re PR tree-optimization/18298 (bad code from lim ssa pass with strcmp)

2004-11-30  Andrew Pinski  <pinskia@physics.uc.edu>

        PR tree-opt/18298
        * tree-optimize.c (init_tree_optimization_passes): Add a may_alias
        pass right after fold builtins.
2004-11-30  Andrew Pinski  <pinskia@physics.uc.edu>

        PR tree-opt/18298
        * gcc.c-torture/execute/p18298.c: New test.

From-SVN: r91529

gcc/ChangeLog

+2004-11-30  Andrew Pinski  <pinskia@physics.uc.edu>
+
+	PR tree-opt/18298
+	* tree-optimize.c (init_tree_optimization_passes): Add a may_alias
+	pass right after fold builtins.
+
 2004-11-30  Andreas Krebbel  <krebbel1@de.ibm.com>
 	
 	* config/s390/s390-modes.def: Added cc modes documentation.

gcc/testsuite/ChangeLog

+2004-11-30  Andrew Pinski  <pinskia@physics.uc.edu>
+
+	PR tree-opt/18298
+	* gcc.c-torture/execute/p18298.c: New test.
+
 2004-11-30  Ira Rosen  <irar@il.ibm.com>
 	    Dorit Naishlos  <dorit@il.ibm.com>
 

gcc/testsuite/gcc.c-torture/execute/p18298.c

+#include <stdbool.h>
+#include <stdlib.h>
+int strcmp (const char*, const char*);
+char s[2048] = "a";
+inline bool foo(const char *str) {
+  return !strcmp(s,str);
+}
+int main() {
+int i = 0;
+  while(!(foo(""))) {
+    i ++;
+    s[0] = '\0';
+    if (i>2)
+     abort ();
+  }
+  return 0;
+}
+

gcc/tree-optimize.c

@@ -372,6 +372,10 @@ init_tree_optimization_passes (void)
   NEXT_PASS (pass_ccp);
   NEXT_PASS (pass_redundant_phi);
   NEXT_PASS (pass_fold_builtins);
+  /* FIXME: May alias should a TODO but for 4.0.0,
+     we add may_alias right after fold builtins
+     which can create arbitrary GIMPLE.  */
+  NEXT_PASS (pass_may_alias);
   NEXT_PASS (pass_split_crit_edges);
   NEXT_PASS (pass_pre);
   NEXT_PASS (pass_loop);