[Bug rtl-optimization/15948] New: THUMB -O2: Very short file causes assert failure

["danfuzz at milk dot com" <gcc-bugzilla at gcc dot gnu dot org>]

Compiling the following file with -O2 causes an assert failure inside gcc:

    void ouch(int *s)
    {
        int e = s[0];
        if ((e & 2) == 0) {
            return;
        }
        s[0]=0;
        s[1]=0;
    }

(That's it.) The reported error is:

    $ arm-elf-gcc -save-temps -c ouch.c -mthumb -O2 -o ouch.o
    ouch.c: In function `ouch':
    ouch.c:9: internal compiler error: in do_output_reload, at reload1.c:6895
    Please submit a full bug report,
    with preprocessed source if appropriate.
    See <URL:http://gcc.gnu.org/bugs.html> for instructions.

Here's the salient part of reload1.c:

    /* If is a JUMP_INSN, we can't support output reloads yet.  */
    if (GET_CODE (insn) == JUMP_INSN)
      abort (); // LINE 6895

Here's how I configured and built the compiler:

$ tar -xjvf gcc-core-3.4.0.tar.bz2
$ cd gcc-3.4.0
$ ./configure --prefix=/usr/local/armdev --target=arm-elf --with-newlib --enable-languages=c

The following lines were uncommented in gcc/config/arm/t-arm-elf:

MULTILIB_OPTIONS    += mno-thumb-interwork/mthumb-interwork
MULTILIB_DIRNAMES   += normal interwork
MULTILIB_EXCEPTIONS += *mapcs-26/*mthumb-interwork*

$ make
$ sudo make install

In case it matters, I'm currently using binutils-2.15.

-- 
           Summary: THUMB -O2: Very short file causes assert failure
           Product: gcc
           Version: 3.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: rtl-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: danfuzz at milk dot com
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: ppc-mac-osx
  GCC host triplet: ppc-mac-osx
GCC target triplet: arm-unknown-elf


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15948