diff --git a/.github/workflows/CI-mingw.yml b/.github/workflows/CI-mingw.yml
deleted file mode 100644
index 390de83d..00000000
--- a/.github/workflows/CI-mingw.yml
+++ /dev/null
@@ -1,141 +0,0 @@
-name: CI-mingw
-
-on: [push, pull_request]
-
-permissions:
-  contents: read
-
-defaults:
-  run:
-    shell: msys2 {0}
-
-jobs:
-  build:
-
-    strategy:
-      matrix:
-        compiler: [g++, clang++]
-        # TODO: add MSYS after #556 is fixed
-        msystem: [MINGW32, MINGW64, CLANG64]
-        include:
-          #- msystem: MSYS
-          #  pkg-prefix: ''
-          - msystem: MINGW32
-            pkg-prefix: 'mingw-w64-i686-'
-          - msystem: MINGW64
-            pkg-prefix: 'mingw-w64-x86_64-'
-          - msystem: CLANG64
-            pkg-prefix: 'mingw-w64-clang-x86_64-'
-          - compiler: g++
-            compiler-pkg: gcc
-          - compiler: clang++
-            compiler-pkg: clang
-        exclude:
-          - msystem: CLANG64
-            compiler: g++
-          # the mingw-w64-i686-clang package is no longer available
-          - msystem: MINGW32
-            compiler: clang++
-      fail-fast: false
-
-    runs-on: windows-2025
-
-    env:
-      CXX: ${{ matrix.compiler }}
-
-    steps:
-      - uses: actions/checkout@v4
-        with:
-          persist-credentials: false
-
-      - name: Set up MSYS2
-        uses: msys2/setup-msys2@v2
-        with:
-          release: false # use pre-installed
-          msystem: ${{ matrix.msystem }}
-          # TODO: install mingw-w64-x86_64-make and use mingw32.make instead - currently fails with "Windows Subsystem for Linux has no installed distributions."
-          # TODO: also run tests with non-prefixed Python?
-          install: >-
-            make
-            ${{ matrix.pkg-prefix }}cmake
-            ${{ matrix.pkg-prefix }}python
-            ${{ matrix.pkg-prefix }}python-pytest
-
-      - name: install compiler
-        run: |
-          pacman -S --noconfirm ${{ matrix.pkg-prefix }}${{ matrix.compiler-pkg }}
-          ${CXX} -v
-
-      - name: make simplecpp
-        run: |
-          make -j$(nproc) CXXOPTS="-Werror"
-
-      # gcc *and* clang are required to run-tests.py
-      # install it at this point since it has gcc as dependency which might interfere with the build
-      - name: install compiler (clang)
-        if: matrix.compiler == 'g++'
-        run: |
-          pacman -S --noconfirm clang
-
-      - name: install compiler (gcc)
-        if: matrix.compiler == 'clang++'
-        run: |
-          pacman -S --noconfirm gcc
-
-      - name: make test
-        run: |
-          # TODO: run tests with Windows paths
-          make -j$(nproc) test
-
-      - name: selfcheck
-        run: |
-          # TODO: run tests with Windows paths
-          make -j$(nproc) selfcheck
-
-      - name: make (c++14)
-        run: |
-          make clean
-          make -j$(nproc) CXXOPTS="-Werror -std=c++14"
-
-      - name: make (c++17)
-        run: |
-          make clean
-          make -j$(nproc) CXXOPTS="-Werror -std=c++17"
-
-      - name: make (c++20)
-        run: |
-          make clean
-          make -j$(nproc) CXXOPTS="-Werror -std=c++20"
-
-      - name: make (c++23)
-        run: |
-          make clean
-          make -j$(nproc) CXXOPTS="-Werror -std=c++23"
-
-      - name: Run CMake
-        run: |
-          cmake -S . -B cmake.output -DCMAKE_COMPILE_WARNING_AS_ERROR=On
-
-      - name: CMake simplecpp
-        run: |
-          cmake --build cmake.output --target simplecpp -- -j $(nproc)
-
-      - name: CMake testrunner
-        run: |
-          cmake --build cmake.output --target testrunner -- -j $(nproc)
-
-      - name: Run testrunner
-        run: |
-          ./cmake.output/testrunner
-
-      - name: Run with libstdc++ debug mode
-        if: matrix.compiler == 'g++'
-        run: |
-          make clean
-          make -j$(nproc) test selfcheck CXXOPTS="-Werror -g3 -D_GLIBCXX_DEBUG"
-
-      - name: Run with libc++ hardening mode
-        if: matrix.compiler == 'clang++' && matrix.msystem == 'CLANG64'
-        run: |
-          make clean
-          make -j$(nproc) test selfcheck CXXOPTS="-Werror -stdlib=libc++ -g3 -D_LIBCPP_HARDENING_MODE=_LIBCPP_HARDENING_MODE_DEBUG" LDOPTS="-lc++"
diff --git a/.github/workflows/CI-unixish.yml b/.github/workflows/CI-unixish.yml
index 1a4ce649..57abb798 100644
--- a/.github/workflows/CI-unixish.yml
+++ b/.github/workflows/CI-unixish.yml
@@ -10,7 +10,7 @@ jobs:
 
     strategy:
       matrix:
-        os: [ubuntu-22.04, ubuntu-22.04-arm, ubuntu-24.04, ubuntu-24.04-arm, macos-14, macos-15, macos-15-intel, macos-26, macos-26-intel]
+        os: [ubuntu-24.04]
         compiler: [clang++]
         include:
           - os: ubuntu-22.04
@@ -32,13 +32,13 @@ jobs:
     # the man-db trigger causes package installations to stall for several minutes at times. so just drop the package.
     # see https://github.com/actions/runner/issues/4030
     - name: Remove man-db package on ubuntu
-      if: matrix.os == 'ubuntu-24.04'
+      if: startsWith(matrix.os, 'ubuntu-24.04')
       run: |
         sudo apt-get update
         sudo apt-get remove man-db
 
     - name: Install missing software on ubuntu
-      if: matrix.os == 'ubuntu-24.04'
+      if: startsWith(matrix.os, 'ubuntu-24.04')
       run: |
           sudo apt-get update
           sudo apt-get install valgrind
@@ -109,7 +109,7 @@ jobs:
         (cd cmake.output && ./testrunner)
 
     - name: Run valgrind
-      if: matrix.os == 'ubuntu-24.04'
+      if: startsWith(matrix.os, 'ubuntu-24.04')
       run: |
           make clean
           make -j$(nproc) CXXOPTS="-O1"
@@ -118,19 +118,19 @@ jobs:
           VALGRIND_TOOL=memcheck ./selfcheck.sh
 
     - name: Run with libstdc++ debug mode
-      if: matrix.os == 'ubuntu-24.04' && matrix.compiler == 'g++'
+      if: startsWith(matrix.os, 'ubuntu-24.04') && matrix.compiler == 'g++'
       run: |
         make clean
         make -j$(nproc) test selfcheck CXXOPTS="-Werror -g3 -D_GLIBCXX_DEBUG"
 
     - name: Run with libc++ hardening mode
-      if: matrix.os == 'ubuntu-24.04' && matrix.compiler == 'clang++'
+      if: startsWith(matrix.os, 'ubuntu-24.04') && matrix.compiler == 'clang++'
       run: |
         make clean
         make -j$(nproc) test selfcheck CXXOPTS="-Werror -stdlib=libc++ -g3 -D_LIBCPP_HARDENING_MODE=_LIBCPP_HARDENING_MODE_DEBUG" LDOPTS="-lc++"
 
     - name: Run AddressSanitizer
-      if: matrix.os == 'ubuntu-24.04' || matrix.os == 'macos-26'
+      if: startsWith(matrix.os, 'ubuntu-24.04') || startsWith(matrix.os, 'macos-26')
       run: |
         make clean
         make -j$(nproc) test selfcheck CXXOPTS="-Werror -O2 -g3 -fsanitize=address" LDOPTS="-fsanitize=address"
@@ -138,7 +138,7 @@ jobs:
         ASAN_OPTIONS: detect_stack_use_after_return=1
 
     - name: Run UndefinedBehaviorSanitizer
-      if: matrix.os == 'ubuntu-24.04' || matrix.os == 'macos-26'
+      if: startsWith(matrix.os, 'ubuntu-24.04') || startsWith(matrix.os, 'macos-26')
       run: |
         make clean
         make -j$(nproc) test selfcheck CXXOPTS="-Werror -O2 -g3 -fsanitize=undefined -fno-sanitize=signed-integer-overflow" LDOPTS="-fsanitize=undefined -fno-sanitize=signed-integer-overflow"
@@ -147,22 +147,45 @@ jobs:
 
     # TODO: requires instrumented libc++
     - name: Run MemorySanitizer
-      if: false && matrix.os == 'ubuntu-24.04' && matrix.compiler == 'clang++'
+      if: false && startsWith(matrix.os, 'ubuntu-24.04') && matrix.compiler == 'clang++'
       run: |
         make clean
         make -j$(nproc) test selfcheck CXXOPTS="-Werror -O2 -g3 -stdlib=libc++ -fsanitize=memory" LDOPTS="-lc++ -fsanitize=memory"
 
     - name: Run callgrind
-      if: matrix.os == 'ubuntu-24.04'
+      if: startsWith(matrix.os, 'ubuntu-24.04')
       run: |
         wget https://github.com/danmar/simplecpp/archive/refs/tags/1.5.1.tar.gz
         tar xvf 1.5.1.tar.gz
         rm -f 1.5.1.tar.gz
         
+        # O2 - start
         make clean
         make -j$(nproc) CXXOPTS="-O2 -g3" simplecpp
-        VALGRIND_TOOL=callgrind SIMPLECPP_PATH=simplecpp-1.5.1 ./selfcheck.sh >callgrind.log || (cat callgrind.log && false)
-        cat callgrind.log
+        VALGRIND_TOOL=callgrind SIMPLECPP_PATH=simplecpp-1.5.1 ./selfcheck.sh >callgrind_o2.log || (cat callgrind_o2.log && false)
+        cat callgrind_o2.log
+        # O2 - end
+        
+        # O3 - start
+        make clean
+        make -j$(nproc) CXXOPTS="-O3 -g3" simplecpp
+        VALGRIND_TOOL=callgrind SIMPLECPP_PATH=simplecpp-1.5.1 ./selfcheck.sh >callgrind_o3.log || (cat callgrind_o3.log && false)
+        cat callgrind_o3.log
+        # O3 - end
+        
+        # O2+LTO - start
+        make clean
+        make -j$(nproc) CXXOPTS="-O2 -g3 -flto" LDOPTS="-flto" simplecpp
+        VALGRIND_TOOL=callgrind SIMPLECPP_PATH=simplecpp-1.5.1 ./selfcheck.sh >callgrind_o2_lto.log || (cat callgrind_o2_lto.log && false)
+        cat callgrind_o2_lto.log
+        # O2+LTO - end
+        
+        # O3+LTO - start
+        make clean
+        make -j$(nproc) CXXOPTS="-O2 -g3 -flto" LDOPTS="-flto" simplecpp
+        VALGRIND_TOOL=callgrind SIMPLECPP_PATH=simplecpp-1.5.1 ./selfcheck.sh >callgrind_o3_lto.log || (cat callgrind_o3_lto.log && false)
+        cat callgrind_o3_lto.log
+        # O3+LTO - end
         
         # PGO - start
         make clean
@@ -179,6 +202,9 @@ jobs:
         cat callgrind_pgo.log
         # PGO - end
         
+        # TODO: PGO+O3
+        # TODO: PGO+LTO
+        
         for f in callgrind.out.*;
         do
           callgrind_annotate --auto=no $f > $f.annotated.log
@@ -187,8 +213,8 @@ jobs:
         rm -rf simplecpp-1.5.1
 
     - uses: actions/upload-artifact@v4
-      if: matrix.os == 'ubuntu-24.04'
+      if: startsWith(matrix.os, 'ubuntu-24.04')
       with:
-        name: Callgrind Output - ${{ matrix.compiler }}
+        name: Callgrind Output - ${{ matrix.os }} - ${{ matrix.compiler }}
         path: |
           ./callgrind.*
diff --git a/.github/workflows/CI-windows.yml b/.github/workflows/CI-windows.yml
deleted file mode 100644
index cfced0d2..00000000
--- a/.github/workflows/CI-windows.yml
+++ /dev/null
@@ -1,82 +0,0 @@
-# Some convenient links:
-# - https://github.com/actions/virtual-environments/blob/master/images/win/Windows2019-Readme.md
-#
-
-name: CI-windows
-
-on: [push,pull_request]
-
-permissions:
-  contents: read
-
-defaults:
-  run:
-    shell: cmd
-    
-jobs:
-
-  build:
-    strategy:
-      matrix:
-        os: [windows-2022, windows-2025, windows-11-arm]
-        config: [Release, Debug]
-      fail-fast: false
-
-    runs-on: ${{ matrix.os }}
-
-    steps:
-      - uses: actions/checkout@v6
-        with:
-          persist-credentials: false
-
-      - name: Setup msbuild.exe
-        uses: microsoft/setup-msbuild@v2
-
-      - name: Set up Python
-        uses: actions/setup-python@v6
-        with:
-          python-version: '3.14'
-          check-latest: true
-
-      - name: Install missing Python packages
-        run: |
-          python -m pip install pip --upgrade || exit /b !errorlevel!
-          python -m pip install pytest || exit /b !errorlevel!
-
-      - name: Run CMake
-        run: |
-          cmake -G "Visual Studio 17 2022" -A x64 -Werror=dev --warn-uninitialized -DCMAKE_COMPILE_WARNING_AS_ERROR=On . || exit /b !errorlevel!
-
-      - name: Build
-        run: |
-           msbuild -m simplecpp.sln /p:Configuration=${{ matrix.config }} /p:Platform=x64 || exit /b !errorlevel!
-           
-      - name: Test
-        run: |
-          .\${{ matrix.config }}\testrunner.exe || exit /b !errorlevel!
-
-      - name: Selfcheck
-        run: |
-          .\${{ matrix.config }}\simplecpp.exe simplecpp.cpp -e || exit /b !errorlevel!
-
-      - name: integration test
-        run: |
-          set SIMPLECPP_EXE_PATH=.\${{ matrix.config }}\simplecpp.exe
-          python -m pytest integration_test.py -vv || exit /b !errorlevel!
-
-      - name: Run CMake (c++17)
-        run: |
-          cmake -S . -B build.cxx17 -G "Visual Studio 17 2022" -A x64 -Werror=dev --warn-uninitialized -DCMAKE_CXX_STANDARD=17 -DCMAKE_COMPILE_WARNING_AS_ERROR=On || exit /b !errorlevel!
-
-      - name: Build (c++17)
-        run: |
-          msbuild -m build.cxx17\simplecpp.sln /p:Configuration=${{ matrix.config }} /p:Platform=x64 || exit /b !errorlevel!
-
-      - name: Run CMake (c++20)
-        run: |
-          cmake -S . -B build.cxx20 -G "Visual Studio 17 2022" -A x64 -Werror=dev --warn-uninitialized -DCMAKE_CXX_STANDARD=20 -DCMAKE_COMPILE_WARNING_AS_ERROR=On || exit /b !errorlevel!
-
-      - name: Build (c++20)
-        run: |
-          msbuild -m build.cxx20\simplecpp.sln /p:Configuration=${{ matrix.config }} /p:Platform=x64 || exit /b !errorlevel!
-    
diff --git a/.github/workflows/clang-tidy.yml b/.github/workflows/clang-tidy.yml
deleted file mode 100644
index 333672d7..00000000
--- a/.github/workflows/clang-tidy.yml
+++ /dev/null
@@ -1,51 +0,0 @@
-# Syntax reference https://help.github.com/en/actions/reference/workflow-syntax-for-github-actions
-# Environment reference https://help.github.com/en/actions/reference/virtual-environments-for-github-hosted-runners
-name: clang-tidy
-
-on: [push, pull_request]
-
-permissions:
-  contents: read
-
-jobs:
-  build:
-
-    runs-on: ubuntu-24.04
-
-    steps:
-      - uses: actions/checkout@v6
-        with:
-          persist-credentials: false
-
-      # the man-db trigger causes package installations to stall for several minutes at times. so just drop the package.
-      # see https://github.com/actions/runner/issues/4030
-      - name: Remove man-db package
-        run: |
-          sudo apt-get update
-          sudo apt-get remove man-db
-
-      - name: Install missing software
-        run: |
-          sudo apt-get update
-          sudo apt-get install -y cmake make
-
-      - name: Install clang
-        run: |
-          wget https://apt.llvm.org/llvm.sh
-          chmod +x llvm.sh
-          sudo ./llvm.sh 22
-          sudo apt-get install clang-tidy-22
-
-      - name: Verify clang-tidy configuration
-        run: |
-          clang-tidy-22 --verify-config
-
-      - name: Prepare CMake
-        run: |
-          cmake -S . -B cmake.output -Werror=dev --warn-uninitialized -DCMAKE_CXX_STANDARD=23 -DCMAKE_COMPILE_WARNING_AS_ERROR=On -DCMAKE_EXPORT_COMPILE_COMMANDS=ON
-        env:
-          CXX: clang-22
-
-      - name: Clang-Tidy
-        run: |
-          run-clang-tidy-22 -q -j $(nproc) -enable-check-profile -p=cmake.output
diff --git a/.github/workflows/format.yml b/.github/workflows/format.yml
deleted file mode 100644
index e9f1361d..00000000
--- a/.github/workflows/format.yml
+++ /dev/null
@@ -1,62 +0,0 @@
-# Syntax reference https://help.github.com/en/actions/reference/workflow-syntax-for-github-actions
-# Environment reference https://help.github.com/en/actions/reference/virtual-environments-for-github-hosted-runners
-name: format
-
-on:
-  push:
-    branches:
-      - 'master'
-      - 'releases/**'
-      - '1.*'
-    tags:
-      - '1.*'
-  pull_request:
-
-permissions:
-  contents: read
-
-jobs:
-  format:
-
-    runs-on: ubuntu-22.04
-
-    defaults:
-      run:
-        shell: bash -euo pipefail {0}
-
-    env:
-      UNCRUSTIFY_INSTALL_DIR: ${{ github.workspace }}/runformat-uncrustify
-
-    steps:
-      - uses: actions/checkout@v6
-        with:
-          persist-credentials: false
-
-      - name: Determine uncrustify version
-        id: get-uncrustify-version
-        run: |
-          version="$(./runformat --expected-uncrustify-version)"
-          echo "Expected uncrustify version: $version"
-          echo "version=$version" >> "$GITHUB_OUTPUT"
-
-      - name: Set UNCRUSTIFY_VERSION env variable
-        run: |
-          version=$(./runformat --expected-uncrustify-version)
-          echo "version [$version]"
-          echo "UNCRUSTIFY_VERSION=${version}" >> "$GITHUB_ENV"
-
-      - name: Cache uncrustify
-        uses: actions/cache@v4
-        id: cache-uncrustify
-        with:
-          path: ${{ env.UNCRUSTIFY_INSTALL_DIR }}
-          key: ${{ runner.os }}-uncrustify-${{ steps.get-uncrustify-version.outputs.version }}
-
-      - name: Install uncrustify
-        if: steps.cache-uncrustify.outputs.cache-hit != 'true'
-        run: |
-          ./runformat --install --install-dir "${UNCRUSTIFY_INSTALL_DIR}"
-
-      - name: Uncrustify check
-        run: |
-          ./runformat