https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91940
--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Untested WIP patch that does both.
If it finds vectorize_bswap will work (the corresponding permutation is
supported), it will just undo the promotion, if target supports vector rotates,
will use vector rotate, if target supports vector shifts, it will use those +
ior. For the first case, e.g. -mavx2 now vectorizes using permutation what
wasn't vectorized, for the second case I don't have any particular target in
mind ATM (e.g. -mxop supports rotates, but will support also the permutations),
and the last case is e.g. SSE2.
--- gcc/tree-vect-patterns.c.jj 2019-09-20 12:25:48.186387075 +0200
+++ gcc/tree-vect-patterns.c 2019-10-01 11:29:18.229215895 +0200
@@ -46,6 +46,8 @@ along with GCC; see the file COPYING3.
#include "cgraph.h"
#include "omp-simd-clone.h"
#include "predict.h"
+#include "tree-vector-builder.h"
+#include "vec-perm-indices.h"
/* Return true if we have a useful VR_RANGE range for VAR, storing it
in *MIN_VALUE and *MAX_VALUE if so. Note the range in the dump files. */
@@ -2168,24 +2170,107 @@ vect_recog_rotate_pattern (stmt_vec_info
enum vect_def_type dt;
optab optab1, optab2;
edge ext_def = NULL;
+ bool bswap16_p = false;
- if (!is_gimple_assign (last_stmt))
- return NULL;
-
- rhs_code = gimple_assign_rhs_code (last_stmt);
- switch (rhs_code)
+ if (is_gimple_assign (last_stmt))
{
- case LROTATE_EXPR:
- case RROTATE_EXPR:
- break;
- default:
- return NULL;
+ rhs_code = gimple_assign_rhs_code (last_stmt);
+ switch (rhs_code)
+ {
+ case LROTATE_EXPR:
+ case RROTATE_EXPR:
+ break;
+ default:
+ return NULL;
+ }
+
+ lhs = gimple_assign_lhs (last_stmt);
+ oprnd0 = gimple_assign_rhs1 (last_stmt);
+ type = TREE_TYPE (oprnd0);
+ oprnd1 = gimple_assign_rhs2 (last_stmt);
+ }
+ else if (gimple_call_builtin_p (last_stmt, BUILT_IN_BSWAP16))
+ {
+ /* __builtin_bswap16 (x) is another form of x r>> 8.
+ The vectorizer has bswap support, but only if the argument isn't
+ promoted. */
+ lhs = gimple_call_lhs (last_stmt);
+ oprnd0 = gimple_call_arg (last_stmt, 0);
+ type = TREE_TYPE (oprnd0);
+ if (TYPE_PRECISION (TREE_TYPE (lhs)) != 16
+ || TYPE_PRECISION (type) <= 16
+ || TREE_CODE (oprnd0) != SSA_NAME
+ || BITS_PER_UNIT != 8
+ || !TYPE_UNSIGNED (TREE_TYPE (lhs)))
+ return NULL;
+
+ stmt_vec_info def_stmt_info;
+ if (!vect_is_simple_use (oprnd0, vinfo, &dt, &def_stmt_info, &def_stmt))
+ return NULL;
+
+ if (dt != vect_internal_def)
+ return NULL;
+
+ if (gimple_assign_cast_p (def_stmt))
+ {
+ def = gimple_assign_rhs1 (def_stmt);
+ if (INTEGRAL_TYPE_P (TREE_TYPE (def))
+ && TYPE_PRECISION (TREE_TYPE (def)) == 16)
+ oprnd0 = def;
+ }
+
+ type = TREE_TYPE (lhs);
+ vectype = get_vectype_for_scalar_type (type);
+ if (vectype == NULL_TREE)
+ return NULL;
+
+ if (tree char_vectype = get_same_sized_vectype (char_type_node,
vectype))
+ {
+ /* The encoding uses one stepped pattern for each byte in the
+ 16-bit word. */
+ vec_perm_builder elts (TYPE_VECTOR_SUBPARTS (char_vectype), 2, 3);
+ for (unsigned i = 0; i < 3; ++i)
+ for (unsigned j = 0; j < 2; ++j)
+ elts.quick_push ((i + 1) * 2 - j - 1);
+
+ vec_perm_indices indices (elts, 1,
+ TYPE_VECTOR_SUBPARTS (char_vectype));
+ if (can_vec_perm_const_p (TYPE_MODE (char_vectype), indices))
+ {
+ /* vectorizable_bswap can handle the __builtin_bswap16 if we
+ undo the argument promotion. */
+ if (!useless_type_conversion_p (type, TREE_TYPE (oprnd0)))
+ {
+ def = vect_recog_temp_ssa_var (type, NULL);
+ def_stmt = gimple_build_assign (def, NOP_EXPR, oprnd0);
+ append_pattern_def_seq (stmt_vinfo, def_stmt);
+ oprnd0 = def;
+ }
+
+ /* Pattern detected. */
+ vect_pattern_detected ("vect_recog_rotate_pattern", last_stmt);
+
+ *type_out = vectype;
+
+ /* Pattern supported. Create a stmt to be used to replace the
+ pattern, with the unpromoted argument. */
+ var = vect_recog_temp_ssa_var (type, NULL);
+ pattern_stmt = gimple_build_call (gimple_call_fndecl (last_stmt),
+ 1, oprnd0);
+ gimple_call_set_lhs (pattern_stmt, var);
+ gimple_call_set_fntype (as_a <gcall *> (pattern_stmt),
+ gimple_call_fntype (last_stmt));
+ return pattern_stmt;
+ }
+ }
+
+ oprnd1 = build_int_cst (integer_type_node, 8);
+ rhs_code = LROTATE_EXPR;
+ bswap16_p = true;
}
+ else
+ return NULL;
- lhs = gimple_assign_lhs (last_stmt);
- oprnd0 = gimple_assign_rhs1 (last_stmt);
- type = TREE_TYPE (oprnd0);
- oprnd1 = gimple_assign_rhs2 (last_stmt);
if (TREE_CODE (oprnd0) != SSA_NAME
|| TYPE_PRECISION (TREE_TYPE (lhs)) != TYPE_PRECISION (type)
|| !INTEGRAL_TYPE_P (type)
@@ -2210,14 +2295,39 @@ vect_recog_rotate_pattern (stmt_vec_info
optab1 = optab_for_tree_code (rhs_code, vectype, optab_vector);
if (optab1
&& optab_handler (optab1, TYPE_MODE (vectype)) != CODE_FOR_nothing)
- return NULL;
+ {
+ use_rotate:
+ if (bswap16_p)
+ {
+ if (!useless_type_conversion_p (type, TREE_TYPE (oprnd0)))
+ {
+ def = vect_recog_temp_ssa_var (type, NULL);
+ def_stmt = gimple_build_assign (def, NOP_EXPR, oprnd0);
+ append_pattern_def_seq (stmt_vinfo, def_stmt);
+ oprnd0 = def;
+ }
+
+ /* Pattern detected. */
+ vect_pattern_detected ("vect_recog_rotate_pattern", last_stmt);
+
+ *type_out = vectype;
+
+ /* Pattern supported. Create a stmt to be used to replace the
+ pattern. */
+ var = vect_recog_temp_ssa_var (type, NULL);
+ pattern_stmt = gimple_build_assign (var, LROTATE_EXPR, oprnd0,
+ oprnd1);
+ return pattern_stmt;
+ }
+ return NULL;
+ }
if (is_a <bb_vec_info> (vinfo) || dt != vect_internal_def)
{
optab2 = optab_for_tree_code (rhs_code, vectype, optab_scalar);
if (optab2
&& optab_handler (optab2, TYPE_MODE (vectype)) != CODE_FOR_nothing)
- return NULL;
+ goto use_rotate;
}
/* If vector/vector or vector/scalar shifts aren't supported by the target,
@@ -2242,6 +2352,14 @@ vect_recog_rotate_pattern (stmt_vec_info
*type_out = vectype;
+ if (bswap16_p && !useless_type_conversion_p (type, TREE_TYPE (oprnd0)))
+ {
+ def = vect_recog_temp_ssa_var (type, NULL);
+ def_stmt = gimple_build_assign (def, NOP_EXPR, oprnd0);
+ append_pattern_def_seq (stmt_vinfo, def_stmt);
+ oprnd0 = def;
+ }
+
if (dt == vect_external_def
&& TREE_CODE (oprnd1) == SSA_NAME)
ext_def = vect_get_external_def_edge (vinfo, oprnd1);
