This tool helps look at very small chunks of assembly code to identify the cost via a simulated execution. Beyond that it focuses on multi-stage execution of in

This tool helps look at very small chunks of assembly code to identify the cost via a simulated execution. Beyond that it focuses on multi-stage execution of instructions in a hardware pipeline, providing tools to show the execution as well as flag which factors would be the limiting factor for the code in question. The level of detail that it provides as well as the apparent simplicity of using the tool makes it unique (from what I've seen). Understanding where the limiting factor is can help optimize and tune small chunks of code.