Refactor call_f in ParticleTransformation and WriteBinaryParticleData…

… to use constexpr if (#3448) This results in much easier-to-interpret error messages, useful in finding #3449 and #3450 Co-authored-by: Weiqun Zhang <WeiqunZhang@lbl.gov>
AMReX-Codes · Jul 26, 2023 · 8aa7dc6 · 8aa7dc6
1 parent a3b69fa
commit 8aa7dc6
Show file tree

Hide file tree

Showing 3 changed files with 37 additions and 45 deletions.
diff --git a/Src/Particle/AMReX_ParticleTransformation.H b/Src/Particle/AMReX_ParticleTransformation.H
@@ -379,10 +379,10 @@ int filterParticles (DstTile& dst, const SrcTile& src, Pred&& p) noexcept
  * \param n the number of particles to apply the operation to
  *
  */
-template <typename DstTile, typename SrcTile, typename Pred, typename Index, typename N>
-auto filterParticles (DstTile& dst, const SrcTile& src, Pred&& p,
-                      Index src_start, Index dst_start, N n) noexcept
-    -> decltype(Index(particle_detail::call_f(p, typename SrcTile::ConstParticleTileDataType(), int{}, RandomEngine{})))
+template <typename DstTile, typename SrcTile, typename Pred, typename Index, typename N,
+          std::enable_if_t<!std::is_pointer_v<std::decay_t<Pred>>,Index> nvccfoo = 0>
+Index filterParticles (DstTile& dst, const SrcTile& src, Pred&& p,
+                       Index src_start, Index dst_start, N n) noexcept
 {
     Gpu::DeviceVector<Index> mask(n);
 
@@ -392,7 +392,12 @@ auto filterParticles (DstTile& dst, const SrcTile& src, Pred&& p,
     amrex::ParallelForRNG(n,
     [=] AMREX_GPU_DEVICE (int i, amrex::RandomEngine const& engine) noexcept
     {
-        p_mask[i] = particle_detail::call_f(p, src_data, src_start+i, engine);
+        amrex::ignore_unused(p, p_mask, src_data, src_start, engine);
+        if constexpr (IsCallable<Pred,decltype(src_data),Index,RandomEngine>::value) {
+            p_mask[i] = p(src_data, src_start+i, engine);
+        } else {
+            p_mask[i] = p(src_data, src_start+i);
+        }
     });
     return filterParticles(dst, src, mask.dataPtr(), src_start, dst_start, n);
 }
@@ -558,7 +563,12 @@ int filterAndTransformParticles (DstTile1& dst1, DstTile2& dst2, const SrcTile&
     amrex::ParallelForRNG(np,
     [=] AMREX_GPU_DEVICE (int i, amrex::RandomEngine const& engine) noexcept
     {
-        p_mask[i] = particle_detail::call_f(p, src_data, i, engine);
+        amrex::ignore_unused(p, p_mask, src_data, engine);
+        if constexpr (IsCallable<Pred,decltype(src_data),int,RandomEngine>::value) {
+            p_mask[i] = p(src_data, i, engine);
+        } else {
+            p_mask[i] = p(src_data, i);
+        }
     });
     return filterAndTransformParticles(dst1, dst2, src, mask.dataPtr(), std::forward<F>(f));
 }
@@ -582,10 +592,10 @@ int filterAndTransformParticles (DstTile1& dst1, DstTile2& dst2, const SrcTile&
  *
  */
 
-template <typename DstTile, typename SrcTile, typename Pred, typename F, typename Index>
-auto filterAndTransformParticles (DstTile& dst, const SrcTile& src, Pred&& p, F&& f,
-                      Index src_start, Index dst_start) noexcept
-    -> decltype(Index(particle_detail::call_f(p, typename SrcTile::ConstParticleTileDataType(), int{}, RandomEngine{})))
+template <typename DstTile, typename SrcTile, typename Pred, typename F, typename Index,
+          std::enable_if_t<!std::is_pointer_v<std::decay_t<Pred>>,Index> nvccfoo = 0>
+Index filterAndTransformParticles (DstTile& dst, const SrcTile& src, Pred&& p, F&& f,
+                                   Index src_start, Index dst_start) noexcept
 {
     auto np = src.numParticles();
     Gpu::DeviceVector<Index> mask(np);
@@ -596,7 +606,12 @@ auto filterAndTransformParticles (DstTile& dst, const SrcTile& src, Pred&& p, F&
     amrex::ParallelForRNG(np,
     [=] AMREX_GPU_DEVICE (int i, amrex::RandomEngine const& engine) noexcept
     {
-        p_mask[i] = particle_detail::call_f(p, src_data, src_start+i, engine);
+        amrex::ignore_unused(p, p_mask, src_data, src_start, engine);
+        if constexpr (IsCallable<Pred,decltype(src_data),Index,RandomEngine>::value) {
+            p_mask[i] = p(src_data, src_start+i, engine);
+        } else {
+            p_mask[i] = p(src_data, src_start+i);
+        }
     });
     return filterAndTransformParticles(dst, src, mask.dataPtr(), std::forward<F>(f), src_start, dst_start);
 }

diff --git a/Src/Particle/AMReX_ParticleUtil.H b/Src/Particle/AMReX_ParticleUtil.H
@@ -22,38 +22,6 @@ namespace amrex
 
 namespace particle_detail {
 
-template <typename F, typename P>
-AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
-auto call_f (F const& f, P const& p, amrex::RandomEngine const& engine) noexcept
-    -> decltype(f(P{},RandomEngine{}))
-{
-    return f(p,engine);
-}
-
-template <typename F, typename P>
-AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
-auto call_f (F const& f, P const& p, amrex::RandomEngine const&) noexcept
-    -> decltype(f(P{}))
-{
-    return f(p);
-}
-
-template <typename F, typename SrcData, typename N>
-AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
-auto call_f (F const& f, SrcData const& src, N i, amrex::RandomEngine const& engine) noexcept
-    -> decltype(f(SrcData{},N{},RandomEngine{}))
-{
-    return f(src,i,engine);
-}
-
-template <typename F, typename SrcData, typename N>
-AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
-auto call_f (F const& f, SrcData const& src, N i, amrex::RandomEngine const&) noexcept
-    -> decltype(f(SrcData{},N{}))
-{
-    return f(src,i);
-}
-
 // The next several functions are used by ParticleReduce
 
 // Lambda takes a Particle

diff --git a/Src/Particle/AMReX_WriteBinaryParticleData.H b/Src/Particle/AMReX_WriteBinaryParticleData.H
@@ -42,7 +42,12 @@ fillFlags (Container<int, Allocator>& pflags, const PTile& ptile, F&& f)
         [=] AMREX_GPU_DEVICE (int k, amrex::RandomEngine const& engine) noexcept
         {
             const auto p = ptd.getSuperParticle(k);
-            flag_ptr[k] = particle_detail::call_f(f,p,engine);
+            amrex::ignore_unused(flag_ptr, f, engine);
+            if constexpr (IsCallable<F,decltype(p),RandomEngine>::value) {
+                flag_ptr[k] = f(p,engine);
+            } else {
+                flag_ptr[k] = f(p);
+            }
         });
 }
 
@@ -59,7 +64,11 @@ fillFlags (Container<int, Allocator>& pflags, const PTile& ptile, F&& f)
     auto flag_ptr = pflags.data();
     for (int k = 0; k < np; ++k) {
         const auto p = ptd.getSuperParticle(k);
-        flag_ptr[k] = particle_detail::call_f(f,p,RandomEngine{});
+        if constexpr (IsCallable<F,decltype(p),RandomEngine>::value) {
+            flag_ptr[k] = f(p,RandomEngine{});
+        } else {
+            flag_ptr[k] = f(p);
+        }
     }
 }