Move setting of compiler optimization flag to top-level CMakeLists.txt (#1000)

Setting `-O3` or `/O2` does not have to be done in each
sub-CMakeLists.txt file. It can be done once in the top-level one.

Author: mhucka

CMakeLists.txt

@@ -52,6 +52,15 @@ else()
     endif()
 endif()
 
+# Add optimization flags to any configuration that is NOT Debug. Note: CMake
+# will automatically use the appropriate debug flags (e.g., /Od and /Zi for
+# MSVC, or -O0 -g for GCC/Clang), so there's no need to do that part.
+if(MSVC)
+    add_compile_options($<$<NOT:$<CONFIG:Debug>>:/O2>)
+else()
+    add_compile_options($<$<NOT:$<CONFIG:Debug>>:-O3>)
+endif()
+
 find_package(OpenMP REQUIRED)
 
 # Always build the basic part.

pybind_interface/avx2/CMakeLists.txt

@@ -15,13 +15,10 @@
 cmake_minimum_required(VERSION 3.28)
 project(qsim)
 
-if(WIN32)
+if(MSVC)
     add_compile_options(/arch:AVX2 /openmp)
-    # Add /O2 to any configuration that is NOT Debug.
-    # This prevents a conflict with /RTC1 in DEBUG builds.
-    add_compile_options($<$<NOT:$<CONFIG:Debug>>:/O2>)
-elseif(LINUX)
-    add_compile_options(-mavx2 -mfma -O3 -flto=auto)
+else()
+    add_compile_options(-mavx2 -mfma -flto=auto)
     execute_process(
         COMMAND bash --noprofile -c "grep -qs bmi2 /proc/cpuinfo"
         RESULT_VARIABLE _EXIT_CODE

pybind_interface/avx512/CMakeLists.txt

@@ -15,13 +15,10 @@
 cmake_minimum_required(VERSION 3.28)
 project(qsim)
 
-if(WIN32)
+if(MSVC)
     add_compile_options(/arch:AVX512 /openmp)
-    # Add /O2 to any configuration that is NOT Debug.
-    # This prevents a conflict with /RTC1 in DEBUG builds.
-    add_compile_options($<$<NOT:$<CONFIG:Debug>>:/O2>)
 else()
-    add_compile_options(-mavx512f -mbmi2 -O3 -flto=auto)
+    add_compile_options(-mavx512f -mbmi2 -flto=auto)
 endif()
 
 if(APPLE)

pybind_interface/basic/CMakeLists.txt

@@ -15,13 +15,10 @@
 cmake_minimum_required(VERSION 3.28)
 project(qsim)
 
-if(WIN32)
+if(MSVC)
     add_compile_options(/openmp)
-    # Add /O2 to any configuration that is NOT Debug.
-    # This prevents a conflict with /RTC1 in DEBUG builds.
-    add_compile_options($<$<NOT:$<CONFIG:Debug>>:/O2>)
 else()
-    add_compile_options(-O3 -flto=auto)
+    add_compile_options(-flto=auto)
 endif()
 
 if(APPLE)

pybind_interface/cuda/CMakeLists.txt

@@ -15,14 +15,11 @@
 cmake_minimum_required(VERSION 3.28)
 project(qsim LANGUAGES CXX CUDA)
 
-if(WIN32)
+if(MSVC)
     # Always apply AVX2 and openmp on Windows
     add_compile_options(/openmp)
-    # Add /O2 to any configuration that is NOT Debug.
-    # This prevents a conflict with /RTC1 in DEBUG builds.
-    add_compile_options($<$<NOT:$<CONFIG:Debug>>:/O2>)
 else()
-    add_compile_options(-O3 -fno-lto)
+    add_compile_options(-fno-lto)
 endif()
 
 if(APPLE)

pybind_interface/custatevec/CMakeLists.txt

@@ -15,13 +15,10 @@
 cmake_minimum_required(VERSION 3.28)
 project(qsim LANGUAGES CXX CUDA)
 
-if(WIN32)
+if(MSVC)
     add_compile_options(/openmp)
-    # Add /O2 to any configuration that is NOT Debug.
-    # This prevents a conflict with /RTC1 in DEBUG builds.
-    add_compile_options($<$<NOT:$<CONFIG:Debug>>:/O2>)
 else()
-    add_compile_options(-O3 -fno-lto)
+    add_compile_options(-fno-lto)
 endif()
 
 if(APPLE)

pybind_interface/custatevecex/CMakeLists.txt

@@ -15,13 +15,10 @@
 cmake_minimum_required(VERSION 3.28)
 project(qsim LANGUAGES CXX CUDA)
 
-if(WIN32)
+if(MSVC)
     add_compile_options(/openmp)
-    # Add /O2 to any configuration that is NOT Debug.
-    # This prevents a conflict with /RTC1 in DEBUG builds.
-    add_compile_options($<$<NOT:$<CONFIG:Debug>>:/O2>)
 else()
-    add_compile_options(-O3 -fno-lto)
+    add_compile_options(-fno-lto)
 endif()
 
 if(APPLE)

pybind_interface/decide/CMakeLists.txt

@@ -18,13 +18,10 @@ project(qsim LANGUAGES CXX)
 include(CheckLanguage)
 check_language(CUDA)
 
-if(WIN32)
+if(MSVC)
     add_compile_options(/openmp)
-    # Add /O2 to any configuration that is NOT Debug.
-    # This prevents a conflict with /RTC1 in DEBUG builds.
-    add_compile_options($<$<NOT:$<CONFIG:Debug>>:/O2>)
 else()
-    add_compile_options(-O3 -fno-lto)
+    add_compile_options(-fno-lto)
 endif()
 
 if(APPLE)

pybind_interface/hip/CMakeLists.txt

@@ -15,13 +15,10 @@
 cmake_minimum_required(VERSION 3.28)
 project(qsim LANGUAGES CXX HIP)
 
-if(WIN32)
+if(MSVC)
     add_compile_options(/openmp)
-    # Add /O2 to any configuration that is NOT Debug.
-    # This prevents a conflict with /RTC1 in DEBUG builds.
-    add_compile_options($<$<NOT:$<CONFIG:Debug>>:/O2>)
 else()
-    add_compile_options(-O3 -fno-lto)
+    add_compile_options(-fno-lto)
 endif()
 
 include(../GetPybind11.cmake)

pybind_interface/sse/CMakeLists.txt

@@ -15,13 +15,10 @@
 cmake_minimum_required(VERSION 3.28)
 project(qsim)
 
-if(WIN32)
+if(MSVC)
     add_compile_options(/openmp)
-    # Add /O2 to any configuration that is NOT Debug.
-    # This prevents a conflict with /RTC1 in DEBUG builds.
-    add_compile_options($<$<NOT:$<CONFIG:Debug>>:/O2>)
 else()
-    add_compile_options(-msse4 -O3 -flto=auto)
+    add_compile_options(-msse4 -flto=auto)
 endif()
 
 if(APPLE)