llama : do not cap thread count when MoE on CPU (ggml-org#5419)

* Not capping thread count when MoE inference is running on CPU

* Whitespace

Author: ptsochantaris

llama.cpp

@@ -7285,7 +7285,9 @@ static int llama_decode_internal(
     // TODO: this is mostly important for Apple Silicon where CBLAS is still performing very well
     //       we still need some threads to process all non-mul_mat ops, but not too much to avoid interfering
     //       with the BLAS calls. need a better solution
-    if (n_tokens >= 32 && ggml_cpu_has_blas() && !ggml_cpu_has_gpublas()) {
+    // MoE Special Case: This logic applies when hparams.n_expert == 0, i.e. the model is NOT an MoE model. When an MoE is
+    //                   being processed then Accelerate/BLAS will not be involved, so capping would limit performance.
+    if (n_tokens >= 32 && hparams.n_expert == 0 && ggml_cpu_has_blas() && !ggml_cpu_has_gpublas()) {
         n_threads = std::min(4, n_threads);
     }