From add86cd7f4070958ae993bd8dff0c6d91c9744e8 Mon Sep 17 00:00:00 2001
From: Daniel Richtmann <daniel.richtmann@gmail.com>
Date: Tue, 1 Feb 2022 21:22:45 +0100
Subject: [PATCH] Abandon ET for clover application, use construct similar to
 multLink

---
 Grid/qcd/action/fermion/WilsonCloverHelpers.h | 20 +++++++++++++++++++
 .../WilsonCloverFermionImplementation.h       |  8 ++++----
 2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/Grid/qcd/action/fermion/WilsonCloverHelpers.h b/Grid/qcd/action/fermion/WilsonCloverHelpers.h
index daf57f78..337af647 100644
--- a/Grid/qcd/action/fermion/WilsonCloverHelpers.h
+++ b/Grid/qcd/action/fermion/WilsonCloverHelpers.h
@@ -186,6 +186,26 @@ public:
 
     return T;
   }
+
+  template<class _Spinor>
+  static accelerator_inline void multClover(_Spinor& phi, const SiteClover& C, const _Spinor& chi) {
+    auto CC = coalescedRead(C);
+    mult(&phi, &CC, &chi);
+  }
+
+  template<class _SpinorField>
+  inline void multCloverField(_SpinorField& out, const CloverField& C, const _SpinorField& phi) {
+    const int Nsimd = SiteSpinor::Nsimd();
+    autoView(out_v, out, AcceleratorWrite);
+    autoView(phi_v, phi, AcceleratorRead);
+    autoView(C_v,   C,   AcceleratorRead);
+    typedef decltype(coalescedRead(out_v[0])) calcSpinor;
+    accelerator_for(sss,out.Grid()->oSites(),Nsimd,{
+      calcSpinor tmp;
+      multClover(tmp,C_v[sss],phi_v(sss));
+      coalescedWrite(out_v[sss],tmp);
+    });
+  }
 };
 
 NAMESPACE_END(Grid);
diff --git a/Grid/qcd/action/fermion/implementation/WilsonCloverFermionImplementation.h b/Grid/qcd/action/fermion/implementation/WilsonCloverFermionImplementation.h
index fd81af11..e4d2e736 100644
--- a/Grid/qcd/action/fermion/implementation/WilsonCloverFermionImplementation.h
+++ b/Grid/qcd/action/fermion/implementation/WilsonCloverFermionImplementation.h
@@ -243,12 +243,12 @@ void WilsonCloverFermion<Impl>::MooeeInternal(const FermionField &in, FermionFie
       {
         Clover = (inv) ? &CloverTermInvDagEven : &CloverTermDagEven;
       }
-      out = *Clover * in;
+      Helpers::multCloverField(out, *Clover, in);
     }
     else
     {
       Clover = (inv) ? &CloverTermInv : &CloverTerm;
-      out = adj(*Clover) * in;
+      Helpers::multCloverField(out, *Clover, in); // don't bother with adj, hermitian anyway
     }
   }
   else
@@ -266,13 +266,13 @@ void WilsonCloverFermion<Impl>::MooeeInternal(const FermionField &in, FermionFie
         //  std::cout << "Calling clover term Even" << std::endl;
         Clover = (inv) ? &CloverTermInvEven : &CloverTermEven;
       }
-      out = *Clover * in;
+      Helpers::multCloverField(out, *Clover, in);
       //  std::cout << GridLogMessage << "*Clover.Checkerboard() "  << (*Clover).Checkerboard() << std::endl;
     }
     else
     {
       Clover = (inv) ? &CloverTermInv : &CloverTerm;
-      out = *Clover * in;
+      Helpers::multCloverField(out, *Clover, in);
     }
   }
 } // MooeeInternal