[AArch64] Rework SVE FP comparisons

[AArch64] Rework SVE FP comparisons

This patch rewrites the SVE FP comparisons so that they always use
unspecs and so that they have an additional operand to indicate
whether the predicate is known to be a PTRUE.  It's part of a series
that rewrites the SVE FP patterns so that they can cope with non-PTRUE
predicates.

2019-08-14  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* config/aarch64/iterators.md (UNSPEC_COND_FCMUO): New unspec.
	(cmp_op): Handle it.
	(SVE_COND_FP_CMP): Rename to...
	(SVE_COND_FP_CMP_I0): ...this.
	(SVE_FP_CMP): Remove.
	* config/aarch64/aarch64-sve.md
	(*fcm<SVE_FP_CMP:cmp_op><SVE_F:mode>): Replace with...
	(*fcm<SVE_COND_FP_CMP_I0:cmp_op><SVE_F:mode>): ...this new pattern,
	using unspecs to represent the comparison.
	(*fcmuo<SVE_F:mode>): Use UNSPEC_COND_FCMUO.
	(*fcm<cmp_op><mode>_and_combine, *fcmuo<mode>_and_combine): Update
	accordingly.
	* config/aarch64/aarch64.c (aarch64_emit_sve_ptrue_op): Delete.
	(aarch64_unspec_cond_code): Move after integer code.  Handle
	UNORDERED.
	(aarch64_emit_sve_predicated_cond): Replace with...
	(aarch64_emit_sve_fp_cond): ...this new function.
	(aarch64_emit_sve_or_conds): Replace with...
	(aarch64_emit_sve_or_fp_conds): ...this new function.
	(aarch64_emit_sve_inverted_cond): Replace with...
	(aarch64_emit_sve_invert_fp_cond): ...this new function.
	(aarch64_expand_sve_vec_cmp_float): Update accordingly.

From-SVN: r274421