return NULL_TREE;
}
+/* Returns true when DEF is used outside the reduction cycle of
+ LOOP_PHI. */
+
+static bool
+used_outside_reduction (tree def, gimple loop_phi)
+{
+ use_operand_p use_p;
+ imm_use_iterator imm_iter;
+ loop_p loop = loop_containing_stmt (loop_phi);
+
+ /* In LOOP, DEF should be used only in LOOP_PHI. */
+ FOR_EACH_IMM_USE_FAST (use_p, imm_iter, def)
+ {
+ gimple stmt = USE_STMT (use_p);
+
+ if (stmt != loop_phi
+ && !is_gimple_debug (stmt)
+ && flow_bb_inside_loop_p (loop, gimple_bb (stmt)))
+ return true;
+ }
+
+ return false;
+}
+
/* Detect commutative and associative scalar reductions belonging to
the SCOP starting at the loop closed phi node STMT. Return the phi
node of the reduction cycle, or NULL. */
{
if (scalar_close_phi_node_p (stmt))
{
- tree arg = gimple_phi_arg_def (stmt, 0);
- gimple def, loop_phi;
+ gimple def, loop_phi, phi, close_phi = stmt;
+ tree init, lhs, arg = gimple_phi_arg_def (close_phi, 0);
if (TREE_CODE (arg) != SSA_NAME)
return NULL;
/* Note that loop close phi nodes should have a single argument
because we translated the representation into a canonical form
before Graphite: see canonicalize_loop_closed_ssa_form. */
- gcc_assert (gimple_phi_num_args (stmt) == 1);
+ gcc_assert (gimple_phi_num_args (close_phi) == 1);
def = SSA_NAME_DEF_STMT (arg);
- if (!stmt_in_sese_p (def, SCOP_REGION (scop)))
+ if (!stmt_in_sese_p (def, SCOP_REGION (scop))
+ || !(loop_phi = detect_commutative_reduction (scop, def, in, out)))
return NULL;
- loop_phi = detect_commutative_reduction (scop, def, in, out);
+ lhs = gimple_phi_result (close_phi);
+ init = initial_value_for_loop_phi (loop_phi);
+ phi = follow_inital_value_to_phi (init, lhs);
- if (loop_phi)
- {
- tree lhs = gimple_phi_result (stmt);
- tree init = initial_value_for_loop_phi (loop_phi);
- gimple phi = follow_inital_value_to_phi (init, lhs);
-
- VEC_safe_push (gimple, heap, *in, loop_phi);
- VEC_safe_push (gimple, heap, *out, stmt);
- return phi;
- }
- else
+ if (phi && (used_outside_reduction (lhs, phi)
+ || !has_single_use (gimple_phi_result (phi))))
return NULL;
+
+ VEC_safe_push (gimple, heap, *in, loop_phi);
+ VEC_safe_push (gimple, heap, *out, close_phi);
+ return phi;
}
if (gimple_code (stmt) == GIMPLE_ASSIGN)
VEC (gimple, heap) *out = VEC_alloc (gimple, heap, 10);
detect_commutative_reduction (scop, close_phi, &in, &out);
- res = VEC_length (gimple, in) > 0;
+ res = VEC_length (gimple, in) > 1;
if (res)
translate_scalar_reduction_to_array (scop, in, out);
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