+/*
+ * 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.
+ */
+
/**
- * Project: libFIRM
- * File name: ir/opt/opt_osr.
- * Purpose: Operator Strength Reduction, based on
- * Keith D. Cooper, L. Taylor Simpson, Christopher A. Vick
- * Author: Michael Beck
- * Modified by:
- * Created: 12.5.2006
- * CVS-ID: $Id$
- * Copyright: (c) 2006 Universität Karlsruhe
- * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
- */
-#ifdef HAVE_CONFIG_H
+ * @file
+ * @brief Operator Strength Reduction.
+ * @date 12.5.2006
+ * @author Michael Beck
+ * @version $Id$
+ * @summary
+ * Implementation of the Operator Strength Reduction algorithm
+ * by Keith D. Cooper, L. Taylor Simpson, Christopher A. Vick.
+ * Extended version.
+ */
#include "config.h"
-#endif
-#ifdef HAVE_MALLOC_H
-#include <malloc.h>
-#endif
-#ifdef HAVE_ALLOCA_H
-#include <alloca.h>
-#endif
-
-#include "opt_osr.h"
+#include "adt/pdeq.h"
+#include "iroptimize.h"
#include "irgraph.h"
#include "ircons.h"
#include "irop_t.h"
-#include "irloop.h"
#include "irdom.h"
#include "irgmod.h"
#include "irflag_t.h"
#include "irgwalk.h"
#include "irouts.h"
+#include "iredges.h"
#include "debug.h"
#include "obst.h"
#include "set.h"
#include "irloop_t.h"
#include "array.h"
#include "firmstat.h"
+#include "error.h"
+#include "irpass_t.h"
/** The debug handle. */
DEBUG_ONLY(static firm_dbg_module_t *dbg;)
/** A scc. */
typedef struct scc {
- ir_node *head; /**< the head of the list */
+ ir_node *head; /**< the head of the list */
+ tarval *init; /**< the init value iff only one exists. */
+ tarval *incr; /**< the induction variable increment if only a single const exists. */
+ unsigned code; /**< == iro_Add if +incr, iro_Sub if -incr, 0 if not analysed, iro_Bad else */
} scc;
/** A node entry */
set *lftr_edges; /**< the set of lftr edges */
unsigned replaced; /**< number of replaced ops */
unsigned lftr_replaced; /**< number of applied linear function test replacements */
- unsigned flags; /**< additional flags */
+ unsigned osr_flags; /**< additional flags steering the transformation */
+ unsigned need_postpass; /**< set, if a post pass is needed to fix Add and Sub nodes */
+ /** Function called to process a SCC. */
+ void (*process_scc)(scc *pscc, struct iv_env *env);
} iv_env;
/**
* An entry in the (op, node, node) -> node map.
*/
-typedef struct quad_t {
- opcode code; /**< the opcode of the reduced operation */
- ir_node *op1; /**< the first operand the reduced operation */
- ir_node *op2; /**< the second operand of the reduced operation */
+typedef struct quadruple_t {
+ ir_opcode code; /**< the opcode of the reduced operation */
+ ir_node *op1; /**< the first operand the reduced operation */
+ ir_node *op2; /**< the second operand of the reduced operation */
- ir_node *res; /**< the reduced operation */
-} quad_t;
+ ir_node *res; /**< the reduced operation */
+} quadruple_t;
/**
* A LFTR edge.
*/
typedef struct LFTR_edge {
- ir_node *src; /**< the source node */
- ir_node *dst; /**< the destination node */
- opcode code; /**< the opcode that must be applied */
- ir_node *rc; /**< the region const that must be applied */
+ ir_node *src; /**< the source node */
+ ir_node *dst; /**< the destination node */
+ ir_opcode code; /**< the opcode that must be applied */
+ ir_node *rc; /**< the region const that must be applied */
} LFTR_edge;
/* forward */
static int LFTR_cmp(const void *e1, const void *e2, size_t size) {
const LFTR_edge *l1 = e1;
const LFTR_edge *l2 = e2;
+ (void) size;
return l1->src != l2->src;
-}
+} /* LFTR_cmp */
/**
* Find a LFTR edge.
+ *
+ * @param src the source node of the transition
*/
static LFTR_edge *LFTR_find(ir_node *src, iv_env *env) {
LFTR_edge key;
key.src = src;
return set_find(env->lftr_edges, &key, sizeof(key), HASH_PTR(src));
-}
+} /* LFTR_find */
/**
* Add a LFTR edge.
+ *
+ * @param src the source node of the edge
+ * @param dst the destination node of the edge
+ * @param code the opcode of the transformed transition
+ * @param rc the region const used in the transition
+ * @param env the environment
*/
-static void LFTR_add(ir_node *src, ir_node *dst, opcode code, ir_node *rc, iv_env *env) {
+static void LFTR_add(ir_node *src, ir_node *dst, ir_opcode code, ir_node *rc, iv_env *env) {
LFTR_edge key;
key.src = src;
*/
// assert(LFTR_find(src, env) == NULL);
set_insert(env->lftr_edges, &key, sizeof(key), HASH_PTR(src));
-}
+} /* LFTR_add */
/**
- * Gets the node_entry of a node
+ * Gets the node_entry of a node.
+ *
+ * @param irn the node
+ * @param env the environment
*/
static node_entry *get_irn_ne(ir_node *irn, iv_env *env) {
node_entry *e = get_irn_link(irn);
- if (! e) {
+ if (e == NULL) {
e = obstack_alloc(&env->obst, sizeof(*e));
memset(e, 0, sizeof(*e));
set_irn_link(irn, e);
}
return e;
-}
+} /* get_irn_ne */
+
+/**
+ * Gets the scc from an induction variable.
+ *
+ * @param iv any node of the induction variable
+ * @param env the environment
+ */
+static scc *get_iv_scc(ir_node *iv, iv_env *env) {
+ node_entry *e = get_irn_ne(iv, env);
+ return e->pscc;
+} /* get_iv_scc */
/**
* Check if irn is an IV.
*/
static ir_node *is_iv(ir_node *irn, iv_env *env) {
return get_irn_ne(irn, env)->header;
-}
+} /* is_iv */
/**
* Check if irn is a region constant.
ir_node *block = get_nodes_block(irn);
return (block != header_block) && block_dominates(block, header_block);
-}
+} /* is_rc */
/**
* Set compare function for the quad set.
*/
static int quad_cmp(const void *e1, const void *e2, size_t size) {
- const quad_t *c1 = e1;
- const quad_t *c2 = e2;
+ const quadruple_t *c1 = e1;
+ const quadruple_t *c2 = e2;
+ (void) size;
return c1->code != c2->code || c1->op1 != c2->op1 || c1->op2 != c2->op2;
-}
+} /* quad_cmp */
/**
* Check if an reduced operation was already calculated.
*
* @return the already reduced node or NULL if this operation is not yet reduced
*/
-static ir_node *search(opcode code, ir_node *op1, ir_node *op2, iv_env *env) {
- quad_t key, *entry;
+static ir_node *search(ir_opcode code, ir_node *op1, ir_node *op2, iv_env *env) {
+ quadruple_t key, *entry;
key.code = code;
key.op1 = op1;
if (entry)
return entry->res;
return NULL;
-}
+} /* search */
/**
* Add an reduced operation.
* @param result the result of the reduced operation
* @param env the environment
*/
-static void add(opcode code, ir_node *op1, ir_node *op2, ir_node *result, iv_env *env) {
- quad_t key;
+static void add(ir_opcode code, ir_node *op1, ir_node *op2, ir_node *result, iv_env *env) {
+ quadruple_t key;
key.code = code;
key.op1 = op1;
set_insert(env->quad_map, &key, sizeof(key),
(code * 9) ^ HASH_PTR(op1) ^HASH_PTR(op2));
-}
+} /* add */
/**
* Find a location where to place a bin-op whose operands are in
return block2;
assert(block_dominates(block2, block1));
return block1;
-}
+} /* find_location */
/**
* Create a node that executes an op1 code op1 operation.
*
* @return the newly created node
*/
-static ir_node *do_apply(opcode code, dbg_info *db, ir_node *op1, ir_node *op2, ir_mode *mode) {
- ir_graph *irg = current_ir_graph;
+static ir_node *do_apply(ir_opcode code, dbg_info *db, ir_node *op1, ir_node *op2, ir_mode *mode) {
ir_node *result;
ir_node *block = find_location(get_nodes_block(op1), get_nodes_block(op2));
switch (code) {
case iro_Mul:
- result = new_rd_Mul(db, irg, block, op1, op2, mode);
+ result = new_rd_Mul(db, block, op1, op2, mode);
break;
case iro_Add:
- result = new_rd_Add(db, irg, block, op1, op2, mode);
+ result = new_rd_Add(db, block, op1, op2, mode);
break;
case iro_Sub:
- result = new_rd_Sub(db, irg, block, op1, op2, mode);
+ result = new_rd_Sub(db, block, op1, op2, mode);
break;
default:
- assert(0);
+ panic("Unsupported opcode");
result = NULL;
}
return result;
-}
+} /* do_apply */
/**
* The Apply operation.
*
* @return the newly created node
*/
-static ir_node *apply(ir_node *orig, ir_node *op1, ir_node *op2, iv_env *env) {
- opcode code = get_irn_opcode(orig);
+static ir_node *apply(ir_node *header, ir_node *orig, ir_node *op1, ir_node *op2, iv_env *env) {
+ ir_opcode code = get_irn_opcode(orig);
ir_node *result = search(code, op1, op2, env);
- if (! result) {
+ if (result == NULL) {
dbg_info *db = get_irn_dbg_info(orig);
ir_node *op1_header = get_irn_ne(op1, env)->header;
ir_node *op2_header = get_irn_ne(op2, env)->header;
- if (op1_header != NULL && is_rc(op2, op1_header)) {
+ if (op1_header == header && is_rc(op2, op1_header)) {
result = reduce(orig, op1, op2, env);
}
- else if (op2_header != NULL && is_rc(op1, op2_header)) {
+ else if (op2_header == header && is_rc(op1, op2_header)) {
result = reduce(orig, op2, op1, env);
}
else {
result = do_apply(code, db, op1, op2, get_irn_mode(orig));
- get_irn_ne(result, env)->header = NULL; }
+ get_irn_ne(result, env)->header = NULL;
+ }
}
return result;
-}
+} /* apply */
/**
* The Reduce operation.
* @return the reduced node
*/
static ir_node *reduce(ir_node *orig, ir_node *iv, ir_node *rc, iv_env *env) {
- opcode code = get_irn_opcode(orig);
+ ir_opcode code = get_irn_opcode(orig);
ir_node *result = search(code, iv, rc, env);
- if (! result) {
+ /* check if we have already done this operation on the iv */
+ if (result == NULL) {
node_entry *e, *iv_e;
- int i, n;
+ int i;
ir_mode *mode = get_irn_mode(orig);
result = exact_copy(iv);
- /* Beware: we must always create a new nduction variable with the same mode
- as the node we are replacing. Espicially this means the mode might be changed
- from P to I and back. This is always possible, because we have only Phi, Add
- and Sub nodes. */
- set_irn_mode(result, mode);
+ if (get_irn_mode(result) != mode) {
+ /*
+ * Beware: we must always create a new induction variable with the same mode
+ * as the node we are replacing. Especially this means the mode might be changed
+ * from P to I and back. This is always possible, because we have only Phi, Add
+ * and Sub nodes.
+ * However, this might lead to AddIs(Iu,Is) which we must fix. The best way to do this
+ * seems to be a post-pass, or we might end with useless Conv's.
+ */
+ set_irn_mode(result, mode);
+ env->need_postpass = 1;
+ }
add(code, iv, rc, result, env);
DB((dbg, LEVEL_3, " Created new %+F for %+F (%s %+F)\n", result, iv,
get_irn_opname(orig), rc));
/* create the LFTR edge */
LFTR_add(iv, result, code, rc, env);
- n = get_irn_arity(result);
- for (i = 0; i < n; ++i) {
+ for (i = get_irn_arity(result) - 1; i >= 0; --i) {
ir_node *o = get_irn_n(result, i);
e = get_irn_ne(o, env);
if (e->header == iv_e->header)
o = reduce(orig, o, rc, env);
- else if (is_Phi(result))
- o = apply(orig, o, rc, env);
- else {
- if (code == iro_Mul)
- o = apply(orig, o, rc, env);
- }
+ else if (is_Phi(result) || code == iro_Mul)
+ o = apply(iv_e->header, orig, o, rc, env);
set_irn_n(result, i, o);
}
- }
- else {
+ } else {
DB((dbg, LEVEL_3, " Already Created %+F for %+F (%s %+F)\n", result, iv,
get_irn_opname(orig), rc));
}
return result;
-}
+} /* reduce */
+
+/**
+ * Update the scc for a newly created IV.
+ */
+static void update_scc(ir_node *iv, node_entry *e, iv_env *env) {
+ scc *pscc = e->pscc;
+ ir_node *header = e->header;
+ waitq *wq = new_waitq();
+
+ DB((dbg, LEVEL_2, " Creating SCC for new an induction variable:\n "));
+ pscc->head = NULL;
+ waitq_put(wq, iv);
+ do {
+ ir_node *irn = waitq_get(wq);
+ node_entry *ne = get_irn_ne(irn, env);
+ int i;
+
+ ne->pscc = pscc;
+ ne->next = pscc->head;
+ pscc->head = irn;
+ DB((dbg, LEVEL_2, " %+F,", irn));
+
+ for (i = get_irn_arity(irn) - 1; i >= 0; --i) {
+ ir_node *pred = get_irn_n(irn, i);
+ node_entry *pe = get_irn_ne(pred, env);
+
+ if (pe->header == header && pe->pscc == NULL) {
+ /* set the pscc here to ensure that the node is NOT enqueued another time */
+ pe->pscc = pscc;
+ waitq_put(wq, pred);
+ }
+ }
+ } while (! waitq_empty(wq));
+ del_waitq(wq);
+ DB((dbg, LEVEL_2, "\n"));
+} /* update_scc */
/**
- * The Replace operation.
+ * The Replace operation. We found a node representing iv (+,-,*) rc
+ * that can be removed by replacing the induction variable iv by a new
+ * one that 'applies' the operation 'irn'.
*
* @param irn the node that will be replaced
* @param iv the induction variable
*/
static int replace(ir_node *irn, ir_node *iv, ir_node *rc, iv_env *env) {
ir_node *result;
- ir_loop *iv_loop = get_irn_loop(get_nodes_block(iv));
- ir_loop *irn_loop = get_irn_loop(get_nodes_block(irn));
- /* only replace nodes that are in the same (or deeper loops) */
- if (get_loop_depth(irn_loop) >= get_loop_depth(iv_loop)) {
- DB((dbg, LEVEL_2, " Replacing %+F\n", irn));
+ DB((dbg, LEVEL_2, " Replacing %+F\n", irn));
- result = reduce(irn, iv, rc, env);
- if (result != irn) {
- node_entry *e, *iv_e;
+ result = reduce(irn, iv, rc, env);
+ if (result != irn) {
+ node_entry *e;
- hook_strength_red(current_ir_graph, irn);
- exchange(irn, result);
- e = get_irn_ne(result, env);
- iv_e = get_irn_ne(iv, env);
- e->header = iv_e->header;
+ hook_strength_red(current_ir_graph, irn);
+ exchange(irn, result);
+ e = get_irn_ne(result, env);
+ if (e->pscc == NULL) {
+ e->pscc = obstack_alloc(&env->obst, sizeof(*e->pscc));
+ memset(e->pscc, 0, sizeof(*e->pscc));
+ update_scc(result, e, env);
}
++env->replaced;
return 1;
}
return 0;
-}
+} /* replace */
+
+#if 0
+/**
+ * check if a given node is a mul with 2, 4, 8
+ */
+static int is_x86_shift_const(ir_node *mul) {
+ ir_node *rc;
+
+ if (! is_Mul(mul))
+ return 0;
+
+ /* normalization put constants on the right side */
+ rc = get_Mul_right(mul);
+ if (is_Const(rc)) {
+ tarval *tv = get_Const_tarval(rc);
+
+ if (tarval_is_long(tv)) {
+ long value = get_tarval_long(tv);
+
+ if (value == 2 || value == 4 || value == 8) {
+ /* do not reduce multiplications by 2, 4, 8 */
+ return 1;
+ }
+ }
+ }
+ return 0;
+} /* is_x86_shift_const */
+#endif
+
+/**
+ * Check if an IV represents a counter with constant limits.
+ *
+ * @param iv any node of the induction variable
+ * @param env the environment
+ */
+static int is_counter_iv(ir_node *iv, iv_env *env) {
+ node_entry *e = get_irn_ne(iv, env);
+ scc *pscc = e->pscc;
+ ir_node *have_init = NULL;
+ ir_node *have_incr = NULL;
+ ir_opcode code = iro_Bad;
+ ir_node *irn;
+
+ if (pscc->code != 0) {
+ /* already analysed */
+ return pscc->code != iro_Bad;
+ }
+
+ pscc->code = iro_Bad;
+ for (irn = pscc->head; irn != NULL; irn = e->next) {
+ if (is_Add(irn)) {
+ if (have_incr != NULL)
+ return 0;
+
+ have_incr = get_Add_right(irn);
+ if (! is_Const(have_incr)) {
+ have_incr = get_Add_left(irn);
+ if (! is_Const(have_incr))
+ return 0;
+ }
+ code = iro_Add;
+ } else if (is_Sub(irn)) {
+ if (have_incr != NULL)
+ return 0;
+
+ have_incr = get_Sub_right(irn);
+ if (! is_Const(have_incr))
+ return 0;
+ code = iro_Sub;
+ } else if (is_Phi(irn)) {
+ int i;
+
+ for (i = get_Phi_n_preds(irn) - 1; i >= 0; --i) {
+ ir_node *pred = get_Phi_pred(irn, i);
+ node_entry *ne = get_irn_ne(pred, env);
+
+ if (ne->header == e->header)
+ continue;
+ if (have_init != NULL)
+ return 0;
+ have_init = pred;
+ if (! is_Const(pred))
+ return 0;
+ }
+ } else
+ return 0;
+ e = get_irn_ne(irn, env);
+ }
+ pscc->init = get_Const_tarval(have_init);
+ pscc->incr = get_Const_tarval(have_incr);
+ pscc->code = code;
+ return code != iro_Bad;
+} /* is_counter_iv */
+
+/**
+ * Check the users of an induction variable for register pressure.
+ *
+ * @param iv any node of the induction variable
+ * @param env the environment
+ *
+ * @return non-zero if the register pressure is estimated
+ * to not increase, zero else
+ */
+static int check_users_for_reg_pressure(ir_node *iv, iv_env *env) {
+ ir_node *irn, *header;
+ ir_node *have_user = NULL;
+ ir_node *have_cmp = NULL;
+ node_entry *e = get_irn_ne(iv, env);
+ scc *pscc = e->pscc;
+
+ header = e->header;
+ for (irn = pscc->head; irn != NULL; irn = e->next) {
+ const ir_edge_t *edge;
+
+ foreach_out_edge(irn, edge) {
+ ir_node *user = get_edge_src_irn(edge);
+ node_entry *ne = get_irn_ne(user, env);
+
+ if (e->header == ne->header) {
+ /* found user from the same IV */
+ continue;
+ }
+ if (is_Cmp(user)) {
+ if (have_cmp != NULL) {
+ /* more than one cmp, for now end here */
+ return 0;
+ }
+ have_cmp = user;
+ } else {
+ /* user is a real user of the IV */
+ if (have_user != NULL) {
+ /* found the second user */
+ return 0;
+ }
+ have_user = user;
+ }
+ }
+ e = get_irn_ne(irn, env);
+ }
+
+ if (have_user == NULL) {
+ /* no user, ignore */
+ return 1;
+ }
+
+ if (have_cmp == NULL) {
+ /* fine, only one user, try to reduce */
+ return 1;
+ }
+ /*
+ * We found one user AND at least one cmp.
+ * We should check here if we can transform the Cmp.
+ *
+ * For now our capabilities for doing linear function test
+ * are limited, so check if the iv has the right form: Only ONE
+ * Phi, only one Add/Sub with a Const.
+ */
+ if (! is_counter_iv(iv, env))
+ return 0;
+
+ /*
+ * Ok, we have only one increment AND it is a Const, we might be able
+ * to do a linear function test replacement, so go on.
+ */
+ return 1;
+} /* check_users_for_reg_pressure */
/**
* Check if a node can be replaced (+, -, *).
* @return non-zero if irn should be Replace'd
*/
static int check_replace(ir_node *irn, iv_env *env) {
- ir_node *left, *right, *iv, *rc;
- ir_op *op = get_irn_op(irn);
- opcode code = get_op_code(op);
- ir_node *liv, *riv;
+ ir_node *left, *right, *iv, *rc;
+ ir_op *op = get_irn_op(irn);
+ ir_opcode code = get_op_code(op);
+ ir_node *liv, *riv;
switch (code) {
case iro_Mul:
}
if (iv) {
- if (env->flags & osr_flag_ignore_x86_shift) {
- if (is_Const(rc)) {
- tarval *tv = get_Const_tarval(rc);
-
- if (tarval_is_long(tv)) {
- long value = get_tarval_long(tv);
-
- if (value == 2 || value == 4 || value == 8) {
- /* do not reduce multiplications by 2, 4, 8 */
- break;
- }
- }
- }
+ if (env->osr_flags & osr_flag_keep_reg_pressure) {
+ if (! check_users_for_reg_pressure(iv, env))
+ return 0;
}
-
return replace(irn, iv, rc, env);
}
break;
break;
}
return 0;
-}
+} /* check_replace */
/**
* Check which SCC's are induction variables.
if (! out_rc) {
out_rc = pred;
++num_outside;
- }
- else if (out_rc != pred)
+ } else if (out_rc != pred) {
++num_outside;
+ }
}
}
break;
/* found an induction variable */
DB((dbg, LEVEL_2, " Found an induction variable:\n "));
if (only_phi && num_outside == 1) {
+ /* a phi cycle with only one real predecessor can be collapsed */
DB((dbg, LEVEL_2, " Found an USELESS Phi cycle:\n "));
+
+ for (irn = pscc->head; irn; irn = next) {
+ node_entry *e = get_irn_ne(irn, env);
+ next = e->next;
+ e->header = NULL;
+ exchange(irn, out_rc);
+ }
+ ++env->replaced;
+ return;
}
/* set the header for every node in this scc */
node_entry *e = get_irn_ne(irn, env);
next = e->next;
- if (! check_replace(irn, env))
- e->header = NULL;
+ e->header = NULL;
}
-}
+} /* classify_iv */
/**
- * Process a SCC.
+ * Process an SCC for the operator strength reduction.
*
* @param pscc the SCC
* @param env the environment
ir_node *irn, *next;
DB((dbg, LEVEL_4, " SCC at %p:\n ", pscc));
- for (irn = pscc->head; irn; irn = next) {
+ for (irn = pscc->head; irn != NULL; irn = next) {
node_entry *e = get_irn_link(irn);
next = e->next;
if (e->next == NULL) {
/* this SCC has only a single member */
check_replace(head, env);
- }
- else {
+ } else {
classify_iv(pscc, env);
}
-}
+} /* process_scc */
+
+/**
+ * If an SCC is a Phi only cycle, remove it.
+ *
+ * @param pscc an SCC that consists of Phi nodes only
+ * @param env the environment
+ */
+static void remove_phi_cycle(scc *pscc, iv_env *env) {
+ ir_node *irn, *next;
+ int j;
+ ir_node *out_rc;
+
+ /* check if this scc contains only Phi, Add or Sub nodes */
+ out_rc = NULL;
+ for (irn = pscc->head; irn; irn = next) {
+ node_entry *e = get_irn_ne(irn, env);
+
+ next = e->next;
+ if (! is_Phi(irn))
+ return;
+
+ for (j = get_irn_arity(irn) - 1; j >= 0; --j) {
+ ir_node *pred = get_irn_n(irn, j);
+ node_entry *pe = get_irn_ne(pred, env);
+
+ if (pe->pscc != e->pscc) {
+ /* not in the same SCC, must be the only input */
+ if (! out_rc) {
+ out_rc = pred;
+ } else if (out_rc != pred) {
+ return;
+ }
+ }
+ }
+ }
+ /* found a Phi cycle */
+ DB((dbg, LEVEL_2, " Found an USELESS Phi cycle:\n "));
+
+ for (irn = pscc->head; irn; irn = next) {
+ node_entry *e = get_irn_ne(irn, env);
+ next = e->next;
+ e->header = NULL;
+ exchange(irn, out_rc);
+ }
+ ++env->replaced;
+} /* remove_phi_cycle */
+
+/**
+ * Process a SCC for the Phi cycle remove.
+ *
+ * @param pscc the SCC
+ * @param env the environment
+ */
+static void process_phi_only_scc(scc *pscc, iv_env *env) {
+ ir_node *head = pscc->head;
+ node_entry *e = get_irn_link(head);
+
+#ifdef DEBUG_libfirm
+ {
+ ir_node *irn, *next;
+
+ DB((dbg, LEVEL_4, " SCC at %p:\n ", pscc));
+ for (irn = pscc->head; irn; irn = next) {
+ node_entry *e = get_irn_link(irn);
+
+ next = e->next;
+
+ DB((dbg, LEVEL_4, " %+F,", irn));
+ }
+ DB((dbg, LEVEL_4, "\n"));
+ }
+#endif
+
+ if (e->next != NULL)
+ remove_phi_cycle(pscc, env);
+} /* process_phi_only_scc */
+
/**
* Push a node onto the stack.
env->stack[env->tos++] = n;
e = get_irn_ne(n, env);
e->in_stack = 1;
-}
+} /* push */
/**
- * pop a node from the stack
+ * Pop a node from the stack.
*
* @param env the environment
*
* @return The topmost node
*/
-static ir_node *pop(iv_env *env)
-{
+static ir_node *pop(iv_env *env) {
ir_node *n = env->stack[--env->tos];
node_entry *e = get_irn_ne(n, env);
e->in_stack = 0;
return n;
-}
+} /* pop */
/**
* Do Tarjan's SCC algorithm and drive OSR.
* @param irn start at this node
* @param env the environment
*/
-static void dfs(ir_node *irn, iv_env *env)
-{
+static void dfs(ir_node *irn, iv_env *env) {
int i, n;
node_entry *node = get_irn_ne(irn, env);
for (i = 0; i < n; ++i) {
ir_node *pred = get_irn_n(irn, i);
- if (irn_not_visited(pred))
+ if (!irn_visited(pred))
dfs(pred, env);
}
- }
- else {
+ } else {
ir_node *block = get_nodes_block(irn);
node->DFSnum = env->nextDFSnum++;
push(env, irn);
/* handle the block */
- if (irn_not_visited(block))
+ if (!irn_visited(block))
dfs(block, env);
n = get_irn_arity(irn);
ir_node *pred = get_irn_n(irn, i);
node_entry *o = get_irn_ne(pred, env);
- if (irn_not_visited(pred)) {
+ if (!irn_visited(pred)) {
dfs(pred, env);
node->low = MIN(node->low, o->low);
}
scc *pscc = obstack_alloc(&env->obst, sizeof(*pscc));
ir_node *x;
- pscc->head = NULL;
+ memset(pscc, 0, sizeof(*pscc));
do {
node_entry *e;
pscc->head = x;
} while (x != irn);
- process_scc(pscc, env);
+ env->process_scc(pscc, env);
}
}
-}
+} /* dfs */
/**
* Do the DFS by starting at the End node of a graph.
*/
static void do_dfs(ir_graph *irg, iv_env *env) {
ir_graph *rem = current_ir_graph;
- ir_node *end = get_irg_end(irg);
- int i, n;
+ ir_node *end = get_irg_end(irg);
+ int i;
+
+ ir_reserve_resources(irg, IR_RESOURCE_IRN_VISITED);
current_ir_graph = irg;
inc_irg_visited(irg);
dfs(end, env);
/* visit the keep-alives */
- n = get_End_n_keepalives(end);
- for (i = 0; i < n; ++i) {
+ for (i = get_End_n_keepalives(end) - 1; i >= 0; --i) {
ir_node *ka = get_End_keepalive(end, i);
- if (irn_not_visited(ka))
+ if (!irn_visited(ka))
dfs(ka, env);
}
+ ir_free_resources(irg, IR_RESOURCE_IRN_VISITED);
+
current_ir_graph = rem;
-}
+} /* do_dfs */
/**
* Post-block-walker: assign the post-order number.
node_entry *e = get_irn_ne(block, env);
e->POnum = env->POnum++;
-}
-
-/**
- * Follows the LFTR edges and return the last node in the chain.
- *
- * @param irn the node that should be followed
- * @param env the IV environment
- *
- * @note
- * In the current implementation only the last edge is stored, so
- * only one chain exists. That's why we might miss some opportunities.
- */
-static ir_node *followEdges(ir_node *irn, iv_env *env) {
- for (;;) {
- LFTR_edge *e = LFTR_find(irn, env);
- if (e)
- irn = e->dst;
- else
- return irn;
- }
-}
+} /* assign_po */
/**
* Apply one LFTR edge operation.
* Return NULL if the transformation cannot be done safely without
* an Overflow.
*
- * @param rc the IV node that should be translated
+ * @param iv the induction variable
+ * @param rc the constant that should be translated
* @param e the LFTR edge
* @param env the IV environment
*
* In the current implementation only the last edge is stored, so
* only one chain exists. That's why we might miss some opportunities.
*/
-static ir_node *applyOneEdge(ir_node *rc, LFTR_edge *e, iv_env *env) {
- if (env->flags & osr_flag_lftr_with_ov_check) {
- tarval *tv_l, *tv_r, *tv;
+static ir_node *applyOneEdge(ir_node *iv, ir_node *rc, LFTR_edge *e, iv_env *env) {
+ if (env->osr_flags & osr_flag_lftr_with_ov_check) {
+ tarval *tv_l, *tv_r, *tv, *tv_init, *tv_incr, *tv_end;
tarval_int_overflow_mode_t ovmode;
+ scc *pscc;
+
+ if (! is_counter_iv(iv, env)) {
+ DB((dbg, LEVEL_4, " not counter IV"));
+ return NULL;
+ }
/* overflow can only be decided for Consts */
if (! is_Const(e->rc)) {
+ if (e->code == iro_Add && mode_is_reference(get_irn_mode(e->rc))) {
+ /* However we allow ONE Pointer Add, as pointer arithmetic with wrap
+ around is undefined anyway */
+ return do_apply(e->code, NULL, rc, e->rc, get_irn_mode(e->rc));
+ }
DB((dbg, LEVEL_4, " = UNKNOWN (%+F)", e->rc));
return NULL;
}
ovmode = tarval_get_integer_overflow_mode();
tarval_set_integer_overflow_mode(TV_OVERFLOW_BAD);
+ pscc = get_iv_scc(iv, env);
+ tv_incr = pscc->incr;
+ tv_init = pscc->init;
+
+ /*
+ * Check that no overflow occurs:
+ * init must be transformed without overflow
+ * the new rc must be transformed without overflow
+ * rc +/- incr must be possible without overflow
+ */
switch (e->code) {
case iro_Mul:
- tv = tarval_mul(tv_l, tv_r);
+ tv = tarval_mul(tv_l, tv_r);
+ tv_init = tarval_mul(tv_init, tv_r);
+ tv_incr = tarval_mul(tv_incr, tv_r);
DB((dbg, LEVEL_4, " * %+F", tv_r));
break;
case iro_Add:
- tv = tarval_add(tv_l, tv_r);
+ tv = tarval_add(tv_l, tv_r);
+ tv_init = tarval_add(tv_init, tv_r);
DB((dbg, LEVEL_4, " + %+F", tv_r));
break;
case iro_Sub:
- tv = tarval_sub(tv_l, tv_r);
+ tv = tarval_sub(tv_l, tv_r, NULL);
+ tv_init = tarval_sub(tv_init, tv_r, NULL);
DB((dbg, LEVEL_4, " - %+F", tv_r));
break;
default:
- assert(0);
+ panic("Unsupported opcode");
tv = tarval_bad;
}
+
+ if (pscc->code == iro_Add) {
+ tv_end = tarval_add(tv, tv_incr);
+ } else {
+ assert(pscc->code == iro_Sub);
+ tv_end = tarval_sub(tv, tv_incr, NULL);
+ }
+
tarval_set_integer_overflow_mode(ovmode);
- if (tv == tarval_bad) {
+ if (tv == tarval_bad || tv_init == tarval_bad || tv_end == tarval_bad) {
DB((dbg, LEVEL_4, " = OVERFLOW"));
return NULL;
}
- return new_r_Const(current_ir_graph, get_irn_n(rc, -1), get_tarval_mode(tv), tv);
+ return new_Const(tv);
}
- return do_apply(e->code, NULL, rc, e->rc, get_irn_mode(rc));
-}
+ return do_apply(e->code, NULL, rc, e->rc, get_irn_mode(e->dst));
+} /* applyOneEdge */
/**
* Applies the operations represented by the LFTR edges to a
* Return NULL if the transformation cannot be done safely without
* an Overflow.
*
- * @param iv the IV node that starts the LFTR edge chain
+ * @param pIV points to the IV node that starts the LFTR edge chain
+ * after translation points to the new IV
* @param rc the region constant that should be translated
* @param env the IV environment
*
* @return the translated region constant or NULL
* if the translation was not possible
*/
-static ir_node *applyEdges(ir_node *iv, ir_node *rc, iv_env *env) {
- ir_node *irn = iv;
-
- if (env->flags & osr_flag_lftr_with_ov_check) {
+static ir_node *applyEdges(ir_node **pIV, ir_node *rc, iv_env *env) {
+ ir_node *iv = *pIV;
+ if (env->osr_flags & osr_flag_lftr_with_ov_check) {
/* overflow can only be decided for Consts */
+ if (! is_counter_iv(iv, env)) {
+ DB((dbg, LEVEL_4, "not counter IV\n", rc));
+ return NULL;
+ }
if (! is_Const(rc)) {
DB((dbg, LEVEL_4, " = UNKNOWN (%+F)\n", rc));
return NULL;
DB((dbg, LEVEL_4, "%+F", get_Const_tarval(rc)));
}
- for (irn = iv; rc;) {
- LFTR_edge *e = LFTR_find(irn, env);
- if (e) {
- rc = applyOneEdge(rc, e, env);
- irn = e->dst;
- }
- else
+ for (; rc;) {
+ LFTR_edge *e = LFTR_find(iv, env);
+ if (e != NULL) {
+ rc = applyOneEdge(iv, rc, e, env);
+ iv = e->dst;
+ } else
break;
}
DB((dbg, LEVEL_3, "\n"));
+ *pIV = iv;
return rc;
-}
+} /* applyEdges */
/**
* Walker, finds Cmp(iv, rc) or Cmp(rc, iv)
ir_node *iv, *rc;
ir_node *nleft = NULL, *nright = NULL;
- if (get_irn_op(cmp) != op_Cmp)
+ if (!is_Cmp(cmp))
return;
left = get_Cmp_left(cmp);
if (liv && is_rc(right, liv)) {
iv = left; rc = right;
- nright = applyEdges(iv, rc, env);
- if (nright && nright != rc) {
- nleft = followEdges(iv, env);
- }
+ nright = applyEdges(&iv, rc, env);
+ nleft = iv;
}
else if (riv && is_rc(left, riv)) {
iv = right; rc = left;
- nleft = applyEdges(iv, rc, env);
- if (nleft && nleft != rc) {
- nright = followEdges(iv, env);
- }
+ nleft = applyEdges(&iv, rc, env);
+ nright = iv;
}
if (nleft && nright) {
set_Cmp_right(cmp, nright);
++env->lftr_replaced;
}
-}
+} /* do_lftr */
/**
* do linear function test replacement.
*/
static void lftr(ir_graph *irg, iv_env *env) {
irg_walk_graph(irg, NULL, do_lftr, env);
-}
+} /* lftr */
/**
* Pre-walker: set all node links to NULL and fix the
* block of Proj nodes.
*/
-static void clear_and_fix(ir_node *irn, void *env)
-{
+static void clear_and_fix(ir_node *irn, void *env) {
+ int *moved = env;
set_irn_link(irn, NULL);
if (is_Proj(irn)) {
- ir_node *pred = get_Proj_pred(irn);
- set_irn_n(irn, -1, get_irn_n(pred, -1));
+ ir_node *pred = get_Proj_pred(irn);
+ ir_node *pred_block = get_nodes_block(pred);
+
+ if (get_nodes_block(irn) != pred_block) {
+ set_nodes_block(irn, pred_block);
+ *moved = 1;
+ }
}
-}
+} /* clear_and_fix */
+
+
+/* Remove any Phi cycles with only one real input. */
+void remove_phi_cycles(ir_graph *irg) {
+ iv_env env;
+ ir_graph *rem;
+ int projs_moved;
+
+ rem = current_ir_graph;
+ current_ir_graph = irg;
+
+ FIRM_DBG_REGISTER(dbg, "firm.opt.remove_phi");
+
+ DB((dbg, LEVEL_1, "Doing Phi cycle removement for %+F\n", irg));
+
+ obstack_init(&env.obst);
+ env.stack = NEW_ARR_F(ir_node *, 128);
+ env.tos = 0;
+ env.nextDFSnum = 0;
+ env.POnum = 0;
+ env.quad_map = NULL;
+ env.lftr_edges = NULL;
+ env.replaced = 0;
+ env.lftr_replaced = 0;
+ env.osr_flags = 0;
+ env.need_postpass = 0;
+ env.process_scc = process_phi_only_scc;
+
+ /* Clear all links and move Proj nodes into the
+ the same block as it's predecessors.
+ This can improve the placement of new nodes.
+ */
+ projs_moved = 0;
+ irg_walk_graph(irg, NULL, clear_and_fix, &projs_moved);
+ if (projs_moved)
+ set_irg_outs_inconsistent(irg);
+
+ /* we need outs for calculating the post order */
+ assure_irg_outs(irg);
+
+ /* calculate the post order number for blocks. */
+ irg_out_block_walk(get_irg_start_block(irg), NULL, assign_po, &env);
+
+ /* calculate the SCC's and drive OSR. */
+ ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
+ do_dfs(irg, &env);
+ ir_free_resources(irg, IR_RESOURCE_IRN_LINK);
+
+ if (env.replaced) {
+ set_irg_outs_inconsistent(irg);
+ DB((dbg, LEVEL_1, "remove_phi_cycles: %u Cycles removed\n\n", env.replaced));
+ }
+
+ DEL_ARR_F(env.stack);
+ obstack_free(&env.obst, NULL);
+
+ current_ir_graph = rem;
+} /* remove_phi_cycles */
+
+ir_graph_pass_t *remove_phi_cycles_pass(const char *name, int verify, int dump)
+{
+ return def_graph_pass(name ? name : "remove_phi_cycles", verify, dump, remove_phi_cycles);
+} /* remove_phi_cycles_pass */
+
+/**
+ * Post-walker: fix Add and Sub nodes that where results of I<->P conversions.
+ */
+static void fix_adds_and_subs(ir_node *irn, void *ctx) {
+ (void) ctx;
+
+ if (is_Add(irn)) {
+ ir_mode *mode = get_irn_mode(irn);
+
+ if (mode_is_int(mode)) {
+ ir_node *pred;
+
+ pred = get_Add_left(irn);
+ if (get_irn_mode(pred) != mode) {
+ ir_node *block = get_nodes_block(pred);
+
+ pred = new_r_Conv(block, pred, mode);
+ set_Add_left(irn, pred);
+ }
+ pred = get_Add_right(irn);
+ if (get_irn_mode(pred) != mode) {
+ ir_node *block = get_nodes_block(pred);
+
+ pred = new_r_Conv(block, pred, mode);
+ set_Add_right(irn, pred);
+ }
+ }
+ } else if (is_Sub(irn)) {
+ ir_mode *mode = get_irn_mode(irn);
+
+ if (mode_is_int(mode)) {
+ ir_node *left = get_Sub_left(irn);
+ ir_node *right = get_Sub_right(irn);
+ ir_mode *l_mode = get_irn_mode(left);
+ ir_mode *r_mode = get_irn_mode(right);
+
+ if (mode_is_int(l_mode) && mode_is_int(r_mode)) {
+ if (l_mode != mode) {
+ ir_node *block = get_nodes_block(left);
+
+ left = new_r_Conv(block, left, mode);
+ set_Sub_left(irn, left);
+ }
+ if (r_mode != mode) {
+ ir_node *block = get_nodes_block(right);
+
+ right = new_r_Conv(block, right, mode);
+ set_Sub_right(irn, right);
+ }
+ }
+ }
+ }
+} /* fix_adds_and_subs */
/* Performs Operator Strength Reduction for the passed graph. */
void opt_osr(ir_graph *irg, unsigned flags) {
- iv_env env;
-
- if (! get_opt_strength_red())
+ iv_env env;
+ ir_graph *rem;
+ int edges;
+ int projs_moved;
+
+ if (! get_opt_strength_red()) {
+ /* only kill Phi cycles */
+ remove_phi_cycles(irg);
return;
+ }
+
+ rem = current_ir_graph;
+ current_ir_graph = irg;
FIRM_DBG_REGISTER(dbg, "firm.opt.osr");
-// firm_dbg_set_mask(dbg, SET_LEVEL_3);
DB((dbg, LEVEL_1, "Doing Operator Strength Reduction for %+F\n", irg));
env.lftr_edges = new_set(LFTR_cmp, 64);
env.replaced = 0;
env.lftr_replaced = 0;
- env.flags = flags;
-
- /* we need control flow loop information to decide whether
- * we should do a replacement or not. */
- construct_cf_backedges(irg);
+ env.osr_flags = flags;
+ env.need_postpass = 0;
+ env.process_scc = process_scc;
/* Clear all links and move Proj nodes into the
the same block as it's predecessors.
This can improve the placement of new nodes.
*/
- irg_walk_graph(irg, NULL, clear_and_fix, NULL);
+ projs_moved = 0;
+ irg_walk_graph(irg, NULL, clear_and_fix, &projs_moved);
+ if (projs_moved)
+ set_irg_outs_inconsistent(irg);
/* we need dominance */
assure_doms(irg);
- assure_irg_outs(irg);
- /* calculate the post order number for blocks. */
- irg_out_block_walk(get_irg_start_block(irg), NULL, assign_po, &env);
+ edges = edges_assure(irg);
+
+ /* calculate the post order number for blocks by walking the out edges. */
+ assure_irg_outs(irg);
+ irg_block_edges_walk(get_irg_start_block(irg), NULL, assign_po, &env);
/* calculate the SCC's and drive OSR. */
+ ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
do_dfs(irg, &env);
if (env.replaced) {
+ if (env.need_postpass)
+ irg_walk_graph(irg, NULL, fix_adds_and_subs, &env);
+
/* try linear function test replacements */
- //lftr(irg, &env);
- (void) lftr;
+ lftr(irg, &env);
+ (void)lftr;
set_irg_outs_inconsistent(irg);
- /* cfg loop still valid */
-
DB((dbg, LEVEL_1, "Replacements: %u + %u (lftr)\n\n", env.replaced, env.lftr_replaced));
}
+ ir_free_resources(irg, IR_RESOURCE_IRN_LINK);
del_set(env.lftr_edges);
del_set(env.quad_map);
DEL_ARR_F(env.stack);
obstack_free(&env.obst, NULL);
-}
+
+ if (! edges)
+ edges_deactivate(irg);
+
+ current_ir_graph = rem;
+} /* opt_osr */
+
+struct pass_t {
+ ir_graph_pass_t pass;
+ unsigned flags;
+};
+
+/**
+* Wrapper for running opt_osr() as an ir_graph pass.
+*/
+static int pass_wrapper(ir_graph *irg, void *context) {
+ struct pass_t *pass = context;
+ opt_osr(irg, pass->flags);
+ return 0;
+} /* pass_wrapper */
+
+ir_graph_pass_t *opt_osr_pass(const char *name, int verify, int dump, unsigned flags)
+{
+ struct pass_t *pass = xmalloc(sizeof(*pass));
+
+ pass->pass.kind = k_ir_prog_pass;
+ pass->pass.run_on_irg = pass_wrapper;
+ pass->pass.context = pass;
+ pass->pass.name = name ? name : "osr";
+ pass->pass.verify = verify != 0;
+ pass->pass.dump = dump != 0;
+
+ pass->flags = flags;
+
+ INIT_LIST_HEAD(&pass->pass.list);
+
+ return &pass->pass;
+} /* opt_osr_pass */
projects / libfirm / blobdiff