1.1 --- a/rt/vm/src/main/java/org/apidesign/vm4brwsr/Bck2Brwsr.java	Thu Mar 12 10:32:13 2015 +0100
     1.2 +++ b/rt/vm/src/main/java/org/apidesign/vm4brwsr/Bck2Brwsr.java	Fri Mar 13 11:41:04 2015 +0100
     1.3 @@ -422,8 +422,10 @@
     1.4       */
     1.5      public static final class Flow {
     1.6          private final MethodData m;
     1.7 +        private byte[] ops;
     1.8          Flow(MethodData m) {
     1.9              this.m = m;
    1.10 +            ops = new byte[m.getCode().length];
    1.11          }
    1.12          
    1.13          /** Access to bytecode of the method to analyse.
    1.14 @@ -441,10 +443,46 @@
    1.15              return m.getName();
    1.16          }
    1.17          
    1.18 -        public void registerCycle(int offset) {
    1.19 +        public void beginLoopAt(int bci) {
    1.20 +            ops[bci] |= 0x10;
    1.21          }
    1.22          
    1.23 -        public void registerIf(int offset) {
    1.24 +        public void beginIfAt(int bci) {
    1.25 +            ops[bci] |= 0x20;
    1.26 +        }
    1.27 +
    1.28 +
    1.29 +        public void breakAt(int bci) {
    1.30 +            ops[bci] |= 0x40;
    1.31 +        }
    1.32 +
    1.33 +        public void beginElseAt(int bci) {
    1.34 +            ops[bci] |= 0x80;
    1.35 +        }
    1.36 +
    1.37 +        public void endAt(int bci) {
    1.38 +            int cnt = (ops[bci] & 0x0f) + 1;
    1.39 +            int rest = ops[bci] & 0xf0;
    1.40 +            ops[bci] = (byte)(rest | cnt);
    1.41 +        }
    1.42 +        
    1.43 +        boolean isFlow(int at) {
    1.44 +            return ops[at] != 0;
    1.45 +        }
    1.46 +        boolean isLoop(int at) {
    1.47 +            return (ops[at] & 0x10) != 0;
    1.48 +        }
    1.49 +        boolean isIf(int at) {
    1.50 +            return (ops[at] & 0x20) != 0;
    1.51 +        }
    1.52 +        boolean isBreak(int at) {
    1.53 +            return (ops[at] & 0x40) != 0;
    1.54 +        }
    1.55 +        boolean isElse(int at) {
    1.56 +            return (ops[at] & 0x80) != 0;
    1.57 +        }
    1.58 +        int isEnd(int at) {
    1.59 +            return (ops[at] & 0x0f);
    1.60          }
    1.61          
    1.62          /** Provider of advanced analysis of the code flow inside of