AVX512FP16: Support vector init/broadcast/set/extract for FP16.

AVX512FP16: Support vector init/broadcast/set/extract for FP16.

gcc/ChangeLog:

	* config/i386/avx512fp16intrin.h (_mm_set_ph): New intrinsic.
	(_mm256_set_ph): Likewise.
	(_mm512_set_ph): Likewise.
	(_mm_setr_ph): Likewise.
	(_mm256_setr_ph): Likewise.
	(_mm512_setr_ph): Likewise.
	(_mm_set1_ph): Likewise.
	(_mm256_set1_ph): Likewise.
	(_mm512_set1_ph): Likewise.
	(_mm_setzero_ph): Likewise.
	(_mm256_setzero_ph): Likewise.
	(_mm512_setzero_ph): Likewise.
	(_mm_set_sh): Likewise.
	(_mm_load_sh): Likewise.
	(_mm_store_sh): Likewise.
	* config/i386/i386-builtin-types.def (V8HF): New type.
	(DEF_FUNCTION_TYPE (V8HF, V8HI)): New builtin function type
	* config/i386/i386-expand.c (ix86_expand_vector_init_duplicate):
	Support vector HFmodes.
	(ix86_expand_vector_init_one_nonzero): Likewise.
	(ix86_expand_vector_init_one_var): Likewise.
	(ix86_expand_vector_init_interleave): Likewise.
	(ix86_expand_vector_init_general): Likewise.
	(ix86_expand_vector_set): Likewise.
	(ix86_expand_vector_extract): Likewise.
	(ix86_expand_vector_init_concat): Likewise.
	(ix86_expand_sse_movcc): Handle vector HFmodes.
	(ix86_expand_vector_set_var): Ditto.
	* config/i386/i386-modes.def: Add HF vector modes in comment.
	* config/i386/i386.c (classify_argument): Add HF vector modes.
	(ix86_hard_regno_mode_ok): Allow HF vector modes for AVX512FP16.
	(ix86_vector_mode_supported_p): Likewise.
	(ix86_set_reg_reg_cost): Handle vector HFmode.
	(ix86_get_ssemov): Handle vector HFmode.
	(function_arg_advance_64): Pass unamed V16HFmode and V32HFmode
	by stack.
	(function_arg_advance_32): Pass V8HF/V16HF/V32HF by sse reg for 32bit
	mode.
	(function_arg_advance_32): Ditto.
	* config/i386/i386.h (VALID_AVX512FP16_REG_MODE): New.
	(VALID_AVX256_REG_OR_OI_MODE): Rename to ..
	(VALID_AVX256_REG_OR_OI_VHF_MODE): .. this, and add V16HF.
	(VALID_SSE2_REG_VHF_MODE): New.
	(VALID_AVX512VL_128_REG_MODE): Add V8HF and TImode.
	(SSE_REG_MODE_P): Add vector HFmode.
	* config/i386/i386.md (mode): Add HF vector modes.
	(MODE_SIZE): Likewise.
	(ssemodesuffix): Add ph suffix for HF vector modes.
	* config/i386/sse.md (VFH_128): New mode iterator.
	(VMOVE): Adjust for HF vector modes.
	(V): Likewise.
	(V_256_512): Likewise.
	(avx512): Likewise.
	(avx512fmaskmode): Likewise.
	(shuffletype): Likewise.
	(sseinsnmode): Likewise.
	(ssedoublevecmode): Likewise.
	(ssehalfvecmode): Likewise.
	(ssehalfvecmodelower): Likewise.
	(ssePScmode): Likewise.
	(ssescalarmode): Likewise.
	(ssescalarmodelower): Likewise.
	(sseintprefix): Likewise.
	(i128): Likewise.
	(bcstscalarsuff): Likewise.
	(xtg_mode): Likewise.
	(VI12HF_AVX512VL): New mode_iterator.
	(VF_AVX512FP16): Likewise.
	(VIHF): Likewise.
	(VIHF_256): Likewise.
	(VIHF_AVX512BW): Likewise.
	(V16_256): Likewise.
	(V32_512): Likewise.
	(sseintmodesuffix): New mode_attr.
	(sse): Add scalar and vector HFmodes.
	(ssescalarmode): Add vector HFmode mapping.
	(ssescalarmodesuffix): Add sh suffix for HFmode.
	(*<sse>_vm<insn><mode>3): Use VFH_128.
	(*<sse>_vm<multdiv_mnemonic><mode>3): Likewise.
	(*ieee_<ieee_maxmin><mode>3): Likewise.
	(<avx512>_blendm<mode>): New define_insn.
	(vec_setv8hf): New define_expand.
	(vec_set<mode>_0): New define_insn for HF vector set.
	(*avx512fp16_movsh): Likewise.
	(avx512fp16_movsh): Likewise.
	(vec_extract_lo_v32hi): Rename to ...
	(vec_extract_lo_<mode>): ... this, and adjust to allow HF
	vector modes.
	(vec_extract_hi_v32hi): Likewise.
	(vec_extract_hi_<mode>): Likewise.
	(vec_extract_lo_v16hi): Likewise.
	(vec_extract_lo_<mode>): Likewise.
	(vec_extract_hi_v16hi): Likewise.
	(vec_extract_hi_<mode>): Likewise.
	(vec_set_hi_v16hi): Likewise.
	(vec_set_hi_<mode>): Likewise.
	(vec_set_lo_v16hi): Likewise.
	(vec_set_lo_<mode>): Likewise.
	(*vec_extract<mode>_0): New define_insn_and_split for HF
	vector extract.
	(*vec_extracthf): New define_insn.
	(VEC_EXTRACT_MODE): Add HF vector modes.
	(PINSR_MODE): Add V8HF.
	(sse2p4_1): Likewise.
	(pinsr_evex_isa): Likewise.
	(<sse2p4_1>_pinsr<ssemodesuffix>): Adjust to support
	insert for V8HFmode.
	(pbroadcast_evex_isa): Add HF vector modes.
	(AVX2_VEC_DUP_MODE): Likewise.
	(VEC_INIT_MODE): Likewise.
	(VEC_INIT_HALF_MODE): Likewise.
	(avx2_pbroadcast<mode>): Adjust to support HF vector mode
	broadcast.
	(avx2_pbroadcast<mode>_1): Likewise.
	(<avx512>_vec_dup<mode>_1): Likewise.
	(<avx512>_vec_dup<mode><mask_name>): Likewise.
	(<mask_codefor><avx512>_vec_dup_gpr<mode><mask_name>):
	Likewise.