amdgcn: Add support for additional natively supported floating-point operations

amdgcn: Add support for additional natively supported floating-point operations

This adds support for the following natively supported floating-point
operations, in scalar and vectorized modes:

floor, ceil, exp2*, log2*, sin*, cos*, ldexp, frexp

* These operations are single-precision float only and are only active
if unsafe_math_optimizations are enabled (due to potential numerical
precision issues).

2022-09-09  Kwok Cheung Yeung  <kcy@codesourcery.com>

	gcc/
	* config/gcn/gcn-builtins.def (FABSVF, LDEXPVF, LDEXPV, FREXPVF_EXP,
	FREXPVF_MANT, FREXPV_EXP, FREXPV_MANT): Add new builtins.
	* config/gcn/gcn-protos.h (gcn_dconst1over2pi): New prototype.
	* config/gcn/gcn-valu.md (MATH_UNOP_1OR2REG, MATH_UNOP_1REG,
	MATH_UNOP_TRIG): New iterators.
	(math_unop): New attributes.
	(<math_unop><mode>2, <math_unop><mode>2<exec>,
	<math_unop><mode>2, <math_unop><mode>2<exec>,
	*<math_unop><mode>2_insn, *<math_unop><mode>2<exec>_insn,
	ldexp<mode>3, ldexp<mode>3<exec>,
	frexp<mode>_exp2, frexp<mode>_mant2,
	frexp<mode>_exp2<exec>, frexp<mode>_mant2<exec>): New instructions.
	(<math_unop><mode>2, <math_unop><mode>2<exec>): New expanders.
	* config/gcn/gcn.cc (init_ext_gcn_constants): Update definition of
	dconst1over2pi.
	(gcn_dconst1over2pi): New.
	(gcn_builtin_type_index): Add entry for v64df type.
	(v64df_type_node): New.
	(gcn_init_builtin_types): Initialize v64df_type_node.
	(gcn_expand_builtin_1): Expand new builtins to instructions.
	(print_operand): Fix assembler output for 1/(2*PI) constant.
	* config/gcn/gcn.md (unspec): Add new entries.