MAGIC_DEFAULT_PN_NUMBER is gone away ...

[r21565]

diff --git a/ast2firm.c b/ast2firm.c
index e370061..127498d 100644 (file)
--- a/ast2firm.c
+++ b/ast2firm.c
@@ -44,8 +44,6 @@
 #include "driver/firm_opt.h"
 #include "driver/firm_cmdline.h"
 
-#define MAGIC_DEFAULT_PN_NUMBER            (long) -314159265
-
 /* some idents needed for name mangling */
 static ident *id_underscore;
 static ident *id_imp;
@@ -68,6 +66,7 @@ static bool constant_folding;
 static const declaration_t *current_function_decl;
 static ir_node             *current_function_name;
 static ir_node             *current_funcsig;
+static switch_statement_t  *current_switch;
 
 static entitymap_t  entitymap;
 
@@ -4398,7 +4397,7 @@ static ir_node *get_break_label(void)
        return break_label;
 }
 
-static void switch_statement_to_firm(const switch_statement_t *statement)
+static void switch_statement_to_firm(switch_statement_t *statement)
 {
        dbg_info *dbgi = get_dbg_info(&statement->base.source_position);
 
@@ -4413,6 +4412,57 @@ static void switch_statement_to_firm(const switch_statement_t *statement)
        saw_default_label                    = false;
        current_switch_cond                  = cond;
        break_label                          = NULL;
+       switch_statement_t *const old_switch = current_switch;
+       current_switch                       = statement;
+
+       /* determine a free number for the default label */
+       unsigned long num_cases = 0;
+       long def_nr = 0;
+       for (case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
+               if (l->expression == NULL) {
+                       /* default case */
+                       continue;
+               }
+               for (long cns = l->first_case; cns <= l->last_case; ++cns)
+                       ++num_cases;
+               if (l->last_case > def_nr)
+                       def_nr = l->last_case;
+       }
+
+       if (def_nr + 1 < 0) {
+               /* Bad: an overflow occurred, we cannot be sure that the
+        * maximum + 1 is a free number. Scan the values a second
+        * time to find a free number.
+        */
+               unsigned char *bits = xmalloc((num_cases + 7) >> 3);
+               unsigned long i;
+
+               memset(bits, 0, (num_cases + 7) >> 3);
+               for (case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
+                       if (l->expression == NULL) {
+                               /* default case */
+                               continue;
+                       }
+                       for (long cns = l->first_case; cns <= l->last_case; ++cns) {
+                               if (cns >= 0 && (unsigned long)cns < num_cases)
+                                       bits[cns >> 3] |= (1 << (cns & 7));
+                       }
+               }
+               /* We look at the first num_cases constants:
+                * Either they are densed, so we took the last (num_cases)
+                * one, or they are non densed, so we will find one free
+                * there...
+                */
+               for (i = 0; i < num_cases; ++i)
+                       if ((bits[i >> 3] & (i & 7)) == 0)
+                               break;
+
+               free(bits);
+               def_nr = i;
+       } else {
+               ++def_nr;
+       }
+       statement->def_proj_nr = def_nr;
 
        if (statement->body != NULL) {
                statement_to_firm(statement->body);
@@ -4426,7 +4476,7 @@ static void switch_statement_to_firm(const switch_statement_t *statement)
        if (!saw_default_label) {
                set_cur_block(get_nodes_block(cond));
                ir_node *const proj = new_d_defaultProj(dbgi, cond,
-                                                       MAGIC_DEFAULT_PN_NUMBER);
+                                                       statement->def_proj_nr);
                add_immBlock_pred(get_break_label(), proj);
        }
 
@@ -4436,6 +4486,7 @@ static void switch_statement_to_firm(const switch_statement_t *statement)
        set_cur_block(break_label);
 
        assert(current_switch_cond == cond);
+       current_switch      = old_switch;
        current_switch_cond = old_switch_cond;
        break_label         = old_break_label;
        saw_default_label   = old_saw_default_label;
@@ -4450,8 +4501,6 @@ static void case_label_to_firm(const case_label_statement_t *statement)
 
        ir_node *const fallthrough = (get_cur_block() == NULL ? NULL : new_Jmp());
 
-       /* let's create a node and hope firm constant folding creates a Const
-        * node... */
        ir_node *proj;
        ir_node *old_block = get_nodes_block(current_switch_cond);
        ir_node *block     = new_immBlock();
@@ -4463,17 +4512,13 @@ static void case_label_to_firm(const case_label_statement_t *statement)
                assert(start_pn <= end_pn);
                /* create jumps for all cases in the given range */
                for (long pn = start_pn; pn <= end_pn; ++pn) {
-                       if (pn == MAGIC_DEFAULT_PN_NUMBER) {
-                               /* oops someone detected our cheating... */
-                               panic("magic default pn used");
-                       }
                        proj = new_d_Proj(dbgi, current_switch_cond, mode_X, pn);
                        add_immBlock_pred(block, proj);
                }
        } else {
                saw_default_label = true;
                proj = new_d_defaultProj(dbgi, current_switch_cond,
-                                        MAGIC_DEFAULT_PN_NUMBER);
+                                        current_switch->def_proj_nr);
 
                add_immBlock_pred(block, proj);
        }

diff --git a/ast_t.h b/ast_t.h
index 52b6dc8..7127c3f 100644 (file)
--- a/ast_t.h
+++ b/ast_t.h
@@ -646,10 +646,11 @@ struct if_statement_t {
 };
 
 struct switch_statement_t {
-       statement_base_t       base;
+       statement_base_t        base;
        expression_t           *expression;
        statement_t            *body;
        case_label_statement_t *first_case, *last_case;
+       unsigned long           def_proj_nr;  /**< the Proj-number for the default Proj. */
 };
 
 struct goto_statement_t {

diff --git a/parsetest/switch.c b/parsetest/switch.c
index 426e5d5..4402758 100644 (file)
--- a/parsetest/switch.c
+++ b/parsetest/switch.c
@@ -6,6 +6,11 @@ static int switch1(int k) {
                return 5;
        case 13:
                return 7;
+       case 0x7FFFFFFF:
+               return 8;
+       case -1:
+       case -314159265:
+               return 9;
        }
        return 3;
 }