf2.o -MD -MP -MF
_powisf2.dep -DL_powisf2 -c /tmp/pr4854\
2bl47/gcc/libgcc/../gcc/libgcc2.c \

/tmp/pr48542bl47/gcc/libgcc/../gcc/libgcc2.c: In function '__powisf2':
/tmp/pr48542bl47/gcc/libgcc/../gcc/libgcc2.c:1730:9: internal compiler error:
in emit_unop_insn, at optabs.c:3555

The last known "working" revision is taken from the gcc-testresults list,
<http://gcc.gnu.org/ml/gcc-testresults/2011-03/msg02147.html>.