Added a kernel selection database to select between the direct and indirect GEMM kernels

1 files changed, 6 insertions, 5 deletions

diff --git a/src/routines/level3/xgemm.cpp b/src/routines/level3/xgemm.cpp
index 93f5d30c..9d912374 100644
--- a/src/routines/level3/xgemm.cpp
+++ b/src/routines/level3/xgemm.cpp
@@ -22,7 +22,8 @@ namespace clblast {
 // Constructor: forwards to base class constructor
 template <typename T>
 Xgemm<T>::Xgemm(Queue &queue, EventPointer event, const std::string &name):
-    Routine(queue, event, name, {"Copy","Pad","Transpose","Padtranspose","Xgemm", "XgemmDirect"},
+    Routine(queue, event, name,
+            {"Copy","Pad","Transpose","Padtranspose","Xgemm","XgemmDirect","KernelSelection"},
             PrecisionValue<T>()) {
   source_string_ =
     #include "../../kernels/level3/level3.opencl"
@@ -102,15 +103,15 @@ StatusCode Xgemm<T>::DoGemm(const Layout layout,
   status = TestMatrixC(c_one, c_two, c_buffer, c_offset, c_ld);
   if (ErrorIn(status)) { return status; }
 
-  // Optionally runs the direct version of GEMM. TODO: Set this based on the arguments
-  const auto do_gemm_direct = true; // for now, for testing
-  if (do_gemm_direct) {
+  // Selects which version of GEMM to run
+  const auto do_gemm_direct = (m * n * k < db_["XGEMM_MIN_INDIRECT_SIZE"]);
+  if (do_gemm_direct) { // for small sizes (single kernel)
     return GemmDirect(m, n, k, alpha,
                       a_buffer, a_offset, a_ld, b_buffer, b_offset, b_ld, beta,
                       c_buffer, c_offset, c_ld,
                       a_do_transpose, b_do_transpose, c_do_transpose, a_conjugate, b_conjugate);
   }
-  else {
+  else { // for larger sizes (pre/post-processing plus a very fast kernel)
     return GemmIndirect(m, n, k, alpha,
                         a_buffer, a_offset, a_ld, b_buffer, b_offset, b_ld, beta,
                         c_buffer, c_offset, c_ld,