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Grid/Grid/qcd/utils/CovariantCshift.h
Christopher Kelly 19da647e3c Added support for non-periodic gauge field implementations in the random gauge shift performed at the start of the HMC trajectory
(The above required exposing the gauge implementation to the HMC class through the Integrator class)
Made the random shift optional (default on) through a parameter in HMCparameters
Modified ConjugateBC::CshiftLink such that it supports any shift in  -L < shift < L rather than just +-1
Added a tester for the BC-respecting Cshift
Fixed a missing system header include in SSE4 intrinsics wrapper
Fixed sumD_cpu for single-prec types performing an incorrect conversion to a single-prec data type at the end, that fails to compile on some systems
2022-09-09 12:47:09 -04:00

269 lines
8.6 KiB
C++

/*************************************************************************************
Grid physics library, www.github.com/paboyle/Grid
Source file: ./lib/qcd/utils/CovariantCshift.h
Copyright (C) 2015
Author: Azusa Yamaguchi <ayamaguc@staffmail.ed.ac.uk>
Author: paboyle <paboyle@ph.ed.ac.uk>
This program is free software; 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.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
See the full license in the file "LICENSE" in the top level distribution directory
*************************************************************************************/
/* END LEGAL */
#ifndef QCD_UTILS_COVARIANT_CSHIFT_H
#define QCD_UTILS_COVARIANT_CSHIFT_H
NAMESPACE_BEGIN(Grid);
////////////////////////////////////////////////////////////////////////
// Low performance implementation of CovariantCshift API
////////////////////////////////////////////////////////////////////////
// Make these members of an Impl class for BC's.
namespace PeriodicBC {
template<class covariant,class gauge> Lattice<covariant> CovShiftForward(const Lattice<gauge> &Link,
int mu,
const Lattice<covariant> &field)
{
return Link*Cshift(field,mu,1);// moves towards negative mu
}
template<class covariant,class gauge> Lattice<covariant> CovShiftBackward(const Lattice<gauge> &Link,
int mu,
const Lattice<covariant> &field)
{
Lattice<covariant> tmp(field.Grid());
tmp = adj(Link)*field;
return Cshift(tmp,mu,-1);// moves towards positive mu
}
template<class gauge> Lattice<gauge>
CovShiftIdentityBackward(const Lattice<gauge> &Link, int mu)
{
return Cshift(adj(Link), mu, -1);
}
template<class gauge> Lattice<gauge>
CovShiftIdentityForward(const Lattice<gauge> &Link, int mu)
{
return Link;
}
template<class gauge> Lattice<gauge>
ShiftStaple(const Lattice<gauge> &Link, int mu)
{
return Cshift(Link, mu, 1);
}
template<class gauge,class Expr,typename std::enable_if<is_lattice_expr<Expr>::value,void>::type * = nullptr>
auto CovShiftForward(const Lattice<gauge> &Link,
int mu,
const Expr &expr) -> decltype(closure(expr))
{
auto arg = closure(expr);
return CovShiftForward(Link,mu,arg);
}
template<class gauge,class Expr,typename std::enable_if<is_lattice_expr<Expr>::value,void>::type * = nullptr>
auto CovShiftBackward(const Lattice<gauge> &Link,
int mu,
const Expr &expr) -> decltype(closure(expr))
{
auto arg = closure(expr);
return CovShiftBackward(Link,mu,arg);
}
//Boundary-aware C-shift of gauge links / gauge transformation matrices
template<class gauge> Lattice<gauge>
CshiftLink(const Lattice<gauge> &Link, int mu, int shift)
{
return Cshift(Link, mu, shift);
}
}
namespace ConjugateBC {
// Must give right answers across boundary
// <----
// --
// | |
// xxxxxxxxxxxxxxxxxxxx
// | |
//
// Stap= Cshift(GImpl::CovShiftForward(U[nu],nu,
// GImpl::CovShiftForward(U[nu],nu,
// GImpl::CovShiftBackward(U[mu],mu,
// GImpl::CovShiftBackward(U[nu],nu,
// GImpl::CovShiftIdentityBackward(U[nu],nu,-1))))) , mu, 1);
//
// U U^* U^* U^T U^adj = U (U U U^dag U^T )^*
// = U (U U U^dag)^* ( U^T )^*
//
// So covariant shift rule: Conjugate inward shifted plane when crossing boundary applies.
//
// This Conjugate should be applied to BOTH the link and the covariant field on backward shift
// boundary wrap.
//
// | |
// xxxxxxxxxxxxxxxxx
// | | <---- this link is Conjugated, and the path leading into it. Segment crossing in and out is double Conjugated.
// --
// ------->
template<class covariant,class gauge> Lattice<covariant> CovShiftForward(const Lattice<gauge> &Link,
int mu,
const Lattice<covariant> &field)
{
GridBase * grid = Link.Grid();
int Lmu = grid->GlobalDimensions()[mu]-1;
conformable(field,Link);
Lattice<iScalar<vInteger> > coor(grid); LatticeCoordinate(coor,mu);
Lattice<covariant> field_bc = Cshift(field,mu,1);// moves towards negative mu;
field_bc = where(coor==Lmu,conjugate(field_bc),field_bc);
// std::cout<<"Gparity::CovCshiftForward mu="<<mu<<std::endl;
return Link*field_bc;
}
template<class covariant,class gauge> Lattice<covariant> CovShiftBackward(const Lattice<gauge> &Link,
int mu,
const Lattice<covariant> &field)
{
GridBase * grid = field.Grid();
int Lmu = grid->GlobalDimensions()[mu]-1;
conformable(field,Link);
Lattice<iScalar<vInteger> > coor(grid); LatticeCoordinate(coor,mu);
Lattice<covariant> tmp(grid);
tmp = adj(Link)*field;
tmp = where(coor==Lmu,conjugate(tmp),tmp);
// std::cout<<"Gparity::CovCshiftBackward mu="<<mu<<std::endl;
return Cshift(tmp,mu,-1);// moves towards positive mu
}
//Out(x) = U^dag_\mu(x-mu) | x_\mu != 0
// = U^T_\mu(L-1) | x_\mu == 0
template<class gauge> Lattice<gauge>
CovShiftIdentityBackward(const Lattice<gauge> &Link, int mu) {
GridBase *grid = Link.Grid();
int Lmu = grid->GlobalDimensions()[mu] - 1;
Lattice<iScalar<vInteger>> coor(grid);
LatticeCoordinate(coor, mu);
Lattice<gauge> tmp(grid);
tmp = adj(Link);
tmp = where(coor == Lmu, conjugate(tmp), tmp);
return Cshift(tmp, mu, -1); // moves towards positive mu
}
template<class gauge> Lattice<gauge>
CovShiftIdentityForward(const Lattice<gauge> &Link, int mu) {
return Link;
}
//Out(x) = S_\mu(x+\hat\mu) | x_\mu != L-1
// = S*_\mu(0) | x_\mu == L-1
//Note: While this is used for Staples it is also applicable for shifting gauge links or gauge transformation matrices
template<class gauge> Lattice<gauge>
ShiftStaple(const Lattice<gauge> &Link, int mu)
{
GridBase *grid = Link.Grid();
int Lmu = grid->GlobalDimensions()[mu] - 1;
Lattice<iScalar<vInteger>> coor(grid);
LatticeCoordinate(coor, mu);
Lattice<gauge> tmp(grid);
tmp = Cshift(Link, mu, 1);
tmp = where(coor == Lmu, conjugate(tmp), tmp);
return tmp;
}
template<class gauge,class Expr,typename std::enable_if<is_lattice_expr<Expr>::value,void>::type * = nullptr>
auto CovShiftForward(const Lattice<gauge> &Link,
int mu,
const Expr &expr) -> decltype(closure(expr))
{
auto arg = closure(expr);
return CovShiftForward(Link,mu,arg);
}
template<class gauge,class Expr,typename std::enable_if<is_lattice_expr<Expr>::value,void>::type * = nullptr>
auto CovShiftBackward(const Lattice<gauge> &Link,
int mu,
const Expr &expr) -> decltype(closure(expr))
{
auto arg = closure(expr);
return CovShiftBackward(Link,mu,arg);
}
//Boundary-aware C-shift of gauge links / gauge transformation matrices
//shift = 1
//Out(x) = U_\mu(x+\hat\mu) | x_\mu != L-1
// = U*_\mu(0) | x_\mu == L-1
//shift = -1
//Out(x) = U_\mu(x-mu) | x_\mu != 0
// = U*_\mu(L-1) | x_\mu == 0
//shift = 2
//Out(x) = U_\mu(x+2\hat\mu) | x_\mu < L-2
// = U*_\mu(1) | x_\mu == L-1
// = U*_\mu(0) | x_\mu == L-2
//shift = -2
//Out(x) = U_\mu(x-2mu) | x_\mu > 1
// = U*_\mu(L-2) | x_\mu == 0
// = U*_\mu(L-1) | x_\mu == 1
//etc
template<class gauge> Lattice<gauge>
CshiftLink(const Lattice<gauge> &Link, int mu, int shift)
{
GridBase *grid = Link.Grid();
int Lmu = grid->GlobalDimensions()[mu];
assert(abs(shift) < Lmu && "Invalid shift value");
Lattice<iScalar<vInteger>> coor(grid);
LatticeCoordinate(coor, mu);
Lattice<gauge> tmp(grid);
if(shift > 0){
tmp = Cshift(Link, mu, shift);
tmp = where(coor >= Lmu-shift, conjugate(tmp), tmp);
return tmp;
}else if(shift < 0){
tmp = Link;
tmp = where(coor >= Lmu+shift, conjugate(tmp), tmp);
return Cshift(tmp, mu, shift);
}
//shift == 0
return Link;
}
}
NAMESPACE_END(Grid);
#endif