Index: imcc/cfg.c
===================================================================
--- imcc/cfg.c	(revision 8911)
+++ imcc/cfg.c	(working copy)
@@ -27,6 +27,7 @@
 static void analyse_life_symbol(Parrot_Interp, IMC_Unit *, SymReg*);
 static void analyse_life_block(Parrot_Interp, Basic_block*, SymReg*);
 static void bb_add_edge(IMC_Unit *, Basic_block*, Basic_block*);
+static void bb_remove_edge(IMC_Unit *, Edge*);
 static Basic_block* make_basic_block(Interp *, IMC_Unit *, Instruction*);
 
 /* Code: */
@@ -238,13 +239,13 @@
             }
     }
 }
+
 /* Once the basic blocks have been computed, build_cfg computes
    the dependencies between them. */
-
 void
 build_cfg(Parrot_Interp interpreter, IMC_Unit * unit)
 {
-    int i, j;
+    int i, j, changes;
     SymReg * addr;
     Basic_block *last = NULL, *bb;
     Edge *pred;
@@ -343,6 +344,24 @@
         last = bb;
     }
 
+    /* Decouple unreachable blocks (not the first block, with no predecessors)
+     * from the CFG
+     */
+    do {
+        changes = 0;
+        for (i = 1; i < unit->n_basic_blocks; i++) {
+            bb = unit->bb_list[i];
+            if (!bb->pred_list) {
+                /* Remove all successor edges of block bb */
+                while (bb->succ_list) { 
+                    bb_remove_edge(unit, bb->succ_list);
+                    fprintf(stderr, "remove edge from bb: %d\n", bb->index); 
+                    changes = 1;
+                }
+            }
+        }
+    } while (changes);
+
     if (IMCC_INFO(interpreter)->debug & DEBUG_CFG)
         dump_cfg(unit);
 }
@@ -423,6 +442,44 @@
 }
 
 static void
+bb_remove_edge(IMC_Unit * unit, Edge * edge)
+{
+    Edge *prev;
+
+    if (edge->from->succ_list == edge) {
+        edge->from->succ_list = edge->succ_next;
+    } else {
+        for (prev = edge->from->succ_list; prev; prev = prev->succ_next) {
+            if (prev->succ_next == edge) {
+                prev->succ_next = edge->succ_next;
+            }
+        }
+    }
+    
+    if (edge->to->pred_list == edge) {
+        edge->to->pred_list = edge->pred_next;
+    } else {
+        for (prev = edge->to->pred_list; prev; prev = prev->pred_next) {
+            if (prev->pred_next == edge) {
+                prev->pred_next = edge->pred_next;
+            }
+        }
+    }
+    
+    if (unit->edge_list == edge) {
+        unit->edge_list = edge->next;
+	free(edge);
+    } else {
+        for (prev = unit->edge_list; prev; prev = prev->next) {
+            if (prev->next == edge) {
+                prev->next = edge->next;
+	        free(edge);
+            }
+        }
+    }
+}
+
+static void
 free_edge(IMC_Unit * unit)
 {
     Edge *e, *next;
@@ -512,8 +569,8 @@
 			   !instruction_reads(ins, r1)) {
 			add_instruct_reads(interpreter, ins, r1);
                         any = 1;
-		    }
-		    else if (instruction_reads(ins, r1) &&
+                    }
+                    else if (instruction_reads(ins, r1) &&
 			   !instruction_reads(ins, r0)) {
 			add_instruct_reads(interpreter, ins, r0);
                         any = 1;
@@ -796,7 +853,12 @@
     dominators[0] = set_make(n);
     set_add(dominators[0], 0);
     for (i = 1; i < n; i++) {
-        dominators[i] = set_make_full(n);
+        if (unit->bb_list[i]->pred_list) {
+            dominators[i] = set_make_full(n);
+        } else {
+            dominators[i] = set_make(n);
+            set_add(dominators[i], i);
+        }
     }
 
 #if USE_BFS