/*
- * Project: libFIRM
- * File name: ir/opt/reassoc.c
- * Purpose: Reassociation
- * Author: Michael Beck
- * Created:
- * CVS-ID: $Id$
- * Copyright: (c) 1998-2004 Universität Karlsruhe
- * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
+ * Copyright (C) 1995-2008 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.
*/
-#ifdef HAVE_CONFIG_H
-# include "config.h"
-#endif
-
-# include "irnode_t.h"
-# include "irgraph_t.h"
-# include "irmode_t.h"
-# include "iropt_t.h"
-# include "ircons_t.h"
-# include "irgmod.h"
-# include "dbginfo.h"
-# include "iropt_dbg.h"
-# include "irflag_t.h"
-# include "irgwalk.h"
-# include "reassoc_t.h"
-# include "irhooks.h"
-# include "irloop.h"
-# include "debug.h"
-
-static firm_dbg_module_t *dbg;
+/**
+ * @file
+ * @brief Reassociation
+ * @author Michael Beck
+ * @version $Id$
+ */
+#include "config.h"
+
+#include "iropt_t.h"
+#include "irnode_t.h"
+#include "irgraph_t.h"
+#include "irmode_t.h"
+#include "ircons_t.h"
+#include "irgmod.h"
+#include "iropt_dbg.h"
+#include "irflag_t.h"
+#include "irgwalk.h"
+#include "irouts.h"
+#include "reassoc_t.h"
+#include "irhooks.h"
+#include "irloop.h"
+#include "pdeq.h"
+#include "debug.h"
+
+//#define NEW_REASSOC
+
+DEBUG_ONLY(static firm_dbg_module_t *dbg;)
typedef struct _walker_t {
- int changes; /* set, if a reassociation take place */
+ int changes; /**< set, if a reassociation take place */
+ waitq *wq; /**< a wait queue */
} walker_t;
typedef enum {
- NO_CONSTANT = 0, /**< node is not constant */
- REAL_CONSTANT = 1, /**< node is a Const that is suitable for constant folding */
- CONST_EXPR = 4 /**< node is a constant expression in the current context,
- use 4 here to simplify implementation of get_comm_Binop_ops() */
+ NO_CONSTANT = 0, /**< node is not constant */
+ REAL_CONSTANT = 1, /**< node is a Const that is suitable for constant folding */
+ REGION_CONST = 4 /**< node is a constant expression in the current context,
+ use 4 here to simplify implementation of get_comm_Binop_ops() */
} const_class_t;
/**
* returns whether a node is constant ie is a constant or
- * is loop invariant
+ * is loop invariant (called region constant)
*
* @param n the node to be checked for constant
* @param block a block that might be in a loop
*/
-static const_class_t get_const_class(ir_node *n, ir_node *block)
+static const_class_t get_const_class(const ir_node *n, const ir_node *block)
{
- ir_op *op = get_irn_op(n);
-
- if (op == op_Const)
- return REAL_CONSTANT;
- if (op == op_SymConst)
- return CONST_EXPR;
- /*
- * Beware: Bad nodes are always loop-invariant, but
- * cannot handles in later code, so filter them here
- */
- if (! is_Bad(n) && is_loop_invariant(n, block))
- return CONST_EXPR;
-
- return NO_CONSTANT;
-}
+ if (is_Const(n))
+ return REAL_CONSTANT;
+
+ /* constant nodes which can't be folded are region constants */
+ if (is_irn_constlike(n))
+ return REGION_CONST;
+
+ /*
+ * Beware: Bad nodes are always loop-invariant, but
+ * cannot handled in later code, so filter them here.
+ */
+ if (! is_Bad(n) && is_loop_invariant(n, block))
+ return REGION_CONST;
+
+ return NO_CONSTANT;
+} /* get_const_class */
/**
* returns the operands of a commutative bin-op, if one operand is
- * a constant in the current context, it is returned as the second one.
+ * a region constant, it is returned as the second one.
*
* Beware: Real constants must be returned with higher priority than
- * constant expression, because they might be folded.
+ * region constants, because they might be folded.
*/
static void get_comm_Binop_ops(ir_node *binop, ir_node **a, ir_node **c)
{
- ir_node *op_a = get_binop_left(binop);
- ir_node *op_b = get_binop_right(binop);
- ir_node *block = get_nodes_block(binop);
- int class_a = get_const_class(op_a, block);
- int class_b = get_const_class(op_b, block);
-
- assert(is_op_commutative(get_irn_op(binop)));
-
- switch (class_a + 2*class_b) {
- case REAL_CONSTANT + 2*NO_CONSTANT:
- case REAL_CONSTANT + 2*REAL_CONSTANT:
- case REAL_CONSTANT + 2*CONST_EXPR:
- case CONST_EXPR + 2*NO_CONSTANT:
- *a = op_b;
- *c = op_a;
- break;
- default:
- *a = op_a;
- *c = op_b;
- break;
- }
-}
+ ir_node *op_a = get_binop_left(binop);
+ ir_node *op_b = get_binop_right(binop);
+ ir_node *block = get_nodes_block(binop);
+ int class_a = get_const_class(op_a, block);
+ int class_b = get_const_class(op_b, block);
+
+ assert(is_op_commutative(get_irn_op(binop)));
+
+ switch (class_a + 2*class_b) {
+ case REAL_CONSTANT + 2*REAL_CONSTANT:
+ /* if both are constants, one might be a
+ * pointer constant like NULL, return the other
+ */
+ if (mode_is_reference(get_irn_mode(op_a))) {
+ *a = op_a;
+ *c = op_b;
+ } else {
+ *a = op_b;
+ *c = op_a;
+ }
+ break;
+ case REAL_CONSTANT + 2*NO_CONSTANT:
+ case REAL_CONSTANT + 2*REGION_CONST:
+ case REGION_CONST + 2*NO_CONSTANT:
+ *a = op_b;
+ *c = op_a;
+ break;
+ default:
+ *a = op_a;
+ *c = op_b;
+ break;
+ }
+} /* get_comm_Binop_ops */
/**
- * reassociate a Sub: x - c = (-c) + x
+ * reassociate a Sub: x - c = x + (-c)
*/
static int reassoc_Sub(ir_node **in)
{
- ir_node *n = *in;
- ir_node *block = get_nodes_block(n);
- ir_node *right = get_Sub_right(n);
-
- /* FIXME: Do not apply this rule for unsigned Sub's because our code
- * generation is currently buggy :-)
- */
- if (! mode_is_signed(get_irn_mode(n)))
- return 0;
-
- /* handles rule R6:
- * convert x - c => (-c) + x
- *
- * As there is NO real Minus in Firm it makes no sense to do this
- * for non-real constants yet.
- * */
- if (get_const_class(right, block) == REAL_CONSTANT) {
- ir_node *left = get_Sub_left(n);
- ir_node *block = get_nodes_block(n);
- ir_mode *mode = get_irn_mode(n);
- dbg_info *dbi = get_irn_dbg_info(n);
- ir_node *irn, *c;
-
- switch (get_const_class(left, block)) {
- case REAL_CONSTANT:
- irn = optimize_in_place(n);
- if (irn != n) {
- exchange(n, irn);
- *in = irn;
- return 1;
- }
- return 0;
- case NO_CONSTANT:
- break;
- default:
- /* already constant, nothing to do */
- return 0;
- }
-
- c = new_r_Const(current_ir_graph, block, mode, get_mode_null(mode));
- irn = new_rd_Sub(dbi, current_ir_graph, block, c, right, mode);
-
- irn = new_rd_Add(dbi, current_ir_graph, block, left, irn, get_irn_mode(n));
-
- DBG((dbg, LEVEL_5, "Applied: %n - %n => %n + (-%n)\n",
- get_Sub_left(n), c, get_Sub_left(n), c));
-
- exchange(n, irn);
+ ir_node *n = *in;
+ ir_node *right = get_Sub_right(n);
+ ir_mode *rmode = get_irn_mode(right);
+ ir_node *block;
+
+ /* cannot handle SubIs(P, P) */
+ if (mode_is_reference(rmode))
+ return 0;
+
+ block = get_nodes_block(n);
+
+ /* handles rule R6:
+ * convert x - c => x + (-c)
+ */
+ if (get_const_class(right, block) == REAL_CONSTANT) {
+ ir_node *left = get_Sub_left(n);
+ ir_mode *mode;
+ dbg_info *dbi;
+ ir_node *irn;
+
+ switch (get_const_class(left, block)) {
+ case REAL_CONSTANT:
+ irn = optimize_in_place(n);
+ if (irn != n) {
+ exchange(n, irn);
+ *in = irn;
+ return 1;
+ }
+ return 0;
+ case NO_CONSTANT:
+ break;
+ default:
+ /* already constant, nothing to do */
+ return 0;
+ }
+
+ mode = get_irn_mode(n);
+ dbi = get_irn_dbg_info(n);
+
+ /* Beware of SubP(P, Is) */
+ irn = new_rd_Minus(dbi, current_ir_graph, block, right, rmode);
+ irn = new_rd_Add(dbi, current_ir_graph, block, left, irn, mode);
+
+ DBG((dbg, LEVEL_5, "Applied: %n - %n => %n + (-%n)\n",
+ get_Sub_left(n), right, get_Sub_left(n), right));
+
+ if (n == irn)
+ return 0;
+
+ exchange(n, irn);
*in = irn;
- return 1;
- }
- return 0;
-}
+ return 1;
+ }
+ return 0;
+} /* reassoc_Sub */
/** Retrieve a mode from the operands. We need this, because
* Add and Sub are allowed to operate on (P, Is)
*/
static ir_mode *get_mode_from_ops(ir_node *op1, ir_node *op2)
{
- ir_mode *m1, *m2;
+ ir_mode *m1, *m2;
- m1 = get_irn_mode(op1);
- if (mode_is_reference(m1))
- return m1;
+ m1 = get_irn_mode(op1);
+ if (mode_is_reference(m1))
+ return m1;
- m2 = get_irn_mode(op2);
- if (mode_is_reference(m2))
- return m2;
+ m2 = get_irn_mode(op2);
+ if (mode_is_reference(m2))
+ return m2;
- assert(m1 == m2);
+ assert(m1 == m2);
- return m1;
-}
+ return m1;
+} /* get_mode_from_ops */
+
+#ifndef NEW_REASSOC
/**
* reassociate a commutative Binop
*
* BEWARE: this rule leads to a potential loop, if
- * two operands are are constant expressions and the third is a
+ * two operands are region constants and the third is a
* constant, so avoid this situation.
*/
static int reassoc_commutative(ir_node **node)
{
- ir_node *n = *node;
- ir_op *op = get_irn_op(n);
- ir_node *block = get_nodes_block(n);
- ir_node *t1, *c1;
-
- get_comm_Binop_ops(n, &t1, &c1);
-
- if (get_irn_op(t1) == op) {
- ir_node *t2, *c2;
- const_class_t c_c1, c_c2, c_t2;
-
- get_comm_Binop_ops(t1, &t2, &c2);
-
- /* do not optimize Bad nodes, will fail later */
- if (is_Bad(t2))
- return 0;
-
- c_c1 = get_const_class(c1, block);
- c_c2 = get_const_class(c2, block);
- c_t2 = get_const_class(t2, block);
-
- if ( ((c_c1 > NO_CONSTANT) & (c_t2 > NO_CONSTANT)) &&
- ((((c_c1 ^ c_c2 ^ c_t2) & CONST_EXPR) == 0) || ((c_c1 & c_c2 & c_t2) == CONST_EXPR)) ) {
- /* All three are constant and either all are constant expressions or two of them are:
- * then applying this rule would lead into a cycle
- *
- * Note that if t2 is a constant so is c2 hence we save one test.
- */
- return 0;
- }
-
- if ((c_c1 != NO_CONSTANT) & (c_c2 != NO_CONSTANT)) {
- /* handles rules R7, R8, R9, R10:
- * convert c1 .OP. (c2 .OP. x) => (c1 .OP. c2) .OP. x
- */
- ir_node *irn, *in[2];
- ir_mode *mode, *mode_c1 = get_irn_mode(c1), *mode_c2 = get_irn_mode(c2);
-
- /* It might happen, that c1 and c2 have different modes, for instance Is and Iu.
- * Handle this here.
- */
- if (mode_c1 != mode_c2) {
- if (mode_is_int(mode_c1) && mode_is_int(mode_c2)) {
- /* get the bigger one */
- if (get_mode_size_bits(mode_c1) > get_mode_size_bits(mode_c2))
- c2 = new_r_Conv(current_ir_graph, block, c2, mode_c1);
- else if (get_mode_size_bits(mode_c1) < get_mode_size_bits(mode_c2))
- c1 = new_r_Conv(current_ir_graph, block, c1, mode_c2);
- else {
- /* Try to cast the real const */
- if (c_c1 == REAL_CONSTANT)
- c1 = new_r_Conv(current_ir_graph, block, c1, mode_c2);
- else
- c2 = new_r_Conv(current_ir_graph, block, c2, mode_c1);
- }
- }
- }
-
- in[0] = c1;
- in[1] = c2;
-
- mode = get_mode_from_ops(in[0], in[1]);
- in[0] = optimize_node(new_ir_node(NULL, current_ir_graph, block, op, mode, 2, in));
- in[1] = t2;
-
- mode = get_mode_from_ops(in[0], in[1]);
- irn = optimize_node(new_ir_node(NULL, current_ir_graph, block, op, mode, 2, in));
-
- DBG((dbg, LEVEL_5, "Applied: %n .%s. (%n .%s. %n) => (%n .%s. %n) .%s. %n\n",
- c1, get_irn_opname(n), c2, get_irn_opname(n),
- t2, c1, get_irn_opname(n), c2, get_irn_opname(n), t2));
- /*
- * In some rare cases it can really happen that we get the same node back.
- * This might be happen in dead loops, were the Phi nodes are already gone away.
- * So check this.
- */
- if (n != irn) {
- exchange(n, irn);
+ ir_node *n = *node;
+ ir_op *op = get_irn_op(n);
+ ir_node *block = get_nodes_block(n);
+ ir_node *t1, *c1;
+
+ get_comm_Binop_ops(n, &t1, &c1);
+
+ if (get_irn_op(t1) == op) {
+ ir_node *t2, *c2;
+ const_class_t c_c1, c_c2, c_t2;
+
+ get_comm_Binop_ops(t1, &t2, &c2);
+
+ /* do not optimize Bad nodes, will fail later */
+ if (is_Bad(t2))
+ return 0;
+
+ c_c1 = get_const_class(c1, block);
+ c_c2 = get_const_class(c2, block);
+ c_t2 = get_const_class(t2, block);
+
+ if ( ((c_c1 > NO_CONSTANT) & (c_t2 > NO_CONSTANT)) &&
+ ((((c_c1 ^ c_c2 ^ c_t2) & REGION_CONST) == 0) || ((c_c1 & c_c2 & c_t2) == REGION_CONST)) ) {
+ /* All three are constant and either all are constant expressions
+ * or two of them are:
+ * then applying this rule would lead into a cycle
+ *
+ * Note that if t2 is a constant so is c2 hence we save one test.
+ */
+ return 0;
+ }
+
+ if ((c_c1 != NO_CONSTANT) /* & (c_c2 != NO_CONSTANT) */) {
+ /* handles rules R7, R8, R9, R10:
+ * convert c1 .OP. (c2 .OP. x) => x .OP. (c1 .OP. c2)
+ */
+ ir_node *irn, *in[2];
+ ir_mode *mode, *mode_c1 = get_irn_mode(c1), *mode_c2 = get_irn_mode(c2);
+
+ /* It might happen, that c1 and c2 have different modes, for
+ * instance Is and Iu.
+ * Handle this here.
+ */
+ if (mode_c1 != mode_c2) {
+ if (mode_is_int(mode_c1) && mode_is_int(mode_c2)) {
+ /* get the bigger one */
+ if (get_mode_size_bits(mode_c1) > get_mode_size_bits(mode_c2))
+ c2 = new_r_Conv(current_ir_graph, block, c2, mode_c1);
+ else if (get_mode_size_bits(mode_c1) < get_mode_size_bits(mode_c2))
+ c1 = new_r_Conv(current_ir_graph, block, c1, mode_c2);
+ else {
+ /* Try to cast the real const */
+ if (c_c1 == REAL_CONSTANT)
+ c1 = new_r_Conv(current_ir_graph, block, c1, mode_c2);
+ else
+ c2 = new_r_Conv(current_ir_graph, block, c2, mode_c1);
+ }
+ }
+ }
+
+ in[0] = c1;
+ in[1] = c2;
+
+ mode = get_mode_from_ops(in[0], in[1]);
+ in[1] = optimize_node(new_ir_node(NULL, current_ir_graph, block, op, mode, 2, in));
+ in[0] = t2;
+
+ mode = get_mode_from_ops(in[0], in[1]);
+ irn = optimize_node(new_ir_node(NULL, current_ir_graph, block, op, mode, 2, in));
+
+ DBG((dbg, LEVEL_5, "Applied: %n .%s. (%n .%s. %n) => %n .%s. (%n .%s. %n)\n",
+ c1, get_irn_opname(n), c2, get_irn_opname(n), t2,
+ t2, get_irn_opname(n), c1, get_irn_opname(n), c2));
+ /*
+ * In some rare cases it can really happen that we get the same
+ * node back. This might be happen in dead loops, were the Phi
+ * nodes are already gone away. So check this.
+ */
+ if (n != irn) {
+ exchange(n, irn);
*node = irn;
- return 1;
- }
- }
- }
- return 0;
+ return 1;
+ }
+ }
+ }
+ return 0;
+} /* reassoc_commutative */
+
+#else
+
+static ir_op *commutative_op;
+static ir_node *commutative_block;
+static struct obstack commutative_args;
+
+static void collect_args(ir_node *node)
+{
+ ir_node *left = get_binop_left(node);
+ ir_node *right = get_binop_right(node);
+
+ if (get_irn_op(left) == commutative_op
+ && (!get_irn_outs_computed(left) || get_irn_n_outs(left) == 1)) {
+ collect_args(left);
+ } else {
+ obstack_ptr_grow(&commutative_args, left);
+ }
+
+ if (get_irn_op(right) == commutative_op
+ && (!get_irn_outs_computed(right) || get_irn_n_outs(right) == 1)) {
+ collect_args(right);
+ } else {
+ obstack_ptr_grow(&commutative_args, right);
+ }
+
+#ifndef NDEBUG
+ {
+ ir_mode *mode = get_irn_mode(node);
+ if (is_Add(node) && mode_is_reference(mode)) {
+ assert(get_irn_mode(left) == mode || get_irn_mode(right) == mode);
+ } else {
+ assert(get_irn_mode(left) == mode);
+ assert(get_irn_mode(right) == mode);
+ }
+ }
+#endif
+}
+
+static int compare_nodes(const ir_node *node1, const ir_node *node2)
+{
+ const_class_t class1 = get_const_class(node1, commutative_block);
+ const_class_t class2 = get_const_class(node2, commutative_block);
+
+ if (class1 == class2)
+ return 0;
+ // return get_irn_idx(node1) - get_irn_idx(node2);
+
+ if (class1 < class2)
+ return -1;
+
+ assert(class1 > class2);
+ return 1;
+}
+
+static int compare_node_ptr(const void *e1, const void *e2)
+{
+ const ir_node *node1 = *((const ir_node *const*) e1);
+ const ir_node *node2 = *((const ir_node *const*) e2);
+ return compare_nodes(node1, node2);
}
+static int reassoc_commutative(ir_node **n)
+{
+ int i;
+ int n_args;
+ ir_node *last;
+ ir_node **args;
+ ir_mode *mode;
+ ir_node *node = *n;
+
+ commutative_op = get_irn_op(node);
+ commutative_block = get_nodes_block(node);
+
+ /* collect all nodes with same op type */
+ collect_args(node);
+
+ n_args = obstack_object_size(&commutative_args) / sizeof(ir_node*);
+ args = obstack_finish(&commutative_args);
+
+ /* shortcut: in most cases there's nothing to do */
+ if (n_args == 2 && compare_nodes(args[0], args[1]) <= 0) {
+ obstack_free(&commutative_args, args);
+ return 0;
+ }
+
+ /* sort the arguments */
+ qsort(args, n_args, sizeof(ir_node*), compare_node_ptr);
+
+ /* build new tree */
+ last = args[n_args-1];
+ mode = get_irn_mode(last);
+ for (i = n_args-2; i >= 0; --i) {
+ ir_mode *mode_right;
+ ir_node *new_node;
+ ir_node *in[2];
+
+ in[0] = last;
+ in[1] = args[i];
+
+ /* AddP violates the assumption that all modes in args are equal...
+ * we need some hacks to cope with this */
+ mode_right = get_irn_mode(in[1]);
+ if (mode_is_reference(mode_right)) {
+ assert(is_Add(node) && mode_is_reference(get_irn_mode(node)));
+ mode = get_irn_mode(in[1]);
+ }
+ if (mode_right != mode) {
+ assert(is_Add(node) && mode_is_reference(get_irn_mode(node)));
+ in[1] = new_r_Conv(current_ir_graph, commutative_block,in[1], mode);
+ }
+
+ /* TODO: produce useful debug info! */
+ new_node = new_ir_node(NULL, current_ir_graph, commutative_block,
+ commutative_op, mode, 2, in);
+ new_node = optimize_node(new_node);
+ last = new_node;
+ }
+
+ /* CSE often returns the old node again, only exchange if needed */
+ if (last != node) {
+ exchange(node, last);
+ *n = last;
+ return 1;
+ }
+ return 0;
+}
+
+#endif
+
#define reassoc_Add reassoc_commutative
#define reassoc_And reassoc_commutative
#define reassoc_Or reassoc_commutative
#define reassoc_Eor reassoc_commutative
/**
- * reassociate using distributive law for Mul and Add/Sub
+ * Reassociate using commutative law for Mul and distributive law for Mul and Add/Sub:
*/
static int reassoc_Mul(ir_node **node)
{
- ir_node *n = *node;
- ir_node *add_sub, *c;
- ir_op *op;
+ ir_node *n = *node;
+ ir_node *add_sub, *c;
+ ir_op *op;
+
+ if (reassoc_commutative(&n))
+ return 1;
+
+ get_comm_Binop_ops(n, &add_sub, &c);
+ op = get_irn_op(add_sub);
+
+ /* handles rules R11, R12, R13, R14, R15, R16, R17, R18, R19, R20 */
+ if (op == op_Add || op == op_Sub) {
+ ir_mode *mode = get_irn_mode(n);
+ ir_node *irn, *block, *t1, *t2, *in[2];
+
+ block = get_nodes_block(n);
+ t1 = get_binop_left(add_sub);
+ t2 = get_binop_right(add_sub);
+
+ /* we can only multiplication rules on integer arithmetic */
+ if (mode_is_int(get_irn_mode(t1)) && mode_is_int(get_irn_mode(t2))) {
+ in[0] = new_rd_Mul(NULL, current_ir_graph, block, c, t1, mode);
+ in[1] = new_rd_Mul(NULL, current_ir_graph, block, c, t2, mode);
+
+ irn = optimize_node(new_ir_node(NULL, current_ir_graph, block, op, mode, 2, in));
+
+ /* In some cases it might happen that the new irn is equal the old one, for
+ * instance in:
+ * (x - 1) * y == x * y - y
+ * will be transformed back by simpler optimization
+ * We could switch simple optimizations off, but this only happens iff y
+ * is a loop-invariant expression and that it is not clear if the new form
+ * is better.
+ * So, we let the old one.
+ */
+ if (irn != n) {
+ DBG((dbg, LEVEL_5, "Applied: (%n .%s. %n) %n %n => (%n %n %n) .%s. (%n %n %n)\n",
+ t1, get_op_name(op), t2, n, c, t1, n, c, get_op_name(op), t2, n, c));
+ exchange(n, irn);
+ *node = irn;
- if (reassoc_commutative(&n))
- return 1;
+ return 1;
+ }
+ }
+ }
+ return 0;
+} /* reassoc_Mul */
- get_comm_Binop_ops(n, &add_sub, &c);
- op = get_irn_op(add_sub);
+/**
+ * Reassociate Shl. We transform Shl(x, const) into Mul's if possible.
+ */
+static int reassoc_Shl(ir_node **node) {
+ ir_node *n = *node;
+ ir_node *c = get_Shl_right(n);
+ ir_node *x, *blk, *irn;
+ ir_mode *mode;
+ tarval *tv;
- /* handles rules R11, R12, R13, R14, R15, R16, R17, R18, R19, R20 */
- if (op == op_Add || op == op_Sub) {
- ir_mode *mode = get_irn_mode(n);
- ir_node *irn, *block, *t1, *t2, *in[2];
+ if (! is_Const(c))
+ return 0;
- block = get_nodes_block(n);
- t1 = get_binop_left(add_sub);
- t2 = get_binop_right(add_sub);
+ x = get_Shl_left(n);
+ mode = get_irn_mode(x);
- in[0] = new_rd_Mul(NULL, current_ir_graph, block, c, t1, mode);
- in[1] = new_rd_Mul(NULL, current_ir_graph, block, c, t2, mode);
+ tv = get_mode_one(mode);
+ tv = tarval_shl(tv, get_Const_tarval(c));
- mode = get_mode_from_ops(in[0], in[1]);
- irn = optimize_node(new_ir_node(NULL, current_ir_graph, block, op, mode, 2, in));
+ if (tv == tarval_bad)
+ return 0;
- DBG((dbg, LEVEL_5, "Applied: (%n .%s. %n) %n %n => (%n %n %n) .%s. (%n %n %n)\n",
- t1, get_op_name(op), t2, n, c, t1, n, c, get_op_name(op), t2, n, c));
- exchange(n, irn);
+ blk = get_nodes_block(n);
+ c = new_r_Const(current_ir_graph, blk, mode, tv);
+ irn = new_rd_Mul(get_irn_dbg_info(n), current_ir_graph, blk, x, c, mode);
+
+ if (irn != n) {
+ exchange(n, irn);
*node = irn;
+ return 1;
+ }
+ return 0;
+} /* reassoc_Shl */
- return 1;
- }
- return 0;
-}
+/**
+ * The walker for the reassociation.
+ */
+static void wq_walker(ir_node *n, void *env)
+{
+ walker_t *wenv = env;
+
+ set_irn_link(n, NULL);
+ if (is_no_Block(n)) {
+ ir_node *blk = get_nodes_block(n);
+
+ if (is_Block_dead(blk) || get_Block_dom_depth(blk) < 0) {
+ /* We are in a dead block, do not optimize or we may fall into an endless
+ loop. We check this here instead of requiring that all dead blocks are removed
+ which or cf_opt do not guarantee yet. */
+ return;
+ }
+ waitq_put(wenv->wq, n);
+ set_irn_link(n, wenv->wq);
+ }
+} /* wq_walker */
/**
* The walker for the reassociation.
*/
-static void do_reassociation(ir_node *n, void *env)
+static void do_reassociation(walker_t *wenv)
{
- walker_t *wenv = env;
- int res;
+ int i, res, changed;
+ ir_node *n, *blk;
+
+ while (! waitq_empty(wenv->wq)) {
+ n = waitq_get(wenv->wq);
+ set_irn_link(n, NULL);
+
+ blk = get_nodes_block(n);
+ if (is_Block_dead(blk) || get_Block_dom_depth(blk) < 0) {
+ /* We are in a dead block, do not optimize or we may fall into an endless
+ loop. We check this here instead of requiring that all dead blocks are removed
+ which or cf_opt do not guarantee yet. */
+ continue;
+ }
+
+
+ hook_reassociate(1);
+
+ /* reassociation must run until a fixpoint is reached. */
+ changed = 0;
+ do {
+ ir_op *op = get_irn_op(n);
+ ir_mode *mode = get_irn_mode(n);
+
+ res = 0;
- hook_reassociate(1);
+ /* for FP these optimizations are only allowed if fp_strict_algebraic is disabled */
+ if (mode_is_float(mode) && get_irg_fp_model(current_ir_graph) & fp_strict_algebraic)
+ break;
- /* Reassociation must run until a fixpoint is reached. */
- do {
- ir_op *op = get_irn_op(n);
- ir_mode *mode = get_irn_mode(n);
+ if (op->ops.reassociate) {
+ res = op->ops.reassociate(&n);
- res = 0;
+ changed |= res;
+ }
+ } while (res == 1);
+ hook_reassociate(0);
+
+ wenv->changes |= changed;
+
+ if (changed) {
+ for (i = get_irn_arity(n) - 1; i >= 0; --i) {
+ ir_node *pred = get_irn_n(n, i);
+
+ if (get_irn_link(pred) != wenv->wq) {
+ waitq_put(wenv->wq, pred);
+ set_irn_link(pred, wenv->wq);
+ }
+ }
+ }
+ }
+} /* do_reassociation */
+
+/**
+ * Returns the earliest were a,b are available.
+ * Note that we know that a, b both dominate
+ * the block of the previous operation, so one must dominate the other.
+ *
+ * If the earliest block is the start block, return curr_blk instead
+ */
+static ir_node *earliest_block(ir_node *a, ir_node *b, ir_node *curr_blk) {
+ ir_node *blk_a = get_nodes_block(a);
+ ir_node *blk_b = get_nodes_block(b);
+ ir_node *res;
+
+ /* if blk_a != blk_b, one must dominate the other */
+ if (block_dominates(blk_a, blk_b))
+ res = blk_b;
+ else
+ res = blk_a;
+ if (res == get_irg_start_block(current_ir_graph))
+ return curr_blk;
+ return res;
+} /* earliest_block */
+
+/**
+ * Checks whether a node is a Constant expression.
+ * The following trees are constant expressions:
+ *
+ * Const, SymConst, Const + SymConst
+ *
+ * Handling SymConsts as const might be not a good idea for all
+ * architectures ...
+ */
+static int is_constant_expr(ir_node *irn) {
+ ir_op *op;
+
+ switch (get_irn_opcode(irn)) {
+ case iro_Const:
+ case iro_SymConst:
+ return 1;
+ case iro_Add:
+ op = get_irn_op(get_Add_left(irn));
+ if (op != op_Const && op != op_SymConst)
+ return 0;
+ op = get_irn_op(get_Add_right(irn));
+ if (op != op_Const && op != op_SymConst)
+ return 0;
+ return 1;
+ default:
+ return 0;
+ }
+} /* is_constant_expr */
- /* reassociation works only for integer or reference modes */
- if (op->reassociate && (mode_is_int(mode) || mode_is_reference(mode))) {
- res = op->reassociate(&n);
+/**
+ * Apply distributive Law for Mul and Add/Sub
+ */
+static int reverse_rule_distributive(ir_node **node) {
+ ir_node *n = *node;
+ ir_node *left = get_binop_left(n);
+ ir_node *right = get_binop_right(n);
+ ir_node *x, *blk, *curr_blk;
+ ir_node *a, *b, *irn;
+ ir_op *op;
+ ir_mode *mode;
+ dbg_info *dbg;
+
+ op = get_irn_op(left);
+ if (op != get_irn_op(right))
+ return 0;
+
+ if (op == op_Shl) {
+ x = get_Shl_right(left);
+
+ if (x == get_Shl_right(right)) {
+ /* (a << x) +/- (b << x) ==> (a +/- b) << x */
+ a = get_Shl_left(left);
+ b = get_Shl_left(right);
+ goto transform;
+ }
+ } else if (op == op_Mul) {
+ x = get_Mul_left(left);
+
+ if (x == get_Mul_left(right)) {
+ /* (x * a) +/- (x * b) ==> (a +/- b) * x */
+ a = get_Mul_right(left);
+ b = get_Mul_right(right);
+ goto transform;
+ } else if (x == get_Mul_right(right)) {
+ /* (x * a) +/- (b * x) ==> (a +/- b) * x */
+ a = get_Mul_right(left);
+ b = get_Mul_left(right);
+ goto transform;
+ }
+
+ x = get_Mul_right(left);
+
+ if (x == get_Mul_right(right)) {
+ /* (a * x) +/- (b * x) ==> (a +/- b) * x */
+ a = get_Mul_left(left);
+ b = get_Mul_left(right);
+ goto transform;
+ } else if (x == get_Mul_left(right)) {
+ /* (a * x) +/- (x * b) ==> (a +/- b) * x */
+ a = get_Mul_left(left);
+ b = get_Mul_right(right);
+ goto transform;
+ }
+ }
+ return 0;
+
+transform:
+ curr_blk = get_nodes_block(n);
+
+ blk = earliest_block(a, b, curr_blk);
+
+ dbg = get_irn_dbg_info(n);
+ mode = get_irn_mode(n);
+
+ if (is_Add(n))
+ irn = new_rd_Add(dbg, current_ir_graph, blk, a, b, mode);
+ else
+ irn = new_rd_Sub(dbg, current_ir_graph, blk, a, b, mode);
+
+ blk = earliest_block(irn, x, curr_blk);
+
+ if (op == op_Mul)
+ irn = new_rd_Mul(dbg, current_ir_graph, blk, irn, x, mode);
+ else
+ irn = new_rd_Shl(dbg, current_ir_graph, blk, irn, x, mode);
+
+ exchange(n, irn);
+ *node = irn;
+ return 1;
+} /* reverse_rule_distributive */
- wenv->changes |= res;
- }
- } while (res == 1);
+/**
+ * Move Constants towards the root.
+ */
+static int move_consts_up(ir_node **node) {
+ ir_node *n = *node;
+ ir_op *op;
+ ir_node *l, *r, *a, *b, *c, *blk, *irn, *in[2];
+ ir_mode *mode, *ma, *mb;
+ dbg_info *dbg;
+
+ l = get_binop_left(n);
+ r = get_binop_right(n);
+
+ /* check if one is already a constant expression */
+ if (is_constant_expr(l) || is_constant_expr(r))
+ return 0;
+
+ dbg = get_irn_dbg_info(n);
+ op = get_irn_op(n);
+ if (get_irn_op(l) == op) {
+ /* (a .op. b) .op. r */
+ a = get_binop_left(l);
+ b = get_binop_right(l);
+
+ if (is_constant_expr(a)) {
+ /* (C .op. b) .op. r ==> (r .op. b) .op. C */
+ c = a;
+ a = r;
+ blk = get_nodes_block(l);
+ dbg = dbg == get_irn_dbg_info(l) ? dbg : NULL;
+ goto transform;
+ } else if (is_constant_expr(b)) {
+ /* (a .op. C) .op. r ==> (a .op. r) .op. C */
+ c = b;
+ b = r;
+ blk = get_nodes_block(l);
+ dbg = dbg == get_irn_dbg_info(l) ? dbg : NULL;
+ goto transform;
+ }
+ } else if (get_irn_op(r) == op) {
+ /* l .op. (a .op. b) */
+ a = get_binop_left(r);
+ b = get_binop_right(r);
+
+ if (is_constant_expr(a)) {
+ /* l .op. (C .op. b) ==> (l .op. b) .op. C */
+ c = a;
+ a = l;
+ blk = get_nodes_block(r);
+ dbg = dbg == get_irn_dbg_info(r) ? dbg : NULL;
+ goto transform;
+ } else if (is_constant_expr(b)) {
+ /* l .op. (a .op. C) ==> (a .op. l) .op. C */
+ c = b;
+ b = l;
+ blk = get_nodes_block(r);
+ dbg = dbg == get_irn_dbg_info(r) ? dbg : NULL;
+ goto transform;
+ }
+ }
+ return 0;
+
+transform:
+ /* In some cases a and b might be both of different integer mode, and c a SymConst.
+ * in that case we could either
+ * 1.) cast into unsigned mode
+ * 2.) ignore
+ * we implement the second here
+ */
+ ma = get_irn_mode(a);
+ mb = get_irn_mode(b);
+ if (ma != mb && mode_is_int(ma) && mode_is_int(mb))
+ return 0;
+
+ /* check if (a .op. b) can be calculated in the same block is the old instruction */
+ if (! block_dominates(get_nodes_block(a), blk))
+ return 0;
+ if (! block_dominates(get_nodes_block(b), blk))
+ return 0;
+ /* ok */
+ in[0] = a;
+ in[1] = b;
+
+ mode = get_mode_from_ops(a, b);
+ in[0] = irn = optimize_node(new_ir_node(dbg, current_ir_graph, blk, op, mode, 2, in));
+
+ /* beware: optimize_node might have changed the opcode, check again */
+ if (is_Add(irn) || is_Sub(irn)) {
+ reverse_rule_distributive(&in[0]);
+ }
+ in[1] = c;
+
+ mode = get_mode_from_ops(in[0], in[1]);
+ irn = optimize_node(new_ir_node(dbg, current_ir_graph, blk, op, mode, 2, in));
+
+ exchange(n, irn);
+ *node = irn;
+ return 1;
+} /* move_consts_up */
- hook_reassociate(0);
+/**
+ * Apply the rules in reverse order, removing code that was not collapsed
+ */
+static void reverse_rules(ir_node *node, void *env) {
+ walker_t *wenv = env;
+ ir_mode *mode = get_irn_mode(node);
+ int res;
+
+ /* for FP these optimizations are only allowed if fp_strict_algebraic is disabled */
+ if (mode_is_float(mode) && get_irg_fp_model(current_ir_graph) & fp_strict_algebraic)
+ return;
+
+ do {
+ ir_op *op = get_irn_op(node);
+
+ res = 0;
+ if (is_op_commutative(op)) {
+ wenv->changes |= res = move_consts_up(&node);
+ }
+ /* beware: move_consts_up might have changed the opcode, check again */
+ if (is_Add(node) || is_Sub(node)) {
+ wenv->changes |= res = reverse_rule_distributive(&node);
+ }
+ } while (res);
}
/*
* do the reassociation
*/
-void optimize_reassociation(ir_graph *irg)
+int optimize_reassociation(ir_graph *irg)
{
- walker_t env;
- irg_loopinfo_state state;
-
- assert(get_irg_phase_state(irg) != phase_building);
-
- /* reassociation needs constant folding */
- if (!get_opt_reassociation() || !get_opt_constant_folding())
- return;
-
- /*
- * Calculate loop info, so we could identify loop-invariant
- * code and threat it like a constant.
- * We only need control flow loops here but can handle generic
- * INTRA info as well.
- */
- state = get_irg_loopinfo_state(irg);
- if ((state & loopinfo_inter) ||
- (state & (loopinfo_constructed | loopinfo_valid)) != (loopinfo_constructed | loopinfo_valid))
- construct_cf_backedges(irg);
-
- env.changes = 0;
-
- /* now we have collected enough information, optimize */
- irg_walk_graph(irg, NULL, do_reassociation, &env);
-
- /* Handle graph state */
- if (env.changes) {
- if (get_irg_outs_state(irg) == outs_consistent)
- set_irg_outs_inconsistent(irg);
- set_irg_loopinfo_inconsistent(irg);
- }
-}
+ walker_t env;
+ irg_loopinfo_state state;
+ ir_graph *rem;
+
+ assert(get_irg_phase_state(irg) != phase_building);
+ assert(get_irg_pinned(irg) != op_pin_state_floats &&
+ "Reassociation needs pinned graph to work properly");
+
+ rem = current_ir_graph;
+ current_ir_graph = irg;
+
+ /* we use dominance to detect dead blocks */
+ assure_doms(irg);
+
+#ifdef NEW_REASSOC
+ assure_irg_outs(irg);
+ obstack_init(&commutative_args);
+#endif
+
+ /*
+ * Calculate loop info, so we could identify loop-invariant
+ * code and threat it like a constant.
+ * We only need control flow loops here but can handle generic
+ * INTRA info as well.
+ */
+ state = get_irg_loopinfo_state(irg);
+ if ((state & loopinfo_inter) ||
+ (state & (loopinfo_constructed | loopinfo_valid)) != (loopinfo_constructed | loopinfo_valid))
+ construct_cf_backedges(irg);
+
+ env.changes = 0;
+ env.wq = new_waitq();
+
+ /* disable some optimizations while reassoc is running to prevent endless loops */
+ set_reassoc_running(1);
+ {
+ /* now we have collected enough information, optimize */
+ irg_walk_graph(irg, NULL, wq_walker, &env);
+ do_reassociation(&env);
+
+ /* reverse those rules that do not result in collapsed constants */
+ irg_walk_graph(irg, NULL, reverse_rules, &env);
+ }
+ set_reassoc_running(0);
+
+ /* Handle graph state */
+ if (env.changes) {
+ set_irg_outs_inconsistent(irg);
+ set_irg_loopinfo_inconsistent(irg);
+ }
+
+#ifdef NEW_REASSOC
+ obstack_free(&commutative_args, NULL);
+#endif
+
+ del_waitq(env.wq);
+ current_ir_graph = rem;
+ return env.changes;
+} /* optimize_reassociation */
+
+/* Sets the default reassociation operation for an ir_op_ops. */
+ir_op_ops *firm_set_default_reassoc(ir_opcode code, ir_op_ops *ops)
+{
+#define CASE(a) case iro_##a: ops->reassociate = reassoc_##a; break
+
+ switch (code) {
+ CASE(Mul);
+ CASE(Add);
+ CASE(Sub);
+ CASE(And);
+ CASE(Or);
+ CASE(Eor);
+ CASE(Shl);
+ default:
+ /* leave NULL */;
+ }
+
+ return ops;
+#undef CASE
+} /* firm_set_default_reassoc */
/* initialize the reassociation by adding operations to some opcodes */
void firm_init_reassociation(void)
{
-#define INIT(a) op_##a->reassociate = reassoc_##a;
- INIT(Mul);
- INIT(Add);
- INIT(Sub);
- INIT(And);
- INIT(Or);
- INIT(Eor);
-#undef INIT
-
- dbg = firm_dbg_register("firm.opt.reassoc");
-}
+ FIRM_DBG_REGISTER(dbg, "firm.opt.reassoc");
+} /* firm_init_reassociation */
projects / libfirm / blobdiff