/** Detect basic iteration variables.
*
- * The variable ir represented by a subgraph as this:
+ * The variable is represented by a subgraph as this:
+ * @verbatim
*
* init
* /|\
* |
- * |-- Phi
+ * +-- Phi
* | /|\
* | |
- * |-->op
+ * +-->op
*
- * Where op is a Add or Sub, and init is loop invariant.
- * @@@ So far we only accept Phi nodes with two predecessors.
- * We could expand this to Phi nodes where all preds are either
- * op or loop invariant.
+ * @endverbatim
+ *
+ * Where op is a Add or Sub node and init is loop invariant.
+ *
+ * @note
+ * So far we only accept Phi nodes with two predecessors.
+ * We could expand this to Phi nodes where all predecessors
+ * are either op or loop invariant.
*
- * @param n A phi node.
* @param info After call contains the induction variable information.
+ *
+ * @return
+ * The info structure.
*/
+induct_var_info *is_induction_variable(induct_var_info *info) {
-induct_var_info *is_induction_variable (induct_var_info *info) {
-
- int i;
- int op_pred, Store_in_op, Store_in_phi, cmp_in_phi;
+ int i, phi_arity;
+ int op_pred, Store_in_op, Store_in_phi;
+ ir_node *cmp_pred_bl, *cond_succ_true, *cond_succ_false, *cmp_const;
+ ir_node *loop_head, *phi;
+ ir_node *cmp_const_block;
info->c = NULL;
info->cmp = NULL;
assert(get_irn_op(info->itervar_phi) == op_Phi);
- /* The necessary conditions for the phi node. */
- if (get_irn_arity(info->itervar_phi) != 2 ||
- !has_backedges(get_nodes_block(info->itervar_phi)) )
+ phi = info->itervar_phi;
+ phi_arity = get_irn_arity(phi);
+
+ /*
+ * The necessary conditions for the phi node:
+ * We can handle currently Phi's with 2 predecessors, one must be a backedge.
+ */
+ if (phi_arity != 2 || !has_backedges(get_nodes_block(phi)))
return NULL;
for (i = 0; i < 2; ++i) {
- ir_node *pred = get_Phi_pred(info->itervar_phi, i);
+ ir_node *pred = get_Phi_pred(phi, i);
ir_op *op = get_irn_op(pred);
- /* Compute if the induction variable is added or substracted with a constant . */
+ /* Compute if the induction variable is added or subtracted with a constant. */
if (op == op_Add || op == op_Sub) {
ir_node *n_l = get_binop_left(pred);
ir_node *n_r = get_binop_right(pred);
- if (n_l == info->itervar_phi) {
+ if (n_l == phi) {
info->operation_code = op;
info->increment = n_r;
info->op_pred_pos = i;
info->init_pred_pos = i ^ 1;
break;
}
- else if (n_r == info->itervar_phi) {
+ else if (n_r == phi) {
info->operation_code = op;
info->increment = n_l;
info->op_pred_pos = i;
return NULL;
/* Compute the position of the backedge. */
- if (is_backedge(get_nodes_block(info->itervar_phi), info->op_pred_pos)){
- info->op = get_Phi_pred(info->itervar_phi, info->op_pred_pos);
- info->init = get_Phi_pred(info->itervar_phi, info->init_pred_pos);
+ if (is_backedge(get_nodes_block(info->itervar_phi), info->op_pred_pos)) {
+ info->op = get_Phi_pred(info->itervar_phi, info->op_pred_pos);
+ info->init = get_Phi_pred(info->itervar_phi, info->init_pred_pos);
}
else {
/* irregular control flow detected. */
return NULL;
}
+ /*
+ * the block of the init code should dominate the loop, else
+ * we have an irregular control flow
+ */
if (get_Block_dom_depth(get_nodes_block(info->init)) >=
get_Block_dom_depth(get_nodes_block(info->itervar_phi))) {
return NULL;
}
- /* This "for" marks if the iteration operation have a Store successor .*/
op_pred = get_irn_n_outs(info->op);
Store_in_op = 0;
Store_in_phi = 0;
- cmp_in_phi = 0;
- for (i = 0; i < op_pred; ++i){
- ir_node *out = get_irn_out(info->op, i);
- ir_op *out_op = get_irn_op(out);
- if (out_op == op_Store)
- Store_in_op++;
- }
/* Information about loop of itervar_phi. */
info->l_itervar_phi = get_irn_loop(get_nodes_block(info->itervar_phi));
- /* This "for" searches for the Cmp successor of the
- iter_var to reduce and marks if the iter_var have a Store
- successor or a successor out of loop.*/
+ /*
+ *This "for" searches for the Cmp successor of the
+ * iter_var to reduce and marks if the iter_var have a Store
+ * successor or a successor out of loop.
+ */
info->phi_pred = get_irn_n_outs(info->itervar_phi);
- for (i = 0; i < info->phi_pred; ++i) {
+ loop_head = get_nodes_block(info->itervar_phi);
+
+ for (i = 0; i < info->phi_pred; i++) {
ir_node *out = get_irn_out(info->itervar_phi, i);
ir_op *out_op = get_irn_op(out);
if (out_op == op_Store)
Store_in_phi++;
- else if (out_op == op_Cmp){
- info->cmp = out;
- cmp_in_phi++;
+ else if (out_op == op_Cmp && !is_loop_invariant(out, loop_head)) {
+ cmp_pred_bl = get_irn_out(out, 0);
+ cmp_pred_bl = get_irn_out(cmp_pred_bl, 0);
+ cond_succ_true = get_irn_out(cmp_pred_bl, 1);
+ cond_succ_false = get_irn_out(cmp_pred_bl, 0);
+
+ if (is_loop_invariant(get_irn_out(cond_succ_false, 0), loop_head) ||
+ is_loop_invariant(get_irn_out(cond_succ_true, 0), loop_head)) {
+ if (get_Cmp_left(out) == info->itervar_phi)
+ cmp_const = get_Cmp_right(out);
+ else
+ cmp_const = get_Cmp_left(out);
+ }
+ else
+ continue;
+
+ if (info->cmp == NULL) {
+ info->cmp = out;
+ info->cmp_const = cmp_const;
+ }
+ else {
+ info->cmp = NULL;
+ return NULL;
+ }
}
}
+ for (i = 0; i < op_pred; ++i) {
+ ir_node *out = get_irn_out(info->op, i);
+ ir_op *out_op = get_irn_op(out);
+ if (out_op == op_Store)
+ Store_in_op++;
+ else {
+ if (out_op == op_Cmp && !is_loop_invariant(out, loop_head)){
+ cmp_pred_bl = get_irn_out(out, 0);
+ cmp_pred_bl = get_irn_out(cmp_pred_bl, 0);
+ cond_succ_true = get_irn_out(cmp_pred_bl, 1);
+ cond_succ_false = get_irn_out(cmp_pred_bl, 0);
+ if(is_loop_invariant(get_irn_out(cond_succ_false, 0), loop_head) ||
+ is_loop_invariant(get_irn_out(cond_succ_true, 0), loop_head)){
+ if (get_Cmp_left(out) == info->op)
+ cmp_const = get_Cmp_right(out);
+ else
+ cmp_const = get_Cmp_left(out);
+ }
+ else
+ continue;
- if((info->phi_pred == 3 && op_pred == 1 && Store_in_phi == 0 && cmp_in_phi == 1) ||
- (info->phi_pred == 2 && op_pred == 2 && Store_in_op == 0 && info->cmp != NULL ) ||
- (info->phi_pred == 1 && Store_in_op == 0))
- info->reducible = 1;
+ if (info->cmp == NULL) {
+ info->cmp = out;
+ info->cmp_const = cmp_const;
+ set_irn_link(info->cmp_const, (void *) 1);
+ }
+ else {
+ info->cmp = NULL;
+ return NULL;
+ }
+ }
+ }
+ }
- // Search for loop invariant of Cmp.
- if (info->cmp != NULL) {
- ir_node *cmp_const_block;
- if (get_Cmp_left(info->cmp) == info->itervar_phi)
- info->cmp_const = get_Cmp_right(info->cmp);
- else
- info->cmp_const = get_Cmp_left(info->cmp);
+ if ((info->phi_pred == 3 && op_pred == 1 && Store_in_phi == 0 && info->cmp != NULL) ||
+ (info->phi_pred == 2 && op_pred == 2 && Store_in_op == 0 && info->cmp != NULL ) ||
+ (info->phi_pred == 1 && Store_in_op == 0))
+ info->reducible = 1;
+ // Search for loop invariant of Cmp.
+ if (info->cmp != NULL){
cmp_const_block = get_nodes_block(info->cmp_const);
if (get_Block_dom_depth(get_nodes_block(info->init)) >=
- get_Block_dom_depth(cmp_const_block))
+ get_Block_dom_depth(cmp_const_block))
info->cmp_init_block = get_nodes_block(info->init);
else
info->cmp_init_block = cmp_const_block;
* Creates a new Add node from operands.
*/
static INLINE ir_node *
-my_new_r_Add (ir_graph *irg, ir_node *b, ir_node *op1, ir_node *op2) {
+my_new_r_Add(ir_graph *irg, ir_node *b, ir_node *op1, ir_node *op2) {
ir_mode *m = get_irn_mode(op1);
ir_mode *m2 = get_irn_mode(op2);
* Creates a new Sub node from operands.
*/
static INLINE ir_node *
-my_new_r_Sub (ir_graph *irg, ir_node *b, ir_node *op1, ir_node *op2) {
+my_new_r_Sub(ir_graph *irg, ir_node *b, ir_node *op1, ir_node *op2) {
ir_mode *m = get_irn_mode(op1);
ir_mode *m2 = get_irn_mode(op2);
*/
static int reduce(ir_node *reduce_var, induct_var_info *ivi)
{
- // Essential conditions for a reducable node.
+ // Essential conditions for a reducible node.
if (get_irn_loop(get_nodes_block(reduce_var)) != ivi->l_itervar_phi)
return 0;
if (mul_const == NULL || mul_init == NULL)
return 0;
- init_block = get_nodes_block(mul_init);
+ init_block = get_nodes_block(ivi->init);
increment_block = get_nodes_block(ivi->increment);
c_block = get_nodes_block(mul_const);
set_Phi_pred(ivi->new_phi, ivi->op_pred_pos, ivi->new_op);
-
-
-
-
// This for search for a reducible successor of reduc_var.
reduce_var_pred = get_irn_n_outs(reduce_var);
if (reduce_var_pred == 1) {
mul_const, ivi->init,
get_irn_mode(mul_const));
if(ivi->cmp != NULL)
- ivi->cmp_const = new_r_Mul (current_ir_graph, ivi->cmp_init_block,
- ivi->cmp_const, mul_const, get_irn_mode(mul_const));
- ivi->increment = new_r_Mul (current_ir_graph, block_init,
- ivi->increment, mul_const, get_irn_mode(mul_const));
- }else {
- ivi->new_init = new_r_Mul (current_ir_graph, get_nodes_block(ivi->init),
- mul_const, ivi->new_init,
- get_irn_mode(mul_const));
- ivi->new_increment = new_r_Mul (current_ir_graph, block_init,
- ivi->new_increment, mul_const,
- get_irn_mode(mul_const));
+ ivi->cmp_const = new_r_Mul(current_ir_graph, ivi->cmp_init_block,
+ ivi->cmp_const, mul_const, get_irn_mode(mul_const));
+ ivi->increment = new_r_Mul(current_ir_graph, block_inc,
+ ivi->increment, mul_const, get_irn_mode(mul_const));
+ } else {
+ ivi->new_init = new_r_Mul(current_ir_graph, block_init,
+ mul_const, ivi->new_init,
+ get_irn_mode(mul_const));
+ ivi->new_increment = new_r_Mul(current_ir_graph, block_inc,
+ ivi->new_increment, mul_const,
+ get_irn_mode(mul_const));
}
if (get_opt_strength_red_verbose() && get_firm_verbosity() > 1) {
printf("\nReducing operation is : "); DDMN(reduce_var);
}
return 1;
}
-
- }else if (get_irn_op (reduce_var) == op_Add){
+ }
+ else if (get_irn_op (reduce_var) == op_Add){
ir_node *add_init = NULL;
ir_node *add_const = NULL;
add_const = add_left;
if (add_const == NULL) return 0;
if (ivi->new_phi == NULL){
- ivi->init = my_new_r_Add (current_ir_graph, get_nodes_block(ivi->init),
- add_const, ivi->init);
- if(ivi->cmp != NULL)
- ivi->cmp_const = my_new_r_Add (current_ir_graph, ivi->cmp_init_block,
- add_const, ivi->cmp_const);
- } else{
- ivi->new_init = my_new_r_Add (current_ir_graph, get_nodes_block(ivi->init),
- add_const, ivi->new_init);
+ ivi->init = my_new_r_Add(current_ir_graph, get_nodes_block(ivi->init),
+ add_const, ivi->init);
+ if (ivi->cmp != NULL)
+ ivi->cmp_const = my_new_r_Add(current_ir_graph, ivi->cmp_init_block,
+ add_const, ivi->cmp_const);
+ } else {
+ ivi->new_init = my_new_r_Add(current_ir_graph, get_nodes_block(ivi->init),
+ add_const, ivi->new_init);
}
if (get_opt_strength_red_verbose() && get_firm_verbosity() > 1) {
printf("\nReducing operation is : "); DDMN(reduce_var);
printf("in graph : "); DDMG(current_ir_graph);
}
return 1;
- } else if(get_irn_op(reduce_var) == op_Sub ){
+ }
+ else if (get_irn_op(reduce_var) == op_Sub) {
ir_node *sub_init = NULL;
ir_node *sub_const = NULL;
- // Search for constant of sub.
ir_node *sub_right = get_Sub_right(reduce_var);
ir_node *sub_left = get_Sub_left(reduce_var);
ir_op *sub_right_op = get_irn_op(sub_right);
n_reduced_expressions++;
+ /* Search for constant of Sub. */
if (sub_right_op != op_Const)
sub_init = sub_right;
else if (sub_left_op != op_Const)
else if (sub_left_op == op_Const)
sub_const = sub_left;
- if (sub_const == NULL) return 0;
+ if (sub_const == NULL)
+ return 0;
if (ivi->new_phi == NULL) {
- ivi->init = my_new_r_Sub (current_ir_graph, get_nodes_block(ivi->init),
- ivi->init, sub_const);
+ ivi->init = my_new_r_Sub(current_ir_graph, get_nodes_block(ivi->init),
+ ivi->init, sub_const);
if (ivi->cmp != NULL)
- ivi->cmp_const =my_new_r_Sub (current_ir_graph, get_nodes_block(ivi->init),
+ ivi->cmp_const = my_new_r_Sub(current_ir_graph, get_nodes_block(ivi->init),
ivi->cmp_const,sub_const);
} else
ivi->new_init = my_new_r_Sub (current_ir_graph, get_nodes_block(ivi->init),
return 0;
}
+/**
+ * What?
+ */
static ir_node *reducible(ir_node *out, induct_var_info *ivi)
{
ir_node *reduced = NULL;
}
/**
- * Reduce a node.
+ * Post walker: Find a Phi node that is a iteration variable and
+ * try to reduce it.
*
- * @param *itervar_phi The iteration variable of a loop.
- * @param *env Free environment pointer.
+ * @param itervar_phi The iteration variable of a loop.
+ * @param env Free environment pointer.
*/
static void reduce_itervar(ir_node *itervar_phi, void *env)
{
ivi.itervar_phi = itervar_phi;
- /* This "if" finds the iteration variable. */
if (is_induction_variable(&ivi)) {
int i, op_out;
for (i = 0; i < ivi.phi_pred; i++) {
ir_node *out = get_irn_out(ivi.itervar_phi, i);
ir_op *out_op = get_irn_op(out);
- if(ivi.reducible){
- if(ivi.phi_pred == 3 && out != ivi.op && out !=ivi.cmp){
+ if (ivi.reducible) {
+ if (ivi.phi_pred == 3 && out != ivi.op && out != ivi.cmp) {
ir_node *reduced = reducible(out, &ivi);
if (reduced != NULL)
exchange( reduced, ivi.itervar_phi);
}
- } else if (out_op == op_Mul)
- if(reduce(out, &ivi) && ivi.reducible){
+ }
+ else if (out_op == op_Mul)
+ if (reduce(out, &ivi) && ivi.reducible) {
ir_node *reduced = reducible(ivi.reducible_node, &ivi);
- if(reduced != NULL)
+
+ if (reduced != NULL)
exchange(reduced, ivi.new_phi);
+
ivi.reducible = 0;
set_Phi_pred(ivi.new_phi, ivi.init_pred_pos, ivi.new_init);
set_irn_mode(ivi.new_phi,get_irn_mode(ivi.new_init));
for (i = 0; i < op_out; i++){
ir_node *out = get_irn_out(ivi.op, i);
ir_op *out_op = get_irn_op(out);
- if(op_out == 2 && out != ivi.itervar_phi){
+
+ if (op_out == 2 && out != ivi.itervar_phi){
ir_node *reduced = reducible(out, &ivi);
if(reduced != NULL)
exchange( reduced, ivi.op);
- }else if (out_op == op_Mul)
- if(reduce(out, &ivi) && ivi.reducible){
+ }
+ else if (out_op == op_Mul)
+ if (reduce(out, &ivi) && ivi.reducible){
ir_node *reduced = reducible(ivi.reducible_node, &ivi);
if(reduced != NULL)
exchange(reduced, ivi.new_phi);
}
}
- if(ivi.reducible){
+ if (ivi.reducible) {
if(get_irn_op(ivi.op) == op_Add)
if(get_Add_left(ivi.op) == ivi.itervar_phi)
set_Add_right(ivi.op, ivi.increment);
/* Performs strength reduction for the passed graph. */
void reduce_strength(ir_graph *irg) {
ir_graph *rem = current_ir_graph;
+ int modifiyed = 1;
if (!get_optimize() || !get_opt_strength_red()) return;
get_entity_name(get_irg_entity(irg)));
}
+ if (modifiyed) {
+ set_irg_outs_inconsistent(irg);
+ set_irg_loopinfo_inconsistent(irg);
+ }
+
current_ir_graph = rem;
}
projects / libfirm / commitdiff