re PR target/71869 (__builtin_isgreater raises an invalid exception on PPC64 using...

re PR target/71869 (__builtin_isgreater raises an invalid exception on PPC64 using __float128 inputs.)

[gcc]
2016-07-26  Michael Meissner  <meissner@linux.vnet.ibm.com>

	PR target/71869
	* config/rs6000/rs6000.c (rs6000_generate_compare): Rework
	__float128 support when we don't have hardware support, so that
	the IEEE built-in functions like isgreater, first call __unordkf3
	to make sure neither operand is a NaN, and if both operands are
	ordered, do the normal comparison.

[gcc/testsuite]
2016-07-26  Michael Meissner  <meissner@linux.vnet.ibm.com>

	PR target/71869
	* gcc.target/powerpc/float128-cmp.c: New test to make sure that
	IEEE built-in functions handle quiet and signalling NaNs
	correctly.

From-SVN: r238779