re PR tree-optimization/24716 (Wrong code generated when optimising)

2005-11-09  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/24716
	* tree-scalar-evolution.c (analyze_evolution_in_loop): Use
	t_bool to track results from follow_ssa_edge.

	* gcc.c-torture/execute/pr24716.c: New testcase.

From-SVN: r106700

gcc/ChangeLog

+2005-11-09  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/24716
+	* tree-scalar-evolution.c (analyze_evolution_in_loop): Use
+	t_bool to track results from follow_ssa_edge.
+
 2005-11-09  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* final.c (force_source_line): New global variable.

gcc/testsuite/ChangeLog

+2005-11-09  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/24716
+	* gcc.c-torture/execute/pr24716.c: New testcase.
+
 2005-11-09  Andreas Krebbel  <krebbel1@de.ibm.com>
 
 	* gcc.dg/pr24624.c: Disable for non S/390 targets.

gcc/testsuite/gcc.c-torture/execute/pr24716.c

+/* PR24716, scalar evolution returning the wrong result
+   for pdest.  */
+
+int Link[] = { -1 };
+int W[] = { 2 };
+
+extern void abort (void);
+
+int f (int k, int p)
+{
+  int pdest, j, D1361;
+  j = 0;
+  pdest = 0;
+  for (;;) {
+    if (pdest > 2)
+      do
+        j--, pdest++;
+      while (j > 2);
+
+    if (j == 1)
+      break;
+
+    while (pdest > p)
+      if (j == p)
+        pdest++;
+
+    do
+      {
+        D1361 = W[k];
+        do
+          if (D1361 != 0)
+            pdest = 1, W[k] = D1361 = 0;
+        while (p < 1);
+    } while (k > 0);
+
+    do
+      {
+        p = 0;
+        k = Link[k];
+        while (p < j)
+          if (k != -1)
+            pdest++, p++;
+      }
+    while (k != -1);
+    j = 1;
+  }
+
+  /* The correct return value should be pdest (1 in the call from main).
+     DOM3 is mistaken and propagates a 0 here.  */
+  return pdest;
+}
+
+int main ()
+{
+  if (!f (0, 2))
+    abort ();
+  return 0;
+}
+

gcc/tree-scalar-evolution.c

@@ -1503,7 +1503,7 @@ analyze_evolution_in_loop (tree loop_phi_node,
     {
       tree arg = PHI_ARG_DEF (loop_phi_node, i);
       tree ssa_chain, ev_fn;
-      bool res;
+      t_bool res;
 
       /* Select the edges that enter the loop body.  */
       bb = PHI_ARG_EDGE (loop_phi_node, i)->src;
@@ -1519,7 +1519,7 @@ analyze_evolution_in_loop (tree loop_phi_node,
 	  res = follow_ssa_edge (loop, ssa_chain, loop_phi_node, &ev_fn, 0);
 	}
       else
-	res = false;
+	res = t_false;
 	      
       /* When it is impossible to go back on the same
 	 loop_phi_node by following the ssa edges, the
@@ -1527,7 +1527,7 @@ analyze_evolution_in_loop (tree loop_phi_node,
 	 first iteration, EV_FN has the value INIT_COND, then
 	 all the other iterations it has the value of ARG.  
 	 For the moment, PEELED_CHREC nodes are not built.  */
-      if (!res)
+      if (res != t_true)
 	ev_fn = chrec_dont_know;
       
       /* When there are multiple back edges of the loop (which in fact never