Altivec port of Complex.h.

Note: For some reason g++ 4.4 is >200% slower than g++ 4.3 on altivec code.
The same benchmark (bench_gemm) was tested, on the same hardware/OS (G4/Debian testing),
with same CFLAGS. With some code reorganizing I managed to get some minor gain
on 4.4, but I just could not reach 4.3 speed. This is most likely a bug, but I'm waiting
to see if it's fixed on 4.5. I'll look into this a bit more.

1 files changed, 216 insertions, 0 deletions

diff --git a/Eigen/src/Core/arch/AltiVec/Complex.h b/Eigen/src/Core/arch/AltiVec/Complex.h
new file mode 100644
index 000000000..62d1d45d1
--- /dev/null
+++ b/Eigen/src/Core/arch/AltiVec/Complex.h
@@ -0,0 +1,216 @@
+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra.
+//
+// Copyright (C) 2010 Gael Guennebaud <gael.guennebaud@inria.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_COMPLEX_ALTIVEC_H
+#define EIGEN_COMPLEX_ALTIVEC_H
+
+static Packet4ui  ei_p4ui_CONJ_XOR = vec_mergeh((Packet4ui)ei_p4i_ZERO, (Packet4ui)ei_p4f_ZERO_);//{ 0x00000000, 0x80000000, 0x00000000, 0x80000000 };
+static Packet16uc ei_p16uc_COMPLEX_RE   = vec_sld((Packet16uc) vec_splat((Packet4ui)ei_p16uc_FORWARD, 0), (Packet16uc) vec_splat((Packet4ui)ei_p16uc_FORWARD, 2), 8);//{ 0,1,2,3, 0,1,2,3, 8,9,10,11, 8,9,10,11 };
+static Packet16uc ei_p16uc_COMPLEX_IM   = vec_sld((Packet16uc) vec_splat((Packet4ui)ei_p16uc_FORWARD, 1), (Packet16uc) vec_splat((Packet4ui)ei_p16uc_FORWARD, 3), 8);//{ 4,5,6,7, 4,5,6,7, 12,13,14,15, 12,13,14,15 };
+static Packet16uc ei_p16uc_COMPLEX_REV  = vec_sld(ei_p16uc_REVERSE, ei_p16uc_REVERSE, 8);//{ 4,5,6,7, 0,1,2,3, 12,13,14,15, 8,9,10,11 };
+static Packet16uc ei_p16uc_COMPLEX_REV2 = vec_sld(ei_p16uc_FORWARD, ei_p16uc_FORWARD, 8);//{ 8,9,10,11, 12,13,14,15, 0,1,2,3, 4,5,6,7 };
+static Packet16uc ei_p16uc_PSET_HI = (Packet16uc) vec_mergeh((Packet4ui) vec_splat((Packet4ui)ei_p16uc_FORWARD, 0), (Packet4ui) vec_splat((Packet4ui)ei_p16uc_FORWARD, 1));//{ 0,1,2,3, 4,5,6,7, 0,1,2,3, 4,5,6,7 };
+static Packet16uc ei_p16uc_PSET_LO = (Packet16uc) vec_mergeh((Packet4ui) vec_splat((Packet4ui)ei_p16uc_FORWARD, 2), (Packet4ui) vec_splat((Packet4ui)ei_p16uc_FORWARD, 3));//{ 8,9,10,11, 12,13,14,15, 8,9,10,11, 12,13,14,15 };
+
+//---------- float ----------
+struct Packet2cf
+{
+  EIGEN_STRONG_INLINE Packet2cf() {}
+  EIGEN_STRONG_INLINE explicit Packet2cf(const Packet4f& a) : v(a) {}
+  Packet4f  v;
+};
+
+template<> struct ei_packet_traits<std::complex<float> >  : ei_default_packet_traits
+{
+  typedef Packet2cf type;
+  enum {
+    Vectorizable = 1,
+    size = 2,
+
+    HasAdd    = 1,
+    HasSub    = 1,
+    HasMul    = 1,
+    HasDiv    = 1,
+    HasNegate = 1,
+    HasAbs    = 0,
+    HasAbs2   = 0,
+    HasMin    = 0,
+    HasMax    = 0,
+    HasSetLinear = 0
+  };
+};
+
+template<> struct ei_unpacket_traits<Packet2cf> { typedef std::complex<float> type; enum {size=2}; };
+
+template<> EIGEN_STRONG_INLINE Packet2cf ei_pset1<std::complex<float> >(const std::complex<float>&  from)
+{
+  Packet2cf res;
+  /* On AltiVec we cannot load 64-bit registers, so wa have to take care of alignment */
+  if ((ptrdiff_t)&from % 16 == 0) {
+    res.v = ei_pload((const float *)&from);
+    res.v = vec_perm(res.v, res.v, ei_p16uc_PSET_HI);
+  } else {
+    res.v = ei_ploadu((const float *)&from);
+    res.v = vec_perm(res.v, res.v, ei_p16uc_PSET_LO);
+  }
+  return res;
+}
+
+template<> EIGEN_STRONG_INLINE Packet2cf ei_padd<Packet2cf>(const Packet2cf& a, const Packet2cf& b) { return Packet2cf(vec_add(a.v,b.v)); }
+template<> EIGEN_STRONG_INLINE Packet2cf ei_psub<Packet2cf>(const Packet2cf& a, const Packet2cf& b) { return Packet2cf(vec_sub(a.v,b.v)); }
+template<> EIGEN_STRONG_INLINE Packet2cf ei_pnegate(const Packet2cf& a) { return Packet2cf(ei_psub<Packet4f>(ei_p4f_ZERO, a.v)); }
+template<> EIGEN_STRONG_INLINE Packet2cf ei_pconj(const Packet2cf& a) { return Packet2cf((Packet4f)vec_xor((Packet4ui)a.v, ei_p4ui_CONJ_XOR)); }
+
+template<> EIGEN_STRONG_INLINE Packet2cf ei_pmul<Packet2cf>(const Packet2cf& a, const Packet2cf& b)
+{
+  Packet4f v1, v2;
+
+  // Permute and multiply the real parts of a and b
+  v1 = vec_perm(a.v, a.v, ei_p16uc_COMPLEX_RE);
+  // Get the imaginary parts of a
+  v2 = vec_perm(a.v, a.v, ei_p16uc_COMPLEX_IM);
+  // multiply a_re * b 
+  v1 = vec_madd(v1, b.v, ei_p4f_ZERO);
+  // multiply a_im * b and get the conjugate result
+  v2 = vec_madd(v2, b.v, ei_p4f_ZERO);
+  v2 = (Packet4f) vec_xor((Packet4ui)v2, ei_p4ui_CONJ_XOR);
+  // permute back to a proper order
+  v2 = vec_perm(v2, v2, ei_p16uc_COMPLEX_REV);
+  
+  return Packet2cf(vec_add(v1, v2));
+}
+
+template<> EIGEN_STRONG_INLINE Packet2cf ei_pand   <Packet2cf>(const Packet2cf& a, const Packet2cf& b) { return Packet2cf(vec_and(a.v,b.v)); }
+template<> EIGEN_STRONG_INLINE Packet2cf ei_por    <Packet2cf>(const Packet2cf& a, const Packet2cf& b) { return Packet2cf(vec_or(a.v,b.v)); }
+template<> EIGEN_STRONG_INLINE Packet2cf ei_pxor   <Packet2cf>(const Packet2cf& a, const Packet2cf& b) { return Packet2cf(vec_xor(a.v,b.v)); }
+template<> EIGEN_STRONG_INLINE Packet2cf ei_pandnot<Packet2cf>(const Packet2cf& a, const Packet2cf& b) { return Packet2cf(vec_and(a.v, vec_nor(b.v,b.v))); }
+
+template<> EIGEN_STRONG_INLINE Packet2cf ei_pload <std::complex<float> >(const std::complex<float>* from) { EIGEN_DEBUG_ALIGNED_LOAD return Packet2cf(ei_pload((const float*)from)); }
+template<> EIGEN_STRONG_INLINE Packet2cf ei_ploadu<std::complex<float> >(const std::complex<float>* from) { EIGEN_DEBUG_UNALIGNED_LOAD return Packet2cf(ei_ploadu((const float*)from)); }
+
+template<> EIGEN_STRONG_INLINE void ei_pstore <std::complex<float> >(std::complex<float> *   to, const Packet2cf& from) { EIGEN_DEBUG_ALIGNED_STORE ei_pstore((float*)to, from.v); }
+template<> EIGEN_STRONG_INLINE void ei_pstoreu<std::complex<float> >(std::complex<float> *   to, const Packet2cf& from) { EIGEN_DEBUG_UNALIGNED_STORE ei_pstoreu((float*)to, from.v); }
+
+template<> EIGEN_STRONG_INLINE void ei_prefetch<std::complex<float> >(const std::complex<float> *   addr) { vec_dstt((float *)addr, DST_CTRL(2,2,32), DST_CHAN); }
+
+template<> EIGEN_STRONG_INLINE std::complex<float>  ei_pfirst<Packet2cf>(const Packet2cf& a)
+{
+  std::complex<float> EIGEN_ALIGN16 res[2];
+  ei_pstore((float *)&res, a.v);
+
+  return res[0];
+}
+
+template<> EIGEN_STRONG_INLINE Packet2cf ei_preverse(const Packet2cf& a)
+{
+  Packet4f rev_a;
+  rev_a = vec_perm(a.v, a.v, ei_p16uc_COMPLEX_REV2);
+  return Packet2cf(rev_a);
+}
+
+template<> EIGEN_STRONG_INLINE std::complex<float> ei_predux<Packet2cf>(const Packet2cf& a)
+{
+  Packet4f b;
+  Packet2cf sum;
+  b = (Packet4f) vec_sld(a.v, a.v, 8);
+  sum = ei_padd(a, Packet2cf(b));
+  return ei_pfirst(sum);
+}
+
+template<> EIGEN_STRONG_INLINE Packet2cf ei_preduxp<Packet2cf>(const Packet2cf* vecs)
+{
+  Packet4f b1, b2;
+  
+  b1 = (Packet4f) vec_sld(vecs[0].v, vecs[1].v, 8);
+  b2 = (Packet4f) vec_sld(vecs[1].v, vecs[0].v, 8);
+  b2 = (Packet4f) vec_sld(b2, b2, 8);
+  b2 = ei_padd(b1, b2);
+
+  return Packet2cf(b2);
+}
+
+template<> EIGEN_STRONG_INLINE std::complex<float> ei_predux_mul<Packet2cf>(const Packet2cf& a)
+{
+  Packet4f b;
+  Packet2cf prod;
+  b = (Packet4f) vec_sld(a.v, a.v, 8);
+  prod = ei_pmul(a, Packet2cf(b));
+
+  return ei_pfirst(prod);
+}
+
+template<int Offset>
+struct ei_palign_impl<Offset,Packet2cf>
+{
+  EIGEN_STRONG_INLINE static void run(Packet2cf& first, const Packet2cf& second)
+  {
+    if (Offset==1)
+    {
+      first.v = vec_sld(first.v, second.v, 8);
+    }
+  }
+};
+
+template<> struct ei_conj_helper<Packet2cf, Packet2cf, false,true>
+{
+  EIGEN_STRONG_INLINE Packet2cf pmadd(const Packet2cf& x, const Packet2cf& y, const Packet2cf& c) const
+  { return ei_padd(pmul(x,y),c); }
+
+  EIGEN_STRONG_INLINE Packet2cf pmul(const Packet2cf& a, const Packet2cf& b) const
+  {
+    return ei_pmul(a, ei_pconj(b));
+  }
+};
+
+template<> struct ei_conj_helper<Packet2cf, Packet2cf, true,false>
+{
+  EIGEN_STRONG_INLINE Packet2cf pmadd(const Packet2cf& x, const Packet2cf& y, const Packet2cf& c) const
+  { return ei_padd(pmul(x,y),c); }
+
+  EIGEN_STRONG_INLINE Packet2cf pmul(const Packet2cf& a, const Packet2cf& b) const
+  {
+    return ei_pmul(ei_pconj(a), b);
+  }
+};
+
+template<> struct ei_conj_helper<Packet2cf, Packet2cf, true,true>
+{
+  EIGEN_STRONG_INLINE Packet2cf pmadd(const Packet2cf& x, const Packet2cf& y, const Packet2cf& c) const
+  { return ei_padd(pmul(x,y),c); }
+
+  EIGEN_STRONG_INLINE Packet2cf pmul(const Packet2cf& a, const Packet2cf& b) const
+  {
+    return ei_pconj(ei_pmul(a, b));
+  }
+};
+
+template<> EIGEN_STRONG_INLINE Packet2cf ei_pdiv<Packet2cf>(const Packet2cf& a, const Packet2cf& b)
+{
+  // TODO optimize it for AltiVec
+  Packet2cf res = ei_conj_helper<Packet2cf,Packet2cf,false,true>().pmul(a,b);
+  Packet4f s = vec_madd(b.v, b.v, ei_p4f_ZERO);
+  return Packet2cf(ei_pdiv(res.v, vec_add(s,vec_perm(s, s, ei_p16uc_COMPLEX_REV))));
+}
+
+#endif // EIGEN_COMPLEX_ALTIVEC_H