CS6600 Computer Architecture (July - Nov 2024)

This repository contains three microarchitecture simulators developed as coursework for CS6600 Computer Architecture (Fall 2024). The simulators model core architectural components including memory hierarchies, dynamic branch prediction, and instruction-level parallelism.

1. Cache Simulator (/CacheSimulator)

A parameterized, multi-level cache simulator written in C++.

• Implementation: Models L1, L2, and a fully-associative Victim Cache.
• Features: Implements a Least Recently Used (LRU) replacement policy and a write-back/write-allocate strategy. It integrates with CACTI to approximate Average Access Time (AAT), Energy-Delay Product (EDP), and total memory traffic.
• Compilation & Execution:

  cd CacheSimulator
  make
  ./cache_sim <L1_SIZE> <L1_ASSOC> <L1_BLOCKSIZE> <VC_NUM_BLOCKS> <L2_SIZE> <L2_ASSOC> <trace_file>

2. Superscalar Out-of-Order Simulator (/TomasuloSimulator)

A cycle-accurate simulator modeling a superscalar processor using Tomasulo's Algorithm.

• Implementation: Models Fetch, Decode/Dispatch, Issue, Execute, Writeback, and Retire stages.
• Features: Utilizes register renaming (tagging) and a Reorder Buffer (ROB) to dynamically schedule instructions, resolve Read-After-Write (RAW) data dependencies, and eliminate Write-After-Write (WAW) and Write-After-Read (WAR) hazards.
• Compilation & Execution:

  cd TomasuloSimulator
  make
  ./ooosim <N> <S> <trace_file>

3. Branch Predictor (/BranchPredictor)

A trace-driven branch prediction simulator to evaluate branch prediction accuracy.

• Implementation: Implements both a Bimodal Predictor (using an array of 2-bit saturating counters) and a Gshare Predictor.
• Features: The Gshare implementation utilizes a Global History Register (GHR) XORed with the PC to improve prediction accuracy on highly correlated branch patterns.
• Compilation & Execution:

  cd BranchPredictor
  make
  ./bpsim bimodal <M> <trace_file>
  # or for gshare:
  ./bpsim gshare <M> <N> <trace_file>

Repository Structure

Each simulator directory is organized as follows:

• / (Root): C++ source code (.cpp), header files (.h), provided dependencies (e.g., cacti), Makefile, and report.pdf.
• /traces: Instruction and memory trace files (e.g., sample_trace.txt).
• /scripts: Bash and Python scripts used for running sweeps, validation, and plotting.
• /outputs: Validation outputs, reference outputs, and generated .csv data.

Academic Integrity

This repository is public for portfolio and reference purposes only. If you are currently taking CS6600 or a similar course at IIT Madras or elsewhere, please adhere to your institution's academic integrity and honour code policies. Do not copy or use this code for your own assignments.