From cfd773a0437c192a0a9d25cf37d241043ab84b5f Mon Sep 17 00:00:00 2001
From: Tobias Ribizel <mail@ribizel.de>
Date: Mon, 13 Jan 2025 10:15:02 +0100
Subject: [PATCH] reduce constexpr complexity

---
 common/unified/components/range_minimum_query_kernels.cpp | 4 ++--
 core/components/range_minimum_query.hpp                   | 4 +---
 core/test/components/range_minimum_query.cpp              | 8 ++++----
 3 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/common/unified/components/range_minimum_query_kernels.cpp b/common/unified/components/range_minimum_query_kernels.cpp
index b44e6fe0ca4..a6de0474d0f 100644
--- a/common/unified/components/range_minimum_query_kernels.cpp
+++ b/common/unified/components/range_minimum_query_kernels.cpp
@@ -35,11 +35,11 @@ void compute_lookup_small(std::shared_ptr<const DefaultExecutor> exec,
         1 << (std::decay_t<decltype(block_argmin)>::bits_per_word_log2 -
               ceil_log2_constexpr(ceil_log2_constexpr(small_block_size)));
     const device_lut_type lut{exec};
-    constexpr auto infinity = std::numeric_limits<IndexType>::max();
     run_kernel(
         exec,
         [] GKO_KERNEL(auto collated_block_idx, auto values, auto block_argmin,
                       auto block_min, auto block_type, auto lut, auto size) {
+            constexpr auto infinity = std::numeric_limits<IndexType>::max();
             const auto num_blocks = ceildiv(size, small_block_size);
             for (auto block_idx = collated_block_idx * collation_width;
                  block_idx <
@@ -87,12 +87,12 @@ void compute_lookup_large(
     // we need to collate all writes that target the same memory word in a
     // single thread
     constexpr auto level0_collation_width = sizeof(word_type) * CHAR_BIT;
-    constexpr auto infinity = std::numeric_limits<IndexType>::max();
     // initialize the first level of blocks
     run_kernel(
         exec,
         [] GKO_KERNEL(auto collated_i, auto block_min, auto superblocks,
                       auto num_blocks) {
+            constexpr auto infinity = std::numeric_limits<IndexType>::max();
             for (auto i = collated_i * level0_collation_width;
                  i < std::min<int64>((collated_i + 1) * level0_collation_width,
                                      num_blocks);
diff --git a/core/components/range_minimum_query.hpp b/core/components/range_minimum_query.hpp
index d9c31c7dd87..3899a40516f 100644
--- a/core/components/range_minimum_query.hpp
+++ b/core/components/range_minimum_query.hpp
@@ -122,8 +122,6 @@ struct cartesian_tree {
         }
         return all_representatives[num_nodes];
     }
-
-    constexpr static auto representatives = compute_tree_representatives();
 };
 
 
@@ -141,7 +139,7 @@ class block_range_minimum_query_lookup_table {
 
     constexpr block_range_minimum_query_lookup_table() : lookup_table{}
     {
-        const auto& representatives = tree::representatives;
+        const auto& representatives = tree::compute_tree_representatives();
         for (int tree = 0; tree < num_trees; tree++) {
             const auto& rep = representatives[tree];
             for (int first = 0; first < block_size; first++) {
diff --git a/core/test/components/range_minimum_query.cpp b/core/test/components/range_minimum_query.cpp
index d00dd7a525f..d35bbbd8555 100644
--- a/core/test/components/range_minimum_query.cpp
+++ b/core/test/components/range_minimum_query.cpp
@@ -17,7 +17,7 @@ TEST(RangeMinimumQuery, RepresentativesAreExhaustive)
     using tree = gko::detail::cartesian_tree<size>;
     int values[size]{};
     std::iota(values, values + size, 0);
-    constexpr auto reps = tree::representatives;
+    const auto reps = tree::compute_tree_representatives();
     do {
         const auto tree_number = tree::compute_tree_index(values);
         const auto rep_tree_number =
@@ -34,7 +34,7 @@ TEST(RangeMinimumQuery, RepresentativesLargeAreExhaustive)
     using tree = gko::detail::cartesian_tree<size>;
     int values[size]{};
     std::iota(values, values + size, 0);
-    constexpr auto reps = tree::representatives;
+    const auto reps = tree::compute_tree_representatives();
     do {
         const auto tree_number = tree::compute_tree_index(values);
         const auto rep_tree_number =
@@ -49,8 +49,8 @@ TEST(RangeMinimumQuery, LookupRepresentatives)
 {
     constexpr auto size = 8;
     using tree = gko::detail::cartesian_tree<size>;
-    /*constexpr*/ gko::block_range_minimum_query_lookup_table<size> table;
-    auto reps = tree::compute_tree_representatives();
+    gko::block_range_minimum_query_lookup_table<size> table;
+    const auto reps = tree::compute_tree_representatives();
     for (const auto& rep : reps) {
         const auto tree = tree::compute_tree_index(rep);
         for (const auto first : gko::irange{size}) {