- BugFix: gcc optimizes def_nr + 1 < 0 away, arg\!

[r23196]

diff --git a/ast2firm.c b/ast2firm.c
index e9dcfa3..f9d4f97 100644 (file)
--- a/ast2firm.c
+++ b/ast2firm.c
@@ -22,6 +22,7 @@
 #include <assert.h>
 #include <string.h>
 #include <stdbool.h>
+#include <limits.h>
 
 #include <libfirm/firm.h>
 #include <libfirm/adt/obst.h>
@@ -4581,13 +4582,12 @@ static void switch_statement_to_firm(switch_statement_t *statement)
                        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.
-        */
+       if (def_nr == INT_MAX) {
+               /* Bad: an overflow will occurr, 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) {
@@ -4595,11 +4595,11 @@ static void switch_statement_to_firm(switch_statement_t *statement)
                                /* default case */
                                continue;
                        }
-                       if (l->first_case < num_cases && l->last_case >= 0) {
-                               long start = l->first_case > 0 ? l->first_case : 0;
-                               long end   = (unsigned long)l->last_case < num_cases ?
-                                       l->last_case : num_cases - 1;
-                               for (long cns = start; cns <= end; ++cns) {
+                       unsigned long start = l->first_case > 0 ? (unsigned long)l->first_case : 0;
+                       if (start < num_cases && l->last_case >= 0) {
+                               unsigned long end  = (unsigned long)l->last_case < num_cases ?
+                                       (unsigned long)l->last_case : num_cases - 1;
+                               for (unsigned long cns = start; cns <= end; ++cns) {
                                        bits[cns >> 3] |= (1 << (cns & 7));
                                }
                        }
@@ -4609,6 +4609,7 @@ static void switch_statement_to_firm(switch_statement_t *statement)
                 * one, or they are non densed, so we will find one free
                 * there...
                 */
+               unsigned long i;
                for (i = 0; i < num_cases; ++i)
                        if ((bits[i >> 3] & (1 << (i & 7))) == 0)
                                break;