From 227aee84e2331cae0f400fb1eaf7b31d74820a6b Mon Sep 17 00:00:00 2001
From: psychocrypt <psychocrypt@users.noreply.github.com>
Date: Mon, 23 Oct 2017 09:39:41 +0200
Subject: [PATCH] prefere AMD OpenCL over NVIDIA, Intel

fix #56

Search for AMD OpenCL inlcude path and libaries to prioritize the AMD implementation over NVIDIA and Intel.
---
 CMakeLists.txt | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9ae7b26..1cc2ef6 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -180,6 +180,38 @@ list(APPEND CMAKE_PREFIX_PATH "$ENV{CMAKE_PREFIX_PATH}")
 
 option(OpenCL_ENABLE "Enable or disable OpenCL spport (AMD GPU support)" ON)
 if(OpenCL_ENABLE)
+    # try to find AMD OpenCL before NVIDIA OpenCL
+    find_path(OpenCL_INCLUDE_DIR
+        NAMES
+            CL/cl.h
+            OpenCL/cl.h
+        NO_DEFAULT_PATH
+        PATHS
+            ENV "OpenCL_ROOT"
+            ENV AMDAPPSDKROOT
+            ENV ATISTREAMSDKROOT
+            ENV "PROGRAMFILES(X86)"
+        PATH_SUFFIXES
+            include
+            OpenCL/common/inc
+            "AMD APP/include")
+
+    find_library(OpenCL_LIBRARY
+        NAMES 
+            OpenCL
+            OpenCL.lib
+        NO_DEFAULT_PATH
+        PATHS
+            ENV "OpenCL_ROOT"
+            ENV AMDAPPSDKROOT
+            ENV ATISTREAMSDKROOT
+            ENV "PROGRAMFILES(X86)"
+        PATH_SUFFIXES
+            "AMD APP/lib/x86_64"
+            lib/x86_64
+            lib/x64
+            OpenCL/common/lib/x64)
+    # find package will use the previews searched path variables
     find_package(OpenCL)
     if(OpenCL_FOUND)
         include_directories(SYSTEM ${OpenCL_INCLUDE_DIRS})