s390.c: (s390_const_double_ok_for_constraint_p): New function.

2005-05-10  Adrian Straetling  <straetling@de.ibm.com>

	* config/s390/s390.c: (s390_const_double_ok_for_constraint_p): New
	function.
	(legitimate_reload_constant_p): Add check for const double zero.
	* config/s390/s390.md: Add comment for constraint letter 'G'.
	("*movdf_64", "*movdf_31", "movsf"): Add constraint and proper
	attributes for new case.
	* config/s390/s390.h: (CONST_DOUBLE_OK_FOR_CONSTRAINT_P): Define it as
	s390_const_double_ok_for_constraint_p.
	* config/s390/s390-protos.h (s390_const_double_ok_for_constraint_p):
	Add prototype.

From-SVN: r99541