[Bug c++/12612] New: ICE when compiling with -O3 -ffast-math

["martin at mpa-garching dot mpg dot de" <gcc-bugzilla at gcc dot gnu dot org>]

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12612

           Summary: ICE when compiling with -O3 -ffast-math
           Product: gcc
           Version: 3.4
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: martin at mpa-garching dot mpg dot de
                CC: gcc-bugs at gcc dot gnu dot org,martin at mpa-garching
                    dot mpg dot de
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu

gcc version 3.4 20031014 (experimental) crashes with an ICE when
compiling the attached code with -O3 -ffast-math:

~/data/planck/LevelS/Sampler>g++ -v -c -O3 -ffast-math sampler.ii
Reading specs from /afs/mpa/data/martin/ugcc/lib/gcc/i686-pc-linux-gnu/3.4/specs
Configured with: /scratch/gcc/configure --prefix=/afs/mpa/data/martin/ugcc
--enable-languages=c++ --disable-checking
Thread model: posix
gcc version 3.4 20031014 (experimental)
 /afs/mpa/data/martin/ugcc/libexec/gcc/i686-pc-linux-gnu/3.4/cc1plus
-fpreprocessed sampler.ii -quiet -dumpbase sampler.ii -mtune=pentiumpro -auxbase
sampler -O3 -version -ffast-math -o /tmp/ccycYGAB.s
GNU C++ version 3.4 20031014 (experimental) (i686-pc-linux-gnu)
        compiled by GNU C version 3.4 20031014 (experimental).
GGC heuristics: --param ggc-min-expand=63 --param ggc-min-heapsize=63442
sampler.cc: In function `int main(int, char**)':
sampler.cc:192: error: unrecognizable insn:
(insn:HI 6444 6442 6445 619 (parallel [
            (set (reg:DF 2256)
                (unspec:DF [
                        (reg:DF 2263)
                        (reg:XF 5025)
                    ] 66))
            (clobber (reg:XF 5412))
        ]) -1 (insn_list 6442 (nil))
    (expr_list:REG_DEAD (reg:DF 2263)
        (expr_list:REG_UNUSED (reg:XF 5412)
            (expr_list:REG_EQUAL (unspec:DF [
                        (reg:DF 2263)
                        (reg:XF 2264)
                    ] 66)
                (nil)))))
sampler.cc:192: internal compiler error: in extract_insn, at recog.c:2064
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.

The bug appears to be relatively new; it didn't trigger about two weeks ago.

Sorry for the long testcase; I currently don't have time to reduce it.