md.texi: Document vec_shl_<mode> pattern.

	* doc/md.texi: Document vec_shl_<mode> pattern.
	* optabs.def (vec_shl_optab): New optab.
	* optabs.c (shift_amt_for_vec_perm_mask): Add shift_optab
	argument, if == vec_shl_optab, check for left whole vector shift
	pattern rather than right shift.
	(expand_vec_perm_const): Add vec_shl_optab support.
	* optabs-query.c (can_vec_perm_var_p): Mention also vec_shl optab
	in the comment.
	* tree-vect-generic.c (lower_vec_perm): Support permutations which
	can be handled by vec_shl_optab.
	* tree-vect-stmts.c (scan_store_can_perm_p): New function.
	(check_scan_store): Use it.
	(vectorizable_scan_store): If target can't do normal permutations,
	try to use whole vector left shifts and if needed a VEC_COND_EXPR
	after it.
	* config/i386/sse.md (vec_shl_<mode>): New expander.

	* gcc.dg/vect/vect-simd-8.c: If main is defined, don't include
	tree-vect.h nor call check_vect.
	* gcc.dg/vect/vect-simd-9.c: Likewise.
	* gcc.dg/vect/vect-simd-10.c: New test.
	* gcc.target/i386/sse2-vect-simd-8.c: New test.
	* gcc.target/i386/sse2-vect-simd-9.c: New test.
	* gcc.target/i386/sse2-vect-simd-10.c: New test.
	* gcc.target/i386/avx2-vect-simd-8.c: New test.
	* gcc.target/i386/avx2-vect-simd-9.c: New test.
	* gcc.target/i386/avx2-vect-simd-10.c: New test.
	* gcc.target/i386/avx512f-vect-simd-8.c: New test.
	* gcc.target/i386/avx512f-vect-simd-9.c: New test.
	* gcc.target/i386/avx512f-vect-simd-10.c: New test.

From-SVN: r272472

1 files changed, 26 insertions, 0 deletions

diff --git a/gcc/tree-vect-generic.c b/gcc/tree-vect-generic.c
index e9f5505..4a53fc4 100644
--- a/gcc/tree-vect-generic.c
+++ b/gcc/tree-vect-generic.c
@@ -1367,6 +1367,32 @@ lower_vec_perm (gimple_stmt_iterator *gsi)
 	      return;
 	    }
 	}
+      /* And similarly vec_shl pattern.  */
+      if (optab_handler (vec_shl_optab, TYPE_MODE (vect_type))
+	  != CODE_FOR_nothing
+	  && TREE_CODE (vec0) == VECTOR_CST
+	  && initializer_zerop (vec0))
+	{
+	  unsigned int first = 0;
+	  for (i = 0; i < elements; ++i)
+	    if (known_eq (poly_uint64 (indices[i]), elements))
+	      {
+		if (i == 0 || first)
+		  break;
+		first = i;
+	      }
+	    else if (first
+		     ? maybe_ne (poly_uint64 (indices[i]),
+					      elements + i - first)
+		     : maybe_ge (poly_uint64 (indices[i]), elements))
+	      break;
+	  if (i == elements)
+	    {
+	      gimple_assign_set_rhs3 (stmt, mask);
+	      update_stmt (stmt);
+	      return;
+	    }
+	}
     }
   else if (can_vec_perm_var_p (TYPE_MODE (vect_type)))
     return;