Seal the body block immediately after the condition in while stmt

Author: dibyendumajumdar

optvm/src/main/java/com/compilerprogramming/ezlang/compiler/CompiledFunction.java

@@ -225,11 +225,10 @@ private void compileWhile(AST.WhileStmt whileStmt) {
             codeIndexedLoad();
         codeCBR(currentBlock, pop(), bodyBlock, exitBlock);
         assert vstackEmpty();
-        startBlock(bodyBlock);  // ISSA If we seal this here fib test fails, wrong code generated, why?
+        startSealedBlock(bodyBlock);  // ISSA If we seal this here fib test fails, wrong code generated, why?
         compileStatement(whileStmt.stmt);
         if (!isBlockTerminated(currentBlock))
             jumpTo(loopHead);
-        issa.sealBlock(bodyBlock);
         issa.sealBlock(loopHead);
         startSealedBlock(exitBlock);
         currentContinueTarget = savedContinueTarget;
@@ -900,7 +899,7 @@ private Register readVariable(Register variable, BasicBlock block) {
          */
         private Register readVariableRecursive(Register variable, BasicBlock block) {
             Register val;
-            if (!sealedBlocks.get(block.bid)) {
+            if (!isSealed(block)) {
                 // incomplete CFG
                 val = makeVersion(variable);
                 Instruction.Phi phi = makePhi(val, block);

optvm/src/test/java/com/compilerprogramming/ezlang/compiler/TestIncrementalSSA.java

@@ -7,8 +7,8 @@
 public class TestIncrementalSSA {
     String compileSrc(String src) {
         var compiler = new Compiler();
-        var typeDict = compiler.compileSrc(src, EnumSet.of(Options.ISSA));
-        return compiler.dumpIR(typeDict);
+        var typeDict = compiler.compileSrc(src, EnumSet.of(Options.ISSA,Options.DUMP_SSA_IR));
+        return compiler.dumpIR(typeDict,true);
     }
 
     @Test
@@ -104,4 +104,29 @@ func example14_66(p: Int, q: Int, r: Int, s: Int, t: Int) {
         String result = compileSrc(src);
         System.out.println(result);
     }
+
+    @Test
+    public void test5() {
+        String src = """
+                func fib(n: Int)->Int {
+                    var i: Int;
+                    var temp: Int;
+                    var f1=1;
+                    var f2=1;
+                    i=n;
+                    while( i>1 ){
+                        temp = f1+f2;
+                        f1=f2;
+                        f2=temp;
+                        i=i-1;
+                    }
+                    return f2;
+                }
+                func foo()->Int {
+                    return fib(10);
+                }
+                """;
+        String result = compileSrc(src);
+        System.out.println(result);
+    }
 }