rdmpw3275m-changelog-20260901-1826-ccache-and-cascadelake-optimizations

Configured ccache compiler wrappers (Option A), performance tuning, Cascade Lake compiler optimization flags, and Homebrew forced source build optimization on rdmpw3275m.

Scope

Host: rdmpw3275m (macOS 26.7 Intel Xeon W-3275M 28-Core / 56 Threads)

Exact Files Touched

/Users/richh/.zshrc: Added ccache wrappers, Cascade Lake compiler flags (CFLAGS, CXXFLAGS, RUSTFLAGS), 56-thread parallel compilation variables (MAKEFLAGS, CMAKE_BUILD_PARALLEL_LEVEL, HOMEBREW_MAKE_JOBS), and Homebrew source optimization variables/aliases (HOMEBREW_OPTFLAGS, HOMEBREW_ARCH, HOMEBREW_OPTIMIZATION_LEVEL, brew-upgrade, brew-install, brew-reinstall).
/Users/richh/.ccache/ccache.conf: Created optimized ccache configuration.
Backup: /Users/richh/.zshrc.bak.20260901182023

Configuration Applied

~/.ccache/ccache.conf:

# ccache configuration - rdmpw3275m
max_size = 25.0G
base_dir = /Users/richh/dev
sloppiness = time_macros,include_file_mtime,include_file_ctime,file_macro
compression = true
compression_level = 1
compiler_check = content
inode_cache = true

~/.zshrc:

# --- ccache compiler wrappers (portable across Apple Silicon & Intel) ---
if command -v brew >/dev/null 2>&1; then
  _ccache_libexec="$(brew --prefix ccache 2>/dev/null)/libexec"
  if [[ -d "$_ccache_libexec" ]]; then
    path=("$_ccache_libexec" $path)
  fi
  unset _ccache_libexec
fi

# --- Cascade Lake architecture optimization flags ---
# Intel Xeon W-3275M (Cascade Lake: AVX-512F/DQ/CD/BW/VL/VNNI - 56 threads)
export CFLAGS="-march=cascadelake -mtune=cascadelake -O3 -pipe"
export CXXFLAGS="-march=cascadelake -mtune=cascadelake -O3 -pipe"
export RUSTFLAGS="-C target-cpu=cascadelake"
export MAKEFLAGS="-j$(sysctl -n hw.ncpu)"
export CMAKE_BUILD_PARALLEL_LEVEL="$(sysctl -n hw.ncpu)"
export HOMEBREW_MAKE_JOBS="$(sysctl -n hw.ncpu)"
export HOMEBREW_OPTIMIZATION_LEVEL="O3"
export HOMEBREW_OPTFLAGS="-march=cascadelake -mtune=cascadelake"
export HOMEBREW_ARCH="cascadelake"

# Homebrew source build aliases
alias brew-upgrade="brew upgrade --build-from-source --greedy"
alias brew-install="brew install --build-from-source"
alias brew-reinstall="brew reinstall --build-from-source"

Verification Evidence

Evaluated environment exports:
- HOMEBREW_MAKE_JOBS = 56
- HOMEBREW_OPTIMIZATION_LEVEL = O3
- HOMEBREW_OPTFLAGS = -march=cascadelake -mtune=cascadelake
- HOMEBREW_ARCH = cascadelake
Verified aliases: brew-upgrade, brew-install, brew-reinstall mapped to --build-from-source.
Verified compiler resolution and AVX-512 VNNI test build.

How to Undo

Restore ~/.zshrc: cp ~/.zshrc.bak.20260901182023 ~/.zshrc and rm ~/.ccache/ccache.conf.