rs6000: Implement vec_perm_const for all vector ISAs

rs6000: Implement vec_perm_const for all vector ISAs

        * config/rs6000/altivec.md (altivec_vmrghb): Rewrite pattern as
        vec_select + vec_concat.
        (altivec_vmrghh, altivec_vmrghw, altivec_vmrghsf, altivec_vmrglb,
        altivec_vmrglh, altivec_vmrglw, altivec_vmrglsf): Likewise.
        (vec_perm_constv16qi): New.
        (vec_extract_evenv4si, vec_extract_evenv4sf, vpkuhum_nomode,
        vpkuwum_nomode, vec_extract_oddv8hi, vec_extract_oddv16qi,
        vec_interleave_high<VI>, vec_interleave_low<VI>): Remove.
        * config/rs6000/paired.md (paired_merge00): Rewrite pattern as
        vec_select + vec_concat.
        (paired_merge10, paired_merge01, paired_merge11): Likewise.
        (vec_perm_constv2sf): New.
        (vec_interleave_highv2sf, vec_interleave_lowv2sf,
        vec_extract_evenv2sf, vec_extract_oddv2sf): Remove.
        * config/rs6000/spe.md (spe_evmergehi): Rewrite pattern as
        vec_select + vec_concat.
        (spe_evmergehilo, spe_evmergelo, spe_evmergelohi): New.
        (vec_perm_constv2si): New.
        * config/rs6000/vector.md (vec_interleave_highv4sf,
        vec_interleave_lowv4sf, vec_interleave_high<VEC_64>,
        vec_interleave_low<VEC_64>): Remove.
        * config/rs6000/vsx.md (VS_double): New mode attribute.
        (UNSPEC_VSX_XXPERMDI): Remove.
        (vsx_xxpermdi_<VSX_L>_1): Rewrite pattern as vec_select + vec_concat.
        (vsx_xxmrghw_<VSX_W>, vsx_xxmrglw_<VSX_W>): Likewise.
        (vsx_xxpermdi_<VSX_L>): Change to expander.
        (vec_perm_const<VSX_D>): New.
        (vsx_mergel_<VSX_D>, vsx_mergeh_<VSX_D>): New.
        * config/rs6000/predicates.md (const_0_to_1_operand): New.
        (const_2_to_3_operand): New.
        * config/rs6000/rs6000.c (TARGET_VECTORIZE_VEC_PERM_CONST_OK): New.
        (altivec_expand_vec_perm_const): New.
        (rs6000_expand_vec_perm_const_1, rs6000_expand_vec_perm_const): New.
        (rs6000_vectorize_vec_perm_const_ok): New.
        (rs6000_do_expand_vec_perm): New.
        (rs6000_expand_extract_even, rs6000_expand_interleave): New.
        * config/rs6000/rs6000-builtin.def (VEC_MERGE*): Update rtx codes.
        * config/rs6000/rs6000-modes.def: Add double-wide vector modes.
        * config/rs6000/rs6000-protos.h: Update.

From-SVN: r182193