Fixed most of the floating-point accuracy problems for x86 gcc

cmake/OpenCVCompilerOptions.cmake

@@ -109,9 +109,13 @@ if(CMAKE_COMPILER_IS_GNUCXX)
 
   if(X86 OR X86_64)
     if(NOT APPLE AND CMAKE_SIZEOF_VOID_P EQUAL 4)
+       if(ENABLE_SSE2)
+         set(OPENCV_EXTRA_C_FLAGS_RELEASE "${OPENCV_EXTRA_C_FLAGS_RELEASE} -mfpmath=sse")# !! important - be on the same wave with x64 compilers
+       else()
          set(OPENCV_EXTRA_C_FLAGS_RELEASE "${OPENCV_EXTRA_C_FLAGS_RELEASE} -mfpmath=387")
        endif()
     endif()
+  endif()
 
   # Profiling?
   if(ENABLE_PROFILING)

modules/core/src/stat.cpp

@@ -834,7 +834,6 @@ float normL2Sqr_(const float* a, const float* b, int n)
     }
     else
 #endif
-    //vz why do we need unroll here? no sse = no need to unroll
 	{
         for( ; j <= n - 4; j += 4 )
         {
@@ -875,7 +874,6 @@ float normL1_(const float* a, const float* b, int n)
     }
     else
 #endif
-     //vz no need to unroll here - if no sse
     {
         for( ; j <= n - 4; j += 4 )
         {
@@ -916,7 +914,6 @@ int normL1_(const uchar* a, const uchar* b, int n)
     }
     else
 #endif
-     //vz why do we need unroll here? no sse = no unroll
     {
         for( ; j <= n - 4; j += 4 )
         {

modules/nonfree/test/test_features2d.cpp

@@ -992,7 +992,7 @@ TEST( Features2d_DescriptorExtractor_SIFT, regression )
 
 TEST( Features2d_DescriptorExtractor_SURF, regression )
 {
-    CV_DescriptorExtractorTest<L2<float> > test( "descriptor-surf",  0.035f,
+    CV_DescriptorExtractorTest<L2<float> > test( "descriptor-surf",  0.05f,
                                                  DescriptorExtractor::create("SURF"), 0.147372f );
     test.safe_run();
 }