* @version $Id$
*/
-#ifdef HAVE_CONFIG_H
#include "config.h"
-#endif
+#include <limits.h>
+
+#include "array_t.h"
#include "ircons.h"
+#include "irgopt.h"
#include "irgwalk.h"
#include "irnode_t.h"
#include "irouts.h"
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 */
+ unsigned spare_size; /**< the allowed spare size for table switches */
int changed; /**< indicates whether a change was performed */
} walk_env_t;
ir_node *target;
} case_data_t;
-/**
- * Add the new predecessor x to node node, which is either a Block or a Phi
- */
-static void add_pred(ir_node* node, ir_node* x)
-{
- ir_node** ins;
- int n;
- int i;
-
- assert(is_Block(node) || is_Phi(node));
-
- n = get_irn_arity(node);
- NEW_ARR_A(ir_node*, ins, n + 1);
- for (i = 0; i < n; i++)
- ins[i] = get_irn_n(node, i);
- ins[n] = x;
- set_irn_in(node, n + 1, ins);
-}
-
-/**
- * Remove the predecessor x from node node one time, which is either a Block or a Phi
- */
-static void remove_pred(ir_node* node, ir_node* x)
-{
- ir_node** ins;
- int n;
- int i, j;
-
- assert(is_Block(node) || is_Phi(node));
-
- n = get_irn_arity(node);
- NEW_ARR_A(ir_node*, ins, n - 1);
- for (i = 0, j = -1; i < n - 1; i++)
- {
- ins[++j] = get_irn_n(node, i);
- if(ins[i] == x) j--;
- }
- assert(i == j + 1 && "x is not a pred of node");
- set_irn_in(node, n - 1, ins);
-}
+typedef struct ifcas_env {
+ ir_node *sel;
+ int defindex;
+ ir_node **defusers; /**< the Projs pointing to the default case */
+} ifcas_env_t;
/**
* Evaluate a switch and decide whether we should build a table switch.
unsigned long spare, num_cases = 0;
/* TODO: Minimum size for jump table? */
- if(get_irn_n_outs(cond) <= 4)
- return;
+ if (get_irn_n_outs(cond) <= 4)
+ return 0;
default_pn = get_Cond_defaultProj(cond);
foreach_out_irn(cond, i, proj) {
long pn = get_Proj_proj(proj);
- if(pn == default_pn)
+ if (pn == default_pn)
continue;
- if(pn < switch_min)
+ if (pn < switch_min)
switch_min = pn;
- if(pn > switch_max)
+ if (pn > switch_max)
switch_max = pn;
- num_cases++;
+ ++num_cases;
}
/*
static int casecmp(const void *a, const void *b)
{
- return ((case_data_t *) a)->value - ((case_data_t *) b)->value;
+ const case_data_t *cda = a;
+ const case_data_t *cdb = b;
+ return (cda->value > cdb->value) - (cda->value < cdb->value);
}
/**
* Creates an if cascade realizing binary search.
*/
-static void create_if_cascade(ir_node *sel, ir_node *curblock, ir_node *defblock,
- case_data_t *curcases, int numcases)
+static void create_if_cascade(ifcas_env_t *env, ir_node *curblock,
+ case_data_t *curcases, int numcases)
{
+ assert(numcases >= 0);
+
set_cur_block(curblock);
- if(numcases == 1)
- {
+ if (numcases == 0) {
+ /* zero cases: "goto default;" */
+ env->defusers[env->defindex++] = new_Jmp();
+ } else if (numcases == 1) {
/* only one case: "if(sel == val) goto target else goto default;" */
- ir_node *val = new_Const_long(get_irn_mode(sel), curcases[0].value);
- ir_node *cmp = new_Cmp(sel, val);
+ 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);
- add_pred(curcases[0].target, new_Proj(cond, mode_X, pn_Cond_true));
- add_pred(defblock, new_Proj(cond, mode_X, pn_Cond_false));
- return;
- } else if(numcases == 2) {
+ 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(sel), curcases[0].value);
- ir_node *cmp = new_Cmp(sel, val);
+ 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_node *in[1];
ir_node *neblock;
- add_pred(curcases[0].target, new_Proj(cond, mode_X, pn_Cond_true));
+ 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);
+ set_cur_block(neblock);
/* second part: "else if(sel == val[1]) goto target[1] else goto default;" */
- val = new_Const_long(get_irn_mode(sel), curcases[1].value);
- cmp = new_Cmp(sel, val);
+ 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);
- add_pred(curcases[1].target, new_Proj(cond, mode_X, pn_Cond_true));
- add_pred(defblock, new_Proj(cond, mode_X, pn_Cond_false));
- return;
+ 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);
} else {
/* recursive case: split cases in the middle */
int midcase = numcases / 2;
- ir_node *val = new_Const_long(get_irn_mode(sel), curcases[midcase].value);
- ir_node *cmp = new_Cmp(sel, val);
+ 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);
ir_node *in[1];
set_cur_block(curblock);
in[0] = new_Proj(cond, mode_X, pn_Cond_false);
geblock = new_Block(1, in);
+ set_cur_block(geblock);
- create_if_cascade(sel, ltblock, defblock, curcases, midcase);
- create_if_cascade(sel, geblock, defblock, curcases + midcase, numcases - midcase);
+ create_if_cascade(env, ltblock, curcases, midcase);
+ create_if_cascade(env, geblock, curcases + midcase, numcases - midcase);
}
}
case_data_t *cases;
ir_node *condblock;
ir_node *defblock = NULL;
+ ifcas_env_t ifcas_env;
- if(get_Block_n_cfgpreds(block) != 1)
+ 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))
+ if (!is_Cond(cond))
return;
sel = get_Cond_selector(cond);
sel_mode = get_irn_mode(sel);
- if(sel_mode == mode_b) /* not a switch? */
+ if (sel_mode == mode_b) /* not a switch? */
return;
- if(should_do_table_switch(cond, env->spare_size))
+ if (should_do_table_switch(cond, env->spare_size))
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 = 1;
numcases = get_irn_n_outs(cond) - 1; // does not contain default case
- cases = obstack_alloc(&env->obst, numcases * sizeof(*cases));
+ NEW_ARR_A(case_data_t, cases, numcases);
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);
- if(pn == default_pn)
- {
- defblock = get_irn_out(proj, 0);
- remove_pred(defblock, 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 = get_irn_out(proj, 0);
- remove_pred(cases[j].target, proj);
+ cases[j].target = target;
j++;
}
+
assert(defblock != NULL && "Switch without default proj");
qsort(cases, numcases, sizeof(*cases), casecmp);
/* Now create the if cascade */
condblock = get_nodes_block(cond);
- create_if_cascade(sel, condblock, defblock, cases, numcases);
+ create_if_cascade(&ifcas_env, condblock, cases, numcases);
- obstack_free(&env->obst, cases);
+ /* Connect new default case users */
+ set_irn_in(defblock, ifcas_env.defindex, ifcas_env.defusers);
}
/**
* @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 spare_size)
{
walk_env_t env;
ir_graph *rem = current_ir_graph;
current_ir_graph = irg;
- obstack_init(&env.obst);
+ env.changed = 0;
env.spare_size = spare_size;
+ remove_critical_cf_edges(irg);
assure_irg_outs(irg);
irg_block_walk_graph(irg, find_cond_nodes, NULL, &env);
- if(env.changed) {
+ 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;
}