gcc-4.3-20070316 and gcc-4.2-20070307 both fail to compile this
one-line file on Mac OS X 10.4.9 (up to current Apple patch levels):

    % cat foo.c
    static const long double X = (27.0L) / (35.0L);

    % gcc-4.3-20070316 -c foo.c
    foo.c:1: error: initializer element is not constant

If the divisor is changed to 32.0L, it compiles, as does any similar
statement where the right-hand side can be evaluated exactly.

The compilers were built like this:

      nice time env LDFLAGS="-L/usr/local/lib" \
                ../gcc-4.3-20070316/configure \
                        --enable-decimal-float \
                        --enable-languages=c,c++ \
                        --with-gmp=/usr/local \
                        --with-mpfr=/usr/local

        nice time make bootstrap

Similar code with float and double initializers compiles without problems.