From abd5df1729126b3a17ceb9208d2696a566246ff4 Mon Sep 17 00:00:00 2001
From: Peter Boyle <paboyle@ph.ed.ac.uk>
Date: Wed, 19 Aug 2026 19:35:59 -0400
Subject: [PATCH] Discourage use of D2 lattices -- it was low performance.
 Introduce scalar lexLattice layout

---
 Grid/qcd/QCD.h | 135 +++++++++++++++++++++++++++++++++----------------
 1 file changed, 92 insertions(+), 43 deletions(-)

diff --git a/Grid/qcd/QCD.h b/Grid/qcd/QCD.h
index 5b35dc646..cff273611 100644
--- a/Grid/qcd/QCD.h
+++ b/Grid/qcd/QCD.h
@@ -127,7 +127,6 @@ typedef iSpinMatrix<ComplexD >          SpinMatrixD;
 typedef iSpinMatrix<vComplex >          vSpinMatrix;
 typedef iSpinMatrix<vComplexF>          vSpinMatrixF;
 typedef iSpinMatrix<vComplexD>          vSpinMatrixD;
-typedef iSpinMatrix<vComplexD2>         vSpinMatrixD2;
 
 // Colour Matrix
 typedef iColourMatrix<Complex  >        ColourMatrix;
@@ -137,7 +136,6 @@ typedef iColourMatrix<ComplexD >        ColourMatrixD;
 typedef iColourMatrix<vComplex >        vColourMatrix;
 typedef iColourMatrix<vComplexF>        vColourMatrixF;
 typedef iColourMatrix<vComplexD>        vColourMatrixD;
-typedef iColourMatrix<vComplexD2>       vColourMatrixD2;
 
 // SpinColour matrix
 typedef iSpinColourMatrix<Complex  >    SpinColourMatrix;
@@ -147,7 +145,6 @@ typedef iSpinColourMatrix<ComplexD >    SpinColourMatrixD;
 typedef iSpinColourMatrix<vComplex >    vSpinColourMatrix;
 typedef iSpinColourMatrix<vComplexF>    vSpinColourMatrixF;
 typedef iSpinColourMatrix<vComplexD>    vSpinColourMatrixD;
-typedef iSpinColourMatrix<vComplexD2>   vSpinColourMatrixD2;
 
 // SpinColourSpinColour matrix
 typedef iSpinColourSpinColourMatrix<Complex  >    SpinColourSpinColourMatrix;
@@ -157,17 +154,6 @@ typedef iSpinColourSpinColourMatrix<ComplexD >    SpinColourSpinColourMatrixD;
 typedef iSpinColourSpinColourMatrix<vComplex >    vSpinColourSpinColourMatrix;
 typedef iSpinColourSpinColourMatrix<vComplexF>    vSpinColourSpinColourMatrixF;
 typedef iSpinColourSpinColourMatrix<vComplexD>    vSpinColourSpinColourMatrixD;
-typedef iSpinColourSpinColourMatrix<vComplexD2>   vSpinColourSpinColourMatrixD2;
-
-// SpinColourSpinColour matrix
-typedef iSpinColourSpinColourMatrix<Complex  >    SpinColourSpinColourMatrix;
-typedef iSpinColourSpinColourMatrix<ComplexF >    SpinColourSpinColourMatrixF;
-typedef iSpinColourSpinColourMatrix<ComplexD >    SpinColourSpinColourMatrixD;
-
-typedef iSpinColourSpinColourMatrix<vComplex >    vSpinColourSpinColourMatrix;
-typedef iSpinColourSpinColourMatrix<vComplexF>    vSpinColourSpinColourMatrixF;
-typedef iSpinColourSpinColourMatrix<vComplexD>    vSpinColourSpinColourMatrixD;
-typedef iSpinColourSpinColourMatrix<vComplexD2>   vSpinColourSpinColourMatrixD2;
 
 // LorentzColour
 typedef iLorentzColourMatrix<Complex  > LorentzColourMatrix;
@@ -177,7 +163,6 @@ typedef iLorentzColourMatrix<ComplexD > LorentzColourMatrixD;
 typedef iLorentzColourMatrix<vComplex >  vLorentzColourMatrix;
 typedef iLorentzColourMatrix<vComplexF>  vLorentzColourMatrixF;
 typedef iLorentzColourMatrix<vComplexD>  vLorentzColourMatrixD;
-typedef iLorentzColourMatrix<vComplexD2> vLorentzColourMatrixD2;
 
 // LorentzComplex
 typedef iLorentzComplex<Complex  > LorentzComplex;
@@ -196,7 +181,6 @@ typedef iDoubleStoredColourMatrix<ComplexD > DoubleStoredColourMatrixD;
 typedef iDoubleStoredColourMatrix<vComplex >  vDoubleStoredColourMatrix;
 typedef iDoubleStoredColourMatrix<vComplexF>  vDoubleStoredColourMatrixF;
 typedef iDoubleStoredColourMatrix<vComplexD>  vDoubleStoredColourMatrixD;
-typedef iDoubleStoredColourMatrix<vComplexD2> vDoubleStoredColourMatrixD2;
 
 //G-parity flavour matrix
 typedef iGparityFlavourMatrix<Complex> GparityFlavourMatrix;
@@ -206,7 +190,6 @@ typedef iGparityFlavourMatrix<ComplexD> GparityFlavourMatrixD;
 typedef iGparityFlavourMatrix<vComplex>   vGparityFlavourMatrix;
 typedef iGparityFlavourMatrix<vComplexF>  vGparityFlavourMatrixF;
 typedef iGparityFlavourMatrix<vComplexD>  vGparityFlavourMatrixD;
-typedef iGparityFlavourMatrix<vComplexD2> vGparityFlavourMatrixD2;
 
 
 // Spin vector
@@ -217,7 +200,6 @@ typedef iSpinVector<ComplexD>           SpinVectorD;
 typedef iSpinVector<vComplex >           vSpinVector;
 typedef iSpinVector<vComplexF>           vSpinVectorF;
 typedef iSpinVector<vComplexD>           vSpinVectorD;
-typedef iSpinVector<vComplexD2>          vSpinVectorD2;
 
 // Colour vector
 typedef iColourVector<Complex >         ColourVector;
@@ -227,7 +209,6 @@ typedef iColourVector<ComplexD>         ColourVectorD;
 typedef iColourVector<vComplex >         vColourVector;
 typedef iColourVector<vComplexF>         vColourVectorF;
 typedef iColourVector<vComplexD>         vColourVectorD;
-typedef iColourVector<vComplexD2>        vColourVectorD2;
 
 // SpinColourVector
 typedef iSpinColourVector<Complex >     SpinColourVector;
@@ -237,7 +218,6 @@ typedef iSpinColourVector<ComplexD>     SpinColourVectorD;
 typedef iSpinColourVector<vComplex >     vSpinColourVector;
 typedef iSpinColourVector<vComplexF>     vSpinColourVectorF;
 typedef iSpinColourVector<vComplexD>     vSpinColourVectorD;
-typedef iSpinColourVector<vComplexD2>    vSpinColourVectorD2;
 
 // HalfSpin vector
 typedef iHalfSpinVector<Complex >       HalfSpinVector;
@@ -247,7 +227,6 @@ typedef iHalfSpinVector<ComplexD>       HalfSpinVectorD;
 typedef iHalfSpinVector<vComplex >       vHalfSpinVector;
 typedef iHalfSpinVector<vComplexF>       vHalfSpinVectorF;
 typedef iHalfSpinVector<vComplexD>       vHalfSpinVectorD;
-typedef iHalfSpinVector<vComplexD2>      vHalfSpinVectorD2;
 
 // HalfSpinColour vector
 typedef iHalfSpinColourVector<Complex > HalfSpinColourVector;
@@ -257,7 +236,6 @@ typedef iHalfSpinColourVector<ComplexD> HalfSpinColourVectorD;
 typedef iHalfSpinColourVector<vComplex >  vHalfSpinColourVector;
 typedef iHalfSpinColourVector<vComplexF>  vHalfSpinColourVectorF;
 typedef iHalfSpinColourVector<vComplexD>  vHalfSpinColourVectorD;
-typedef iHalfSpinColourVector<vComplexD2> vHalfSpinColourVectorD2;
 
 //G-parity flavour vector
 typedef iGparityFlavourVector<Complex >         GparityFlavourVector;
@@ -267,7 +245,6 @@ typedef iGparityFlavourVector<ComplexD>         GparityFlavourVectorD;
 typedef iGparityFlavourVector<vComplex >         vGparityFlavourVector;
 typedef iGparityFlavourVector<vComplexF>         vGparityFlavourVectorF;
 typedef iGparityFlavourVector<vComplexD>         vGparityFlavourVectorD;
-typedef iGparityFlavourVector<vComplexD2>        vGparityFlavourVectorD2;
     
 // singlets
 typedef iSinglet<Complex >         TComplex;     // FIXME This is painful. Tensor singlet complex type.
@@ -277,7 +254,6 @@ typedef iSinglet<ComplexD>         TComplexD;    // FIXME This is painful. Tenso
 typedef iSinglet<vComplex >        vTComplex ;   // what if we don't know the tensor structure
 typedef iSinglet<vComplexF>        vTComplexF;   // what if we don't know the tensor structure
 typedef iSinglet<vComplexD>        vTComplexD;   // what if we don't know the tensor structure
-typedef iSinglet<vComplexD2>       vTComplexD2;   // what if we don't know the tensor structure
 
 typedef iSinglet<Real >            TReal;        // Shouldn't need these; can I make it work without?
 typedef iSinglet<RealF>            TRealF;       // Shouldn't need these; can I make it work without?
@@ -295,27 +271,22 @@ typedef iSinglet<Integer >         TInteger;
 typedef Lattice<vColourMatrix>          LatticeColourMatrix;
 typedef Lattice<vColourMatrixF>         LatticeColourMatrixF;
 typedef Lattice<vColourMatrixD>         LatticeColourMatrixD;
-typedef Lattice<vColourMatrixD2>        LatticeColourMatrixD2;
 
 typedef Lattice<vSpinMatrix>            LatticeSpinMatrix;
 typedef Lattice<vSpinMatrixF>           LatticeSpinMatrixF;
 typedef Lattice<vSpinMatrixD>           LatticeSpinMatrixD;
-typedef Lattice<vSpinMatrixD2>          LatticeSpinMatrixD2;
 
 typedef Lattice<vSpinColourMatrix>      LatticeSpinColourMatrix;
 typedef Lattice<vSpinColourMatrixF>     LatticeSpinColourMatrixF;
 typedef Lattice<vSpinColourMatrixD>     LatticeSpinColourMatrixD;
-typedef Lattice<vSpinColourMatrixD2>    LatticeSpinColourMatrixD2;
 
 typedef Lattice<vSpinColourSpinColourMatrix>      LatticeSpinColourSpinColourMatrix;
 typedef Lattice<vSpinColourSpinColourMatrixF>     LatticeSpinColourSpinColourMatrixF;
 typedef Lattice<vSpinColourSpinColourMatrixD>     LatticeSpinColourSpinColourMatrixD;
-typedef Lattice<vSpinColourSpinColourMatrixD2>    LatticeSpinColourSpinColourMatrixD2;
 
 typedef Lattice<vLorentzColourMatrix>   LatticeLorentzColourMatrix;
 typedef Lattice<vLorentzColourMatrixF>  LatticeLorentzColourMatrixF;
 typedef Lattice<vLorentzColourMatrixD>  LatticeLorentzColourMatrixD;
-typedef Lattice<vLorentzColourMatrixD2> LatticeLorentzColourMatrixD2;
 
 typedef Lattice<vLorentzComplex>  LatticeLorentzComplex;
 typedef Lattice<vLorentzComplexF> LatticeLorentzComplexF;
@@ -325,32 +296,26 @@ typedef Lattice<vLorentzComplexD> LatticeLorentzComplexD;
 typedef Lattice<vDoubleStoredColourMatrix>   LatticeDoubleStoredColourMatrix;
 typedef Lattice<vDoubleStoredColourMatrixF>  LatticeDoubleStoredColourMatrixF;
 typedef Lattice<vDoubleStoredColourMatrixD>  LatticeDoubleStoredColourMatrixD;
-typedef Lattice<vDoubleStoredColourMatrixD2> LatticeDoubleStoredColourMatrixD2;
 
 typedef Lattice<vSpinVector>            LatticeSpinVector;
 typedef Lattice<vSpinVectorF>           LatticeSpinVectorF;
 typedef Lattice<vSpinVectorD>           LatticeSpinVectorD;
-typedef Lattice<vSpinVectorD2>          LatticeSpinVectorD2;
 
 typedef Lattice<vColourVector>          LatticeColourVector;
 typedef Lattice<vColourVectorF>         LatticeColourVectorF;
 typedef Lattice<vColourVectorD>         LatticeColourVectorD;
-typedef Lattice<vColourVectorD2>        LatticeColourVectorD2;
 
 typedef Lattice<vSpinColourVector>      LatticeSpinColourVector;
 typedef Lattice<vSpinColourVectorF>     LatticeSpinColourVectorF;
 typedef Lattice<vSpinColourVectorD>     LatticeSpinColourVectorD;
-typedef Lattice<vSpinColourVectorD2>    LatticeSpinColourVectorD2;
 
 typedef Lattice<vHalfSpinVector>        LatticeHalfSpinVector;
 typedef Lattice<vHalfSpinVectorF>       LatticeHalfSpinVectorF;
 typedef Lattice<vHalfSpinVectorD>       LatticeHalfSpinVectorD;
-typedef Lattice<vHalfSpinVectorD2>      LatticeHalfSpinVectorD2;
 
 typedef Lattice<vHalfSpinColourVector>   LatticeHalfSpinColourVector;
 typedef Lattice<vHalfSpinColourVectorF>  LatticeHalfSpinColourVectorF;
 typedef Lattice<vHalfSpinColourVectorD>  LatticeHalfSpinColourVectorD;
-typedef Lattice<vHalfSpinColourVectorD2> LatticeHalfSpinColourVectorD2;
 
 typedef Lattice<vTReal>            LatticeReal;
 typedef Lattice<vTRealF>           LatticeRealF;
@@ -359,7 +324,6 @@ typedef Lattice<vTRealD>           LatticeRealD;
 typedef Lattice<vTComplex>         LatticeComplex;
 typedef Lattice<vTComplexF>        LatticeComplexF;
 typedef Lattice<vTComplexD>        LatticeComplexD;
-typedef Lattice<vTComplexD2>       LatticeComplexD2;
 
 typedef Lattice<vTInteger>         LatticeInteger; // Predicates for "where"
 
@@ -370,39 +334,124 @@ typedef Lattice<vTInteger>         LatticeInteger; // Predicates for "where"
 typedef LatticeHalfSpinColourVector   LatticeHalfFermion;
 typedef LatticeHalfSpinColourVectorF  LatticeHalfFermionF;
 typedef LatticeHalfSpinColourVectorD  LatticeHalfFermionD;
-typedef LatticeHalfSpinColourVectorD2 LatticeHalfFermionD2;
 
 typedef LatticeSpinColourVector      LatticeFermion;
 typedef LatticeSpinColourVectorF     LatticeFermionF;
 typedef LatticeSpinColourVectorD     LatticeFermionD;
-typedef LatticeSpinColourVectorD2    LatticeFermionD2;
 
 typedef LatticeSpinColourMatrix                LatticePropagator;
 typedef LatticeSpinColourMatrixF               LatticePropagatorF;
 typedef LatticeSpinColourMatrixD               LatticePropagatorD;
-typedef LatticeSpinColourMatrixD2              LatticePropagatorD2;
 
 typedef LatticeLorentzColourMatrix             LatticeGaugeField;
 typedef LatticeLorentzColourMatrixF            LatticeGaugeFieldF;
 typedef LatticeLorentzColourMatrixD            LatticeGaugeFieldD;
-typedef LatticeLorentzColourMatrixD2           LatticeGaugeFieldD2;
 
 typedef LatticeDoubleStoredColourMatrix        LatticeDoubledGaugeField;
 typedef LatticeDoubleStoredColourMatrixF       LatticeDoubledGaugeFieldF;
 typedef LatticeDoubleStoredColourMatrixD       LatticeDoubledGaugeFieldD;
-typedef LatticeDoubleStoredColourMatrixD2      LatticeDoubledGaugeFieldD2;
 
 template<class GF> using LorentzScalar = Lattice<iScalar<typename GF::vector_object::element> >;
 
 typedef Lattice<vColourVector>          LatticeStaggeredFermion;    
 typedef Lattice<vColourVectorF>         LatticeStaggeredFermionF;    
 typedef Lattice<vColourVectorD>         LatticeStaggeredFermionD;    
-typedef Lattice<vColourVectorD2>        LatticeStaggeredFermionD2;    
 
 typedef Lattice<vColourMatrix>          LatticeStaggeredPropagator; 
 typedef Lattice<vColourMatrixF>         LatticeStaggeredPropagatorF; 
 typedef Lattice<vColourMatrixD>         LatticeStaggeredPropagatorD; 
-typedef Lattice<vColourMatrixD2>        LatticeStaggeredPropagatorD2; 
+
+
+/////////////////////////////////////////////////////////////////////////////
+// Lexicographic lattice types: Nsimd()==1 containers of the same tensors.
+// Single and double precision only; no default precision alias.
+/////////////////////////////////////////////////////////////////////////////
+
+// Site objects over the width one simd types
+typedef iSpinMatrix<sComplexF>                        sSpinMatrixF;
+typedef iSpinMatrix<sComplexD>                        sSpinMatrixD;
+typedef iColourMatrix<sComplexF>                      sColourMatrixF;
+typedef iColourMatrix<sComplexD>                      sColourMatrixD;
+typedef iSpinColourMatrix<sComplexF>                  sSpinColourMatrixF;
+typedef iSpinColourMatrix<sComplexD>                  sSpinColourMatrixD;
+typedef iSpinColourSpinColourMatrix<sComplexF>        sSpinColourSpinColourMatrixF;
+typedef iSpinColourSpinColourMatrix<sComplexD>        sSpinColourSpinColourMatrixD;
+typedef iLorentzColourMatrix<sComplexF>               sLorentzColourMatrixF;
+typedef iLorentzColourMatrix<sComplexD>               sLorentzColourMatrixD;
+typedef iLorentzComplex<sComplexF>                    sLorentzComplexF;
+typedef iLorentzComplex<sComplexD>                    sLorentzComplexD;
+typedef iDoubleStoredColourMatrix<sComplexF>          sDoubleStoredColourMatrixF;
+typedef iDoubleStoredColourMatrix<sComplexD>          sDoubleStoredColourMatrixD;
+typedef iGparityFlavourMatrix<sComplexF>              sGparityFlavourMatrixF;
+typedef iGparityFlavourMatrix<sComplexD>              sGparityFlavourMatrixD;
+typedef iSpinVector<sComplexF>                        sSpinVectorF;
+typedef iSpinVector<sComplexD>                        sSpinVectorD;
+typedef iColourVector<sComplexF>                      sColourVectorF;
+typedef iColourVector<sComplexD>                      sColourVectorD;
+typedef iSpinColourVector<sComplexF>                  sSpinColourVectorF;
+typedef iSpinColourVector<sComplexD>                  sSpinColourVectorD;
+typedef iHalfSpinVector<sComplexF>                    sHalfSpinVectorF;
+typedef iHalfSpinVector<sComplexD>                    sHalfSpinVectorD;
+typedef iHalfSpinColourVector<sComplexF>              sHalfSpinColourVectorF;
+typedef iHalfSpinColourVector<sComplexD>              sHalfSpinColourVectorD;
+typedef iGparityFlavourVector<sComplexF>              sGparityFlavourVectorF;
+typedef iGparityFlavourVector<sComplexD>              sGparityFlavourVectorD;
+typedef iSinglet<sComplexF>                           sTComplexF;
+typedef iSinglet<sComplexD>                           sTComplexD;
+typedef iSinglet<sRealF>                              sTRealF;
+typedef iSinglet<sRealD>                              sTRealD;
+typedef iSinglet<sInteger>                            sTInteger;
+
+// Lattices of these
+typedef Lattice<sColourMatrixF>                       lexLatticeColourMatrixF;
+typedef Lattice<sColourMatrixD>                       lexLatticeColourMatrixD;
+typedef Lattice<sSpinMatrixF>                         lexLatticeSpinMatrixF;
+typedef Lattice<sSpinMatrixD>                         lexLatticeSpinMatrixD;
+typedef Lattice<sSpinColourMatrixF>                   lexLatticeSpinColourMatrixF;
+typedef Lattice<sSpinColourMatrixD>                   lexLatticeSpinColourMatrixD;
+typedef Lattice<sSpinColourSpinColourMatrixF>         lexLatticeSpinColourSpinColourMatrixF;
+typedef Lattice<sSpinColourSpinColourMatrixD>         lexLatticeSpinColourSpinColourMatrixD;
+typedef Lattice<sLorentzColourMatrixF>                lexLatticeLorentzColourMatrixF;
+typedef Lattice<sLorentzColourMatrixD>                lexLatticeLorentzColourMatrixD;
+typedef Lattice<sLorentzComplexF>                     lexLatticeLorentzComplexF;
+typedef Lattice<sLorentzComplexD>                     lexLatticeLorentzComplexD;
+typedef Lattice<sDoubleStoredColourMatrixF>           lexLatticeDoubleStoredColourMatrixF;
+typedef Lattice<sDoubleStoredColourMatrixD>           lexLatticeDoubleStoredColourMatrixD;
+typedef Lattice<sSpinVectorF>                         lexLatticeSpinVectorF;
+typedef Lattice<sSpinVectorD>                         lexLatticeSpinVectorD;
+typedef Lattice<sColourVectorF>                       lexLatticeColourVectorF;
+typedef Lattice<sColourVectorD>                       lexLatticeColourVectorD;
+typedef Lattice<sSpinColourVectorF>                   lexLatticeSpinColourVectorF;
+typedef Lattice<sSpinColourVectorD>                   lexLatticeSpinColourVectorD;
+typedef Lattice<sHalfSpinVectorF>                     lexLatticeHalfSpinVectorF;
+typedef Lattice<sHalfSpinVectorD>                     lexLatticeHalfSpinVectorD;
+typedef Lattice<sHalfSpinColourVectorF>               lexLatticeHalfSpinColourVectorF;
+typedef Lattice<sHalfSpinColourVectorD>               lexLatticeHalfSpinColourVectorD;
+typedef Lattice<sTRealF>                              lexLatticeRealF;
+typedef Lattice<sTRealD>                              lexLatticeRealD;
+typedef Lattice<sTComplexF>                           lexLatticeComplexF;
+typedef Lattice<sTComplexD>                           lexLatticeComplexD;
+typedef Lattice<sTInteger>                            lexLatticeInteger;
+typedef Lattice<sColourVectorF>                       lexLatticeStaggeredFermionF;
+typedef Lattice<sColourVectorD>                       lexLatticeStaggeredFermionD;
+typedef Lattice<sColourMatrixF>                       lexLatticeStaggeredPropagatorF;
+typedef Lattice<sColourMatrixD>                       lexLatticeStaggeredPropagatorD;
+
+// Physical names for things
+typedef lexLatticeHalfSpinColourVectorF               lexLatticeHalfFermionF;
+typedef lexLatticeHalfSpinColourVectorD               lexLatticeHalfFermionD;
+typedef lexLatticeSpinColourVectorF                   lexLatticeFermionF;
+typedef lexLatticeSpinColourVectorD                   lexLatticeFermionD;
+typedef lexLatticeSpinColourMatrixF                   lexLatticePropagatorF;
+typedef lexLatticeSpinColourMatrixD                   lexLatticePropagatorD;
+typedef lexLatticeLorentzColourMatrixF                lexLatticeGaugeFieldF;
+typedef lexLatticeLorentzColourMatrixD                lexLatticeGaugeFieldD;
+typedef lexLatticeDoubleStoredColourMatrixF           lexLatticeDoubledGaugeFieldF;
+typedef lexLatticeDoubleStoredColourMatrixD           lexLatticeDoubledGaugeFieldD;
+
+/////////////////////////////////////////////////////////////////////////////
+// End lexicographic lattice types
+/////////////////////////////////////////////////////////////////////////////
 
 //////////////////////////////////////////////////////////////////////////////
 // Peek and Poke named after physics attributes