+/*
+ * Copyright (C) 1995-2007 University of Karlsruhe. All right reserved.
+ *
+ * This file is part of libFirm.
+ *
+ * This file may be distributed and/or modified under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation and appearing in the file LICENSE.GPL included in the
+ * packaging of this file.
+ *
+ * Licensees holding valid libFirm Professional Edition licenses may use
+ * this file in accordance with the libFirm Commercial License.
+ * Agreement provided with the Software.
+ *
+ * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
+ * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE.
+ */
+
/**
*
* @file strength_red.c
* Created: 22.8.2004
* CVS-ID: $Id$
* Copyright: (c) 2004 Universität Karlsruhe
- * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
*/
-
-
-/*
-
-reducible(o)
- while (reducible)
- o = reduce(o)
-
-reduce_itervar(induct_var_info *iv)
- for each (out o of iv) {
- if (o is reducible) {
- if (o is strong (Mul))
- iv_new = reduce(o), remember_pattern(o)
- else // o is not strong (Add ...)
- if (o is the only user)
- iv_new = reducible(o)
- }
- }
-
-*/
-
-# include "strength_red.h"
-
-# include "irouts.h"
-# include "irnode_t.h"
-# include "irgwalk.h"
-# include "irloop_t.h"
-# include "ircons.h"
-# include "irgmod.h"
-# include "irdump_t.h"
-# include "firmstat.h"
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "strength_red_t.h"
+#include "iroptimize.h"
+#include "irouts.h"
+#include "irnode_t.h"
+#include "irgwalk.h"
+#include "irloop_t.h"
+#include "ircons.h"
+#include "irgmod.h"
+#include "irdump_t.h"
+#include "irprintf.h"
+#include "firmstat.h"
/** Counter for verbose information about optimization. */
/** 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
+ *
+ * @endverbatim
*
- * 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.
+ * 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) {
-
- int i;
- int op_pred, Store_in_op, Store_in_phi, cmp_in_phi;
-
- info->c = NULL;
- info->cmp = NULL;
- info->cmp_const = NULL;
- info->cmp_init_block = NULL;
- info->increment = NULL;
- info->init = NULL;
- info->l_itervar_phi = NULL;
- info->new_add = NULL;
- info->new_cmp = NULL;
- info->new_increment = NULL;
- info->new_init = NULL;
- info->new_op = NULL;
- info->new_phi = NULL;
- info->operation_code = NULL;
- info->op = NULL;
- info->old_ind = NULL;
- info->reducible_node = NULL;
- info->out_loop_res = 1;
- info->reducible = 0;
- info->phi_pred = 0;
- info->strong_reduced = 0;
- info->init_pred_pos = -1;
- info->op_pred_pos = -1;
+induct_var_info *is_induction_variable(induct_var_info *info) {
+
+ int i, q, r;
+ int op_pred, Store_in_op, Store_in_phi;
+ ir_node *cmp_pred_bl, *cond_succ_0, *cond_succ_1, *cmp_const;
+ ir_node *loop_head;
+ ir_node *cmp_const_block;
+
+ info->operation_code = NULL; /* The opcode of "op". */
+ info->increment = NULL; /* The value which increase or decrease the iteration variable. */
+ info->init = NULL; /* The start value of the iteration variable. */
+ info->op = NULL; /* The operation which increase or decrease the iteration variable. */
+ info->l_itervar_phi = NULL; /* The iteration variable. */
+ info->new_phi = NULL; /* The new iteration variable. */
+ info->new_increment = NULL; /* The new increment which replace the old one.*/
+ info->new_init = NULL; /* The new init value of the iteration variable. */
+ info->new_op = NULL; /* The new operation that we need after replace. */
+ info->new_cmp = NULL; /* The new Cmp which replaces the old one. */
+ info->cmp = NULL; /* The Cmp which breaks the loop and compares the iteration variable with a constant. */
+ info->cmp_const = NULL; /* The other operand of Cmp. */
+ info->cmp_init_block = NULL; /* The initial block of the Cmp. */
+ info->reducible_node = NULL; /* The reducible nodes are save here. */
+ info->is_reducible = 0; /* To save information if anything is reducible. */
+ info->phi_pred = 0; /* To save the value of iteration variable predecessors. */
+ info->init_pred_pos = -1; /* To save the position of iteration variable start value. */
+ info->op_pred_pos = -1; /* To save the backedge of iteration variable. */
+ info->l_itervar_phi = NULL; /* Information about loop of itervar_phi. */
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)) )
+ /*
+ * The necessary conditions for the phi node:
+ * We can handle currently Phi's with 2 predecessors, one must be a backedge.
+ */
+ if (get_irn_arity(info->itervar_phi) != 2 || !has_backedges(get_nodes_block(info->itervar_phi)))
return NULL;
for (i = 0; i < 2; ++i) {
ir_node *pred = get_Phi_pred(info->itervar_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);
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.*/
+
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);
+
+ /*
+ * 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.
+ */
+ 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 ((get_irn_loop(get_nodes_block(out)) != info->l_itervar_phi) &&
- ( get_Block_dom_depth(get_nodes_block(out)) >
- get_Block_dom_depth(get_nodes_block(info->itervar_phi))))
- info->out_loop_res = 0;
-
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)) {
+ /* a Cmp can have more than one successor therefore we need this loop.*/
+ for (q = get_irn_n_outs(out) - 1; q >= 0; --q) {
+ ir_node *proj = get_irn_out(out, q);
+
+ for (r = get_irn_n_outs(proj) -1; r >= 0; --r) {
+ cmp_pred_bl = get_irn_out(proj, r);
+
+ /* The wanted Cmp must be followed by a Cond successor
+ not by a Mux. */
+ if (get_irn_op(cmp_pred_bl) != op_Cond)
+ continue;
+
+ /* the binary Cond should have two successors */
+ if (get_irn_n_outs(cmp_pred_bl) != 2)
+ continue;
+
+ cond_succ_0 = get_irn_out(cmp_pred_bl, 0);
+ cond_succ_1 = get_irn_out(cmp_pred_bl, 1);
+
+ if (is_loop_invariant(get_irn_out(cond_succ_1, 0), loop_head) ||
+ is_loop_invariant(get_irn_out(cond_succ_0, 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) {
+ /* A cmp is found.*/
+ info->cmp = out;
+ info->cmp_const = cmp_const;
+ }
+ else {
+ /* We have more then one cmp with our requests, that mean cmp isn't found */
+ info->cmp = NULL;
+ return NULL;
+ }
+ }
+ }
}
}
- 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;
+ for (i = 0; i < op_pred; ++i) {
+ ir_node *out = get_irn_out(info->op, i);
+ ir_op *out_op = get_irn_op(out);
- // Search for loop invariant of Cmp.
- if (info->cmp != NULL) {
- ir_node *cmp_const_block;
+ if (out_op == op_Store)
+ Store_in_op++;
+ else if (out_op == op_Cmp && !is_loop_invariant(out, loop_head)) {
+ /* a Cmp can have more as one successor therefore
+ I need this for loop. */
+ for (q = get_irn_n_outs(out) - 1; q >= 0; --q) {
+ ir_node *proj = get_irn_out(out, q);
+
+ for (r = get_irn_n_outs(proj) -1; r >= 0; --r) {
+ cmp_pred_bl = get_irn_out(proj, r);
+
+ /* The wanted Cmp must be followed by a Cond successor. */
+ if (get_irn_op(cmp_pred_bl) != op_Cond)
+ continue;
+
+ cond_succ_0 = get_irn_out(cmp_pred_bl, 0);
+ cond_succ_1 = get_irn_out(cmp_pred_bl, 1);
+
+ if (is_loop_invariant(get_irn_out(cond_succ_0, 0), loop_head) ||
+ is_loop_invariant(get_irn_out(cond_succ_1, 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->cmp == NULL) {
+ /* A cmp is found*/
+ info->cmp = out;
+ info->cmp_const = cmp_const;
+ }
+ else {
+ /* We have more then one cmp with our requests, that mean cmp isn't found*/
+ info->cmp = NULL;
+ return NULL;
+ }
+ }
+ }
+ }
+ }
- 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->is_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.
+ * Creates a new Add node with the correct mode from its two 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);
if (mode_is_reference(m2))
m = m2;
+
return new_r_Add(irg, b, op1, op2, m);
}
/**
- * Creates a new Sub node from operands.
+ * Creates a new Sub node with the correct mode from its two 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);
return new_r_Sub(irg, b, op1, op2, m);
}
-/* Reduce a Add, Sub or Mul node
+/**
+ * Reduce an Add, Sub or Mul node
*
* @param *reduce_var The node to reduce.
* @param *ivi Contains the induction variable information.
*/
static int reduce(ir_node *reduce_var, induct_var_info *ivi)
{
- // Essential conditions for a reducable node.
+ ir_node *iter_varblk, *init_block, *irg_startblk, *block_init;
+
+ /* Essential conditions for a reducible node. */
if (get_irn_loop(get_nodes_block(reduce_var)) != ivi->l_itervar_phi)
return 0;
+ iter_varblk = get_nodes_block(ivi->itervar_phi);
+ init_block = get_nodes_block(ivi->init);
+ irg_startblk = get_irg_start_block(current_ir_graph);
+
+ /* The "new_init" and the "new_cmp_const" must not be in the start block.*/
+ if (get_Block_dom_depth(init_block) > get_Block_dom_depth(irg_startblk) &&
+ init_block != iter_varblk)
+ block_init = init_block;
+ else
+ block_init = get_nodes_block(get_Block_cfgpred(iter_varblk, ivi->init_pred_pos));
+
+ /* To avoid that cmp is placed in the start block.*/
+ if (ivi->cmp_init_block == irg_startblk)
+ ivi->cmp_init_block = iter_varblk;
+
if (get_irn_op(reduce_var) == op_Mul) {
ir_node *mul_init = NULL;
ir_node *mul_const = NULL;
- // Search for constant and init of strong.
+ /* Search for constant and init of strong. */
ir_node *mul_right = get_Mul_right(reduce_var);
ir_node *mul_left = get_Mul_left(reduce_var);
ir_op *mul_right_op = get_irn_op(mul_right);
ir_op *mul_left_op = get_irn_op(mul_left);
- ir_node *in[2], *block_init;
+ ir_node *in[2];
ir_node *block_inc;
- ir_node *init_block;
ir_node *increment_block;
ir_node *c_block;
if (mul_const == NULL || mul_init == NULL)
return 0;
- init_block = get_nodes_block(mul_init);
increment_block = get_nodes_block(ivi->increment);
c_block = get_nodes_block(mul_const);
else
block_inc = c_block;
- if (get_Block_dom_depth(init_block) >= get_Block_dom_depth(c_block))
- block_init = init_block;
- else
- block_init = c_block;
-
- if (! ivi->reducible){
+ if (! ivi->is_reducible){
int reduce_var_pred;
- // Essential condition for the constant of strong.
+ /* Essential condition for the constant of strong. */
if (get_Block_dom_depth(get_nodes_block(mul_const)) >=
get_Block_dom_depth(get_nodes_block(ivi->itervar_phi)))
return 0;
n_made_new_phis++;
if (get_opt_strength_red_verbose() && get_firm_verbosity() > 1) {
- printf("The new Phi node is : "); DDMN(ivi->itervar_phi);
- printf("reducing operation is : "); DDMN(reduce_var);
- printf("in graph : "); DDMG(current_ir_graph);
+ ir_printf("The new Phi node is : %+F\n", ivi->itervar_phi);
+ ir_printf("reducing operation is : %+F\n", reduce_var);
+ ir_printf("in graph : %+F\n", current_ir_graph);
}
ivi->new_increment = new_r_Mul (current_ir_graph, block_inc, ivi->increment, 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) {
ir_node *old_ind =get_irn_out(reduce_var, 0);
if(get_irn_op(old_ind) == op_Add || get_irn_op(old_ind) == op_Sub ||
get_irn_op(old_ind) == op_Mul){
- ivi->reducible = 1;
+ ivi->is_reducible = 1;
ivi->reducible_node = old_ind;
}
}
exchange(reduce_var, ivi->new_phi);
return 1;
}
- else { /* ivi->reducible */
- if(ivi->new_phi == NULL){
- ivi->init = new_r_Mul (current_ir_graph, get_nodes_block(ivi->init),
+ else { /* ivi->is_reducible */
+ if (ivi->new_phi == NULL) {
+ ivi->init = new_r_Mul (current_ir_graph, block_init,
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 = 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, get_nodes_block(ivi->init),
+ }
+ 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_init,
+ 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);
- printf("in graph : "); DDMG(current_ir_graph);
+ ir_printf("\nReducing operation is : %+F\n", reduce_var);
+ ir_printf("in graph : %+F\n", current_ir_graph);
}
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;
- // Search for constant of add.
+ /* Search for constant of add. */
ir_node *add_right = get_Add_right(reduce_var);
ir_node *add_left = get_Add_left(reduce_var);
ir_op *add_right_op = get_irn_op(add_right);
ir_op *add_left_op = get_irn_op(add_left);
- n_reduced_expressions++;
+ ++n_reduced_expressions;
if (add_right_op != op_Const)
add_init = add_right;
add_const = add_right;
else if (add_left_op == op_Const || add_left_op == op_SymConst)
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);
+ if (add_const == NULL)
+ return 0;
+ if (ivi->new_phi == NULL) {
+ ivi->init = my_new_r_Add(current_ir_graph, block_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, block_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);
+ ir_printf("\nReducing operation is : %+F\n", reduce_var);
+ ir_printf("in graph : %+F\n", 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);
ir_op *sub_left_op = get_irn_op(sub_left);
- n_reduced_expressions++;
+ ++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, block_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, ivi->cmp_init_block,
ivi->cmp_const,sub_const);
} else
- ivi->new_init = my_new_r_Sub (current_ir_graph, get_nodes_block(ivi->init),
+ ivi->new_init = my_new_r_Sub (current_ir_graph, block_init,
ivi->new_init, sub_const);
if (get_opt_strength_red_verbose() && get_firm_verbosity() > 1) {
- printf("\nReducing operation is : "); DDMN(reduce_var);
- printf("in graph : "); DDMG(current_ir_graph);
+ ir_printf("\nReducing operation is : %+F", reduce_var);
+ ir_printf("in graph : %+F", current_ir_graph);
}
return 1;
}
return 0;
}
+/**
+ * Search for reducible successor of iteration variable.
+ * If such successor is found it will be reduced and returned,
+ * else return NULL.
+ *
+ * @param ivi Contains information about the induction variable.
+ * @param out A successor of iteration variable.
+ */
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)
{
induct_var_info ivi;
+ /* check if a iteration variable be reduced.*/
+ int reduced = 0;
+ (void) env;
- if (get_irn_op(itervar_phi) != op_Phi)
+ if (! is_Phi(itervar_phi))
return;
+ /* A potential candidate is found.*/
ivi.itervar_phi = itervar_phi;
- /* This "if" finds the iteration variable. */
+ /* check if it's a induction 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){
- ir_node *reduced = reducible(out, &ivi);
- if (reduced != NULL)
- exchange( reduced, ivi.itervar_phi);
+ /* Reduce a induction variable.*/
+ if (ivi.is_reducible) {
+ if (ivi.phi_pred == 3 && out != ivi.op && out != ivi.cmp) {
+ ir_node *irn_reduced = reducible(out, &ivi);
+ if (irn_reduced != NULL){
+ reduced = 1;
+ exchange(irn_reduced, ivi.itervar_phi);
+ }
}
- } else if (out_op == op_Mul)
- if(reduce(out, &ivi) && ivi.reducible){
+ }
+ /* Reduce a multiplication*/
+ else if (out_op == op_Mul)
+ if (reduce(out, &ivi) && ivi.is_reducible) {
ir_node *reduced = reducible(ivi.reducible_node, &ivi);
- if(reduced != NULL)
+
+ if (reduced != NULL)
exchange(reduced, ivi.new_phi);
- ivi.reducible = 0;
+
+ ivi.is_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));
set_irn_mode(ivi.new_op,get_irn_mode(ivi.new_phi));
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){
+ /* Try to reduce the second successor of the "ivi.op"*/
+ 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){
+ }
+ /* Try to reduce a multiplication, that is successor of "ivi.op".*/
+ else if (out_op == op_Mul)
+ if (reduce(out, &ivi) && ivi.is_reducible){
ir_node *reduced = reducible(ivi.reducible_node, &ivi);
if(reduced != NULL)
exchange(reduced, ivi.new_phi);
- ivi.reducible = 0;
+ ivi.is_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));
set_irn_mode(ivi.new_op,get_irn_mode(ivi.new_phi));
}
}
-
- if(ivi.reducible){
+ /* Set some predecessors and modes after reduce.*/
+ if (ivi.is_reducible && reduced) {
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;
/* Call algorithm that computes the backedges */
construct_cf_backedges(irg);
/* Call algorithm that computes the dominator trees. */
- compute_doms(irg);
+ assure_doms(irg);
/* Call algorithm that computes the out edges */
- compute_outs(irg);
+ assure_irg_outs(irg);
/* -- Search expressions that can be optimized -- */
irg_walk_graph(irg, NULL, reduce_itervar, NULL);
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 / blobdiff