/*
- * 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.
+ * Copyright (C) 2012 University of Karlsruhe.
*/
/**
* @file
* @brief Lowering of Switches if necessary or advantageous.
* @author Moritz Kroll
- * @version $Id$
*/
-
-#ifdef HAVE_CONFIG_H
#include "config.h"
-#endif
#include <limits.h>
+#include <stdbool.h>
+#include "array_t.h"
#include "ircons.h"
#include "irgopt.h"
#include "irgwalk.h"
#include "irnode_t.h"
#include "irouts.h"
+#include "irpass_t.h"
+#include "lowering.h"
+#include "error.h"
+#include "irnodeset.h"
-#define foreach_out_irn(irn, i, outirn) for(i = get_irn_n_outs(irn) - 1;\
+#define foreach_out_irn(irn, i, outirn) for (i = get_irn_n_outs(irn) - 1;\
i >= 0 && (outirn = get_irn_out(irn, i)); --i)
-typedef struct walk_env {
- unsigned spare_size; /**< the allowed spare size for table switches */
- struct obstack obst; /**< the obstack where data is allocated on */
- int changed; /**< indicates whether a change was performed */
+typedef struct walk_env_t {
+ ir_nodeset_t processed;
+ ir_mode *selector_mode;
+ unsigned spare_size; /**< the allowed spare size for table switches */
+ unsigned small_switch;
+ bool changed; /**< indicates whether a change was performed */
} walk_env_t;
-typedef struct case_data {
- long value;
- ir_node *target;
+typedef struct case_data_t {
+ const ir_switch_table_entry *entry;
+ ir_node *target;
} case_data_t;
-typedef struct ifcas_env {
- ir_node *sel;
- int defindex;
- ir_node **defusers; /**< the Projs pointing to the default case */
-} ifcas_env_t;
+typedef struct switch_info_t {
+ ir_node *switchn;
+ ir_tarval *switch_min;
+ ir_tarval *switch_max;
+ ir_node *default_block;
+ unsigned num_cases;
+ case_data_t *cases;
+ ir_node **defusers; /**< the Projs pointing to the default case */
+} switch_info_t;
/**
- * Evaluate a switch and decide whether we should build a table switch.
- *
- * @param cond The Cond node representing the switch.
- * @param spare_size Allowed spare size for table switches in machine words.
- * (Default in edgfe: 128)
+ * analyze enough to decide if we should lower the switch
*/
-static int should_do_table_switch(ir_node *cond, unsigned spare_size)
+static void analyse_switch0(switch_info_t *info, ir_node *switchn)
+{
+ const ir_switch_table *table = get_Switch_table(switchn);
+ size_t n_entries = ir_switch_table_get_n_entries(table);
+ ir_mode *mode = get_irn_mode(get_Switch_selector(switchn));
+ ir_tarval *switch_min = get_mode_max(mode);
+ ir_tarval *switch_max = get_mode_min(mode);
+ unsigned num_cases = 0;
+
+ for (size_t e = 0; e < n_entries; ++e) {
+ const ir_switch_table_entry *entry
+ = ir_switch_table_get_entry_const(table, e);
+ if (entry->pn == 0)
+ continue;
+
+ if (tarval_cmp(entry->min, switch_min) == ir_relation_less)
+ switch_min = entry->min;
+ if (tarval_cmp(entry->max, switch_max) == ir_relation_greater)
+ switch_max = entry->max;
+
+ ++num_cases;
+ }
+
+ info->switchn = switchn;
+ info->switch_min = switch_min;
+ info->switch_max = switch_max;
+ info->num_cases = num_cases;
+}
+
+static int casecmp(const void *a, const void *b)
{
- long default_pn;
- int i;
- ir_node *proj;
- long switch_min = LONG_MAX, switch_max = LONG_MIN;
- unsigned long spare, num_cases = 0;
-
- /* TODO: Minimum size for jump table? */
- if(get_irn_n_outs(cond) <= 4)
+ const case_data_t *cda = (const case_data_t*)a;
+ const case_data_t *cdb = (const case_data_t*)b;
+ const ir_switch_table_entry *ea = cda->entry;
+ const ir_switch_table_entry *eb = cdb->entry;
+
+ if (ea == eb)
return 0;
- default_pn = get_Cond_defaultProj(cond);
+ if (tarval_cmp(ea->max, eb->min) == ir_relation_less)
+ return -1;
+ /* cases must be non overlapping, so the only remaining case is greater */
+ assert(tarval_cmp(ea->min, eb->max) == ir_relation_greater);
+ return 1;
+}
- foreach_out_irn(cond, i, proj) {
- long pn = get_Proj_proj(proj);
- if(pn == default_pn)
+/**
+ * Analyse the stuff that anayse_switch0() left out
+ */
+static void analyse_switch1(switch_info_t *info)
+{
+ const ir_node *switchn = info->switchn;
+ const ir_switch_table *table = get_Switch_table(switchn);
+ size_t n_entries = ir_switch_table_get_n_entries(table);
+ unsigned n_outs = get_Switch_n_outs(switchn);
+ ir_node **targets = XMALLOCNZ(ir_node*, n_outs);
+ unsigned num_cases = info->num_cases;
+ case_data_t *cases = XMALLOCN(case_data_t, num_cases);
+ unsigned c = 0;
+ size_t e;
+ int i;
+ ir_node *proj;
+
+ foreach_out_irn(switchn, i, proj) {
+ long pn = get_Proj_proj(proj);
+ ir_node *target = get_irn_out(proj, 0);
+
+ assert((unsigned)pn < n_outs);
+ assert(targets[(unsigned)pn] == NULL);
+ targets[(unsigned)pn] = target;
+ }
+
+ for (e = 0; e < n_entries; ++e) {
+ const ir_switch_table_entry *entry
+ = ir_switch_table_get_entry_const(table, e);
+ if (entry->pn == 0)
continue;
- if(pn < switch_min)
- switch_min = pn;
- if(pn > switch_max)
- switch_max = pn;
- num_cases++;
+ cases[c].entry = entry;
+ cases[c].target = targets[entry->pn];
+ ++c;
}
+ assert(c == num_cases);
/*
- * Here we have: num_cases and [switch_min, switch_max] interval.
- * We do an if-cascade if there are too many spare numbers.
+ * Switch should be transformed into an if cascade.
+ * So first order the cases, so we can do a binary search on them.
*/
- spare = (unsigned long) switch_max - (unsigned long) switch_min - num_cases + 1;
- return spare < spare_size;
+ qsort(cases, num_cases, sizeof(cases[0]), casecmp);
+
+ info->default_block = targets[pn_Switch_default];
+ info->cases = cases;
+ free(targets);
}
-static int casecmp(const void *a, const void *b)
+static void normalize_table(ir_node *switchn, ir_mode *new_mode,
+ ir_tarval *delta)
+{
+ ir_switch_table *table = get_Switch_table(switchn);
+ size_t n_entries = ir_switch_table_get_n_entries(table);
+ size_t e;
+ /* adapt switch_table */
+ for (e = 0; e < n_entries; ++e) {
+ ir_switch_table_entry *entry = ir_switch_table_get_entry(table, e);
+ ir_tarval *min = entry->min;
+
+ if (entry->pn == 0)
+ continue;
+
+ min = tarval_convert_to(min, new_mode);
+ if (delta != NULL)
+ min = tarval_sub(min, delta, NULL);
+
+ if (entry->min == entry->max) {
+ entry->min = min;
+ entry->max = min;
+ } else {
+ ir_tarval *max = entry->max;
+ max = tarval_convert_to(max, new_mode);
+ if (delta != NULL)
+ max = tarval_sub(max, delta, NULL);
+ entry->min = min;
+ entry->max = max;
+ }
+ }
+}
+
+static void create_out_of_bounds_check(switch_info_t *info)
{
- return ((case_data_t *) a)->value - ((case_data_t *) b)->value;
+ ir_node *switchn = info->switchn;
+ ir_graph *irg = get_irn_irg(switchn);
+ dbg_info *dbgi = get_irn_dbg_info(switchn);
+ ir_node *selector = get_Switch_selector(switchn);
+ ir_node *block = get_nodes_block(switchn);
+ ir_node **default_preds = NEW_ARR_F(ir_node*, 0);
+ ir_node *default_block = NULL;
+ ir_node *max_const;
+ ir_node *proj_true;
+ ir_node *proj_false;
+ ir_node *cmp;
+ ir_node *oob_cond;
+ ir_node *in[1];
+ ir_node *new_block;
+ int i;
+ ir_node *proj;
+ size_t n_default_preds;
+
+ assert(tarval_is_null(info->switch_min));
+
+ /* check for out-of-bounds */
+ max_const = new_r_Const(irg, info->switch_max);
+ cmp = new_rd_Cmp(dbgi, block, selector, max_const, ir_relation_less_equal);
+ oob_cond = new_rd_Cond(dbgi, block, cmp);
+ proj_true = new_r_Proj(oob_cond, mode_X, pn_Cond_true);
+ proj_false = new_r_Proj(oob_cond, mode_X, pn_Cond_false);
+
+ ARR_APP1(ir_node*, default_preds, proj_false);
+
+ /* create new block containing the switch */
+ in[0] = proj_true;
+ new_block = new_r_Block(irg, 1, in);
+ set_nodes_block(switchn, new_block);
+
+ /* adjust projs */
+ foreach_out_irn(switchn, i, proj) {
+ long pn = get_Proj_proj(proj);
+ if (pn == pn_Switch_default) {
+ assert(default_block == NULL);
+ default_block = get_irn_out(proj, 0);
+ ARR_APP1(ir_node*, default_preds, proj);
+ }
+ set_nodes_block(proj, new_block);
+ }
+
+ /* adapt default block */
+ n_default_preds = ARR_LEN(default_preds);
+ if (n_default_preds > 1) {
+ /* create new intermediate blocks so we don't have critical edges */
+ size_t p;
+ for (p = 0; p < n_default_preds; ++p) {
+ ir_node *pred = default_preds[p];
+ ir_node *split_block;
+ ir_node *block_in[1];
+
+ block_in[0] = pred;
+ split_block = new_r_Block(irg, 1, block_in);
+
+ default_preds[p] = new_r_Jmp(split_block);
+ }
+ }
+ set_irn_in(default_block, n_default_preds, default_preds);
+
+ DEL_ARR_F(default_preds);
+
+ clear_irg_properties(irg, IR_GRAPH_PROPERTY_CONSISTENT_DOMINANCE);
+}
+
+/**
+ * normalize switch to work on an unsigned input with the first case at 0
+ */
+static void normalize_switch(switch_info_t *info, ir_mode *selector_mode)
+{
+ ir_node *switchn = info->switchn;
+ ir_graph *irg = get_irn_irg(switchn);
+ ir_node *block = get_nodes_block(switchn);
+ ir_node *selector = get_Switch_selector(switchn);
+ ir_mode *mode = get_irn_mode(selector);
+ ir_tarval *delta = NULL;
+ bool needs_normalize = false;
+
+ ir_tarval *min = info->switch_min;
+ if (mode_is_signed(mode)) {
+ mode = find_unsigned_mode(mode);
+ selector = new_r_Conv(block, selector, mode);
+ min = tarval_convert_to(min, mode);
+ info->switch_min = min;
+ info->switch_max = tarval_convert_to(info->switch_max, mode);
+ needs_normalize = true;
+ }
+
+ /* normalize so switch_min is at 0 */
+ if (min != get_mode_null(mode)) {
+ ir_node *min_const = new_r_Const(irg, min);
+ dbg_info *dbgi = get_irn_dbg_info(switchn);
+ selector = new_rd_Sub(dbgi, block, selector, min_const, mode);
+
+ info->switch_max = tarval_sub(info->switch_max, min, mode);
+ info->switch_min = get_mode_null(mode);
+ delta = min;
+
+ needs_normalize = true;
+ }
+
+ /* if we have a selector_mode set, then the we will have a switch node,
+ * we have to construct an out-of-bounds check then and after that convert
+ * the switch/selector to the backends desired switch mode */
+ if (selector_mode != NULL) {
+ set_Switch_selector(switchn, selector);
+ create_out_of_bounds_check(info);
+
+ selector = new_r_Conv(block, selector, selector_mode);
+ mode = selector_mode;
+ info->switch_min = tarval_convert_to(info->switch_min, mode);
+ info->switch_max = tarval_convert_to(info->switch_max, mode);
+ if (delta != NULL)
+ delta = tarval_convert_to(delta, mode);
+ needs_normalize = true;
+ }
+
+ if (needs_normalize) {
+ set_Switch_selector(switchn, selector);
+ normalize_table(switchn, mode, delta);
+ }
+}
+
+/**
+ * Create an if (selector == caseval) Cond node (and handle the special case
+ * of ranged cases)
+ */
+static ir_node *create_case_cond(const ir_switch_table_entry *entry,
+ dbg_info *dbgi, ir_node *block,
+ ir_node *selector)
+{
+ ir_graph *irg = get_irn_irg(block);
+ ir_node *minconst = new_r_Const(irg, entry->min);
+ ir_node *cmp;
+
+ if (entry->min == entry->max) {
+ cmp = new_rd_Cmp(dbgi, block, selector, minconst, ir_relation_equal);
+ } else {
+ ir_tarval *adjusted_max = tarval_sub(entry->max, entry->min, NULL);
+ ir_node *sub = new_rd_Sub(dbgi, block, selector, minconst,
+ get_tarval_mode(adjusted_max));
+ ir_node *maxconst = new_r_Const(irg, adjusted_max);
+ cmp = new_rd_Cmp(dbgi, block, sub, maxconst, ir_relation_less_equal);
+ }
+
+ return new_rd_Cond(dbgi, block, cmp);
}
/**
* Creates an if cascade realizing binary search.
*/
-static void create_if_cascade(ifcas_env_t *env, ir_node *curblock,
- case_data_t *curcases, int numcases)
+static void create_if_cascade(switch_info_t *info, ir_node *block,
+ case_data_t *curcases, unsigned numcases)
{
- set_cur_block(curblock);
-
- if(numcases == 1)
- {
- /* only one case: "if(sel == val) goto target else goto default;" */
- ir_node *val = new_Const_long(get_irn_mode(env->sel), curcases[0].value);
- ir_node *cmp = new_Cmp(env->sel, val);
- ir_node *proj = new_Proj(cmp, mode_b, pn_Cmp_Eq);
- ir_node *cond = new_Cond(proj);
- set_Block_cfgpred(curcases[0].target, 0, new_Proj(cond, mode_X, pn_Cond_true));
- env->defusers[env->defindex++] = new_Proj(cond, mode_X, pn_Cond_false);
- } else if(numcases == 2) {
- /* only two cases: "if(sel == val[0]) goto target[0];" */
- ir_node *val = new_Const_long(get_irn_mode(env->sel), curcases[0].value);
- ir_node *cmp = new_Cmp(env->sel, val);
- ir_node *proj = new_Proj(cmp, mode_b, pn_Cmp_Eq);
- ir_node *cond = new_Cond(proj);
+ ir_graph *irg = get_irn_irg(block);
+ const ir_node *switchn = info->switchn;
+ dbg_info *dbgi = get_irn_dbg_info(switchn);
+ ir_node *selector = get_Switch_selector(switchn);
+
+ if (numcases == 0) {
+ /* zero cases: "goto default;" */
+ ARR_APP1(ir_node*, info->defusers, new_r_Jmp(block));
+ } else if (numcases == 1) {
+ /*only one case: "if (sel == val) goto target else goto default;"*/
+ const ir_switch_table_entry *entry = curcases[0].entry;
+ ir_node *cond = create_case_cond(entry, dbgi, block, selector);
+ ir_node *trueproj = new_r_Proj(cond, mode_X, pn_Cond_true);
+ ir_node *falseproj = new_r_Proj(cond, mode_X, pn_Cond_false);
+
+ set_Block_cfgpred(curcases[0].target, 0, trueproj);
+ ARR_APP1(ir_node*, info->defusers, falseproj);
+ } else if (numcases == 2) {
+ /* only two cases: "if (sel == val[0]) goto target[0];" */
+ const ir_switch_table_entry *entry0 = curcases[0].entry;
+ const ir_switch_table_entry *entry1 = curcases[1].entry;
+ ir_node *cond = create_case_cond(entry0, dbgi, block, selector);
+ ir_node *trueproj = new_r_Proj(cond, mode_X, pn_Cond_true);
+ ir_node *falseproj = new_r_Proj(cond, mode_X, pn_Cond_false);
ir_node *in[1];
ir_node *neblock;
- set_Block_cfgpred(curcases[0].target, 0, new_Proj(cond, mode_X, pn_Cond_true));
- in[0] = new_Proj(cond, mode_X, pn_Cond_false);
- neblock = new_Block(1, in);
-
- /* second part: "else if(sel == val[1]) goto target[1] else goto default;" */
- val = new_Const_long(get_irn_mode(env->sel), curcases[1].value);
- cmp = new_Cmp(env->sel, val);
- proj = new_Proj(cmp, mode_b, pn_Cmp_Eq);
- cond = new_Cond(proj);
- set_Block_cfgpred(curcases[1].target, 0, new_Proj(cond, mode_X, pn_Cond_true));
- env->defusers[env->defindex++] = new_Proj(cond, mode_X, pn_Cond_false);
+ set_Block_cfgpred(curcases[0].target, 0, trueproj);
+
+ in[0] = falseproj;
+ neblock = new_r_Block(irg, 1, in);
+
+ /* second part: "else if (sel == val[1]) goto target[1] else goto default;" */
+ cond = create_case_cond(entry1, dbgi, neblock, selector);
+ trueproj = new_r_Proj(cond, mode_X, pn_Cond_true);
+ falseproj = new_r_Proj(cond, mode_X, pn_Cond_false);
+ set_Block_cfgpred(curcases[1].target, 0, trueproj);
+ ARR_APP1(ir_node*, info->defusers, falseproj);
} else {
/* recursive case: split cases in the middle */
- int midcase = numcases / 2;
- ir_node *val = new_Const_long(get_irn_mode(env->sel), curcases[midcase].value);
- ir_node *cmp = new_Cmp(env->sel, val);
- ir_node *proj = new_Proj(cmp, mode_b, pn_Cmp_Lt);
- ir_node *cond = new_Cond(proj);
+ unsigned midcase = numcases / 2;
+ const ir_switch_table_entry *entry = curcases[midcase].entry;
+ ir_node *val = new_r_Const(irg, entry->min);
+ ir_node *cmp = new_rd_Cmp(dbgi, block, selector, val, ir_relation_less);
+ ir_node *cond = new_rd_Cond(dbgi, block, cmp);
ir_node *in[1];
ir_node *ltblock;
ir_node *geblock;
- in[0] = new_Proj(cond, mode_X, pn_Cond_true);
- ltblock = new_Block(1, in);
+ in[0] = new_r_Proj(cond, mode_X, pn_Cond_true);
+ ltblock = new_r_Block(irg, 1, in);
- set_cur_block(curblock);
- in[0] = new_Proj(cond, mode_X, pn_Cond_false);
- geblock = new_Block(1, in);
+ in[0] = new_r_Proj(cond, mode_X, pn_Cond_false);
+ geblock = new_r_Block(irg, 1, in);
- create_if_cascade(env, ltblock, curcases, midcase);
- create_if_cascade(env, geblock, curcases + midcase, numcases - midcase);
+ create_if_cascade(info, ltblock, curcases, midcase);
+ create_if_cascade(info, geblock, curcases + midcase, numcases - midcase);
}
}
/**
- * Block-Walker: searches for Cond nodes with a non-boolean mode
+ * Block-Walker: searches for Switch nodes
*/
-static void find_cond_nodes(ir_node *block, void *ctx)
+static void find_switch_nodes(ir_node *block, void *ctx)
{
- walk_env_t *env = ctx;
- ir_node *projx;
- ir_node *cond;
- ir_node *sel;
- ir_mode *sel_mode;
- long default_pn;
- int i, j = 0, numcases;
- ir_node *proj;
- case_data_t *cases;
- ir_node *condblock;
- ir_node *defblock = NULL;
- ifcas_env_t ifcas_env;
-
- if(get_Block_n_cfgpreds(block) != 1)
+ walk_env_t *env = (walk_env_t *)ctx;
+ ir_node *projx;
+ ir_node *switchn;
+ switch_info_t info;
+
+ /* because we split critical blocks only blocks with 1 predecessors may
+ * contain Proj->Cond nodes */
+ if (get_Block_n_cfgpreds(block) != 1)
return;
projx = get_Block_cfgpred(block, 0);
- if(!is_Proj(projx))
+ if (!is_Proj(projx))
return;
assert(get_irn_mode(projx) == mode_X);
- cond = get_Proj_pred(projx);
- if(!is_Cond(cond))
+ switchn = get_Proj_pred(projx);
+ if (!is_Switch(switchn))
return;
- sel = get_Cond_selector(cond);
- sel_mode = get_irn_mode(sel);
-
- if(sel_mode == mode_b) /* not a switch? */
+ if (ir_nodeset_contains(&env->processed, switchn))
return;
+ ir_nodeset_insert(&env->processed, switchn);
- if(should_do_table_switch(cond, env->spare_size))
- return;
+ analyse_switch0(&info, switchn);
/*
- * Switch should be transformed into an if cascade.
- * So first order the cases, so we can do a binary search on them.
+ * Here we have: num_cases and [switch_min, switch_max] interval.
+ * We do an if-cascade if there are too many spare numbers.
*/
-
- numcases = get_irn_n_outs(cond) - 1; // does not contain default case
- cases = obstack_alloc(&env->obst, numcases * sizeof(*cases));
-
- default_pn = get_Cond_defaultProj(cond);
- ifcas_env.sel = sel;
- ifcas_env.defindex = 0;
- NEW_ARR_A(ir_node*, ifcas_env.defusers, numcases);
-
- foreach_out_irn(cond, i, proj) {
- long pn = get_Proj_proj(proj);
- ir_node *target = get_irn_out(proj, 0);
- assert(get_Block_n_cfgpreds(target) == 1 && "Encountered critical edge in switch");
-
- if(pn == default_pn)
- {
- defblock = target;
- continue;
- }
-
- cases[j].value = pn;
- cases[j].target = target;
- j++;
+ ir_mode *mode = get_irn_mode(get_Switch_selector(switchn));
+ ir_tarval *spare = tarval_sub(info.switch_max, info.switch_min, mode);
+ mode = find_unsigned_mode(mode);
+ spare = tarval_convert_to(spare, mode);
+ ir_tarval *num_cases_minus_one
+ = new_tarval_from_long(info.num_cases-1, mode);
+ spare = tarval_sub(spare, num_cases_minus_one, mode);
+ ir_tarval *spare_size = new_tarval_from_long(env->spare_size, mode);
+ bool lower_switch = (info.num_cases <= env->small_switch
+ || (tarval_cmp(spare, spare_size) & ir_relation_greater_equal));
+
+ if (!lower_switch) {
+ /* we won't decompose the switch. But we must add an out-of-bounds
+ * check */
+ normalize_switch(&info, env->selector_mode);
+ return;
}
- assert(defblock != NULL && "Switch without default proj");
- qsort(cases, numcases, sizeof(*cases), casecmp);
+ normalize_switch(&info, NULL);
+ analyse_switch1(&info);
/* Now create the if cascade */
- condblock = get_nodes_block(cond);
- create_if_cascade(&ifcas_env, condblock, cases, numcases);
+ env->changed = true;
+ info.defusers = NEW_ARR_F(ir_node*, 0);
+ block = get_nodes_block(switchn);
+ create_if_cascade(&info, block, info.cases, info.num_cases);
/* Connect new default case users */
- set_irn_in(defblock, ifcas_env.defindex, ifcas_env.defusers);
+ set_irn_in(info.default_block, ARR_LEN(info.defusers), info.defusers);
- obstack_free(&env->obst, cases);
+ DEL_ARR_F(info.defusers);
+ xfree(info.cases);
+ clear_irg_properties(get_irn_irg(block), IR_GRAPH_PROPERTY_NO_CRITICAL_EDGES
+ | IR_GRAPH_PROPERTY_CONSISTENT_DOMINANCE);
}
-/**
- * Lowers all Switches (Cond nodes with non-boolean mode) depending on spare_size.
- * They will either remain the same or be converted into if-cascades.
- *
- * @param irg The ir graph to be lowered.
- * @param spare_size Allowed spare size for table switches in machine words.
- * (Default in edgfe: 128)
- */
-void lower_switch(ir_graph *irg, unsigned spare_size)
+void lower_switch(ir_graph *irg, unsigned small_switch, unsigned spare_size,
+ ir_mode *selector_mode)
{
- walk_env_t env;
- ir_graph *rem = current_ir_graph;
+ if (mode_is_signed(selector_mode))
+ panic("expected unsigned mode for switch selector");
- current_ir_graph = irg;
-
- obstack_init(&env.obst);
- env.spare_size = spare_size;
+ walk_env_t env;
+ env.selector_mode = selector_mode;
+ env.spare_size = spare_size;
+ env.small_switch = small_switch;
+ env.changed = false;
+ ir_nodeset_init(&env.processed);
remove_critical_cf_edges(irg);
assure_irg_outs(irg);
- irg_block_walk_graph(irg, find_cond_nodes, NULL, &env);
-
- if(env.changed) {
- /* control flow changed */
- set_irg_outs_inconsistent(irg);
- set_irg_doms_inconsistent(irg);
- set_irg_extblk_inconsistent(irg);
- set_irg_loopinfo_inconsistent(irg);
- }
-
- obstack_free(&env.obst, NULL);
- current_ir_graph = rem;
+ irg_block_walk_graph(irg, find_switch_nodes, NULL, &env);
+ ir_nodeset_destroy(&env.processed);
}
projects / libfirm / blobdiff