https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83338
--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
This works for me, but I'll leave testcase and testing for tomorrow.
--- gcc/tree-vect-stmts.c.jj 2017-12-08 12:21:58.000000000 +0100
+++ gcc/tree-vect-stmts.c 2017-12-09 00:55:17.614147824 +0100
@@ -5226,7 +5226,7 @@ vectorizable_operation (gimple *stmt, gi
stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
tree vectype;
loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
- enum tree_code code;
+ enum tree_code code, orig_code;
machine_mode vec_mode;
tree new_temp;
int op_type;
@@ -5264,7 +5264,7 @@ vectorizable_operation (gimple *stmt, gi
if (TREE_CODE (gimple_assign_lhs (stmt)) != SSA_NAME)
return false;
- code = gimple_assign_rhs_code (stmt);
+ orig_code = code = gimple_assign_rhs_code (stmt);
/* For pointer addition and subtraction, we should use the normal
plus and minus for the vector operation. */
@@ -5455,6 +5455,14 @@ vectorizable_operation (gimple *stmt, gi
/* Handle def. */
vec_dest = vect_create_destination_var (scalar_dest, vectype);
+ /* POINTER_DIFF_EXPR has pointer arguments which are vectorized as
+ vectors with unsigned elements, but the result is signed. So, we
+ need to compute the MINUS_EXPR into vectype temporary and
+ VIEW_CONVERT_EXPR it into the final vectype_out result. */
+ tree vec_cvt_dest = NULL_TREE;
+ if (orig_code == POINTER_DIFF_EXPR)
+ vec_cvt_dest = vect_create_destination_var (scalar_dest, vectype_out);
+
/* In case the vectorization factor (VF) is bigger than the number
of elements that we can fit in a vectype (nunits), we have to generate
more than one vector stmt - i.e - we need to "unroll" the
@@ -5546,6 +5554,15 @@ vectorizable_operation (gimple *stmt, gi
new_temp = make_ssa_name (vec_dest, new_stmt);
gimple_assign_set_lhs (new_stmt, new_temp);
vect_finish_stmt_generation (stmt, new_stmt, gsi);
+ if (vec_cvt_dest)
+ {
+ new_temp = build1 (VIEW_CONVERT_EXPR, vectype_out, new_temp);
+ new_stmt = gimple_build_assign (vec_cvt_dest, VIEW_CONVERT_EXPR,
+ new_temp);
+ new_temp = make_ssa_name (vec_cvt_dest, new_stmt);
+ gimple_assign_set_lhs (new_stmt, new_temp);
+ vect_finish_stmt_generation (stmt, new_stmt, gsi);
+ }
if (slp_node)
SLP_TREE_VEC_STMTS (slp_node).quick_push (new_stmt);
}
