quda/tests/wilson_dslash_reference.cpp

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#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#include <util_quda.h>

#include <test_util.h>
#include <blas_reference.h>
#include <wilson_dslash_reference.h>

#include <gauge_field.h>
#include <color_spinor_field.h>
#include <face_quda.h>

static int mySpinorSiteSize = 24;

#include <dslash_util.h>

static const double projector[8][4][4][2] = {
  {
    {{1,0}, {0,0}, {0,0}, {0,-1}},
    {{0,0}, {1,0}, {0,-1}, {0,0}},
    {{0,0}, {0,1}, {1,0}, {0,0}},
    {{0,1}, {0,0}, {0,0}, {1,0}}
  },
  {
    {{1,0}, {0,0}, {0,0}, {0,1}},
    {{0,0}, {1,0}, {0,1}, {0,0}},
    {{0,0}, {0,-1}, {1,0}, {0,0}},
    {{0,-1}, {0,0}, {0,0}, {1,0}}
  },
  {
    {{1,0}, {0,0}, {0,0}, {1,0}},
    {{0,0}, {1,0}, {-1,0}, {0,0}},
    {{0,0}, {-1,0}, {1,0}, {0,0}},
    {{1,0}, {0,0}, {0,0}, {1,0}}
  },
  {
    {{1,0}, {0,0}, {0,0}, {-1,0}},
    {{0,0}, {1,0}, {1,0}, {0,0}},
    {{0,0}, {1,0}, {1,0}, {0,0}},
    {{-1,0}, {0,0}, {0,0}, {1,0}}
  },
  {
    {{1,0}, {0,0}, {0,-1}, {0,0}},
    {{0,0}, {1,0}, {0,0}, {0,1}},
    {{0,1}, {0,0}, {1,0}, {0,0}},
    {{0,0}, {0,-1}, {0,0}, {1,0}}
  },
  {
    {{1,0}, {0,0}, {0,1}, {0,0}},
    {{0,0}, {1,0}, {0,0}, {0,-1}},
    {{0,-1}, {0,0}, {1,0}, {0,0}},
    {{0,0}, {0,1}, {0,0}, {1,0}}
  },
  {
    {{1,0}, {0,0}, {-1,0}, {0,0}},
    {{0,0}, {1,0}, {0,0}, {-1,0}},
    {{-1,0}, {0,0}, {1,0}, {0,0}},
    {{0,0}, {-1,0}, {0,0}, {1,0}}
  },
  {
    {{1,0}, {0,0}, {1,0}, {0,0}},
    {{0,0}, {1,0}, {0,0}, {1,0}},
    {{1,0}, {0,0}, {1,0}, {0,0}},
    {{0,0}, {1,0}, {0,0}, {1,0}}
  }
};


// todo pass projector
template <typename Float>
void multiplySpinorByDiracProjector(Float *res, int projIdx, Float *spinorIn) {
  for (int i=0; i<4*3*2; i++) res[i] = 0.0;

  for (int s = 0; s < 4; s++) {
    for (int t = 0; t < 4; t++) {
      Float projRe = projector[projIdx][s][t][0];
      Float projIm = projector[projIdx][s][t][1];
      
      for (int m = 0; m < 3; m++) {
        Float spinorRe = spinorIn[t*(3*2) + m*(2) + 0];
        Float spinorIm = spinorIn[t*(3*2) + m*(2) + 1];
        res[s*(3*2) + m*(2) + 0] += projRe*spinorRe - projIm*spinorIm;
        res[s*(3*2) + m*(2) + 1] += projRe*spinorIm + projIm*spinorRe;
      }
    }
  }
}


//
// dslashReference()
//
// if oddBit is zero: calculate odd parity spinor elements (using even parity spinor)
// if oddBit is one:  calculate even parity spinor elements
//
// if daggerBit is zero: perform ordinary dslash operator
// if daggerBit is one:  perform hermitian conjugate of dslash
//

#ifndef MULTI_GPU

template <typename sFloat, typename gFloat>
void dslashReference(sFloat *res, gFloat **gaugeFull, sFloat *spinorField, int oddBit, int daggerBit) {
  for (int i=0; i<Vh*mySpinorSiteSize; i++) res[i] = 0.0;
  
  gFloat *gaugeEven[4], *gaugeOdd[4];
  for (int dir = 0; dir < 4; dir++) {  
    gaugeEven[dir] = gaugeFull[dir];
    gaugeOdd[dir]  = gaugeFull[dir]+Vh*gaugeSiteSize;
  }
  
  for (int i = 0; i < Vh; i++) {
    for (int dir = 0; dir < 8; dir++) {
      gFloat *gauge = gaugeLink(i, dir, oddBit, gaugeEven, gaugeOdd, 1);
      sFloat *spinor = spinorNeighbor(i, dir, oddBit, spinorField, 1);
      
      sFloat projectedSpinor[4*3*2], gaugedSpinor[4*3*2];
      int projIdx = 2*(dir/2)+(dir+daggerBit)%2;
      multiplySpinorByDiracProjector(projectedSpinor, projIdx, spinor);
      
      for (int s = 0; s < 4; s++) {
        if (dir % 2 == 0) su3Mul(&gaugedSpinor[s*(3*2)], gauge, &projectedSpinor[s*(3*2)]);
        else su3Tmul(&gaugedSpinor[s*(3*2)], gauge, &projectedSpinor[s*(3*2)]);
      }
      
      sum(&res[i*(4*3*2)], &res[i*(4*3*2)], gaugedSpinor, 4*3*2);
    }
  }
}

#else

template <typename sFloat, typename gFloat>
void dslashReference(sFloat *res, gFloat **gaugeFull,  gFloat **ghostGauge, sFloat *spinorField, 
                     sFloat **fwdSpinor, sFloat **backSpinor, int oddBit, int daggerBit) {
  for (int i=0; i<Vh*mySpinorSiteSize; i++) res[i] = 0.0;
  
  gFloat *gaugeEven[4], *gaugeOdd[4];
  gFloat *ghostGaugeEven[4], *ghostGaugeOdd[4];
  for (int dir = 0; dir < 4; dir++) {  
    gaugeEven[dir] = gaugeFull[dir];
    gaugeOdd[dir]  = gaugeFull[dir]+Vh*gaugeSiteSize;

    ghostGaugeEven[dir] = ghostGauge[dir];
    ghostGaugeOdd[dir] = ghostGauge[dir] + (faceVolume[dir]/2)*gaugeSiteSize;
  }
  
  for (int i = 0; i < Vh; i++) {

    for (int dir = 0; dir < 8; dir++) {
      gFloat *gauge = gaugeLink_mg4dir(i, dir, oddBit, gaugeEven, gaugeOdd, ghostGaugeEven, ghostGaugeOdd, 1, 1);
      sFloat *spinor = spinorNeighbor_mg4dir(i, dir, oddBit, spinorField, fwdSpinor, backSpinor, 1, 1);
      
      sFloat projectedSpinor[mySpinorSiteSize], gaugedSpinor[mySpinorSiteSize];
      int projIdx = 2*(dir/2)+(dir+daggerBit)%2;
      multiplySpinorByDiracProjector(projectedSpinor, projIdx, spinor);
      
      for (int s = 0; s < 4; s++) {
        if (dir % 2 == 0) su3Mul(&gaugedSpinor[s*(3*2)], gauge, &projectedSpinor[s*(3*2)]);
        else su3Tmul(&gaugedSpinor[s*(3*2)], gauge, &projectedSpinor[s*(3*2)]);
      }
      
      sum(&res[i*(4*3*2)], &res[i*(4*3*2)], gaugedSpinor, 4*3*2);
    }

  }
}

#endif

// this actually applies the preconditioned dslash, e.g., D_ee^{-1} D_eo or D_oo^{-1} D_oe
void wil_dslash(void *out, void **gauge, void *in, int oddBit, int daggerBit,
                QudaPrecision precision, QudaGaugeParam &gauge_param) {
  
#ifndef MULTI_GPU  
  if (precision == QUDA_DOUBLE_PRECISION)
    dslashReference((double*)out, (double**)gauge, (double*)in, oddBit, daggerBit);
  else
    dslashReference((float*)out, (float**)gauge, (float*)in, oddBit, daggerBit);
#else

  GaugeFieldParam gauge_field_param(gauge, gauge_param);
  cpuGaugeField cpu(gauge_field_param);
  cpu.exchangeGhost();
  void **ghostGauge = (void**)cpu.Ghost();

  // Get spinor ghost fields
  // First wrap the input spinor into a ColorSpinorField
  ColorSpinorParam csParam;
  csParam.v = in;
  csParam.fieldLocation = QUDA_CPU_FIELD_LOCATION;
  csParam.nColor = 3;
  csParam.nSpin = 4;
  csParam.nDim = 4;
  for (int d=0; d<4; d++) csParam.x[d] = Z[d];
  csParam.precision = precision;
  csParam.pad = 0;
  csParam.siteSubset = QUDA_PARITY_SITE_SUBSET;
  csParam.x[0] /= 2;
  csParam.siteOrder = QUDA_EVEN_ODD_SITE_ORDER;
  csParam.fieldOrder = QUDA_SPACE_SPIN_COLOR_FIELD_ORDER;
  csParam.gammaBasis = QUDA_DEGRAND_ROSSI_GAMMA_BASIS;
  csParam.create = QUDA_REFERENCE_FIELD_CREATE;
  
  cpuColorSpinorField inField(csParam);

  {  // Now do the exchange
    QudaParity otherParity = QUDA_INVALID_PARITY;
    if (oddBit == QUDA_EVEN_PARITY) otherParity = QUDA_ODD_PARITY;
    else if (oddBit == QUDA_ODD_PARITY) otherParity = QUDA_EVEN_PARITY;
    else errorQuda("ERROR: full parity not supported in function %s", __FUNCTION__);

    int nFace = 1;
    FaceBuffer faceBuf(Z, 4, mySpinorSiteSize, nFace, precision);
    faceBuf.exchangeCpuSpinor(inField, otherParity, daggerBit); 
  }
  void** fwd_nbr_spinor = inField.fwdGhostFaceBuffer;
  void** back_nbr_spinor = inField.backGhostFaceBuffer;

  if (precision == QUDA_DOUBLE_PRECISION) {
    dslashReference((double*)out, (double**)gauge, (double**)ghostGauge, (double*)in, 
                    (double**)fwd_nbr_spinor, (double**)back_nbr_spinor, oddBit, daggerBit);
  } else{
    dslashReference((float*)out, (float**)gauge, (float**)ghostGauge, (float*)in, 
                    (float**)fwd_nbr_spinor, (float**)back_nbr_spinor, oddBit, daggerBit);
  }

#endif

}

// applies b*(1 + i*a*gamma_5)
template <typename sFloat>
void twistGamma5(sFloat *out, sFloat *in, const int dagger, const sFloat kappa, const sFloat mu, 
                 const QudaTwistFlavorType flavor, const int V, QudaTwistGamma5Type twist) {

  sFloat a=0.0,b=0.0;
  if (twist == QUDA_TWIST_GAMMA5_DIRECT) { // applying the twist
    a = 2.0 * kappa * mu * flavor; // mu already includes the flavor
    b = 1.0;
  } else if (twist == QUDA_TWIST_GAMMA5_INVERSE) { // applying the inverse twist
    a = -2.0 * kappa * mu * flavor;
    b = 1.0 / (1.0 + a*a);
  } else {
    printf("Twist type %d not defined\n", twist);
    exit(0);
  }

  if (dagger) a *= -1.0;

  for(int i = 0; i < V; i++) {
    sFloat tmp[24];
    for(int s = 0; s < 4; s++)
      for(int c = 0; c < 3; c++) {
        sFloat a5 = ((s / 2) ? -1.0 : +1.0) * a;          
        tmp[s * 6 + c * 2 + 0] = b* (in[i * 24 + s * 6 + c * 2 + 0] - a5*in[i * 24 + s * 6 + c * 2 + 1]);
        tmp[s * 6 + c * 2 + 1] = b* (in[i * 24 + s * 6 + c * 2 + 1] + a5*in[i * 24 + s * 6 + c * 2 + 0]);
      }

    for (int j=0; j<24; j++) out[i*24+j] = tmp[j];
  }
  
}

void twist_gamma5(void *out, void *in,  int daggerBit, double kappa, double mu, QudaTwistFlavorType flavor, 
                 int V, QudaTwistGamma5Type twist, QudaPrecision precision) {

  if (precision == QUDA_DOUBLE_PRECISION) {
    twistGamma5((double*)out, (double*)in, daggerBit, kappa, mu, flavor, V, twist);
  } else {
    twistGamma5((float*)out, (float*)in, daggerBit, (float)kappa, (float)mu, flavor, V, twist);
  } 
}


void tm_dslash(void *res, void **gaugeFull, void *spinorField, double kappa, double mu, 
               QudaTwistFlavorType flavor, int oddBit, int daggerBit, QudaPrecision precision,
               QudaGaugeParam &gauge_param)
{

  if (daggerBit) twist_gamma5(spinorField, spinorField, daggerBit, kappa, mu, 
                              flavor, Vh, QUDA_TWIST_GAMMA5_INVERSE, precision);

  wil_dslash(res, gaugeFull, spinorField, oddBit, daggerBit, precision, gauge_param);

  if (!daggerBit) {
    twist_gamma5(res, res, daggerBit, kappa, mu, flavor,
                 Vh, QUDA_TWIST_GAMMA5_INVERSE, precision);
  } else {
    twist_gamma5(spinorField, spinorField,  daggerBit, kappa, mu, flavor, 
                 Vh, QUDA_TWIST_GAMMA5_DIRECT, precision);
  }

}

void wil_mat(void *out, void **gauge, void *in, double kappa, int dagger_bit, QudaPrecision precision,
             QudaGaugeParam &gauge_param) {

  void *inEven = in;
  void *inOdd  = (char*)in + Vh*spinorSiteSize*precision;
  void *outEven = out;
  void *outOdd = (char*)out + Vh*spinorSiteSize*precision;

  wil_dslash(outOdd, gauge, inEven, 1, dagger_bit, precision, gauge_param);
  wil_dslash(outEven, gauge, inOdd, 0, dagger_bit, precision, gauge_param);

  // lastly apply the kappa term
  if (precision == QUDA_DOUBLE_PRECISION) xpay((double*)in, -kappa, (double*)out, V*spinorSiteSize);
  else xpay((float*)in, -(float)kappa, (float*)out, V*spinorSiteSize);
}

void tm_mat(void *out, void **gauge, void *in, double kappa, double mu, 
            QudaTwistFlavorType flavor, int dagger_bit, QudaPrecision precision,
            QudaGaugeParam &gauge_param) {

  void *inEven = in;
  void *inOdd  = (char*)in + Vh*spinorSiteSize*precision;
  void *outEven = out;
  void *outOdd = (char*)out + Vh*spinorSiteSize*precision;
  void *tmp = malloc(V*spinorSiteSize*precision);

  wil_dslash(outOdd, gauge, inEven, 1, dagger_bit, precision, gauge_param);
  wil_dslash(outEven, gauge, inOdd, 0, dagger_bit, precision, gauge_param);

  // apply the twist term to the full lattice
  twist_gamma5(tmp, in, dagger_bit, kappa, mu, flavor, V, QUDA_TWIST_GAMMA5_DIRECT, precision);

  // combine
  if (precision == QUDA_DOUBLE_PRECISION) xpay((double*)tmp, -kappa, (double*)out, V*spinorSiteSize);
  else xpay((float*)tmp, -(float)kappa, (float*)out, V*spinorSiteSize);

  free(tmp);
}

// Apply the even-odd preconditioned Dirac operator
void wil_matpc(void *outEven, void **gauge, void *inEven, double kappa, 
               QudaMatPCType matpc_type, int daggerBit, QudaPrecision precision,
               QudaGaugeParam &gauge_param) {

  void *tmp = malloc(Vh*spinorSiteSize*precision);
    
  // full dslash operator
  if (matpc_type == QUDA_MATPC_EVEN_EVEN) {
    wil_dslash(tmp, gauge, inEven, 1, daggerBit, precision, gauge_param);
    wil_dslash(outEven, gauge, tmp, 0, daggerBit, precision, gauge_param);
  } else {
    wil_dslash(tmp, gauge, inEven, 0, daggerBit, precision, gauge_param);
    wil_dslash(outEven, gauge, tmp, 1, daggerBit, precision, gauge_param);
  }    
  
  // lastly apply the kappa term
  double kappa2 = -kappa*kappa;
  if (precision == QUDA_DOUBLE_PRECISION) xpay((double*)inEven, kappa2, (double*)outEven, Vh*spinorSiteSize);
  else xpay((float*)inEven, (float)kappa2, (float*)outEven, Vh*spinorSiteSize);

  free(tmp);
}

// Apply the even-odd preconditioned Dirac operator
void tm_matpc(void *outEven, void **gauge, void *inEven, double kappa, double mu, QudaTwistFlavorType flavor,
              QudaMatPCType matpc_type, int daggerBit, QudaPrecision precision, QudaGaugeParam &gauge_param) {

  void *tmp = malloc(Vh*spinorSiteSize*precision);
    
  if (matpc_type == QUDA_MATPC_EVEN_EVEN_ASYMMETRIC) {
    wil_dslash(tmp, gauge, inEven, 1, daggerBit, precision, gauge_param);
    twist_gamma5(tmp, tmp, daggerBit, kappa, mu, flavor, Vh, QUDA_TWIST_GAMMA5_INVERSE, precision);
    wil_dslash(outEven, gauge, tmp, 0, daggerBit, precision, gauge_param);
    twist_gamma5(tmp, inEven, daggerBit, kappa, mu, flavor, Vh, QUDA_TWIST_GAMMA5_DIRECT, precision);
  } else if (matpc_type == QUDA_MATPC_ODD_ODD_ASYMMETRIC) {
    wil_dslash(tmp, gauge, inEven, 0, daggerBit, precision, gauge_param);
    twist_gamma5(tmp, tmp, daggerBit, kappa, mu, flavor, Vh, QUDA_TWIST_GAMMA5_INVERSE, precision);
    wil_dslash(outEven, gauge, tmp, 1, daggerBit, precision, gauge_param);
    twist_gamma5(tmp, inEven, daggerBit, kappa, mu, flavor, Vh, QUDA_TWIST_GAMMA5_DIRECT, precision);
  } else if (!daggerBit) {
    if (matpc_type == QUDA_MATPC_EVEN_EVEN) {
      wil_dslash(tmp, gauge, inEven, 1, daggerBit, precision, gauge_param);
      twist_gamma5(tmp, tmp, daggerBit, kappa, mu, flavor, Vh, QUDA_TWIST_GAMMA5_INVERSE, precision);
      wil_dslash(outEven, gauge, tmp, 0, daggerBit, precision, gauge_param);
      twist_gamma5(outEven, outEven, daggerBit, kappa, mu, flavor, Vh, QUDA_TWIST_GAMMA5_INVERSE, precision);
    } else if (matpc_type == QUDA_MATPC_ODD_ODD) {
      wil_dslash(tmp, gauge, inEven, 0, daggerBit, precision, gauge_param);
      twist_gamma5(tmp, tmp, daggerBit, kappa, mu, flavor, Vh, QUDA_TWIST_GAMMA5_INVERSE, precision);
      wil_dslash(outEven, gauge, tmp, 1, daggerBit, precision, gauge_param);
      twist_gamma5(outEven, outEven, daggerBit, kappa, mu, flavor, Vh, QUDA_TWIST_GAMMA5_INVERSE, precision);
    }
  } else {
    if (matpc_type == QUDA_MATPC_EVEN_EVEN) {
      twist_gamma5(inEven, inEven, daggerBit, kappa, mu, flavor, Vh, QUDA_TWIST_GAMMA5_INVERSE, precision);
      wil_dslash(tmp, gauge, inEven, 1, daggerBit, precision, gauge_param);
      twist_gamma5(tmp, tmp, daggerBit, kappa, mu, flavor, Vh, QUDA_TWIST_GAMMA5_INVERSE, precision);
      wil_dslash(outEven, gauge, tmp, 0, daggerBit, precision, gauge_param);
      twist_gamma5(inEven, inEven, daggerBit, kappa, mu, flavor, Vh, QUDA_TWIST_GAMMA5_DIRECT, precision);
    } else if (matpc_type == QUDA_MATPC_ODD_ODD) {
      twist_gamma5(inEven, inEven, daggerBit, kappa, mu, flavor, Vh, QUDA_TWIST_GAMMA5_INVERSE, precision);
      wil_dslash(tmp, gauge, inEven, 0, daggerBit, precision, gauge_param);
      twist_gamma5(tmp, tmp, daggerBit, kappa, mu, flavor, Vh, QUDA_TWIST_GAMMA5_INVERSE, precision);
      wil_dslash(outEven, gauge, tmp, 1, daggerBit, precision, gauge_param);
      twist_gamma5(inEven, inEven, daggerBit, kappa, mu, flavor, Vh, QUDA_TWIST_GAMMA5_DIRECT, precision); // undo
    }
  }
  // lastly apply the kappa term
  double kappa2 = -kappa*kappa;
  if (matpc_type == QUDA_MATPC_EVEN_EVEN || matpc_type == QUDA_MATPC_ODD_ODD) {
    if (precision == QUDA_DOUBLE_PRECISION) xpay((double*)inEven, kappa2, (double*)outEven, Vh*spinorSiteSize);
    else xpay((float*)inEven, (float)kappa2, (float*)outEven, Vh*spinorSiteSize);
  } else {
    if (precision == QUDA_DOUBLE_PRECISION) xpay((double*)tmp, kappa2, (double*)outEven, Vh*spinorSiteSize);
    else xpay((float*)tmp, (float)kappa2, (float*)outEven, Vh*spinorSiteSize);
  }

  free(tmp);
}