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Grid/Grid/qcd/action/fermion/CloverHelpers.h
2023-03-21 16:05:46 -04:00

335 lines
10 KiB
C++

/*************************************************************************************
Grid physics library, www.github.com/paboyle/Grid
Source file: ./lib/qcd/action/fermion/WilsonCloverFermionImplementation.h
Copyright (C) 2017 - 2022
Author: paboyle <paboyle@ph.ed.ac.uk>
Author: Daniel Richtmann <daniel.richtmann@gmail.com>
Author: Mattia Bruno <mattia.bruno@cern.ch>
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 */
#pragma once
#include <Grid/Grid.h>
#include <Grid/qcd/spin/Dirac.h>
#include <Grid/qcd/action/fermion/WilsonCloverHelpers.h>
////////////////////////////////////////////
// Standard Clover
// (4+m0) + csw * clover_term
// Exp Clover
// (4+m0) * exp(csw/(4+m0) clover_term)
// = (4+m0) + csw * clover_term + ...
////////////////////////////////////////////
NAMESPACE_BEGIN(Grid);
//////////////////////////////////
// Generic Standard Clover
//////////////////////////////////
template<class Impl>
class CloverHelpers: public WilsonCloverHelpers<Impl> {
public:
INHERIT_IMPL_TYPES(Impl);
INHERIT_CLOVER_TYPES(Impl);
typedef WilsonCloverHelpers<Impl> Helpers;
static void Instantiate(CloverField& CloverTerm, CloverField& CloverTermInv, RealD csw_t, RealD diag_mass) {
GridBase *grid = CloverTerm.Grid();
CloverTerm += diag_mass;
int lvol = grid->lSites();
int DimRep = Impl::Dimension;
{
autoView(CTv,CloverTerm,CpuRead);
autoView(CTIv,CloverTermInv,CpuWrite);
thread_for(site, lvol, {
Coordinate lcoor;
grid->LocalIndexToLocalCoor(site, lcoor);
Eigen::MatrixXcd EigenCloverOp = Eigen::MatrixXcd::Zero(Ns * DimRep, Ns * DimRep);
Eigen::MatrixXcd EigenInvCloverOp = Eigen::MatrixXcd::Zero(Ns * DimRep, Ns * DimRep);
typename SiteClover::scalar_object Qx = Zero(), Qxinv = Zero();
peekLocalSite(Qx, CTv, lcoor);
for (int j = 0; j < Ns; j++)
for (int k = 0; k < Ns; k++)
for (int a = 0; a < DimRep; a++)
for (int b = 0; b < DimRep; b++){
auto zz = Qx()(j, k)(a, b);
EigenCloverOp(a + j * DimRep, b + k * DimRep) = std::complex<double>(zz);
}
EigenInvCloverOp = EigenCloverOp.inverse();
for (int j = 0; j < Ns; j++)
for (int k = 0; k < Ns; k++)
for (int a = 0; a < DimRep; a++)
for (int b = 0; b < DimRep; b++)
Qxinv()(j, k)(a, b) = EigenInvCloverOp(a + j * DimRep, b + k * DimRep);
pokeLocalSite(Qxinv, CTIv, lcoor);
});
}
}
static GaugeLinkField Cmunu(std::vector<GaugeLinkField> &U, GaugeLinkField &lambda, int mu, int nu) {
return Helpers::Cmunu(U, lambda, mu, nu);
}
};
//////////////////////////////////
// Generic Exp Clover
//////////////////////////////////
template<class Impl>
class ExpCloverHelpers: public WilsonCloverHelpers<Impl> {
public:
INHERIT_IMPL_TYPES(Impl);
INHERIT_CLOVER_TYPES(Impl);
template <typename vtype> using iImplClover = iScalar<iMatrix<iMatrix<vtype, Impl::Dimension>, Ns>>;
typedef WilsonCloverHelpers<Impl> Helpers;
// Can this be avoided?
static void IdentityTimesC(const CloverField& in, RealD c) {
int DimRep = Impl::Dimension;
autoView(in_v, in, AcceleratorWrite);
accelerator_for(ss, in.Grid()->oSites(), 1, {
for (int sa=0; sa<Ns; sa++)
for (int ca=0; ca<DimRep; ca++)
in_v[ss]()(sa,sa)(ca,ca) = c;
});
}
static int getNMAX(RealD prec, RealD R) {
/* compute stop condition for exponential */
int NMAX=1;
RealD cond=R*R/2.;
while (cond*std::exp(R)>prec) {
NMAX++;
cond*=R/(double)(NMAX+1);
}
return NMAX;
}
static int getNMAX(Lattice<iImplClover<vComplexD2>> &t, RealD R) {return getNMAX(1e-12,R);}
static int getNMAX(Lattice<iImplClover<vComplexD>> &t, RealD R) {return getNMAX(1e-12,R);}
static int getNMAX(Lattice<iImplClover<vComplexF>> &t, RealD R) {return getNMAX(1e-6,R);}
static void Instantiate(CloverField& Clover, CloverField& CloverInv, RealD csw_t, RealD diag_mass) {
GridBase* grid = Clover.Grid();
CloverField ExpClover(grid);
int NMAX = getNMAX(Clover, 3.*csw_t/diag_mass);
Clover *= (1.0/diag_mass);
// Taylor expansion, slow but generic
// Horner scheme: a0 + a1 x + a2 x^2 + .. = a0 + x (a1 + x(...))
// qN = cN
// qn = cn + qn+1 X
std::vector<RealD> cn(NMAX+1);
cn[0] = 1.0;
for (int i=1; i<=NMAX; i++)
cn[i] = cn[i-1] / RealD(i);
ExpClover = Zero();
IdentityTimesC(ExpClover, cn[NMAX]);
for (int i=NMAX-1; i>=0; i--)
ExpClover = ExpClover * Clover + cn[i];
// prepare inverse
CloverInv = (-1.0)*Clover;
Clover = ExpClover * diag_mass;
ExpClover = Zero();
IdentityTimesC(ExpClover, cn[NMAX]);
for (int i=NMAX-1; i>=0; i--)
ExpClover = ExpClover * CloverInv + cn[i];
CloverInv = ExpClover * (1.0/diag_mass);
}
static GaugeLinkField Cmunu(std::vector<GaugeLinkField> &U, GaugeLinkField &lambda, int mu, int nu) {
assert(0);
return lambda;
}
};
//////////////////////////////////
// Compact Standard Clover
//////////////////////////////////
template<class Impl>
class CompactCloverHelpers: public CompactWilsonCloverHelpers<Impl>,
public WilsonCloverHelpers<Impl> {
public:
INHERIT_IMPL_TYPES(Impl);
INHERIT_CLOVER_TYPES(Impl);
INHERIT_COMPACT_CLOVER_TYPES(Impl);
typedef WilsonCloverHelpers<Impl> Helpers;
typedef CompactWilsonCloverHelpers<Impl> CompactHelpers;
static void InstantiateClover(CloverField& Clover, CloverField& CloverInv, RealD csw_t, RealD diag_mass) {
Clover += diag_mass;
}
static void InvertClover(CloverField& InvClover,
const CloverDiagonalField& diagonal,
const CloverTriangleField& triangle,
CloverDiagonalField& diagonalInv,
CloverTriangleField& triangleInv,
bool fixedBoundaries) {
CompactHelpers::Invert(diagonal, triangle, diagonalInv, triangleInv);
}
// TODO: implement Cmunu for better performances with compact layout, but don't do it
// here, but rather in WilsonCloverHelpers.h -> CompactWilsonCloverHelpers
static GaugeLinkField Cmunu(std::vector<GaugeLinkField> &U, GaugeLinkField &lambda, int mu, int nu) {
return Helpers::Cmunu(U, lambda, mu, nu);
}
};
//////////////////////////////////
// Compact Exp Clover
//////////////////////////////////
template<class Impl>
class CompactExpCloverHelpers: public CompactWilsonCloverHelpers<Impl> {
public:
INHERIT_IMPL_TYPES(Impl);
INHERIT_CLOVER_TYPES(Impl);
INHERIT_COMPACT_CLOVER_TYPES(Impl);
template <typename vtype> using iImplClover = iScalar<iMatrix<iMatrix<vtype, Impl::Dimension>, Ns>>;
typedef CompactWilsonCloverHelpers<Impl> CompactHelpers;
// Can this be avoided?
static void IdentityTimesC(const CloverField& in, RealD c) {
int DimRep = Impl::Dimension;
autoView(in_v, in, AcceleratorWrite);
accelerator_for(ss, in.Grid()->oSites(), 1, {
for (int sa=0; sa<Ns; sa++)
for (int ca=0; ca<DimRep; ca++)
in_v[ss]()(sa,sa)(ca,ca) = c;
});
}
static int getNMAX(RealD prec, RealD R) {
/* compute stop condition for exponential */
int NMAX=1;
RealD cond=R*R/2.;
while (cond*std::exp(R)>prec) {
NMAX++;
cond*=R/(double)(NMAX+1);
}
return NMAX;
}
static int getNMAX(Lattice<iImplClover<vComplexD>> &t, RealD R) {return getNMAX(1e-12,R);}
static int getNMAX(Lattice<iImplClover<vComplexF>> &t, RealD R) {return getNMAX(1e-6,R);}
static void InstantiateClover(CloverField& Clover, CloverField& CloverInv, RealD csw_t, RealD diag_mass) {
GridBase* grid = Clover.Grid();
CloverField ExpClover(grid);
int NMAX = getNMAX(Clover, 3.*csw_t/diag_mass);
Clover *= (1.0/diag_mass);
// Taylor expansion, slow but generic
// Horner scheme: a0 + a1 x + a2 x^2 + .. = a0 + x (a1 + x(...))
// qN = cN
// qn = cn + qn+1 X
std::vector<RealD> cn(NMAX+1);
cn[0] = 1.0;
for (int i=1; i<=NMAX; i++)
cn[i] = cn[i-1] / RealD(i);
ExpClover = Zero();
IdentityTimesC(ExpClover, cn[NMAX]);
for (int i=NMAX-1; i>=0; i--)
ExpClover = ExpClover * Clover + cn[i];
// prepare inverse
CloverInv = (-1.0)*Clover;
Clover = ExpClover * diag_mass;
ExpClover = Zero();
IdentityTimesC(ExpClover, cn[NMAX]);
for (int i=NMAX-1; i>=0; i--)
ExpClover = ExpClover * CloverInv + cn[i];
CloverInv = ExpClover * (1.0/diag_mass);
}
static void InvertClover(CloverField& InvClover,
const CloverDiagonalField& diagonal,
const CloverTriangleField& triangle,
CloverDiagonalField& diagonalInv,
CloverTriangleField& triangleInv,
bool fixedBoundaries) {
if (fixedBoundaries)
{
CompactHelpers::Invert(diagonal, triangle, diagonalInv, triangleInv);
}
else
{
CompactHelpers::ConvertLayout(InvClover, diagonalInv, triangleInv);
}
}
static GaugeLinkField Cmunu(std::vector<GaugeLinkField> &U, GaugeLinkField &lambda, int mu, int nu) {
assert(0);
return lambda;
}
};
NAMESPACE_END(Grid);