Optimize for V{8,16,32}HFmode vec_set/extract/init.
gcc/ChangeLog:
PR target/102327
* config/i386/i386-expand.c
(ix86_expand_vector_init_interleave): Use puncklwd to pack 2
HFmodes.
(ix86_expand_vector_set): Use blendw instead of pinsrw.
* config/i386/i386.c (ix86_can_change_mode_class): Adjust for
AVX512FP16 which supports 16bit vector load.
* config/i386/sse.md (avx512bw_interleave_highv32hi<mask_name>):
Rename to ..
(avx512bw_interleave_high<mode><mask_name>): .. this, and
extend to V32HFmode.
(avx2_interleave_highv16hi<mask_name>): Rename to ..
(avx2_interleave_high<mode><mask_name>): .. this, and extend
to V16HFmode.
(vec_interleave_highv8hi<mask_name>): Rename to ..
(vec_interleave_high<mode><mask_name>): .. this, and extend to V8HFmode.
(<mask_codefor>avx512bw_interleave_lowv32hi<mask_name>):
Rename to ..
(<mask_codefor>avx512bw_interleave_low<mode><mask_name>):
this, and extend to V32HFmode.
(avx2_interleave_lowv16hi<mask_name>): Rename to ..
(avx2_interleave_low<mode><mask_name>): .. this, and extend to V16HFmode.
(vec_interleave_lowv8hi<mask_name>): Rename to ..
(vec_interleave_low<mode><mask_name>): .. this, and extend to V8HFmode.
(sse4_1_pblendw): Rename to ..
(sse4_1_pblend<blendsuf>): .. this, and extend to V8HFmode.
(avx2_pblendph): New define_expand.
(<sse2p4_1>_pinsr<ssemodesuffix>): Refactor, use
sseintmodesuffix instead of ssemodesuffix.
(blendsuf): New mode attr.
gcc/testsuite/ChangeLog:
* gcc.target/i386/pr102327-1.c: New test.
* gcc.target/i386/pr102327-2.c: New test.
* gcc.target/i386/avx512fp16-1c.c: Adjust testcase.