/*
- * Copyright (C) 1995-2011 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 $Id$
*/
#include "config.h"
i >= 0 && (outirn = get_irn_out(irn, i)); --i)
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 allow_out_of_bounds;
bool changed; /**< indicates whether a change was performed */
- ir_nodeset_t processed;
} walk_env_t;
typedef struct case_data_t {
- long value;
- ir_node *target;
+ const ir_switch_table_entry *entry;
+ ir_node *target;
} case_data_t;
-typedef struct cond_env_t {
- ir_node *sel;
- long switch_min;
- long switch_max;
- ir_node *default_block;
- unsigned num_cases;
- ir_node **defusers; /**< the Projs pointing to the default case */
-} cond_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;
-static void analyse_switch(cond_env_t *env, ir_node *cond)
+/**
+ * analyze enough to decide if we should lower the switch
+ */
+static void analyse_switch0(switch_info_t *info, ir_node *switchn)
{
- long default_pn = get_Cond_default_proj(cond);
- long switch_min = LONG_MAX;
- long switch_max = LONG_MIN;
- ir_node *default_block = NULL;
- unsigned num_cases = 0;
- int i;
- ir_node *proj;
-
- foreach_out_irn(cond, i, proj) {
- long pn = get_Proj_proj(proj);
- if (pn == default_pn) {
- ir_node *target = get_irn_out(proj, 0);
- assert(default_block == NULL || default_block == target);
- default_block = target;
+ 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 (pn < switch_min)
- switch_min = pn;
- if (pn > switch_max)
- switch_max = pn;
+ 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;
}
- assert(default_block != NULL);
- env->switch_min = switch_min;
- env->switch_max = switch_max;
- env->num_cases = num_cases;
- env->default_block = default_block;
+ 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)
{
- const case_data_t *cda = (const case_data_t*)a;
- const case_data_t *cdb = (const case_data_t*)b;
-
- /*
- * Enforce unsigned sorting. Signed comparison will behave differently for
- * 32-bit values, depending on sizeof(long). This will make the resulting
- * array deterministic.
- */
- return ((unsigned long)cda->value > (unsigned long)cdb->value) -
- ((unsigned long)cda->value < (unsigned long)cdb->value);
+ 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;
+
+ 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;
}
/**
- * Creates an if cascade realizing binary search.
+ * Analyse the stuff that anayse_switch0() left out
*/
-static void create_if_cascade(cond_env_t *env, dbg_info *dbgi, ir_node *block,
- case_data_t *curcases, unsigned numcases)
+static void analyse_switch1(switch_info_t *info)
{
- ir_graph *irg = get_irn_irg(block);
- ir_mode *cmp_mode;
- ir_node *cmp_sel;
- ir_node *sel_block;
-
- /* Get the mode and sel node for the comparison. */
- cmp_mode = get_irn_mode(env->sel);
- cmp_sel = env->sel;
- sel_block = get_nodes_block(cmp_sel);
-
- /*
- * Make sure that an unsigned comparison is used, by converting the sel
- * node to an unsigned mode and using that mode for the constants, too.
- * This is important, because the qsort applied to the case labels uses
- * an unsigned comparison and both comparison methods have to match.
- */
- if (mode_is_signed(cmp_mode)) {
- cmp_mode = find_unsigned_mode(cmp_mode);
- cmp_sel = new_r_Conv(sel_block, cmp_sel, cmp_mode);
- }
-
- if (numcases == 0) {
- /* zero cases: "goto default;" */
- ARR_APP1(ir_node*, env->defusers, new_r_Jmp(block));
- } else if (numcases == 1) {
- /* only one case: "if (sel == val) goto target else goto default;" */
- ir_node *val = new_r_Const_long(irg, cmp_mode, curcases[0].value);
- ir_node *cmp = new_rd_Cmp(dbgi, block, cmp_sel, val,
- ir_relation_equal);
- ir_node *cond = new_rd_Cond(dbgi, block, cmp);
- ir_node *trueproj = new_r_Proj(cond, mode_X, pn_Cond_true);
- ir_node *falseproj = new_r_Proj(cond, mode_X, pn_Cond_false);
+ 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);
- set_Block_cfgpred(curcases[0].target, 0, trueproj);
- ARR_APP1(ir_node*, env->defusers, falseproj);
- } else if (numcases == 2) {
- /* only two cases: "if (sel == val[0]) goto target[0];" */
- ir_node *val = new_r_Const_long(irg, cmp_mode, curcases[0].value);
- ir_node *cmp = new_rd_Cmp(dbgi, block, cmp_sel, val,
- ir_relation_equal);
- ir_node *cond = new_rd_Cond(dbgi, block, cmp);
- 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;
+ assert((unsigned)pn < n_outs);
+ assert(targets[(unsigned)pn] == NULL);
+ targets[(unsigned)pn] = target;
+ }
- set_Block_cfgpred(curcases[0].target, 0, trueproj);
+ 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;
- in[0] = falseproj;
- neblock = new_r_Block(irg, 1, in);
+ cases[c].entry = entry;
+ cases[c].target = targets[entry->pn];
+ ++c;
+ }
+ assert(c == num_cases);
- /* second part: "else if (sel == val[1]) goto target[1] else goto default;" */
- val = new_r_Const_long(irg, cmp_mode, curcases[1].value);
- cmp = new_rd_Cmp(dbgi, neblock, cmp_sel, val, ir_relation_equal);
- cond = new_rd_Cond(dbgi, neblock, cmp);
- 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*, env->defusers, falseproj);
- } else {
- /* recursive case: split cases in the middle */
- int midcase = numcases / 2;
- ir_node *val = new_r_Const_long(irg, cmp_mode,
- curcases[midcase].value);
- ir_node *cmp = new_rd_Cmp(dbgi, block, cmp_sel, val, ir_relation_less);
- ir_node *cond = new_rd_Cond(dbgi, block, cmp);
- ir_node *in[1];
- ir_node *ltblock;
- ir_node *geblock;
+ /*
+ * Switch should be transformed into an if cascade.
+ * So first order the cases, so we can do a binary search on them.
+ */
+ qsort(cases, num_cases, sizeof(cases[0]), casecmp);
- in[0] = new_r_Proj(cond, mode_X, pn_Cond_true);
- ltblock = new_r_Block(irg, 1, in);
+ info->default_block = targets[pn_Switch_default];
+ info->cases = cases;
+ free(targets);
+}
- in[0] = new_r_Proj(cond, mode_X, pn_Cond_false);
- geblock = new_r_Block(irg, 1, in);
+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;
- create_if_cascade(env, dbgi, ltblock, curcases, midcase);
- create_if_cascade(env, dbgi, geblock, curcases + midcase,
- numcases - midcase);
+ 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(cond_env_t *env, ir_node *cond)
+static void create_out_of_bounds_check(switch_info_t *info)
{
- ir_graph *irg = get_irn_irg(cond);
- dbg_info *dbgi = get_irn_dbg_info(cond);
- ir_node *sel = get_Cond_selector(cond);
- ir_node *block = get_nodes_block(cond);
- ir_mode *cmp_mode = get_irn_mode(sel);
- ir_node **default_preds = NEW_ARR_F(ir_node*, 0);
- long default_pn = get_Cond_default_proj(cond);
- long delta = 0;
- 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;
- size_t n_default_preds;
- int i;
- ir_node *proj;
-
- if (mode_is_signed(cmp_mode)) {
- cmp_mode = find_unsigned_mode(cmp_mode);
- sel = new_r_Conv(block, sel, cmp_mode);
- }
-
- /* normalize so switch_min is at 0 */
- if (env->switch_min != 0) {
- ir_node *min_const = new_r_Const_long(irg, cmp_mode, env->switch_min);
- sel = new_rd_Sub(dbgi, block, sel, min_const, cmp_mode);
-
- delta = env->switch_min;
- env->switch_min = 0;
- env->switch_max -= delta;
- set_Cond_selector(cond, sel);
- }
+ 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_long(irg, cmp_mode, env->switch_max);
- cmp = new_rd_Cmp(dbgi, block, sel, max_const, ir_relation_less_equal);
+ 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 cond */
+ /* create new block containing the switch */
in[0] = proj_true;
new_block = new_r_Block(irg, 1, in);
- set_nodes_block(cond, new_block);
-
- /* adapt projs */
- foreach_out_irn(cond, i, proj) {
- long pn = get_Proj_proj(proj);
- long new_pn = pn - delta;
- if (pn == default_pn) {
- set_Cond_default_proj(cond, new_pn);
+ 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_Proj_proj(proj, new_pn);
set_nodes_block(proj, new_block);
}
/* adapt default block */
n_default_preds = ARR_LEN(default_preds);
if (n_default_preds > 1) {
- size_t p;
-
/* 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;
default_preds[p] = new_r_Jmp(split_block);
}
}
- set_irn_in(env->default_block, n_default_preds, default_preds);
+ set_irn_in(default_block, n_default_preds, default_preds);
DEL_ARR_F(default_preds);
+
+ clear_irg_properties(irg, IR_GRAPH_PROPERTY_CONSISTENT_DOMINANCE);
}
/**
- * Block-Walker: searches for Cond nodes with a non-boolean mode
+ * normalize switch to work on an unsigned input with the first case at 0
*/
-static void find_cond_nodes(ir_node *block, void *ctx)
+static void normalize_switch(switch_info_t *info, ir_mode *selector_mode)
{
- walk_env_t *env = (walk_env_t *)ctx;
- ir_node *projx;
- ir_node *cond;
- ir_node *sel;
- ir_mode *sel_mode;
- long default_pn;
- int i;
- unsigned j = 0;
- unsigned numcases;
- ir_node *proj;
- case_data_t *cases;
- ir_node *condblock;
- ir_node *defblock = NULL;
- dbg_info *dbgi;
- cond_env_t cond_env;
- unsigned long spare;
- bool lower_switch = false;
+ 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(switch_info_t *info, ir_node *block,
+ case_data_t *curcases, unsigned numcases)
+{
+ 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, 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 */
+ 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_r_Proj(cond, mode_X, pn_Cond_true);
+ ltblock = new_r_Block(irg, 1, in);
+
+ in[0] = new_r_Proj(cond, mode_X, pn_Cond_false);
+ geblock = new_r_Block(irg, 1, in);
+
+ create_if_cascade(info, ltblock, curcases, midcase);
+ create_if_cascade(info, geblock, curcases + midcase, numcases - midcase);
+ }
+}
+
+/**
+ * Block-Walker: searches for Switch nodes
+ */
+static void find_switch_nodes(ir_node *block, void *ctx)
+{
+ 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 */
return;
assert(get_irn_mode(projx) == mode_X);
- cond = get_Proj_pred(projx);
- if (!is_Cond(cond))
- return;
-
- sel = get_Cond_selector(cond);
- sel_mode = get_irn_mode(sel);
-
- if (sel_mode == mode_b)
+ switchn = get_Proj_pred(projx);
+ if (!is_Switch(switchn))
return;
- if (ir_nodeset_contains(&env->processed, cond))
+ if (ir_nodeset_contains(&env->processed, switchn))
return;
- ir_nodeset_insert(&env->processed, cond);
-
- /* the algorithms here don't work reliable for modes bigger than 32
- * since we operate with long numbers */
- assert(get_mode_size_bits(sel_mode) <= 32);
+ ir_nodeset_insert(&env->processed, switchn);
- analyse_switch(&cond_env, cond);
+ analyse_switch0(&info, switchn);
/*
* Here we have: num_cases and [switch_min, switch_max] interval.
* We do an if-cascade if there are too many spare numbers.
*/
- spare = (unsigned long) cond_env.switch_max
- - (unsigned long) cond_env.switch_min
- - (unsigned long) cond_env.num_cases + 1;
- lower_switch |= spare >= env->spare_size;
- lower_switch |= cond_env.num_cases <= env->small_switch;
+ 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 might have to add
- * out-of-bounds checking */
- if (!env->allow_out_of_bounds) {
- create_out_of_bounds_check(&cond_env, cond);
- env->changed = true;
- }
+ /* we won't decompose the switch. But we must add an out-of-bounds
+ * check */
+ normalize_switch(&info, env->selector_mode);
return;
}
- /*
- * Switch should be transformed into an if cascade.
- * So first order the cases, so we can do a binary search on them.
- */
- env->changed = true;
-
- numcases = get_irn_n_outs(cond) - 1; /* does not contain default case */
- cases = XMALLOCN(case_data_t, numcases);
-
- default_pn = get_Cond_default_proj(cond);
- cond_env.sel = sel;
- cond_env.defusers = NEW_ARR_F(ir_node*, 0);
-
- 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);
-
- if (pn == default_pn) {
- defblock = target;
- continue;
- }
-
- cases[j].value = pn;
- cases[j].target = target;
- j++;
- }
- assert(j == numcases);
-
- if (defblock == NULL)
- panic("Switch %+F has no default proj", cond);
-
- qsort(cases, numcases, sizeof(cases[0]), casecmp);
+ normalize_switch(&info, NULL);
+ analyse_switch1(&info);
/* Now create the if cascade */
- condblock = get_nodes_block(cond);
- dbgi = get_irn_dbg_info(cond);
- create_if_cascade(&cond_env, dbgi, 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, ARR_LEN(cond_env.defusers), cond_env.defusers);
+ set_irn_in(info.default_block, ARR_LEN(info.defusers), info.defusers);
- xfree(cases);
- DEL_ARR_F(cond_env.defusers);
+ 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);
}
void lower_switch(ir_graph *irg, unsigned small_switch, unsigned spare_size,
- int allow_out_of_bounds)
+ ir_mode *selector_mode)
{
+ if (mode_is_signed(selector_mode))
+ panic("expected unsigned mode for switch selector");
+
walk_env_t env;
- env.changed = false;
+ env.selector_mode = selector_mode;
env.spare_size = spare_size;
env.small_switch = small_switch;
- env.allow_out_of_bounds = allow_out_of_bounds;
+ 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);
+ irg_block_walk_graph(irg, find_switch_nodes, NULL, &env);
ir_nodeset_destroy(&env.processed);
-
- if (env.changed) {
- /* control flow changed */
- set_irg_doms_inconsistent(irg);
- set_irg_extblk_inconsistent(irg);
- }
}
projects / libfirm / blobdiff