From 6254fe21b0c5d5d7a46ec3096aa71fa0af8776c2 Mon Sep 17 00:00:00 2001
From: Braxton Cuneo <braxton.s.cuneo@gmail.com>
Date: Mon, 6 May 2024 10:26:49 -0700
Subject: [PATCH] Cleaned up

---
 mcdc/adapt.py  |  3 ++-
 mcdc/kernel.py |  6 ------
 mcdc/type_.py  | 35 ++++++++++++++++++++++++++++-------
 3 files changed, 30 insertions(+), 14 deletions(-)

diff --git a/mcdc/adapt.py b/mcdc/adapt.py
index 55bd0ae7..9a11abb9 100644
--- a/mcdc/adapt.py
+++ b/mcdc/adapt.py
@@ -12,7 +12,8 @@
 
     HAS_GPU = False
 except:
-    print("Warning: GPU capability is not available")
+    if mcdc.main.target == "gpu":
+        print("Warning: GPU capability is not available")
     HAS_GPU = False
 
 import math
diff --git a/mcdc/kernel.py b/mcdc/kernel.py
index 09d8e412..551912e4 100644
--- a/mcdc/kernel.py
+++ b/mcdc/kernel.py
@@ -997,7 +997,6 @@ def get_particle(P, bank, mcdc):
     return True
 
 
-#! Don't touch for now
 @njit
 def manage_particle_banks(seed, mcdc):
     # Record time
@@ -1038,7 +1037,6 @@ def manage_particle_banks(seed, mcdc):
         mcdc["runtime_bank_management"] += time_end - time_start
 
 
-#! Don't touch for now
 @njit
 def manage_IC_bank(mcdc):
     # Buffer bank
@@ -1421,7 +1419,6 @@ def bank_IC(P, prog):
         precursor["y"] = P["y"]
         precursor["z"] = P["z"]
         precursor["w"] = wp_prime / wn_prime
-        #! Ask Ilham about this
 
         # Sample group
         xi = rng(P) * total
@@ -2184,7 +2181,6 @@ def score_eddington(s, g, t, x, y, z, flux, P, score):
     adapt.global_add(score["bin"], (s, g, t, x, y, z, 5), flux * uz * uz)
 
 
-#! Don't touch for now
 @njit
 def score_reduce_bin(score, mcdc):
     # Normalize
@@ -2207,7 +2203,6 @@ def score_closeout_history(score):
     score["bin"].fill(0.0)
 
 
-#! Don't touch for now
 @njit
 def score_closeout(score, mcdc):
     N_history = mcdc["setting"]["N_particle"]
@@ -2321,7 +2316,6 @@ def eigenvalue_tally(P, distance, mcdc):
             mcdc["C_max"] = C_density
 
 
-#! Don't touch for now
 @njit
 def eigenvalue_tally_closeout_history(mcdc):
     N_particle = mcdc["setting"]["N_particle"]
diff --git a/mcdc/type_.py b/mcdc/type_.py
index ac9b1a3a..d4cae5b2 100644
--- a/mcdc/type_.py
+++ b/mcdc/type_.py
@@ -41,6 +41,34 @@
 # ==============================================================================
 
 
+# While CPU execution can robustly handle all sorts of Numba types, GPU
+# execution requires structs to follow some of the basic properties expected of
+# C-style structs with standard layout:
+#
+#      - Every primitive field is aligned by its size, and padding is inserted
+#        between fields to ensure alignment in arrays and nested data structures
+#
+#      - Every field has a unique address
+#
+# If these rules are violated, memory accesses made in GPUs may encounter
+# problems. For example, in cases where an access is not at an address aligned
+# by their size, a segfault or similar fault will occur, or information will be
+# lost. These issues were fixed by providing a function, align, which ensures the
+# field lists fed to np.dtype fulfill these requirements.
+#
+# The align function does the following:
+#
+#      - Tracks the cumulative offset of fields as they appear in the input list.
+#
+#      - Inserts additional padding fields to ensure that primitive fields are
+#        aligned by their size
+#
+#      - Re-sizes arrays to have at least one element in their array (this ensure
+#        they have a non-zero size, and hence cannot overlap base addresses with
+#        other fields.
+#
+
+
 def fixup_dims(dim_tuple):
     return tuple([max(d, 1) for d in dim_tuple])
 
@@ -70,9 +98,6 @@ def align(field_list):
         else:
             print_error("Unexpected field item type")
 
-        if multiplier == 0:
-            multiplier = 1
-
         size *= multiplier
 
         if offset % alignment != 0:
@@ -1188,10 +1213,6 @@ def make_type_domain_decomp(input_deck):
 # ==============================================================================
 
 
-def copy_global(dst, src):
-    pass
-
-
 def make_type_global(input_deck):
     global global_