* implement a second level of micro blocking (faster for small sizes)

* workaround GCC bad implementation of _mm_set1_p*

1 files changed, 15 insertions, 0 deletions

diff --git a/Eigen/src/Core/arch/SSE/PacketMath.h b/Eigen/src/Core/arch/SSE/PacketMath.h
index 3f1fd8ef5..3fd33afbf 100644
--- a/Eigen/src/Core/arch/SSE/PacketMath.h
+++ b/Eigen/src/Core/arch/SSE/PacketMath.h
@@ -74,8 +74,23 @@ template<> struct ei_unpacket_traits<Packet4f> { typedef float  type; enum {size
 template<> struct ei_unpacket_traits<Packet2d> { typedef double type; enum {size=2}; };
 template<> struct ei_unpacket_traits<Packet4i> { typedef int    type; enum {size=4}; };
 
+#ifdef __GNUC__
+// Sometimes GCC implements _mm_set1_p* using multiple moves,
+// that is inefficient :(
+template<> EIGEN_STRONG_INLINE Packet4f ei_pset1<float>(const float&  from) {
+  Packet4f res = _mm_set_ss(from);
+  asm("shufps $0, %[x], %[x]" : [x] "+x" (res) : );
+  return res;
+}
+template<> EIGEN_STRONG_INLINE Packet2d ei_pset1<double>(const double&  from) {
+  Packet2d res = _mm_set_sd(from);
+  asm("unpcklpd %[x], %[x]" : [x] "+x" (res) : );
+  return res;
+}
+#else
 template<> EIGEN_STRONG_INLINE Packet4f ei_pset1<float>(const float&  from) { return _mm_set1_ps(from); }
 template<> EIGEN_STRONG_INLINE Packet2d ei_pset1<double>(const double& from) { return _mm_set1_pd(from); }
+#endif
 template<> EIGEN_STRONG_INLINE Packet4i ei_pset1<int>(const int&    from) { return _mm_set1_epi32(from); }
 
 template<> EIGEN_STRONG_INLINE Packet4f ei_padd<Packet4f>(const Packet4f& a, const Packet4f& b) { return _mm_add_ps(a,b); }