* config/dfp-bit.c (dfp_compare_op): Return separate value for NaN.
(DFP_NE, DFP_LE, DFP_GE): Return false for NaN.
gcc/testsuite/
* gcc.dg/dfp/compare-special.h: New file.
* gcc.dg/dfp/compare-special-32.c: New test.
* gcc.dg/dfp/compare-special-64.c: New test.
* gcc.dg/dfp/compare-special-128.c: New test.