some opt

midend/llvm/value/IrFuncValue.java

@@ -45,6 +45,27 @@ public class IrFuncValue extends IrValue {
         bblocks.add(bblock);
     }
 
+    public void deleteBBlock(IrBasicBlock bblock) {
+        bblocks.remove(bblock);
+        bblock.clearAllInstrs();
+    }
+
+    public void deleteDeadBlock() {
+        ArrayList<IrBasicBlock> liveBlocks = new ArrayList<>();
+        ArrayList<IrBasicBlock> deadBlocks = new ArrayList<>();
+        for (IrBasicBlock bb : bblocks) {
+            if (!bb.getPreds().isEmpty() || bb.isEntry()) {
+                liveBlocks.add(bb);
+            } else {
+                deadBlocks.add(bb);
+            }
+        }
+        bblocks = liveBlocks;
+        for (IrBasicBlock bb : deadBlocks) {
+            bb.clearAllInstrs();
+        }
+    }
+
     public Register getRegister(IrValue value) {
         return valueRegisterMap.get(value);
     }