From b3b3c225e8aa6996208eb88a97e26a94de7d726e Mon Sep 17 00:00:00 2001
From: Christoph Junghans <junghans@lanl.gov>
Date: Fri, 11 May 2018 15:27:24 -0600
Subject: [PATCH] cmake: check that USER-INTEL flags actually work

---
 cmake/CMakeLists.txt | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/cmake/CMakeLists.txt b/cmake/CMakeLists.txt
index 59f6545a5c..e4a8231684 100644
--- a/cmake/CMakeLists.txt
+++ b/cmake/CMakeLists.txt
@@ -182,7 +182,7 @@ if(PKG_KSPACE)
   if(NOT FFT STREQUAL "KISSFFT")
     find_package(${FFT} REQUIRED)
     if(NOT FFT STREQUAL "FFTW3F")
-	    add_definitions(-DFFT_FFTW)
+      add_definitions(-DFFT_FFTW)
     else()
       add_definitions(-DFFT_${FFT})
     endif()
@@ -614,7 +614,13 @@ if(PKG_USER-INTEL)
     else()
       set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -xHost")
     endif()
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -qopenmp -qno-offload -fno-alias -ansi-alias -restrict -DLMP_INTEL_USELRT -DLMP_USE_MKL_RNG -O2 -fp-model fast=2 -no-prec-div -qoverride-limits -qopt-zmm-usage=high")
+    include(CheckCXXCompilerFlag)
+    foreach(_FLAG -qopenmp -qno-offload -fno-alias -ansi-alias -restrict -DLMP_INTEL_USELRT -DLMP_USE_MKL_RNG -O2 "-fp-model fast=2" -no-prec-div -qoverride-limits -qopt-zmm-usage=high)
+      check_cxx_compiler_flag("${__FLAG}" COMPILER_SUPPORTS${_FLAG})
+      if(COMPILER_SUPPORTS${_FLAG})
+        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${_FLAG}")
+      endif()
+    endforeach()
     set(USER-INTEL_SOURCES_DIR ${LAMMPS_SOURCE_DIR}/USER-INTEL)
     set(USER-INTEL_SOURCES ${USER-INTEL_SOURCES_DIR}/intel_preprocess.h
                            ${USER-INTEL_SOURCES_DIR}/intel_buffers.h
@@ -856,5 +862,5 @@ if(ENABLED_GPU)
   endif()
 endif()
 if(PKG_KSPACE)
-	message(STATUS "Using ${FFT} as FFT")
+  message(STATUS "Using ${FFT} as FFT")
 endif()