Momentum push conversion clean up for clarity and optimization

1 files changed, 25 insertions, 29 deletions

diff --git a/Source/Particles/PhysicalParticleContainer.cpp b/Source/Particles/PhysicalParticleContainer.cpp
index 132224db2..5ee2ef5b6 100644
--- a/Source/Particles/PhysicalParticleContainer.cpp
+++ b/Source/Particles/PhysicalParticleContainer.cpp
@@ -1751,19 +1751,19 @@ PhysicalParticleContainer::PushPX(WarpXParIter& pti,
     // This wraps the momentum and position advance so that inheritors can modify the call.
     auto& attribs = pti.GetAttribs();
     // Extract pointers to the different particle quantities
-    Real* AMREX_RESTRICT x = xp.dataPtr();
-    Real* AMREX_RESTRICT y = yp.dataPtr();
-    Real* AMREX_RESTRICT z = zp.dataPtr();
-    Real* AMREX_RESTRICT gi = giv.dataPtr();
-    Real* AMREX_RESTRICT ux = attribs[PIdx::ux].dataPtr();
-    Real* AMREX_RESTRICT uy = attribs[PIdx::uy].dataPtr();
-    Real* AMREX_RESTRICT uz = attribs[PIdx::uz].dataPtr();
-    Real* AMREX_RESTRICT Ex = attribs[PIdx::Ex].dataPtr();
-    Real* AMREX_RESTRICT Ey = attribs[PIdx::Ey].dataPtr();
-    Real* AMREX_RESTRICT Ez = attribs[PIdx::Ez].dataPtr();
-    Real* AMREX_RESTRICT Bx = attribs[PIdx::Bx].dataPtr();
-    Real* AMREX_RESTRICT By = attribs[PIdx::By].dataPtr();
-    Real* AMREX_RESTRICT Bz = attribs[PIdx::Bz].dataPtr();
+    Real* const AMREX_RESTRICT x = xp.dataPtr();
+    Real* const AMREX_RESTRICT y = yp.dataPtr();
+    Real* const AMREX_RESTRICT z = zp.dataPtr();
+    Real* const AMREX_RESTRICT gi = giv.dataPtr();
+    Real* const AMREX_RESTRICT ux = attribs[PIdx::ux].dataPtr();
+    Real* const AMREX_RESTRICT uy = attribs[PIdx::uy].dataPtr();
+    Real* const AMREX_RESTRICT uz = attribs[PIdx::uz].dataPtr();
+    const Real* AMREX_RESTRICT Ex = attribs[PIdx::Ex].dataPtr();
+    const Real* AMREX_RESTRICT Ey = attribs[PIdx::Ey].dataPtr();
+    const Real* AMREX_RESTRICT Ez = attribs[PIdx::Ez].dataPtr();
+    const Real* AMREX_RESTRICT Bx = attribs[PIdx::Bx].dataPtr();
+    const Real* AMREX_RESTRICT By = attribs[PIdx::By].dataPtr();
+    const Real* AMREX_RESTRICT Bz = attribs[PIdx::Bz].dataPtr();
 
     if (WarpX::do_boosted_frame_diagnostic && do_boosted_frame_diags)
     {
@@ -1794,7 +1794,6 @@ PhysicalParticleContainer::PushPX(WarpXParIter& pti,
     } else {
       amrex::Abort("Unknown particle pusher");
     };
-
 }
 
 void
@@ -1823,9 +1822,6 @@ PhysicalParticleContainer::PushP (int lev, Real dt,
 
             auto& attribs = pti.GetAttribs();
 
-            auto& uxp = attribs[PIdx::ux];
-            auto& uyp = attribs[PIdx::uy];
-            auto& uzp = attribs[PIdx::uz];
             auto& Exp = attribs[PIdx::Ex];
             auto& Eyp = attribs[PIdx::Ey];
             auto& Ezp = attribs[PIdx::Ez];
@@ -1885,16 +1881,16 @@ PhysicalParticleContainer::PushP (int lev, Real dt,
 
             // This wraps the momentum advance so that inheritors can modify the call.
             // Extract pointers to the different particle quantities
-            Real* AMREX_RESTRICT gi = m_giv[thread_num].dataPtr();
-            Real* AMREX_RESTRICT uxpp = uxp.dataPtr();
-            Real* AMREX_RESTRICT uypp = uyp.dataPtr();
-            Real* AMREX_RESTRICT uzpp = uzp.dataPtr();
-            Real* AMREX_RESTRICT Expp = Exp.dataPtr();
-            Real* AMREX_RESTRICT Eypp = Eyp.dataPtr();
-            Real* AMREX_RESTRICT Ezpp = Ezp.dataPtr();
-            Real* AMREX_RESTRICT Bxpp = Bxp.dataPtr();
-            Real* AMREX_RESTRICT Bypp = Byp.dataPtr();
-            Real* AMREX_RESTRICT Bzpp = Bzp.dataPtr();
+            Real* const AMREX_RESTRICT gi = m_giv[thread_num].dataPtr();
+            Real* const AMREX_RESTRICT ux = attribs[PIdx::ux].dataPtr();
+            Real* const AMREX_RESTRICT uy = attribs[PIdx::uy].dataPtr();
+            Real* const AMREX_RESTRICT uz = attribs[PIdx::uz].dataPtr();
+            const Real* AMREX_RESTRICT Expp = Exp.dataPtr();
+            const Real* AMREX_RESTRICT Eypp = Eyp.dataPtr();
+            const Real* AMREX_RESTRICT Ezpp = Ezp.dataPtr();
+            const Real* AMREX_RESTRICT Bxpp = Bxp.dataPtr();
+            const Real* AMREX_RESTRICT Bypp = Byp.dataPtr();
+            const Real* AMREX_RESTRICT Bzpp = Bzp.dataPtr();
 
             // Loop over the particles and update their momentum
             const Real q = this->charge;
@@ -1902,14 +1898,14 @@ PhysicalParticleContainer::PushP (int lev, Real dt,
             if (WarpX::particle_pusher_algo == ParticlePusherAlgo::Boris){
                 amrex::ParallelFor( pti.numParticles(),
                     [=] AMREX_GPU_DEVICE (long i) {
-                        UpdateMomentumBoris( uxpp[i], uypp[i], uzpp[i], gi[i],
+                        UpdateMomentumBoris( ux[i], uy[i], uz[i], gi[i],
                               Expp[i], Eypp[i], Ezpp[i], Bxpp[i], Bypp[i], Bzpp[i], q, m, dt);
                     }
                 );
             } else if (WarpX::particle_pusher_algo == ParticlePusherAlgo::Vay) {
                 amrex::ParallelFor( pti.numParticles(),
                     [=] AMREX_GPU_DEVICE (long i) {
-                        UpdateMomentumVay( uxpp[i], uypp[i], uzpp[i], gi[i],
+                        UpdateMomentumVay( ux[i], uy[i], uz[i], gi[i],
                               Expp[i], Eypp[i], Ezpp[i], Bxpp[i], Bypp[i], Bzpp[i], q, m, dt);
                     }
                 );