/*
- * Project: libFIRM
- * File name: ir/opt/return.c
- * Purpose: normalize returns
- * Author:
- * Created:
- * CVS-ID: $Id$
- * Copyright: (c) 1998-2005 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.
+ */
+
+/**
+ * @file
+ * @brief Normalize returns.
+ * @author Michael Beck
+ * @version $Id$
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
-#ifdef HAVE_ALLOCA_H
-# include <alloca.h>
-#endif
-#ifdef HAVE_MALLOC_H
-# include <malloc.h>
-#endif
-
+#include "iroptimize.h"
#include "irgraph_t.h"
#include "ircons_t.h"
#include "irnode_t.h"
#include "irgmod.h"
+#include "xmalloc.h"
#define set_bit(n) (returns[(n) >> 3] |= 1 << ((n) & 7))
#define get_bit(n) (returns[(n) >> 3] & (1 << ((n) & 7)))
* res = c;
* return res;
*/
-void normalize_one_return(ir_graph *irg)
-{
- ir_node *endbl = get_irg_end_block(irg);
- int i, j, k, n, last_idx, n_rets, n_ret_vals = -1;
- unsigned char *returns;
- ir_node **in, **retvals;
-
- ir_node *block, *new_ret;
-
- /* look, if we have more than one return */
- n = get_Block_n_cfgpreds(endbl);
- assert(n > 0);
- returns = alloca((n + 7) >> 3);
- memset(returns, 0, (n + 7) >> 3);
-
- for (n_rets = i = 0; i < n; ++i) {
- ir_node *node = get_Block_cfgpred(endbl, i);
-
- if (get_irn_op(node) == op_Return) {
- ++n_rets;
-
- set_bit(i);
-
- if (n_ret_vals < 0)
- n_ret_vals = get_irn_arity(node);
- }
- }
-
- /* there should be at least one Return node in Firm */
- if (n_rets <= 1)
- return;
-
- in = alloca(sizeof(*in) * IMAX(n_rets, n_ret_vals));
- retvals = alloca(sizeof(*in) * n_rets * n_ret_vals);
-
- for (j = i = 0; i < n; ++i) {
- if (get_bit(i)) {
- ir_node *ret = get_Block_cfgpred(endbl, i);
- ir_node *block = get_nodes_block(ret);
-
- /* create a new Jmp for every Ret and place the in in */
- in[j] = new_r_Jmp(irg, block);
-
- /* save the return values and shuffle them */
- for (k = 0; k < n_ret_vals; ++k)
- retvals[j + k*n_rets] = get_irn_n(ret, k);
-
- set_Block_cfgpred(endbl, i, new_r_Bad(irg));
- last_idx = i;
-
- ++j;
- }
- }
-
- /* ok, create a new block with all created in's */
- block = new_r_Block(irg, n_rets, in);
-
- /* now create the Phi nodes */
- for (j = i = 0; i < n_ret_vals; ++i, j += n_rets) {
- /* the return values are already shuffled */
- in[i] = new_r_Phi(irg, block, n_rets, &retvals[j], get_irn_mode(retvals[j]));
- }
-
- new_ret = new_r_Return(irg, block, in[0], n_ret_vals-1, &in[1]);
-
- set_Block_cfgpred(endbl, last_idx, new_ret);
-
- /* invalidate analysis information:
- * a new Block was added, so dominator, outs and loop are inconsistent,
- * trouts and callee-state should be still valid
- */
- set_irg_doms_inconsistent(irg);
- set_irg_outs_inconsistent(irg);
- set_irg_loopinfo_state(current_ir_graph, loopinfo_cf_inconsistent);
+void normalize_one_return(ir_graph *irg) {
+ ir_node *endbl = get_irg_end_block(irg);
+ int i, j, k, n, last_idx, n_rets, n_ret_vals = -1;
+ unsigned char *returns;
+ ir_node **in, **retvals, **endbl_in;
+
+ ir_node *block;
+
+ /* look, if we have more than one return */
+ n = get_Block_n_cfgpreds(endbl);
+ if (n <= 0) {
+ /* The end block has no predecessors, we have an endless
+ loop. In that case, no returns exists. */
+ return;
+ }
+
+ returns = alloca((n + 7) >> 3);
+ memset(returns, 0, (n + 7) >> 3);
+
+ for (n_rets = i = 0; i < n; ++i) {
+ ir_node *node = get_Block_cfgpred(endbl, i);
+
+ if (is_Return(node)) {
+ ++n_rets;
+
+ set_bit(i);
+
+ if (n_ret_vals < 0)
+ n_ret_vals = get_irn_arity(node);
+ }
+ }
+
+ /* there should be at least one Return node in Firm */
+ if (n_rets <= 1)
+ return;
+
+ in = alloca(sizeof(*in) * IMAX(n_rets, n_ret_vals));
+ retvals = alloca(sizeof(*retvals) * n_rets * n_ret_vals);
+ endbl_in = alloca(sizeof(*endbl_in) * n);
+
+ last_idx = 0;
+ for (j = i = 0; i < n; ++i) {
+ ir_node *ret = get_Block_cfgpred(endbl, i);
+
+ if (get_bit(i)) {
+ ir_node *block = get_nodes_block(ret);
+
+ /* create a new Jmp for every Ret and place the in in */
+ in[j] = new_r_Jmp(irg, block);
+
+ /* save the return values and shuffle them */
+ for (k = 0; k < n_ret_vals; ++k)
+ retvals[j + k*n_rets] = get_irn_n(ret, k);
+
+ ++j;
+ } else
+ endbl_in[last_idx++] = ret;
+ }
+
+ /* ok, create a new block with all created in's */
+ block = new_r_Block(irg, n_rets, in);
+
+ /* now create the Phi nodes */
+ for (j = i = 0; i < n_ret_vals; ++i, j += n_rets) {
+ int k;
+ ir_node *first;
+ /* the return values are already shuffled */
+
+ /* Beware: normally the Phi constructor automatically replaces a Phi(a,...a) into a
+ but NOT, if a is Unknown. Here, we known that this case can be optimize also,
+ so do it here */
+ first = retvals[j + 0];
+ for (k = 1; k < n_rets; ++k) {
+ if (retvals[j + k] != first) {
+ first = NULL;
+ break;
+ }
+ }
+ if (first)
+ in[i] = first;
+ else
+ in[i] = new_r_Phi(irg, block, n_rets, &retvals[j], get_irn_mode(retvals[j]));
+ }
+
+ endbl_in[last_idx++] = new_r_Return(irg, block, in[0], n_ret_vals-1, &in[1]);
+
+ set_irn_in(endbl, last_idx, endbl_in);
+
+ /* invalidate analysis information:
+ * a new Block was added, so dominator, outs and loop are inconsistent,
+ * trouts and callee-state should be still valid
+ */
+ set_irg_doms_inconsistent(irg);
+ set_irg_outs_inconsistent(irg);
+ set_irg_extblk_inconsistent(irg);
+ set_irg_loopinfo_state(irg, loopinfo_cf_inconsistent);
}
/**
* All predecessors of the Return block must be Jmp's of course, or we
* cannot move it up, so we check this either.
*/
-static int can_move_ret(ir_node *ret)
-{
- ir_node *retbl = get_nodes_block(ret);
- int i, n = get_irn_arity(ret);
-
- for (i = 0; i < n; ++i) {
- ir_node *pred = get_irn_n(ret, i);
-
- if (! is_Phi(pred) && retbl == get_nodes_block(pred)) {
- /* first condition failed, found a non-Phi predecessor
- * then is in the Return block */
- return 0;
- }
- }
-
- /* check, that predecessors are Jmps */
- n = get_Block_n_cfgpreds(retbl);
- for (i = 0; i < n; ++i)
- if (get_irn_op(get_Block_cfgpred(retbl, i)) != op_Jmp)
- return 0;
-
- /* if we have 0 control flow predecessors, we cannot move :-) */
- return n > 0;
+static int can_move_ret(ir_node *ret) {
+ ir_node *retbl = get_nodes_block(ret);
+ int i, n = get_irn_arity(ret);
+
+ for (i = 0; i < n; ++i) {
+ ir_node *pred = get_irn_n(ret, i);
+
+ if (! is_Phi(pred) && retbl == get_nodes_block(pred)) {
+ /* first condition failed, found a non-Phi predecessor
+ * then is in the Return block */
+ return 0;
+ }
+ }
+
+ /* check, that predecessors are Jmps */
+ n = get_Block_n_cfgpreds(retbl);
+ for (i = 0; i < n; ++i)
+ if (get_irn_op(get_Block_cfgpred(retbl, i)) != op_Jmp)
+ return 0;
+
+ /* if we have 0 control flow predecessors, we cannot move :-) */
+ return n > 0;
}
/*
* else
* return c;
*/
-void normalize_n_returns(ir_graph *irg)
-{
- int i, j, n, n_rets, n_finals, n_ret_vals;
- ir_node *list = NULL;
- ir_node *final = NULL;
- ir_node **in;
- ir_node *endbl = get_irg_end_block(irg);
- ir_node *end;
-
- /*
- * First, link all returns:
- * These must be predecessors of the endblock.
- * Place Returns that can be moved on list, all others
- * on final.
- */
- n = get_Block_n_cfgpreds(endbl);
- for (n_finals = n_rets = i = 0; i < n; ++i) {
- ir_node *ret = get_Block_cfgpred(endbl, i);
-
- if (get_irn_op(ret) == op_Return && can_move_ret(ret)) {
- /*
- * Ok, all conditions met, we can move this Return, put it
- * on our work list.
- */
- set_irn_link(ret, list);
- list = ret;
- ++n_rets;
- }
- else {
- /* Put all nodes that are not changed on the final list. */
- set_irn_link(ret, final);
- final = ret;
- ++n_finals;
- }
- }
-
- if (n_rets <= 0)
- return;
-
- /*
- * Now move the Returns upwards. We move always one block up (and create n
- * new Returns), than we check if a newly created Return can be moved even further.
- * If yes, we simply add it to our work list, else to the final list.
- */
- end = get_irg_end(irg);
- n_ret_vals = get_irn_arity(list);
- in = alloca(sizeof(*in) * n_ret_vals);
- while (list) {
- ir_node *ret = list;
- ir_node *block = get_nodes_block(ret);
- ir_node *phiM;
-
- list = get_irn_link(ret);
- --n_rets;
-
- n = get_Block_n_cfgpreds(block);
- for (i = 0; i < n; ++i) {
- ir_node *jmp = get_Block_cfgpred(block, i);
- ir_node *new_bl, *new_ret;
-
- if (get_irn_op(jmp) != op_Jmp)
- continue;
-
- new_bl = get_nodes_block(jmp);
-
- /* create the in-array for the new Ret */
- for (j = 0; j < n_ret_vals; ++j) {
- ir_node *pred = get_irn_n(ret, j);
-
- in[j] = (is_Phi(pred) && get_nodes_block(pred) == block) ? get_Phi_pred(pred, i) : pred;
- }
-
- new_ret = new_r_Return(irg, new_bl, in[0], n_ret_vals - 1, &in[1]);
-
- if (! is_Bad(new_ret)) {
- /*
- * The newly created node might be bad, if we
- * create it in a block with only Bad predecessors.
- * In that case ignore this block.
- *
- * We could even kill the jmp then ...
- */
- if (can_move_ret(new_ret)) {
- set_irn_link(new_ret, list);
- list = new_ret;
- ++n_rets;
- }
- else {
- set_irn_link(new_ret, final);
- final = new_ret;
- ++n_finals;
- }
- }
-
- /* remove the Jmp, we have placed a Return here */
- exchange(jmp, new_r_Bad(irg));
- }
-
- /*
- * if the memory of the old Return is a PhiM, remove it
- * from the keep-alives, or it will keep the block which
- * will crash the dominator algorithm.
- */
- phiM = get_Return_mem(ret);
- if (is_Phi(phiM)) {
- n = get_End_n_keepalives(end);
- for (i = 0; i < n; ++i) {
- if (get_End_keepalive(end, i) == phiM) {
- set_End_keepalive(end, i, new_r_Bad(irg));
- break;
- }
- }
- }
- }
-
- /*
- * Last step: Create a new endblock, with all nodes on the final
- * list as predecessors.
- */
- in = alloca(sizeof(*in) * n_finals);
-
- for (i = 0; final; ++i, final = get_irn_link(final))
- in[i] = final;
-
- exchange(endbl, new_r_Block(irg, n_finals, in));
-
- /* the end block is not automatically skipped, so do it here */
- set_irg_end_block(irg, skip_Id(get_irg_end_block(irg)));
-
- /* Invalidate analysis information:
- * Blocks become dead and new Returns were deleted, so dominator, outs and loop are inconsistent,
- * trouts and callee-state should be still valid
- */
- set_irg_doms_inconsistent(irg);
- set_irg_outs_inconsistent(irg);
- set_irg_loopinfo_state(current_ir_graph, loopinfo_cf_inconsistent);
+void normalize_n_returns(ir_graph *irg) {
+ int i, j, n, n_rets, n_finals, n_ret_vals;
+ ir_node *list = NULL;
+ ir_node *final = NULL;
+ ir_node **in;
+ ir_node *endbl = get_irg_end_block(irg);
+ ir_node *end;
+
+ /*
+ * First, link all returns:
+ * These must be predecessors of the endblock.
+ * Place Returns that can be moved on list, all others
+ * on final.
+ */
+ n = get_Block_n_cfgpreds(endbl);
+ for (n_finals = n_rets = i = 0; i < n; ++i) {
+ ir_node *ret = get_Block_cfgpred(endbl, i);
+
+ if (is_Return(ret) && can_move_ret(ret)) {
+ /*
+ * Ok, all conditions met, we can move this Return, put it
+ * on our work list.
+ */
+ set_irn_link(ret, list);
+ list = ret;
+ ++n_rets;
+ } else {
+ /* Put all nodes that are not changed on the final list. */
+ set_irn_link(ret, final);
+ final = ret;
+ ++n_finals;
+ }
+ }
+
+ if (n_rets <= 0)
+ return;
+
+ /*
+ * Now move the Returns upwards. We move always one block up (and create n
+ * new Returns), than we check if a newly created Return can be moved even further.
+ * If yes, we simply add it to our work list, else to the final list.
+ */
+ end = get_irg_end(irg);
+ n_ret_vals = get_irn_arity(list);
+ in = alloca(sizeof(*in) * n_ret_vals);
+ while (list) {
+ ir_node *ret = list;
+ ir_node *block = get_nodes_block(ret);
+ ir_node *phiM;
+
+ list = get_irn_link(ret);
+ --n_rets;
+
+ n = get_Block_n_cfgpreds(block);
+ for (i = 0; i < n; ++i) {
+ ir_node *jmp = get_Block_cfgpred(block, i);
+ ir_node *new_bl, *new_ret;
+
+ if (get_irn_op(jmp) != op_Jmp)
+ continue;
+
+ new_bl = get_nodes_block(jmp);
+
+ /* create the in-array for the new Ret */
+ for (j = 0; j < n_ret_vals; ++j) {
+ ir_node *pred = get_irn_n(ret, j);
+
+ in[j] = (is_Phi(pred) && get_nodes_block(pred) == block) ? get_Phi_pred(pred, i) : pred;
+ }
+
+ new_ret = new_r_Return(irg, new_bl, in[0], n_ret_vals - 1, &in[1]);
+
+ if (! is_Bad(new_ret)) {
+ /*
+ * The newly created node might be bad, if we
+ * create it in a block with only Bad predecessors.
+ * In that case ignore this block.
+ *
+ * We could even kill the jmp then ...
+ */
+ if (can_move_ret(new_ret)) {
+ set_irn_link(new_ret, list);
+ list = new_ret;
+ ++n_rets;
+ }
+ else {
+ set_irn_link(new_ret, final);
+ final = new_ret;
+ ++n_finals;
+ }
+ }
+
+ /* remove the Jmp, we have placed a Return here */
+ exchange(jmp, new_r_Bad(irg));
+ }
+
+ /*
+ * if the memory of the old Return is a PhiM, remove it
+ * from the keep-alives, or it will keep the block which
+ * will crash the dominator algorithm.
+ */
+ phiM = get_Return_mem(ret);
+ if (is_Phi(phiM)) {
+ n = get_End_n_keepalives(end);
+ for (i = 0; i < n; ++i) {
+ if (get_End_keepalive(end, i) == phiM) {
+ set_End_keepalive(end, i, new_r_Bad(irg));
+ break;
+ }
+ }
+ }
+ }
+
+ /*
+ * Last step: Create a new endblock, with all nodes on the final
+ * list as predecessors.
+ */
+ in = alloca(sizeof(*in) * n_finals);
+
+ for (i = 0; final; ++i, final = get_irn_link(final))
+ in[i] = final;
+
+ exchange(endbl, new_r_Block(irg, n_finals, in));
+
+ /* the end block is not automatically skipped, so do it here */
+ set_irg_end_block(irg, skip_Id(get_irg_end_block(irg)));
+
+ /* Invalidate analysis information:
+ * Blocks become dead and new Returns were deleted, so dominator, outs and loop are inconsistent,
+ * trouts and callee-state should be still valid
+ */
+ set_irg_doms_inconsistent(irg);
+ set_irg_extblk_inconsistent(irg); /* may not be needed */
+ set_irg_outs_inconsistent(irg);
+ set_irg_loopinfo_state(current_ir_graph, loopinfo_cf_inconsistent);
}
projects / libfirm / blobdiff