private void handleLocalAssociatedParams() {
    for (ArrayList<RegisterSpec> ssaRegs : localVariables.values()) {
      int sz = ssaRegs.size();
      int paramIndex = -1;
      int paramCategory = 0;

      // First, find out if this local variable is a parameter.
      for (int i = 0; i < sz; i++) {
        RegisterSpec ssaSpec = ssaRegs.get(i);
        int ssaReg = ssaSpec.getReg();

        paramIndex = getParameterIndexForReg(ssaReg);

        if (paramIndex >= 0) {
          paramCategory = ssaSpec.getCategory();
          addMapping(ssaSpec, paramIndex);
          break;
        }
      }

      if (paramIndex < 0) {
        // This local wasn't a parameter.
        continue;
      }

      // Any remaining local-associated registers will be mapped later.
      tryMapRegs(ssaRegs, paramIndex, paramCategory, true);
    }
  }
Maps all local-associated parameters to rop registers.
android/android_framework/dex-maker/src/main/java/com/android/dx/ssa/back/FirstFitLocalCombiningAllocator.java