# Current compiler flags (Line 7)
CXXFLAGS = -std=c++17 -O3 -march=native -mtune=native -pthread -Wall -Wextra

# Missing optimizations:
# - Link Time Optimization (LTO)
# - Function inlining optimizations  
# - Loop optimization flags
# - Vectorization optimizations
# - Profile-guided optimization support
# - Debug symbol stripping for release builds

# Enhanced Makefile with comprehensive optimization settings

# Compiler selection with version detection
CXX := $(shell which g++-12 2>/dev/null || which g++-11 2>/dev/null || which g++ 2>/dev/null)
CC := $(shell which gcc-12 2>/dev/null || which gcc-11 2>/dev/null || which gcc 2>/dev/null)

# Build type detection
BUILD_TYPE ?= release
DEBUG ?= 0

# Base flags
BASE_CXXFLAGS = -std=c++17 -pthread -Wall -Wextra -Wpedantic

# Debug build optimizations
DEBUG_CXXFLAGS = $(BASE_CXXFLAGS) \
	-g3 -O0 \
	-DDEBUG \
	-fsanitize=address \
	-fsanitize=undefined \
	-fno-omit-frame-pointer \
	-fstack-protector-strong

# Release build optimizations
RELEASE_CXXFLAGS = $(BASE_CXXFLAGS) \
	-O3 -DNDEBUG \
	-march=native -mtune=native \
	-flto=auto \
	-ffast-math \
	-funroll-loops \
	-finline-functions \
	-fomit-frame-pointer \
	-fno-stack-protector \
	-DEIGEN_NO_DEBUG \
	-DARMA_NO_DEBUG

# Performance build optimizations (for benchmarking)
PERFORMANCE_CXXFLAGS = $(RELEASE_CXXFLAGS) \
	-fprofile-generate \
	-fprofile-correction

# Link-time optimizations
RELEASE_LDFLAGS = -flto=auto -s -Wl,--gc-sections -Wl,--strip-all
DEBUG_LDFLAGS = -fsanitize=address -fsanitize=undefined

# Platform-specific optimizations
ifeq ($(shell uname),Darwin)
    # macOS optimizations
    RELEASE_CXXFLAGS += -framework Accelerate -DUSE_ACCELERATE
    ifeq ($(shell sysctl -n machdep.cpu.brand_string | grep -c "Apple"),1)
        # Apple Silicon specific
        RELEASE_CXXFLAGS += -mcpu=apple-a14 -mfpu=neon
    endif
else ifeq ($(shell uname),Linux)
    # Linux optimizations
    ARCH := $(shell uname -m)
    ifeq ($(ARCH),x86_64)
        # Intel/AMD x86_64 optimizations
        RELEASE_CXXFLAGS += -mavx2 -mfma -mbmi -mbmi2
        # Check for AVX-512 support
        ifneq ($(shell grep -c avx512 /proc/cpuinfo 2>/dev/null),0)
            RELEASE_CXXFLAGS += -mavx512f -mavx512cd
        endif
    else ifeq ($(ARCH),aarch64)
        # ARM64 optimizations
        RELEASE_CXXFLAGS += -mcpu=native -mfpu=neon
    endif
endif

# Build type selection
ifeq ($(BUILD_TYPE),debug)
    CXXFLAGS = $(DEBUG_CXXFLAGS)
    LDFLAGS += $(DEBUG_LDFLAGS)
else ifeq ($(BUILD_TYPE),performance)
    CXXFLAGS = $(PERFORMANCE_CXXFLAGS)
    LDFLAGS += $(RELEASE_LDFLAGS)
else
    CXXFLAGS = $(RELEASE_CXXFLAGS)
    LDFLAGS += $(RELEASE_LDFLAGS)
endif

# Profile-guided optimization targets
pgo-generate: CXXFLAGS += -fprofile-generate
pgo-generate: $(TARGET)

pgo-use: CXXFLAGS += -fprofile-use -fprofile-correction
pgo-use: $(TARGET)

# Optimized build workflow
pgo-optimized: pgo-generate
	@echo "Running profile generation workload..."
	./$(TARGET) --cache-hierarchy --size 1024
	./$(TARGET) --pattern matrix --size 512
	@echo "Building optimized binary with profile data..."
	$(MAKE) clean
	$(MAKE) pgo-use
	@echo "Profile-guided optimization complete"