public static void updateSsaMethod(SsaMethod ssaMeth, int threshold) {
    LocalVariableInfo localInfo = LocalVariableExtractor.extract(ssaMeth);
    placePhiFunctions(ssaMeth, localInfo, threshold);
    new SsaRenamer(ssaMeth, threshold).run();
  }
Updates an SSA representation, placing phi functions and renaming all registers above a certain
threshold number.

@param ssaMeth input
@param threshold registers below this number are unchanged
android/android_framework/dex-maker/src/main/java/com/android/dx/ssa/SsaConverter.java