Support chirally-projected fields

[mchengcit]

Add support for chirally-projected fields, i.e. a full four-component field \psi, stored as two two-component fields (1+\gamma_5)/2 * \psi and (1-\gamma_5)/2 * \psi. Or, in QDP notation:

void QCDPC(V2eqD)(QDPN(ColorVector) _v[2], QDP_DiracFermion d, QDP_Subset sub) { int g5[2] = {4,4}; int pm[2] = {1,-1}; QDP_DiracFermion d2[2] = {d,d}; QDP_H_veq_spproj_D((QDPHalfFermion *)v, d2, g5, pm, sub, 2); }

Necessary for Wilson multigrid, where it is convenient to use this storage scheme.

[maddyscientist]

Assigning to me. These are stored in a single contiguous array though aren't they, just separated into two separate fields? Am I correct in thinking that the field ordering is thus:

[chirality][single parity spacetime][color][spin mod 2][complex]

where I am assuming C ordering (fastest on the right). I presume that full fields would have the parity index as a slower running index than chirality.

[maddyscientist]

Closing this issue, since it was only relevant for interfacing QUDA with the QOP multigrid solver, which isn't relevant now since QUDA has it's own multigrid solver now.