[Build] Add LTO, PGO, and -march=native CMake options

CMakeLists.txt

@@ -1,5 +1,5 @@
 # Projects Settings
-cmake_minimum_required (VERSION 3.10...3.22)
+cmake_minimum_required (VERSION 3.13...3.22)
 
 # Set OSX minimum version parity with Qt project
 set(CMAKE_OSX_DEPLOYMENT_TARGET 10.15)
@@ -18,6 +18,15 @@ option(SC_USE_FLAT_INSTALL "Install files into a flat folder structure" ${WIN32}
 
 option(SC_EVENT_QUEUE_DEBUG "Enable Event Queue Debug Info" OFF)
 
+option(SC_LTO          "Enable Link-Time Optimization"         OFF)
+option(SC_MARCH_NATIVE "Tune for the host CPU (-march=native)" OFF)
+option(SC_PGO_GENERATE "Instrument for PGO profile collection" OFF)
+set(SC_PGO_USE "" CACHE STRING "Absolute path to .profdata for PGO-optimized build")
+
+if(SC_PGO_GENERATE AND SC_PGO_USE)
+  message(FATAL_ERROR "SC_PGO_GENERATE and SC_PGO_USE are mutually exclusive.")
+endif()
+
 set(CMAKE_CXX_STANDARD 17 CACHE STRING "C++ standard to conform to")
 set(CMAKE_CXX_STANDARD_REQUIRED YES)
 set(CMAKE_CXX_EXTENSIONS OFF)
@@ -51,6 +60,34 @@ function(sc_common_compiler_options target)
     $<$<CXX_COMPILER_ID:MSVC>:/utf-8> # required for fmt 11.2
     $<$<NOT:$<CXX_COMPILER_ID:MSVC>>:-Wall -Wextra -Wpedantic>
   )
+  if(NOT MSVC)
+    set(_sc_extra_flags "")
+    if(SC_LTO)
+      list(APPEND _sc_extra_flags
+        $<$<CXX_COMPILER_ID:Clang,AppleClang>:-flto=thin>
+        $<$<CXX_COMPILER_ID:GNU>:-flto>
+      )
+    endif()
+    if(SC_MARCH_NATIVE)
+      list(APPEND _sc_extra_flags -march=native)
+    endif()
+    if(SC_PGO_GENERATE)
+      list(APPEND _sc_extra_flags
+        $<$<CXX_COMPILER_ID:Clang,AppleClang>:-fprofile-instr-generate>
+        $<$<CXX_COMPILER_ID:GNU>:-fprofile-generate>
+      )
+    endif()
+    if(SC_PGO_USE)
+      list(APPEND _sc_extra_flags
+        $<$<CXX_COMPILER_ID:Clang,AppleClang>:-fprofile-instr-use=${SC_PGO_USE}>
+        $<$<CXX_COMPILER_ID:GNU>:-fprofile-use=${SC_PGO_USE}>
+      )
+    endif()
+    if(_sc_extra_flags)
+      target_compile_options(${target} PRIVATE ${_sc_extra_flags})
+      target_link_options(${target} PRIVATE ${_sc_extra_flags})
+    endif()
+  endif()
 endfunction()
 
 

scripts/benchmark.sh

@@ -0,0 +1,121 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# ---------- Config ----------
+ITERATIONS=1000
+THREADS=4
+RUNS=3
+PROFILE="profiles/MID1/MID1_Priest_Shadow.simc"
+WORKDIR="${TMPDIR:-/tmp}/simc-bench"
+SRCDIR="$(cd "$(dirname "$0")/.." && pwd)"
+
+# ---------- Helpers ----------
+die()  { echo "FATAL: $*" >&2; exit 1; }
+info() { echo "==> $*" >&2; }
+
+best_of() {
+  printf '%s\n' "$@" | sort -g | head -1
+}
+
+bench_variant() {
+  local binary="$1" label="$2"
+  local best=999999 t
+  for i in $(seq 1 "$RUNS"); do
+    info "  run $i/$RUNS"
+    t=$( { /usr/bin/time -p "$binary" \
+        "$SRCDIR/$PROFILE" \
+        iterations="$ITERATIONS" \
+        threads="$THREADS" \
+        output=/dev/null \
+        html=/dev/null ; } 2>&1 | awk '/^real/ {print $2}' )
+    [[ -n "$t" ]] || die "failed to capture time for $label run $i"
+    best=$(best_of "$best" "$t")
+  done
+  echo "$best"
+}
+
+cmake_build() {
+  local builddir="$1"; shift
+  cmake -S "$SRCDIR" -B "$builddir" \
+    -DCMAKE_BUILD_TYPE=Release \
+    -DBUILD_GUI=OFF \
+    -DBUILD_TESTING=OFF \
+    "$@"
+  cmake --build "$builddir" --target simc -j "$(nproc 2>/dev/null || sysctl -n hw.ncpu 2>/dev/null || echo 4)"
+}
+
+# ---------- Pre-checks ----------
+command -v cmake >/dev/null || die "cmake not found"
+
+# llvm-profdata: try PATH first, then xcrun (macOS Xcode toolchain)
+if command -v llvm-profdata >/dev/null 2>&1; then
+  LLVM_PROFDATA="llvm-profdata"
+elif xcrun -f llvm-profdata >/dev/null 2>&1; then
+  LLVM_PROFDATA="$(xcrun -f llvm-profdata)"
+else
+  die "llvm-profdata not found (install llvm toolchain)"
+fi
+[[ -f "$SRCDIR/CMakeLists.txt" ]] || die "cannot find $SRCDIR/CMakeLists.txt"
+[[ -f "$SRCDIR/$PROFILE" ]]       || die "cannot find $SRCDIR/$PROFILE"
+
+rm -rf "$WORKDIR"
+mkdir -p "$WORKDIR"
+
+# ---------- 1. Baseline ----------
+info "Building baseline (Release, no extras)"
+cmake_build "$WORKDIR/build-baseline"
+info "Benchmarking baseline"
+TIME_BASELINE=$(bench_variant "$WORKDIR/build-baseline/simc" "baseline")
+info "  best: ${TIME_BASELINE}s"
+
+# ---------- 2. LTO + march=native ----------
+info "Building LTO + march=native"
+cmake_build "$WORKDIR/build-lto" -DSC_LTO=ON -DSC_MARCH_NATIVE=ON
+info "Benchmarking LTO + march=native"
+TIME_LTO=$(bench_variant "$WORKDIR/build-lto/simc" "lto+march")
+info "  best: ${TIME_LTO}s"
+
+# ---------- 3. PGO ----------
+info "Building PGO instrumented"
+cmake_build "$WORKDIR/build-pgo-gen" -DSC_PGO_GENERATE=ON
+
+info "Collecting PGO profile data"
+LLVM_PROFILE_FILE="$WORKDIR/pgo-%p.profraw" \
+  "$WORKDIR/build-pgo-gen/simc" \
+  "$SRCDIR/$PROFILE" \
+  iterations="$ITERATIONS" \
+  threads="$THREADS" \
+  output=/dev/null \
+  html=/dev/null
+
+info "Merging profile data"
+PROFDATA="$WORKDIR/merged.profdata"
+"$LLVM_PROFDATA" merge -output="$PROFDATA" "$WORKDIR"/pgo-*.profraw
+
+info "Building PGO optimized (+ LTO + march=native)"
+cmake_build "$WORKDIR/build-pgo-use" \
+  -DSC_LTO=ON \
+  -DSC_MARCH_NATIVE=ON \
+  -DSC_PGO_USE="$PROFDATA"
+
+info "Benchmarking PGO optimized"
+TIME_PGO=$(bench_variant "$WORKDIR/build-pgo-use/simc" "pgo")
+info "  best: ${TIME_PGO}s"
+
+# ---------- Results ----------
+echo ""
+echo "=============================================="
+echo " SimC build benchmark  (best of $RUNS runs)"
+echo " iterations=$ITERATIONS  threads=$THREADS"
+echo "=============================================="
+printf "%-28s %8s %8s\n" "Variant" "Time(s)" "Speedup"
+echo "----------------------------------------------"
+
+for label_key in "Release (baseline):$TIME_BASELINE" "LTO + march=native:$TIME_LTO" "PGO + LTO + march=native:$TIME_PGO"; do
+  label="${label_key%%:*}"
+  t="${label_key#*:}"
+  speedup=$(awk "BEGIN {printf \"%.2fx\", $TIME_BASELINE / $t}")
+  printf "%-28s %8s %8s\n" "$label" "$t" "$speedup"
+done
+echo "=============================================="
+echo "Build artifacts in: $WORKDIR"