GEMscript and Virtual Machines  If you've been using GEMstudio, you’re probably familiar with our programming language, GEMscript. We designed GEMscript to be a user-friendly, C-like language with the intention of enabling a “write once, run anywhere” approach. This means it can be used seamlessly across all our platforms, including GEMplayer on PC and various hardware devices.  GEMscript is a VM (virtual machine) based language, meaning your code gets compiled into "bytecode" and runs in a VM interpreter instead of being compiled down to native machine code. This allows us to achieve our goal of running the same compiled code across multiple platforms. Additionally, by sandboxing GEMscript from our OS in a VM, we avoid some pitfalls of writing in native C, such as unsafe memory access and code execution. However, there’s a big trade-off when using VMs: speed.  It's no secret that VMs are generally slower than native machine code. Therefore, optimizing VMs is crucial, particularly for limited hardware where every bit of speed counts. So, I rolled up my sleeves and started exploring ways to optimize our code. And guess what? I found a neat and easy trick for speeding up opcode dispatch. This article discusses the performance improvements I achieved by optimizing opcode dispatch in GEMscript using GCC's "Label as Value" feature, demonstrating a significant speed increase.  Enhancing VM Performance: Speeding Up Opcode Dispatch  When I started looking at our VM, I realized that focusing on opcode dispatch could yield significant performance gains. Efficient opcode dispatch is key to faster execution because it reduces the overhead of interpreting each instruction in the VM. Let me put this in simpler terms:  Imagine you’ve got a list of vocabulary words to study. One way to do this is by using the index at the back of a dictionary. For each word, you:  Look up the page number in the index.  Flip to the correct page to read about the word.  Return to the index for the next word.  Doing this for each word is straightforward but slow and tedious.  Now, imagine using index cards with all the vocabulary words printed in order. For each word, you:  Read the information on the top index card.  Move instantly to the next card.  No more flipping back and forth! This method is much faster and more efficient, even though it takes a bit of effort upfront to set up the index cards. Similarly, by optimizing our opcode dispatch, we can make our VM run instructions more quickly and efficiently.  The Basics of VM Interpreting  Let’s start with a basic interpreter loop for a VM, which is similar to using the dictionary index method. Instead of a list of vocabulary words, we have bytecode, which is a list of opcodes in memory. Instead of searching an index for the correct page, we use a switch statement, with each opcode case representing a different operation. This switch case is in a loop, so we repeatedly look for our current opcode and execute it until we run out of opcodes. Here’s a simple example in C:  void runVM(){     uint32_t pc