Introduce optimisations to make the Z80 CPU emulation some 80% faster

.clang-format

@@ -0,0 +1,82 @@
+---
+Language: Cpp
+Standard: c++17
+BasedOnStyle: LLVM
+
+# Line length
+ColumnLimit: 120
+
+# Indentation
+IndentWidth: 4
+UseTab: Never
+IndentCaseLabels: true
+IndentPPDirectives: AfterHash
+
+# Spacing
+SpaceBeforeParens: ControlStatements
+SpaceAfterCStyleCast: false
+SpacesInAngles: false
+SpaceInEmptyParentheses: false
+SpaceBeforeAssignmentOperators: true
+
+# Pointers and references
+PointerAlignment: Left
+
+# Braces
+BraceWrapping:
+  AfterCaseLabel: false
+  AfterClass: false
+  AfterControlStatement: Never
+  AfterEnum: false
+  AfterFunction: false
+  AfterNamespace: false
+  AfterStruct: false
+  AfterUnion: false
+  AfterExternBlock: false
+  BeforeCatch: false
+  BeforeElse: false
+  BeforeLambdaBody: false
+  BeforeWhile: false
+  IndentBraces: false
+  SplitEmptyFunction: false
+  SplitEmptyRecord: false
+  SplitEmptyNamespace: false
+
+# Function definitions
+AllowShortFunctionsOnASingleLine: None
+SeparateDefinitionBlocks: Always
+AllowShortBlocksOnASingleLine: Empty
+AllowShortIfStatementsOnASingleLine: Never
+AllowShortLoopsOnASingleLine: false
+AllowAllArgumentsOnNextLine: true
+AllowAllParametersOfDeclarationOnNextLine: true
+
+# Constructor/Destructor
+ConstructorInitializerAllOnOneLineOrOnePerLine: true
+ConstructorInitializerIndentWidth: 4
+Cpp11BracedListStyle: true
+
+# Operators
+BreakBeforeBinaryOperators: NonAssignment
+BreakBeforeTernaryOperators: true
+
+# Includes
+SortIncludes: true
+IncludeBlocks: Preserve
+
+# Comments
+ReflowComments: true
+
+# Other
+AlignAfterOpenBracket: Align
+AlignConsecutiveAssignments: None
+AlignConsecutiveDeclarations: None
+AlignConsecutiveMacros: true
+AlignEscapedNewlines: Left
+AlignTrailingComments: true
+
+AccessModifierOffset: -2
+CompactNamespaces: false
+FixNamespaceComments: true
+MaxEmptyLinesToKeep: 1
+NamespaceIndentation: None

.clang-tidy

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+---
+# Clang-tidy configuration for Z80 emulator project
+Checks: |
+  -*, 
+  readability-*,
+  performance-*,
+  modernize-*,
+  bugprone-*,
+  clang-diagnostic-*,
+  cppcoreguidelines-*,
+  google-*,
+  -readability-magic-numbers,
+  -readability-uppercase-literal-suffix,
+  -cppcoreguidelines-avoid-magic-numbers,
+  -cppcoreguidelines-pro-bounds-array-to-pointer-decay,
+  -cppcoreguidelines-pro-type-cstyle-cast,
+  -cppcoreguidelines-pro-type-reinterpret-cast,
+  -google-readability-function-size,
+  -google-runtime-references,
+  -modernize-use-trailing-return-type,
+  -cppcoreguidelines-pro-bounds-constant-array-index,
+  -readability-function-cognitive-complexity,
+  -readability-function-size
+
+WarningsAsErrors: ''
+
+# Configure individual checks
+CheckOptions:
+  - key: 'readability-function-cognitive-complexity.Threshold'
+    value: '25'
+  - key: 'readability-function-size.StatementThreshold'
+    value: '800'
+  - key: 'readability-identifier-length.MinimumVariableNameLength'
+    value: '2'
+  - key: 'readability-identifier-length.MinimumParameterNameLength'
+    value: '2'
+  - key: 'readability-identifier-length.MinimumLoopCounterNameLength'
+    value: '1'
+  - key: 'readability-line-length.LineLength'
+    value: '120'
+  - key: 'bugprone-easily-swappable-parameters.MinimumLength'
+    value: '3'
+
+HeaderFilterRegex: '.*'
+InheritParentConfig: true

.devcontainer/Dockerfile

@@ -0,0 +1,70 @@
+FROM ubuntu:22.04
+
+# Install build dependencies
+RUN apt-get update && export DEBIAN_FRONTEND=noninteractive \
+    && apt-get -y install --no-install-recommends \
+    cmake \
+    make \
+    git \
+    curl \
+    ca-certificates \
+    xz-utils \
+    sudo \
+    g++ \
+    gcc \
+    qemu-user-static \
+    && apt-get clean \
+    && rm -rf /var/lib/apt/lists/*
+
+# Download and install ARM GNU toolchain for Raspberry Pi 4
+# Detect architecture and download appropriate toolchain
+RUN ARCH=$(uname -m) && \
+    if [ "$ARCH" = "aarch64" ] || [ "$ARCH" = "arm64" ]; then \
+        TOOLCHAIN_URL="https://armkeil.blob.core.windows.net/developer/files/downloads/gnu/15.2.rel1/binrel/arm-gnu-toolchain-15.2.rel1-aarch64-aarch64-none-linux-gnu.tar.xz"; \
+    else \
+        TOOLCHAIN_URL="https://armkeil.blob.core.windows.net/developer/files/downloads/gnu/15.2.rel1/binrel/arm-gnu-toolchain-15.2.rel1-x86_64-aarch64-none-linux-gnu.tar.xz"; \
+    fi && \
+    curl -L "$TOOLCHAIN_URL" -o /tmp/arm-toolchain.tar.xz && \
+    mkdir -p /opt/arm-toolchain && \
+    tar -xf /tmp/arm-toolchain.tar.xz -C /opt/arm-toolchain --strip-components=1 && \
+    rm /tmp/arm-toolchain.tar.xz
+
+# Add toolchain to PATH
+ENV PATH="/opt/arm-toolchain/bin:${PATH}"
+
+# Create a non-root user
+ARG USERNAME=vscode
+ARG USER_UID=1000
+ARG USER_GID=$USER_UID
+
+RUN groupadd --gid $USER_GID $USERNAME \
+    && useradd --uid $USER_UID --gid $USER_GID -m $USERNAME \
+    && echo $USERNAME ALL=\(root\) NOPASSWD:ALL > /etc/sudoers.d/$USERNAME \
+    && chmod 0440 /etc/sudoers.d/$USERNAME
+
+# Create CMake toolchain file for ARM64 cross-compilation (Raspberry Pi 4)
+RUN echo 'set(CMAKE_SYSTEM_NAME Linux)\n\
+set(CMAKE_SYSTEM_PROCESSOR aarch64)\n\
+\n\
+set(CMAKE_C_COMPILER aarch64-none-linux-gnu-gcc)\n\
+set(CMAKE_CXX_COMPILER aarch64-none-linux-gnu-g++)\n\
+\n\
+# Optimize for Raspberry Pi 4 (Cortex-A72)\n\
+set(CMAKE_C_FLAGS_INIT "-mcpu=cortex-a72 -mtune=cortex-a72")\n\
+set(CMAKE_CXX_FLAGS_INIT "-mcpu=cortex-a72 -mtune=cortex-a72")\n\
+\n\
+# Static link all libraries for tests (to run with QEMU)\n\
+# For production builds on the target, remove -static flag\n\
+set(CMAKE_EXE_LINKER_FLAGS_INIT "-static")\n\
+set(CMAKE_SHARED_LINKER_FLAGS_INIT "-static-libstdc++ -static-libgcc")\n\
+\n\
+set(CMAKE_FIND_ROOT_PATH /opt/arm-toolchain/aarch64-none-linux-gnu)\n\
+set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)\n\
+set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)\n\
+set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)\n\
+set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)\n\
+\n\
+# Use QEMU for running cross-compiled tests\n\
+set(CMAKE_CROSSCOMPILING_EMULATOR /usr/bin/qemu-aarch64-static)\n' > /opt/toolchain-aarch64.cmake
+
+USER $USERNAME

.devcontainer/devcontainer.json

@@ -0,0 +1,22 @@
+{
+  "name": "Z80 C++ ARM64 Cross-Compilation",
+  "build": {
+    "dockerfile": "Dockerfile"
+  },
+  "customizations": {
+    "vscode": {
+      "extensions": [
+        "ms-vscode.cmake-tools",
+        "ms-vscode.cpptools",
+        "twxs.cmake"
+      ],
+      "settings": {
+        "cmake.configureArgs": [
+          "-DCMAKE_TOOLCHAIN_FILE=/opt/toolchain-aarch64.cmake"
+        ]
+      }
+    }
+  },
+  "postCreateCommand": "sudo bash -c 'echo \"#!/bin/bash\" > /usr/local/bin/cmake-rpi && echo \"cmake -DCMAKE_TOOLCHAIN_FILE=/opt/toolchain-aarch64.cmake \\\"\\$@\\\"\" >> /usr/local/bin/cmake-rpi && chmod +x /usr/local/bin/cmake-rpi' && echo 'ARM64 cross-compilation environment ready. Use: cmake-rpi .. (or cmake -DCMAKE_TOOLCHAIN_FILE=/opt/toolchain-aarch64.cmake ..)'",
+  "remoteUser": "vscode"
+}

.github/workflows/build-and-test-with-cmake.yml

@@ -0,0 +1,39 @@
+# This starter workflow is for a CMake project running on a single platform. There is a different starter workflow if you need cross-platform coverage.
+# See: https://github.com/actions/starter-workflows/blob/main/ci/cmake-multi-platform.yml
+name: Build and Test with CMake
+
+on:
+  push:
+    branches: [ "master" ]
+  pull_request:
+    branches: [ "master" ]
+  workflow_dispatch:
+
+env:
+  # Customize the CMake build type here (Release, Debug, RelWithDebInfo, etc.)
+  BUILD_TYPE: Release
+
+jobs:
+  build:
+    # The CMake configure and build commands are platform agnostic and should work equally well on Windows or Mac.
+    # You can convert this to a matrix build if you need cross-platform coverage.
+    # See: https://docs.github.com/en/free-pro-team@latest/actions/learn-github-actions/managing-complex-workflows#using-a-build-matrix
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Configure CMake
+      # Configure CMake in a 'build' subdirectory. `CMAKE_BUILD_TYPE` is only required if you are using a single-configuration generator such as make.
+      # See https://cmake.org/cmake/help/latest/variable/CMAKE_BUILD_TYPE.html?highlight=cmake_build_type
+      run: cmake -B ${{github.workspace}}/build -DCMAKE_BUILD_TYPE=${{env.BUILD_TYPE}}
+
+    - name: Build
+      # Build your program with the given configuration
+      run: cmake --build ${{github.workspace}}/build --config ${{env.BUILD_TYPE}}
+
+    - name: Test
+      working-directory: ${{github.workspace}}/build
+      # Execute tests defined by the CMake configuration.
+      # See https://cmake.org/cmake/help/latest/manual/ctest.1.html for more detail
+      run: ctest -C ${{env.BUILD_TYPE}} --output-on-failure -V

.github/workflows/code-quality.yml

@@ -0,0 +1,68 @@
+name: Code Quality
+
+on: [push, pull_request]
+
+jobs:
+  formatting:
+    name: Check Code Formatting
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install clang-format
+        run: sudo apt-get install -y clang-format
+
+      - name: Check formatting
+        run: |
+          files=$(find include tests -type f \( -name "*.cpp" -o -name "*.h" -o -name "*.tpp" \))
+          for file in $files; do
+            clang-format --dry-run -Werror "$file" || exit 1
+          done
+          echo "All files are properly formatted!"
+
+  static-analysis:
+    name: Static Analysis with clang-tidy
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y clang-tidy cmake build-essential
+
+      - name: Build with compile_commands.json
+        run: |
+          mkdir -p build
+          cd build
+          cmake -DCMAKE_EXPORT_COMPILE_COMMANDS=ON ..
+          make
+
+      - name: Run clang-tidy
+        run: |
+          cd build
+          files=$(find ../tests -type f -name "*.cpp")
+          clang-tidy -p . $files
+
+  build:
+    name: Build Project
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y cmake build-essential
+
+      - name: Build
+        run: |
+          mkdir -p build
+          cd build
+          cmake ..
+          make -j4
+
+      - name: Run tests
+        run: |
+          cd build
+          ctest --output-on-failure

.gitignore

@@ -1,5 +1,12 @@
-build*/
-cmake-build*/
-.vscode/
+# Editor and OS files
+.cache/
 .idea/
-example/z80sim
+.vscode/
+.DS_Store
+
+# Build directories
+build*/
+
+# Test ROMs
+tests/roms/*
+tests/roms/*.tap