From d7e36f9f5b875a79f24ec4664a9c1504a11bc226 Mon Sep 17 00:00:00 2001
From: makise-homura <akemi_homura@kurisa.ch>
Date: Tue, 18 Aug 2020 15:50:50 +0300
Subject: [PATCH] cmake: Conditionalize -fopenmp-simd

---
 CMakeLists.txt | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 56bb1a3da..63d68fae6 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -62,6 +62,8 @@ set(SCRIPTING_ENABLED OFF CACHE BOOL "Internal global cmake variable" FORCE)
 include(ObsHelpers)
 include(ObsCpack)
 include(GNUInstallDirs)
+include(CheckCCompilerFlag)
+include(CheckCXXCompilerFlag)
 
 # Must be a string in the format of "x.x.x-rcx"
 if(DEFINED RELEASE_CANDIDATE)
@@ -133,8 +135,16 @@ else()
 	set(NEEDS_SIMDE "1")
 	add_definitions(-DNEEDS_SIMDE=1)
 	if(CMAKE_COMPILER_IS_GNUCC OR CMAKE_COMPILER_IS_GNUCXX)
-		set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fopenmp-simd -DSIMDE_ENABLE_OPENMP")
-		set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fopenmp-simd -DSIMDE_ENABLE_OPENMP")
+		set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DSIMDE_ENABLE_OPENMP")
+		set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DSIMDE_ENABLE_OPENMP")
+		CHECK_C_COMPILER_FLAG("-fopenmp-simd" C_COMPILER_SUPPORTS_OPENMP_SIMD)
+		if(C_COMPILER_SUPPORTS_OPENMP_SIMD)
+			set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fopenmp-simd")
+		endif()
+		CHECK_CXX_COMPILER_FLAG("-fopenmp-simd" CXX_COMPILER_SUPPORTS_OPENMP_SIMD)
+		if(CXX_COMPILER_SUPPORTS_OPENMP_SIMD)
+			set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fopenmp-simd")
+		endif()
 	endif()
 	set(ARCH_SIMD_FLAGS "")
 	message(STATUS "No Native SSE2 SIMD Support - Using SIMDE")