From 788ce62be11e8a79410e127bbc2a081ebf2e1db0 Mon Sep 17 00:00:00 2001
From: Umang Yadav <29876643+umangyadav@users.noreply.github.com>
Date: Fri, 28 Oct 2022 11:34:17 -0400
Subject: [PATCH] Use minimum block size of 64 threads  (#1427)

Local Threads of multiples 32 were introduced in #1348
But LocalThreads that are not multiple of 64 are causing correctness issues.
---
 src/targets/gpu/compile_hip_code_object.cpp |  5 ++---
 test/verify/test_reduce_op_large.cpp        | 15 ++++++++++++++-
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/src/targets/gpu/compile_hip_code_object.cpp b/src/targets/gpu/compile_hip_code_object.cpp
index 415ce9ca426..5edde29c2aa 100644
--- a/src/targets/gpu/compile_hip_code_object.cpp
+++ b/src/targets/gpu/compile_hip_code_object.cpp
@@ -144,9 +144,8 @@ compute_global_for(context& ctx, std::size_t n, std::size_t over)
 
 std::size_t compute_block_size(std::size_t n, std::size_t max_block_size)
 {
-    const std::size_t min_block_size  = 64;
-    const std::size_t base_block_size = 32;
-    auto block_size                   = (((n - 1) / base_block_size + 1)) * base_block_size;
+    const std::size_t min_block_size = 64;
+    auto block_size                  = (((n - 1) / min_block_size + 1)) * min_block_size;
     return std::min(std::max(min_block_size, block_size), max_block_size);
 }
 
diff --git a/test/verify/test_reduce_op_large.cpp b/test/verify/test_reduce_op_large.cpp
index c6fc0331918..a7f600dab40 100644
--- a/test/verify/test_reduce_op_large.cpp
+++ b/test/verify/test_reduce_op_large.cpp
@@ -51,7 +51,7 @@ template struct test_reduce_op_large<migraphx::op::reduce_min, 1, migraphx::shap
 template struct test_reduce_op_large<migraphx::op::reduce_prod, 2, migraphx::shape::float_type>;
 template struct test_reduce_op_large<migraphx::op::reduce_sum, 1, migraphx::shape::float_type>;
 
-struct test_reduce_mean : verify_program<test_reduce_mean>
+struct test_reduce_mean_1 : verify_program<test_reduce_mean_1>
 {
     migraphx::program create_program() const
     {
@@ -63,3 +63,16 @@ struct test_reduce_mean : verify_program<test_reduce_mean>
         return p;
     };
 };
+
+struct test_reduce_mean_2 : verify_program<test_reduce_mean_2>
+{
+    migraphx::program create_program() const
+    {
+        migraphx::program p;
+        auto* mm = p.get_main_module();
+        migraphx::shape s{migraphx::shape::float_type, {336, 400}};
+        auto x = mm->add_parameter("x", s);
+        mm->add_instruction(migraphx::op::reduce_mean{{1}}, x);
+        return p;
+    };
+};