[Bug c/14470] New: x86 optimizer error (?)

["lvoge at cs dot vu dot nl" <gcc-bugzilla at gcc dot gnu dot org>]

excuse me if this is stupidity on my part or me not understanding C properly, but:

int main() {
        int t[123] = { 1024 }, d;

        d = 0;
        d = t[d]++;
        printf("%d\n", d);
        return 0;
}

dumps core when compiled with -O2 on intel. the trouble is that the fifth line
gets compiled as if it says d = t[d]; t[d]++;, it re-uses the register to index
the increment that just got the result of the dereference.

compiles and runs correctly with any optimization with the Intel compiler v7.0.
gcc without optimization runs correctly on intel. gcc on sparc64 and ppc with
any optimization also runs correctly.

-- 
           Summary: x86 optimizer error (?)
           Product: gcc
           Version: 3.3.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: lvoge at cs dot vu dot nl
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: GNU C version 3.3.3 (Debian) (i486-linux)
  GCC host triplet: GNU C version 3.3.3 (Debian) (i486-linux)
GCC target triplet: GNU C version 3.3.3 (Debian) (i486-linux)


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14470