add optimized quaternion * quaternion product specialization for

float/SSE using code from Rohit Garg

Eigen/Geometry

@@ -45,6 +45,10 @@ namespace Eigen {
 #include "src/Geometry/ParametrizedLine.h"
 #include "src/Geometry/AlignedBox.h"
 
+#if defined EIGEN_VECTORIZE_SSE
+  #include "src/Geometry/arch/Geometry_SSE.h"
+#endif
+
 } // namespace Eigen
 
 #include "src/Core/util/EnableMSVCWarnings.h"

Eigen/src/Core/util/Constants.h

@@ -247,4 +247,16 @@ enum TransformTraits {
   Projective    = 0x30
 };
 
+const int EiArch_Generic = 0x0;
+const int EiArch_SSE     = 0x1;
+const int EiArch_AltiVec = 0x2;
+
+#if defined EIGEN_VECTORIZE_SSE
+  const int EiArch = EiArch_SSE;
+#elif defined EIGEN_VECTORIZE_ALTIVEC
+  const int EiArch = EiArch_AltiVec;
+#else
+  const int EiArch = EiArch_Generic;
+#endif
+
 #endif // EIGEN_CONSTANTS_H

Eigen/src/Geometry/Quaternion.h

@@ -225,17 +225,24 @@ typedef Quaternion<float> Quaternionf;
   * double precision quaternion type */
 typedef Quaternion<double> Quaterniond;
 
+// Generic Quaternion * Quaternion product
+template<int Arch,typename Scalar> inline Quaternion<Scalar>
+ei_quaternion_product(const Quaternion<Scalar>& a, const Quaternion<Scalar>& b)
+{
+  return Quaternion<Scalar>
+  (
+    a.w() * b.w() - a.x() * b.x() - a.y() * b.y() - a.z() * b.z(),
+    a.w() * b.x() + a.x() * b.w() + a.y() * b.z() - a.z() * b.y(),
+    a.w() * b.y() + a.y() * b.w() + a.z() * b.x() - a.x() * b.z(),
+    a.w() * b.z() + a.z() * b.w() + a.x() * b.y() - a.y() * b.x()
+  );
+}
+
 /** \returns the concatenation of two rotations as a quaternion-quaternion product */
 template <typename Scalar>
 inline Quaternion<Scalar> Quaternion<Scalar>::operator* (const Quaternion& other) const
 {
-  return Quaternion
-  (
-    this->w() * other.w() - this->x() * other.x() - this->y() * other.y() - this->z() * other.z(),
-    this->w() * other.x() + this->x() * other.w() + this->y() * other.z() - this->z() * other.y(),
-    this->w() * other.y() + this->y() * other.w() + this->z() * other.x() - this->x() * other.z(),
-    this->w() * other.z() + this->z() * other.w() + this->x() * other.y() - this->y() * other.x()
-  );
+  return ei_quaternion_product<EiArch>(*this,other);
 }
 
 /** \sa operator*(Quaternion) */

Eigen/src/Geometry/arch/Geometry_SSE.h

@@ -0,0 +1,51 @@
+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra. Eigen itself is part of the KDE project.
+//
+// Copyright (C) 2009 Rohit Garg <rpg.314@gmail.com>
+// Copyright (C) 2009 Gael Guennebaud <g.gael@free.fr>
+//
+// Eigen is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 3 of the License, or (at your option) any later version.
+//
+// Alternatively, you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of
+// the License, or (at your option) any later version.
+//
+// Eigen is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License or the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License and a copy of the GNU General Public License along with
+// Eigen. If not, see <http://www.gnu.org/licenses/>.
+
+#ifndef EIGEN_GEOMETRY_SSE_H
+#define EIGEN_GEOMETRY_SSE_H
+
+#define vec4f_swizzle(v,p,q,r,s) (_mm_castsi128_ps(_mm_shuffle_epi32( _mm_castps_si128(v), \
+  ((s)<<6|(r)<<4|(q)<<2|(p)))))
+
+template<> inline Quaternion<float>
+ei_quaternion_product<EiArch_SSE,float>(const Quaternion<float>& _a, const Quaternion<float>& _b)
+{
+  const __m128 mask = _mm_castsi128_ps(_mm_setr_epi32(0,0,0,0x80000000));
+  Quaternion<float> res;
+  __m128 a = _a.coeffs().packet<Aligned>(0);
+  __m128 b = _b.coeffs().packet<Aligned>(0);
+  __m128 flip1 = _mm_xor_ps(_mm_mul_ps(vec4f_swizzle(a,1,2,0,2),
+                                       vec4f_swizzle(b,2,0,1,2)),mask);
+  __m128 flip2 = _mm_xor_ps(_mm_mul_ps(vec4f_swizzle(a,3,3,3,1),
+                                       vec4f_swizzle(b,0,1,2,1)),mask);
+  ei_pstore(&res.x(),
+            _mm_add_ps(_mm_sub_ps(_mm_mul_ps(a,vec4f_swizzle(b,3,3,3,3)),
+                                  _mm_mul_ps(vec4f_swizzle(a,2,0,1,0),
+                                             vec4f_swizzle(b,1,2,0,0))),
+                       _mm_add_ps(flip1,flip2)));
+  return res;
+}
+
+#endif // EIGEN_GEOMETRY_SSE_H