Add IFN_COND_FMA functions

Add IFN_COND_FMA functions

This patch adds conditional equivalents of the IFN_FMA built-in functions.
Most of it is just a mechanical extension of the binary stuff.

2018-07-12  Richard Sandiford  <richard.sandiford@linaro.org>

gcc/
	* doc/md.texi (cond_fma, cond_fms, cond_fnma, cond_fnms): Document.
	* optabs.def (cond_fma_optab, cond_fms_optab, cond_fnma_optab)
	(cond_fnms_optab): New optabs.
	* internal-fn.def (COND_FMA, COND_FMS, COND_FNMA, COND_FNMS): New
	internal functions.
	(FMA): Use DEF_INTERNAL_FLT_FN rather than DEF_INTERNAL_FLT_FLOATN_FN.
	* internal-fn.h (get_conditional_internal_fn): Declare.
	(get_unconditional_internal_fn): Likewise.
	* internal-fn.c (cond_ternary_direct): New macro.
	(expand_cond_ternary_optab_fn): Likewise.
	(direct_cond_ternary_optab_supported_p): Likewise.
	(FOR_EACH_COND_FN_PAIR): Likewise.
	(get_conditional_internal_fn): New function.
	(get_unconditional_internal_fn): Likewise.
	* gimple-match.h (gimple_match_op::MAX_NUM_OPS): Bump to 5.
	(gimple_match_op::gimple_match_op): Add a new overload for 5
	operands.
	(gimple_match_op::set_op): Likewise.
	(gimple_resimplify5): Declare.
	* genmatch.c (decision_tree::gen): Generate simplifications for
	5 operands.
	* gimple-match-head.c (gimple_simplify): Define an overload for
	5 operands.  Handle calls with 5 arguments in the top-level overload.
	(convert_conditional_op): Handle conversions from unconditional
	internal functions to conditional ones.
	(gimple_resimplify5): New function.
	(build_call_internal): Pass a fifth operand.
	(maybe_push_res_to_seq): Likewise.
	(try_conditional_simplification): Try converting conditional
	internal functions to unconditional internal functions.
	Handle 3-operand unconditional forms.
	* match.pd (UNCOND_TERNARY, COND_TERNARY): Operator lists.
	Define ternary equivalents of the current rules for binary conditional
	internal functions.
	* config/aarch64/aarch64.c (aarch64_preferred_else_value): Handle
	ternary operations.
	* config/aarch64/iterators.md (UNSPEC_COND_FMLA, UNSPEC_COND_FMLS)
	(UNSPEC_COND_FNMLA, UNSPEC_COND_FNMLS): New unspecs.
	(optab): Handle them.
	(SVE_COND_FP_TERNARY): New int iterator.
	(sve_fmla_op, sve_fmad_op): New int attributes.
	* config/aarch64/aarch64-sve.md (cond_<optab><mode>)
	(*cond_<optab><mode>_2, *cond_<optab><mode_4)
	(*cond_<optab><mode>_any): New SVE_COND_FP_TERNARY patterns.

gcc/testsuite/
	* gcc.dg/vect/vect-cond-arith-3.c: New test.
	* gcc.target/aarch64/sve/vcond_13.c: Likewise.
	* gcc.target/aarch64/sve/vcond_13_run.c: Likewise.
	* gcc.target/aarch64/sve/vcond_14.c: Likewise.
	* gcc.target/aarch64/sve/vcond_14_run.c: Likewise.
	* gcc.target/aarch64/sve/vcond_15.c: Likewise.
	* gcc.target/aarch64/sve/vcond_15_run.c: Likewise.
	* gcc.target/aarch64/sve/vcond_16.c: Likewise.
	* gcc.target/aarch64/sve/vcond_16_run.c: Likewise.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@262587 138bc75d-0d04-0410-961f-82ee72b054a4