that word number zero is the most significant part; otherwise, it is
the least significant part.
+@cindex @code{FLOAT_WORDS_BIG_ENDIAN}, (lack of) effect on @code{subreg}
+On a few targets, @code{FLOAT_WORDS_BIG_ENDIAN} disagrees with
+@code{WORDS_BIG_ENDIAN}.
+However, most parts of the compiler treat floating point values as if
+they had the same endianness as integer values. This works because
+they handle them solely as a collection of integer values, with no
+particular numerical value. Only real.c and the runtime libraries
+care about @code{FLOAT_WORDS_BIG_ENDIAN}.
+
@cindex combiner pass
@cindex reload pass
@cindex @code{subreg}, special reload handling