asm.emitMOV_Reg_RegDisp (EBX, S0, VM_Entrypoints.JNIRefsField.getOffset());
asm.emitMOV_Reg_RegDisp (EBX, S0, VM_Entrypoints.JNIRefsField.getOffsetAsInt());
  static void startJNIrefForProlog(VM_Assembler asm, int numRefsExpected) {    // on entry, S0 contains a pointer to the VM_Thread.jniEnv    asm.emitMOV_Reg_RegDisp (EBX, S0, VM_Entrypoints.JNIRefsField.getOffset());    // ebx <- JNIRefs base    // get and check index of top for overflow    asm.emitMOV_Reg_RegDisp (T0, S0, VM_Entrypoints.JNIRefsTopField.getOffset());  // T0 <- index of top    asm.emitADD_Reg_Imm(T0, numRefsExpected * WORDSIZE);                // increment index of top     asm.emitCMP_Reg_RegDisp(T0, S0, VM_Entrypoints.JNIRefsMaxField.getOffset());   // check against JNIRefsMax for overflow     // TODO:  Do something if overflow!!!    asm.emitADD_RegDisp_Imm (S0, VM_Entrypoints.JNIRefsTopField.getOffset(), WORDSIZE); // increment index of top    asm.emitMOV_Reg_RegDisp (T0, S0, VM_Entrypoints.JNIRefsTopField.getOffset());  // T0 <- index of top    asm.emitADD_Reg_Reg(T0, EBX);                                       // T0 <- address of top (not index)    // start new frame:  push current JNIRefsSavedFP onto stack and set it to the new top index        asm.emitMOV_Reg_RegDisp (EBX, S0, VM_Entrypoints.JNIRefsSavedFPField.getOffset()); // ebx <- jniEnv.JNIRefsSavedFP    asm.emitMOV_RegInd_Reg  (T0, EBX);                                   // push (T0) <- ebx    asm.emitMOV_Reg_RegDisp (T0, S0, VM_Entrypoints.JNIRefsTopField.getOffset());   // reload T0 <- index of top    asm.emitMOV_RegDisp_Reg (S0, VM_Entrypoints.JNIRefsSavedFPField.getOffset(), T0); // jniEnv.JNIRefsSavedFP <- index of top     // leave T0 with address pointing to the top of the frame for more push later    asm.emitADD_Reg_RegDisp(T0, S0, VM_Entrypoints.JNIRefsField.getOffset());       // recompute T0 <- address of top (not index)    // and go ahead and bump up the Top offset by the amount expected    asm.emitADD_RegDisp_Imm(S0, VM_Entrypoints.JNIRefsTopField.getOffset(), numRefsExpected * WORDSIZE);  }