From fe006897572de0fa9a9efc1d5937837d110f4da8 Mon Sep 17 00:00:00 2001
From: Alexander Alekhin <alexander.alekhin@itseez.com>
Date: Tue, 6 Oct 2015 20:42:21 +0300
Subject: [PATCH] workaround for 32-bit OS on 64-bit x86 CPU

---
 cmake/OpenCVDetectCXXCompiler.cmake | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/cmake/OpenCVDetectCXXCompiler.cmake b/cmake/OpenCVDetectCXXCompiler.cmake
index 360a08fec1..bd3cf49d02 100644
--- a/cmake/OpenCVDetectCXXCompiler.cmake
+++ b/cmake/OpenCVDetectCXXCompiler.cmake
@@ -116,6 +116,12 @@ elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "^(aarch64.*|AARCH64.*)")
   set(AARCH64 1)
 endif()
 
+# Workaround for 32-bit operating systems on 64-bit x86_64 processor
+if(X86_64 AND CMAKE_SIZEOF_VOID_P EQUAL 4 AND NOT FORCE_X86_64)
+  message(STATUS "sizeof(void) = 4 on x86 / x86_64 processor. Assume 32-bit compilation mode (X86=1)")
+  unset(X86_64)
+  set(X86 1)
+endif()
 
 # Similar code exists in OpenCVConfig.cmake
 if(NOT DEFINED OpenCV_STATIC)