From af915b27164115db4263c4e7a5e7736c2b86647c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Vladim=C3=ADr=20Vondru=C5=A1?= <mosra@centrum.cz>
Date: Thu, 5 Jul 2012 21:29:11 +0200
Subject: [PATCH] GCC 4.5 compatibility: GCC badly optimizes
 Matrix4::rotation*().

Redone in a way that the unit test passes.
---
 src/Math/Matrix.h  |  6 ++++++
 src/Math/Matrix4.h | 13 +++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/src/Math/Matrix.h b/src/Math/Matrix.h
index 24dee3c7d..d5a18dad9 100644
--- a/src/Math/Matrix.h
+++ b/src/Math/Matrix.h
@@ -248,6 +248,9 @@ template<size_t size, class T> class Matrix {
             return Matrix<size, T>(first, next...);
         }
 
+    #ifdef MAGNUM_GCC45_COMPATIBILITY
+    protected:
+    #endif
         /* Used internally instead of [][], because GCC does some heavy
            optimalization in release mode which breaks it */
         inline T& operator()(size_t col, size_t row) {
@@ -257,6 +260,9 @@ template<size_t size, class T> class Matrix {
             return _data[col*size+row];
         }
 
+    #ifdef MAGNUM_GCC45_COMPATIBILITY
+    private:
+    #endif
         T _data[size*size];
 };
 
diff --git a/src/Math/Matrix4.h b/src/Math/Matrix4.h
index 87e585f92..12bcf7cee 100644
--- a/src/Math/Matrix4.h
+++ b/src/Math/Matrix4.h
@@ -120,18 +120,31 @@ template<class T> class Matrix4: public Matrix<4, T> {
 
         /** @brief Rotation and scaling part of the matrix */
         inline Matrix3<T> rotationScaling() const {
+            #ifndef MAGNUM_GCC45_COMPATIBILITY /* GCC 4.5 badly optimizes this */
             return Matrix3<T>::from(
                 (*this)[0].xyz(),
                 (*this)[1].xyz(),
                 (*this)[2].xyz());
+            #else
+            return Matrix3<T>(
+                (*this)(0, 0), (*this)(0, 1), (*this)(0, 2),
+                (*this)(1, 0), (*this)(1, 1), (*this)(1, 2),
+                (*this)(2, 0), (*this)(2, 1), (*this)(2, 2));
+            #endif
         }
 
         /** @brief Rotation part of the matrix */
         inline Matrix3<T> rotation() const {
             return Matrix3<T>::from(
+                #ifndef MAGNUM_GCC45_COMPATIBILITY /* GCC 4.5 badly optimizes this */
                 (*this)[0].xyz().normalized(),
                 (*this)[1].xyz().normalized(),
                 (*this)[2].xyz().normalized());
+                #else
+                Vector3<T>((*this)(0, 0), (*this)(0, 1), (*this)(0, 2)).normalized(),
+                Vector3<T>((*this)(1, 0), (*this)(1, 1), (*this)(1, 2)).normalized(),
+                Vector3<T>((*this)(2, 0), (*this)(2, 1), (*this)(2, 2)).normalized());
+                #endif
         }
 
         MAGNUM_MATRIX_SUBCLASS_IMPLEMENTATION(Matrix4, Vector4, 4)