reductions. */
if (simple_iv (loop, loop, res, &iv, true))
{
- gsi_next (psi);
+ if (integer_zerop (iv.step))
+ remove_invariant_phi (region, psi);
+ else
+ gsi_next (psi);
+
return false;
}
information. */
static void
-try_generate_gimple_bb (scop_p scop, basic_block bb)
+try_generate_gimple_bb (scop_p scop, basic_block bb, sbitmap reductions)
{
VEC (data_reference_p, heap) *drs = VEC_alloc (data_reference_p, heap, 5);
loop_p nest = outermost_loop_in_sese (SCOP_REGION (scop), bb);
if (!graphite_stmt_p (SCOP_REGION (scop), bb, drs))
free_data_refs (drs);
else
- new_poly_bb (scop, new_gimple_bb (bb, drs));
+ new_poly_bb (scop, new_gimple_bb (bb, drs), TEST_BIT (reductions,
+ bb->index));
}
/* Returns true if all predecessors of BB, that are not dominated by BB, are
/* Recursive helper function for build_scops_bbs. */
static void
-build_scop_bbs_1 (scop_p scop, sbitmap visited, basic_block bb)
+build_scop_bbs_1 (scop_p scop, sbitmap visited, basic_block bb, sbitmap reductions)
{
sese region = SCOP_REGION (scop);
VEC (basic_block, heap) *dom;
|| !bb_in_sese_p (bb, region))
return;
- try_generate_gimple_bb (scop, bb);
+ try_generate_gimple_bb (scop, bb, reductions);
SET_BIT (visited, bb->index);
dom = get_dominated_by (CDI_DOMINATORS, bb);
for (i = 0; VEC_iterate (basic_block, dom, i, dom_bb); i++)
if (all_non_dominated_preds_marked_p (dom_bb, visited))
{
- build_scop_bbs_1 (scop, visited, dom_bb);
+ build_scop_bbs_1 (scop, visited, dom_bb, reductions);
VEC_unordered_remove (basic_block, dom, i);
break;
}
/* Gather the basic blocks belonging to the SCOP. */
-void
-build_scop_bbs (scop_p scop)
+static void
+build_scop_bbs (scop_p scop, sbitmap reductions)
{
sbitmap visited = sbitmap_alloc (last_basic_block);
sese region = SCOP_REGION (scop);
sbitmap_zero (visited);
- build_scop_bbs_1 (scop, visited, SESE_ENTRY_BB (region));
-
+ build_scop_bbs_1 (scop, visited, SESE_ENTRY_BB (region), reductions);
sbitmap_free (visited);
}
build_pbb_drs (pbb);
}
+/* Return a gsi at the position of the phi node STMT. */
+
+static gimple_stmt_iterator
+gsi_for_phi_node (gimple stmt)
+{
+ gimple_stmt_iterator psi;
+ basic_block bb = gimple_bb (stmt);
+
+ for (psi = gsi_start_phis (bb); !gsi_end_p (psi); gsi_next (&psi))
+ if (stmt == gsi_stmt (psi))
+ return psi;
+
+ gcc_unreachable ();
+ return psi;
+}
+
/* Insert the assignment "RES := VAR" just after the definition of VAR. */
static void
}
else
{
- gcc_assert (gimple_code (stmt) == GIMPLE_ASSIGN);
gsi = gsi_for_stmt (stmt);
gsi_insert_seq_after (&gsi, stmts, GSI_NEW_STMT);
}
static bool
scalar_close_phi_node_p (gimple phi)
{
- gcc_assert (gimple_code (phi) == GIMPLE_PHI);
-
- if (!is_gimple_reg (gimple_phi_result (phi)))
+ if (gimple_code (phi) != GIMPLE_PHI
+ || !is_gimple_reg (gimple_phi_result (phi)))
return false;
return (gimple_phi_num_args (phi) == 1);
return res;
}
+/* Return the number of data references in BB that write in
+ memory. */
+
+static int
+nb_data_writes_in_bb (basic_block bb)
+{
+ int res = 0;
+ gimple_stmt_iterator gsi;
+
+ for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ if (gimple_vdef (gsi_stmt (gsi)))
+ res++;
+
+ return res;
+}
+
+/* Splits STMT out of its current BB. */
+
+static basic_block
+split_reduction_stmt (gimple stmt)
+{
+ gimple_stmt_iterator gsi;
+ basic_block bb = gimple_bb (stmt);
+ edge e;
+
+ /* Do not split basic blocks with no writes to memory: the reduction
+ will be the only write to memory. */
+ if (nb_data_writes_in_bb (bb) == 0)
+ return bb;
+
+ split_block (bb, stmt);
+
+ gsi = gsi_last_bb (bb);
+ gsi_prev (&gsi);
+ e = split_block (bb, gsi_stmt (gsi));
+
+ return e->dest;
+}
+
+/* Return true when stmt is a reduction operation. */
+
+static inline bool
+is_reduction_operation_p (gimple stmt)
+{
+ return flag_associative_math
+ && commutative_tree_code (gimple_assign_rhs_code (stmt))
+ && associative_tree_code (gimple_assign_rhs_code (stmt));
+}
+
+/* Returns true when PHI contains an argument ARG. */
+
+static bool
+phi_contains_arg (gimple phi, tree arg)
+{
+ size_t i;
+
+ for (i = 0; i < gimple_phi_num_args (phi); i++)
+ if (operand_equal_p (arg, gimple_phi_arg_def (phi, i), 0))
+ return true;
+
+ return false;
+}
+
+/* Return a loop phi node that corresponds to a reduction containing LHS. */
+
+static gimple
+follow_ssa_with_commutative_ops (tree arg, tree lhs)
+{
+ gimple stmt;
+
+ if (TREE_CODE (arg) != SSA_NAME)
+ return NULL;
+
+ stmt = SSA_NAME_DEF_STMT (arg);
+
+ if (gimple_code (stmt) == GIMPLE_PHI)
+ {
+ if (phi_contains_arg (stmt, lhs))
+ return stmt;
+ return NULL;
+ }
+
+ if (gimple_num_ops (stmt) == 2)
+ return follow_ssa_with_commutative_ops (gimple_assign_rhs1 (stmt), lhs);
+
+ if (is_reduction_operation_p (stmt))
+ {
+ gimple res = follow_ssa_with_commutative_ops (gimple_assign_rhs1 (stmt), lhs);
+
+ return res ? res :
+ follow_ssa_with_commutative_ops (gimple_assign_rhs2 (stmt), lhs);
+ }
+
+ return NULL;
+}
+
+/* Detect commutative and associative scalar reductions starting at
+ the STMT. */
+
+static gimple
+detect_commutative_reduction_arg (tree lhs, gimple stmt, tree arg,
+ VEC (gimple, heap) **in,
+ VEC (gimple, heap) **out)
+{
+ gimple phi = follow_ssa_with_commutative_ops (arg, lhs);
+
+ if (phi)
+ {
+ VEC_safe_push (gimple, heap, *in, stmt);
+ VEC_safe_push (gimple, heap, *out, stmt);
+ return phi;
+ }
+
+ return NULL;
+}
+
+/* Detect commutative and associative scalar reductions starting at
+ the STMT. */
+
+static gimple
+detect_commutative_reduction_assign (gimple stmt, VEC (gimple, heap) **in,
+ VEC (gimple, heap) **out)
+{
+ tree lhs = gimple_assign_lhs (stmt);
+
+ if (gimple_num_ops (stmt) == 2)
+ return detect_commutative_reduction_arg (lhs, stmt,
+ gimple_assign_rhs1 (stmt),
+ in, out);
+
+ if (is_reduction_operation_p (stmt))
+ {
+ gimple res = detect_commutative_reduction_arg (lhs, stmt,
+ gimple_assign_rhs1 (stmt),
+ in, out);
+ return res ? res
+ : detect_commutative_reduction_arg (lhs, stmt,
+ gimple_assign_rhs2 (stmt),
+ in, out);
+ }
+
+ return NULL;
+}
+
+/* Return a loop phi node that corresponds to a reduction containing LHS. */
+
+static gimple
+follow_inital_value_to_phi (tree arg, tree lhs)
+{
+ gimple stmt;
+
+ if (!arg || TREE_CODE (arg) != SSA_NAME)
+ return NULL;
+
+ stmt = SSA_NAME_DEF_STMT (arg);
+
+ if (gimple_code (stmt) == GIMPLE_PHI
+ && phi_contains_arg (stmt, lhs))
+ return stmt;
+
+ return NULL;
+}
+
+
+/* Return the argument of the loop PHI that is the inital value coming
+ from outside the loop. */
+
+static edge
+edge_initial_value_for_loop_phi (gimple phi)
+{
+ size_t i;
+
+ for (i = 0; i < gimple_phi_num_args (phi); i++)
+ {
+ edge e = gimple_phi_arg_edge (phi, i);
+
+ if (loop_depth (e->src->loop_father)
+ < loop_depth (e->dest->loop_father))
+ return e;
+ }
+
+ return NULL;
+}
+
+/* Return the argument of the loop PHI that is the inital value coming
+ from outside the loop. */
+
+static tree
+initial_value_for_loop_phi (gimple phi)
+{
+ size_t i;
+
+ for (i = 0; i < gimple_phi_num_args (phi); i++)
+ {
+ edge e = gimple_phi_arg_edge (phi, i);
+
+ if (loop_depth (e->src->loop_father)
+ < loop_depth (e->dest->loop_father))
+ return gimple_phi_arg_def (phi, i);
+ }
+
+ return NULL_TREE;
+}
+
+/* Detect commutative and associative scalar reductions starting at
+ the loop closed phi node CLOSE_PHI. */
+
+static gimple
+detect_commutative_reduction (gimple stmt, VEC (gimple, heap) **in,
+ VEC (gimple, heap) **out)
+{
+ if (scalar_close_phi_node_p (stmt))
+ {
+ tree arg = gimple_phi_arg_def (stmt, 0);
+ gimple def = SSA_NAME_DEF_STMT (arg);
+ gimple loop_phi = detect_commutative_reduction (def, in, out);
+
+ 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
+ return NULL;
+ }
+
+ if (gimple_code (stmt) == GIMPLE_ASSIGN)
+ return detect_commutative_reduction_assign (stmt, in, out);
+
+ return NULL;
+}
+
+/* Translate the scalar reduction statement STMT to an array RED
+ knowing that its recursive phi node is LOOP_PHI. */
+
+static void
+translate_scalar_reduction_to_array_for_stmt (tree red, gimple stmt,
+ gimple loop_phi)
+{
+ basic_block bb = gimple_bb (stmt);
+ gimple_stmt_iterator insert_gsi = gsi_after_labels (bb);
+ tree res = gimple_phi_result (loop_phi);
+ gimple assign = gimple_build_assign (res, red);
+
+ gsi_insert_before (&insert_gsi, assign, GSI_SAME_STMT);
+
+ assign = gimple_build_assign (red, gimple_assign_lhs (stmt));
+ insert_gsi = gsi_for_stmt (stmt);
+ gsi_insert_after (&insert_gsi, assign, GSI_SAME_STMT);
+}
+
+/* Insert the assignment "result (CLOSE_PHI) = RED". */
+
+static void
+insert_copyout (tree red, gimple close_phi)
+{
+ tree res = gimple_phi_result (close_phi);
+ basic_block bb = gimple_bb (close_phi);
+ gimple_stmt_iterator insert_gsi = gsi_after_labels (bb);
+ gimple assign = gimple_build_assign (res, red);
+
+ gsi_insert_before (&insert_gsi, assign, GSI_SAME_STMT);
+}
+
+/* Insert the assignment "RED = initial_value (LOOP_PHI)". */
+
+static void
+insert_copyin (tree red, gimple loop_phi)
+{
+ gimple_seq stmts;
+ tree init = initial_value_for_loop_phi (loop_phi);
+ edge e = edge_initial_value_for_loop_phi (loop_phi);
+ basic_block bb = e->src;
+ gimple_stmt_iterator insert_gsi = gsi_last_bb (bb);
+ tree expr = build2 (MODIFY_EXPR, TREE_TYPE (init), red, init);
+
+ force_gimple_operand (expr, &stmts, true, NULL);
+ gsi_insert_seq_before (&insert_gsi, stmts, GSI_SAME_STMT);
+}
+
+/* Rewrite out of SSA the reduction described by the loop phi nodes
+ IN, and the close phi nodes OUT. IN and OUT are structured by loop
+ levels like this:
+
+ IN: stmt, loop_n, ..., loop_0
+ OUT: stmt, close_n, ..., close_0
+
+ the first element is the reduction statement, and the next elements
+ are the loop and close phi nodes of each of the outer loops. */
+
+static void
+translate_scalar_reduction_to_array (VEC (gimple, heap) *in,
+ VEC (gimple, heap) *out,
+ sbitmap reductions)
+{
+ unsigned int i;
+ gimple loop_phi;
+ tree red;
+ gimple_stmt_iterator gsi;
+
+ for (i = 0; VEC_iterate (gimple, in, i, loop_phi); i++)
+ {
+ gimple close_phi = VEC_index (gimple, out, i);
+
+ if (i == 0)
+ {
+ gimple stmt = loop_phi;
+ basic_block bb = split_reduction_stmt (stmt);
+
+ SET_BIT (reductions, bb->index);
+ gcc_assert (close_phi == loop_phi);
+
+ red = create_zero_dim_array (gimple_assign_lhs (stmt));
+ translate_scalar_reduction_to_array_for_stmt
+ (red, stmt, VEC_index (gimple, in, 1));
+ continue;
+ }
+
+ if (i == VEC_length (gimple, in) - 1)
+ {
+ insert_copyout (red, close_phi);
+ insert_copyin (red, loop_phi);
+ }
+
+ gsi = gsi_for_phi_node (loop_phi);
+ remove_phi_node (&gsi, false);
+
+ gsi = gsi_for_phi_node (close_phi);
+ remove_phi_node (&gsi, false);
+ }
+}
+
+/* Rewrites out of SSA a commutative reduction at CLOSE_PHI. */
+
+static void
+rewrite_commutative_reductions_out_of_ssa_close_phi (gimple close_phi,
+ sbitmap reductions)
+{
+ VEC (gimple, heap) *in = VEC_alloc (gimple, heap, 10);
+ VEC (gimple, heap) *out = VEC_alloc (gimple, heap, 10);
+
+ detect_commutative_reduction (close_phi, &in, &out);
+ if (VEC_length (gimple, in) > 0)
+ translate_scalar_reduction_to_array (in, out, reductions);
+
+ VEC_free (gimple, heap, in);
+ VEC_free (gimple, heap, out);
+}
+
+/* Rewrites all the commutative reductions from LOOP out of SSA. */
+
+static void
+rewrite_commutative_reductions_out_of_ssa_loop (loop_p loop,
+ sbitmap reductions)
+{
+ gimple_stmt_iterator gsi;
+ edge exit = single_exit (loop);
+
+ if (!exit)
+ return;
+
+ for (gsi = gsi_start_phis (exit->dest); !gsi_end_p (gsi); gsi_next (&gsi))
+ rewrite_commutative_reductions_out_of_ssa_close_phi (gsi_stmt (gsi),
+ reductions);
+}
+
+/* Rewrites all the commutative reductions from SCOP out of SSA. */
+
+static void
+rewrite_commutative_reductions_out_of_ssa (sese region, sbitmap reductions)
+{
+ loop_iterator li;
+ loop_p loop;
+
+ FOR_EACH_LOOP (li, loop, 0)
+ if (loop_in_sese_p (loop, region))
+ rewrite_commutative_reductions_out_of_ssa_loop (loop, reductions);
+}
+
/* Builds the polyhedral representation for a SESE region. */
bool
build_poly_scop (scop_p scop)
{
sese region = SCOP_REGION (scop);
+ sbitmap reductions = sbitmap_alloc (last_basic_block * 2);
+
+ sbitmap_zero (reductions);
+ rewrite_commutative_reductions_out_of_ssa (region, reductions);
rewrite_reductions_out_of_ssa (scop);
- build_scop_bbs (scop);
+ build_scop_bbs (scop, reductions);
+ sbitmap_free (reductions);
/* FIXME: This restriction is needed to avoid a problem in CLooG.
Once CLooG is fixed, remove this guard. Anyways, it makes no
build_scop_context (scop);
add_conditions_to_constraints (scop);
+ scop_to_lst (scop);
build_scop_scattering (scop);
build_scop_drs (scop);
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