Integrated Lebesgue code and been playing with alternate implementations of the wilson dop without

any particular success in increasing the performance.

lib/Grid_stencil.h

@@ -44,6 +44,24 @@ namespace Grid {
   class CartesianStencil { // Stencil runs along coordinate axes only; NO diagonal fill in.
   public:
 
+      typedef uint32_t StencilInteger;
+      
+
+
+      StencilInteger alignup(StencilInteger n){
+	n--;           // 1000 0011 --> 1000 0010
+	n |= n >> 1;   // 1000 0010 | 0100 0001 = 1100 0011
+	n |= n >> 2;   // 1100 0011 | 0011 0000 = 1111 0011
+	n |= n >> 4;   // 1111 0011 | 0000 1111 = 1111 1111
+	n |= n >> 8;   // ... (At this point all bits are 1, so further bitwise-or
+	n |= n >> 16;  //      operations produce no effect.)
+	n++;           // 1111 1111 --> 1 0000 0000
+	return n;
+      };
+      void LebesgueOrder(void);
+
+      std::vector<StencilInteger> _LebesgueReorder;
+
       int                               _checkerboard;
       int                               _npoints; // Move to template param?
       GridBase *                        _grid;

lib/qcd/Grid_qcd_dirac.cc

@@ -34,6 +34,10 @@ namespace Grid {
       "         "
     };
 
-
+    //    void sprojMul( vHalfSpinColourVector &out,vColourMatrix &u, vSpinColourVector &in){
+    //      vHalfSpinColourVector hspin;
+    //      spProjXp(hspin,in);
+    //      mult(&out,&u,&hspin);
+    //    }
   }
 }

lib/qcd/Grid_qcd_wilson_dop.cc

@@ -96,17 +96,17 @@ void WilsonMatrix::Dhop(const LatticeFermion &in, LatticeFermion &out)
   WilsonCompressor compressor;
   Stencil.HaloExchange<vSpinColourVector,vHalfSpinColourVector,WilsonCompressor>(in,comm_buf,compressor);
 
-  for(int ss=0;ss<grid->oSites();ss++){
-
-    int offset,local,perm, ptype;
-
-    vSpinColourVector result;
-    vHalfSpinColourVector  chi;    
   vHalfSpinColourVector  tmp;    
+  vHalfSpinColourVector  chi;    
+  vSpinColourVector result;
   vHalfSpinColourVector Uchi;
   vHalfSpinColourVector *chi_p;
+  int offset,local,perm, ptype;
 
-    result=zero;
+  for(int sss=0;sss<grid->oSites();sss++){
+
+    int ss = sss;
+	//int ss = Stencil._LebesgueReorder[sss];
 
     // Xp
     offset = Stencil._offsets [Xp][ss];
@@ -114,15 +114,16 @@ void WilsonMatrix::Dhop(const LatticeFermion &in, LatticeFermion &out)
     perm   = Stencil._permute[Xp][ss];
     ptype  = Stencil._permute_type[Xp];
     chi_p  = &comm_buf[offset];
-    if ( local ) {
+    if ( local && perm ) 
-      chi_p = &chi;
+    {
+      spProjXp(tmp,in._odata[offset]);
+      permute(chi,tmp,ptype);
+    } else if ( local ) {
       spProjXp(chi,in._odata[offset]);
-      if ( perm ) {
+    } else { 
-	permute(tmp,chi,ptype);
+      chi=comm_buf[offset];
-	chi_p = &tmp;
     }
-    }
+    mult(&Uchi(),&Umu._odata[ss](Xp),&chi());
-    mult(&(Uchi()),&(Umu._odata[ss](Xp)),&(*chi_p)());
     spReconXp(result,Uchi);
 
     // Yp
@@ -130,16 +131,17 @@ void WilsonMatrix::Dhop(const LatticeFermion &in, LatticeFermion &out)
     local  = Stencil._is_local[Yp][ss];
     perm   = Stencil._permute[Yp][ss];
     ptype  = Stencil._permute_type[Yp];
-    chi_p  = &comm_buf[offset];
+
-    if ( local ) {
+    if ( local && perm ) 
-      chi_p = &chi;
+    {
+      spProjYp(tmp,in._odata[offset]);
+      permute(chi,tmp,ptype);
+    } else if ( local ) {
       spProjYp(chi,in._odata[offset]);
-      if ( perm ) {
+    } else { 
-	permute(tmp,chi,ptype);
+      chi=comm_buf[offset];
-	chi_p = &tmp;
     }
-    }
+    mult(&Uchi(),&Umu._odata[ss](Yp),&chi());
-    mult(&(Uchi()),&(Umu._odata[ss](Yp)),&(*chi_p)());
     accumReconYp(result,Uchi);
 
     // Zp
@@ -147,17 +149,17 @@ void WilsonMatrix::Dhop(const LatticeFermion &in, LatticeFermion &out)
     local  = Stencil._is_local[Zp][ss];
     perm   = Stencil._permute[Zp][ss];
     ptype  = Stencil._permute_type[Zp];
-    chi_p  = &comm_buf[offset];
 
-    if ( local ) {
+    if ( local && perm ) 
-      chi_p = &chi;
+    {
+      spProjZp(tmp,in._odata[offset]);
+      permute(chi,tmp,ptype);
+    } else if ( local ) {
       spProjZp(chi,in._odata[offset]);
-      if ( perm ) {
+    } else { 
-	permute(tmp,chi,ptype);
+      chi=comm_buf[offset];
-	chi_p = &tmp;
     }
-    }
+    mult(&Uchi(),&Umu._odata[ss](Zp),&chi());
-    mult(&(Uchi()),&(Umu._odata[ss](Zp)),&(*chi_p)());
     accumReconZp(result,Uchi);
 
     // Tp
@@ -165,17 +167,17 @@ void WilsonMatrix::Dhop(const LatticeFermion &in, LatticeFermion &out)
     local  = Stencil._is_local[Tp][ss];
     perm   = Stencil._permute[Tp][ss];
     ptype  = Stencil._permute_type[Tp];
-    chi_p  = &comm_buf[offset];
 
-    if ( local ) {
+    if ( local && perm ) 
-      chi_p = &chi;
+    {
+      spProjTp(tmp,in._odata[offset]);
+      permute(chi,tmp,ptype);
+    } else if ( local ) {
       spProjTp(chi,in._odata[offset]);
-      if ( perm ) {
+    } else { 
-	permute(tmp,chi,ptype);
+      chi=comm_buf[offset];
-	chi_p = &tmp;
     }
-    }
+    mult(&Uchi(),&Umu._odata[ss](Tp),&chi());
-    mult(&(Uchi()),&(Umu._odata[ss](Tp)),&(*chi_p)());
     accumReconTp(result,Uchi);
 
     // Xm
@@ -183,16 +185,17 @@ void WilsonMatrix::Dhop(const LatticeFermion &in, LatticeFermion &out)
     local  = Stencil._is_local[Xm][ss];
     perm   = Stencil._permute[Xm][ss];
     ptype  = Stencil._permute_type[Xm];
-    chi_p  = &comm_buf[offset];
+
-    if ( local ) {
+    if ( local && perm ) 
-      chi_p = &chi;
+    {
+      spProjXm(tmp,in._odata[offset]);
+      permute(chi,tmp,ptype);
+    } else if ( local ) {
       spProjXm(chi,in._odata[offset]);
-      if ( perm ) {
+    } else { 
-	permute(tmp,chi,ptype);
+      chi=comm_buf[offset];
-	chi_p = &tmp;
     }
-    }
+    mult(&Uchi(),&Umu._odata[ss](Xm),&chi());
-    mult(&(Uchi()),&(Umu._odata[ss](Xm)),&(*chi_p)());
     accumReconXm(result,Uchi);
 
 
@@ -201,17 +204,17 @@ void WilsonMatrix::Dhop(const LatticeFermion &in, LatticeFermion &out)
     local  = Stencil._is_local[Ym][ss];
     perm   = Stencil._permute[Ym][ss];
     ptype  = Stencil._permute_type[Ym];
-    chi_p  = &comm_buf[offset];
 
-    if ( local ) {
+    if ( local && perm ) 
-      chi_p = &chi;
+    {
+      spProjYm(tmp,in._odata[offset]);
+      permute(chi,tmp,ptype);
+    } else if ( local ) {
       spProjYm(chi,in._odata[offset]);
-      if ( perm ) {
+    } else { 
-	permute(tmp,chi,ptype);
+      chi=comm_buf[offset];
-	chi_p = &tmp;
     }
-    }
+    mult(&Uchi(),&Umu._odata[ss](Ym),&chi());
-    mult(&(Uchi()),&(Umu._odata[ss](Ym)),&(*chi_p)());
     accumReconYm(result,Uchi);
 
     // Zm
@@ -219,17 +222,17 @@ void WilsonMatrix::Dhop(const LatticeFermion &in, LatticeFermion &out)
     local  = Stencil._is_local[Zm][ss];
     perm   = Stencil._permute[Zm][ss];
     ptype  = Stencil._permute_type[Zm];
-    chi_p  = &comm_buf[offset];
 
-    if ( local ) {
+    if ( local && perm ) 
-      chi_p = &chi;
+    {
+      spProjZm(tmp,in._odata[offset]);
+      permute(chi,tmp,ptype);
+    } else if ( local ) {
       spProjZm(chi,in._odata[offset]);
-      if ( perm ) {
+    } else { 
-	permute(tmp,chi,ptype);
+      chi=comm_buf[offset];
-	chi_p = &tmp;
     }
-    }
+    mult(&Uchi(),&Umu._odata[ss](Zm),&chi());
-    mult(&(Uchi()),&(Umu._odata[ss](Zm)),&(*chi_p)());
     accumReconZm(result,Uchi);
 
     // Tm
@@ -237,24 +240,25 @@ void WilsonMatrix::Dhop(const LatticeFermion &in, LatticeFermion &out)
     local  = Stencil._is_local[Tm][ss];
     perm   = Stencil._permute[Tm][ss];
     ptype  = Stencil._permute_type[Tm];
-    chi_p  = &comm_buf[offset];
 
-    if ( local ) {
+    if ( local && perm ) 
-      chi_p = &chi;
+    {
+      spProjTm(tmp,in._odata[offset]);
+      permute(chi,tmp,ptype);
+    } else if ( local ) {
       spProjTm(chi,in._odata[offset]);
-      if ( perm ) {
+    } else { 
-	permute(tmp,chi,ptype);
+      chi=comm_buf[offset];
-	chi_p = &tmp;
     }
-    }
+    mult(&Uchi(),&Umu._odata[ss](Tm),&chi());
-    mult(&(Uchi()),&(Umu._odata[ss](Tm)),&(*chi_p)());
     accumReconTm(result,Uchi);
 
-
     out._odata[ss] = result;
   }
 
 }
+
+
 void WilsonMatrix::Dw(const LatticeFermion &in, LatticeFermion &out)
 {
   return;

lib/qcd/Grid_qcd_wilson_dop.h

@@ -48,6 +48,8 @@ namespace Grid {
       // m+4r -1/2 Dhop; both cb's
       void Dw(const LatticeFermion &in, LatticeFermion &out);
 
+      typedef iScalar<iMatrix<vComplex, Nc> > matrix;
+
       // half checkerboard operaions
       void MpcDag   (const LatticeFermion &in, LatticeFermion &out);
       void Mpc      (const LatticeFermion &in, LatticeFermion &out);

lib/stencil/Grid_stencil_common.cc

@@ -2,6 +2,96 @@
 
 namespace Grid {
 
+
+
+void CartesianStencil::LebesgueOrder(void) 
+{
+  _LebesgueReorder.resize(0);
+  
+  // Align up dimensions to power of two.
+  const StencilInteger one=1;
+  StencilInteger ND = _grid->_ndimension;
+  std::vector<StencilInteger> dims(ND);
+  std::vector<StencilInteger> adims(ND);
+  std::vector<std::vector<StencilInteger> > bitlist(ND);
+
+
+  for(StencilInteger mu=0;mu<ND;mu++){
+    dims[mu] = _grid->_rdimensions[mu];
+    assert ( dims[mu] != 0 );
+    adims[mu] = alignup(dims[mu]);
+  }
+
+  // List which bits of padded volume coordinate contribute; this strategy 
+  // i) avoids recursion 
+  // ii) has loop lengths at most the width of a 32 bit word.
+  int sitebit=0;
+  int split=24;
+  for(int mu=0;mu<ND;mu++){   // mu 0 takes bit 0; mu 1 takes bit 1 etc...
+    for(int bit=0;bit<split;bit++){
+    StencilInteger mask = one<<bit;
+      if ( mask&(adims[mu]-1) ){
+	bitlist[mu].push_back(sitebit);
+	sitebit++;
+      }
+    }
+  }
+  for(int bit=split;bit<32;bit++){
+    StencilInteger mask = one<<bit;
+    for(int mu=0;mu<ND;mu++){   // mu 0 takes bit 0; mu 1 takes bit 1 etc...
+      if ( mask&(adims[mu]-1) ){
+	bitlist[mu].push_back(sitebit);
+	sitebit++;
+      }
+    }
+  }
+
+  // Work out padded and unpadded volumes
+  StencilInteger avol = 1;
+  for(int mu=0;mu<ND;mu++) avol = avol * adims[mu];
+
+  StencilInteger vol = 1;
+  for(int mu=0;mu<ND;mu++) vol = vol * dims[mu];
+  
+  // Loop over padded volume, following Lebesgue curve
+  // We interleave the bits from sequential "mu".
+  std::vector<StencilInteger> ax(ND);
+  
+  for(StencilInteger asite=0;asite<avol;asite++){
+
+    // Start with zero and collect bits
+    for(int mu=0;mu<ND;mu++) ax[mu] = 0;
+
+    int contained = 1;
+    for(int mu=0;mu<ND;mu++){
+
+      // Build the coordinate on the aligned volume
+      for(int bit=0;bit<bitlist[mu].size();bit++){
+	int sbit=bitlist[mu][bit];
+
+	if(asite&(one<<sbit)){
+	  ax[mu]|=one<<bit;
+	}
+      }
+
+      // Is it contained in original box
+      if ( ax[mu]>dims[mu]-1 ) contained = 0;
+
+    }
+
+    if ( contained ) {
+      int site = ax[0]
+	+        dims[0]*ax[1]
+        +dims[0]*dims[1]*ax[2]
+        +dims[0]*dims[1]*dims[2]*ax[3];
+
+      _LebesgueReorder.push_back(site);
+    }
+  }
+
+  assert( _LebesgueReorder.size() == vol );
+}
+
   CartesianStencil::CartesianStencil(GridBase *grid,
 				     int npoints,
 				     int checkerboard,
@@ -20,6 +110,8 @@ namespace Grid {
       _unified_buffer_size=0;
       _request_count =0;
 
+      LebesgueOrder();
+
       int osites  = _grid->oSites();
 
       for(int i=0;i<npoints;i++){

tests/Grid_wilson.cc

@@ -22,7 +22,7 @@ int main (int argc, char ** argv)
 
   std::vector<int> simd_layout({1,1,2,2});
   std::vector<int> mpi_layout ({1,1,1,1});
-  std::vector<int> latt_size  ({4,4,8,8});
+  std::vector<int> latt_size  ({8,8,8,8});
     
   GridCartesian     Grid(latt_size,simd_layout,mpi_layout);
   std::vector<int> seeds({1,2,3,4});
@@ -45,9 +45,7 @@ int main (int argc, char ** argv)
   }  
 
   for(int mu=0;mu<Nd;mu++){
-    //    U[mu] = 1.0;
+    U[mu] = peekIndex<LorentzIndex>(Umu,mu);
-    //    pokeIndex<3>(Umu,U[mu],mu);
-    U[mu] = peekIndex<3>(Umu,mu);
   }
   
   std::vector<int> mask({1,1,1,1,1,1,1,1});