Fold blendv builtins into gimple.
Fold __builtin_ia32_pblendvb128 (a, b, c) as VEC_COND_EXPR (c < 0, b,
a), similar for float version but with mask operand VIEW_CONVERT_EXPR
to same sized integer vectype.
gcc/ChangeLog:
* config/i386/i386-builtin.def (IX86_BUILTIN_BLENDVPD256,
IX86_BUILTIN_BLENDVPS256, IX86_BUILTIN_PBLENDVB256,
IX86_BUILTIN_BLENDVPD, IX86_BUILTIN_BLENDVPS,
IX86_BUILTIN_PBLENDVB128): Replace icode with
CODE_FOR_nothing.
* config/i386/i386.c (ix86_gimple_fold_builtin): Fold blendv
builtins.
* config/i386/sse.md (*<sse4_1_avx2>_pblendvb_lt_subreg_not):
New pre_reload splitter.
gcc/testsuite/ChangeLog:
* gcc.target/i386/funcspec-8.c: Replace
__builtin_ia32_blendvpd with __builtin_ia32_roundps_az.
* gcc.target/i386/blendv-1.c: New test.
* gcc.target/i386/blendv-2.c: New test.