COMPMID-1177: Improved native GEMM.

Improve the native GEMM so it can cope with any value for M.  Also
change the selection code so that the native GEMM is selected if M is
small and nmulti is large - Winograd needs GEMMs like this and they
don't thread properly with the blocked GEMM.

(also rename gemm_batched.hpp back to gemv_batched.hpp)

Change-Id: I736c33373ada562cbc0c00540520a58103faa9d5
Reviewed-on: https://eu-gerrit-1.euhpc.arm.com/131739
Tested-by: Jenkins <bsgcomp@arm.com>
Reviewed-by: Pablo Tello <pablo.tello@arm.com>
Reviewed-by: Anthony Barbier <anthony.barbier@arm.com>

1 files changed, 110 insertions, 0 deletions

diff --git a/src/core/NEON/kernels/arm_gemm/gemv_batched.hpp b/src/core/NEON/kernels/arm_gemm/gemv_batched.hpp
new file mode 100644
index 0000000000..bb09770efc
--- /dev/null
+++ b/src/core/NEON/kernels/arm_gemm/gemv_batched.hpp
@@ -0,0 +1,110 @@
+/*
+ * Copyright (c) 2017-2018 ARM Limited.
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#pragma once
+
+#include "arm_gemm.hpp"
+
+namespace arm_gemm
+{
+
+/* "Batched GEMV" (where M=1 and nbatches>1) can be executed much more
+ * efficiently as a GEMM (with M'=nbatches and nbatches'=1).  This wrapper
+ * implements this.  */
+template <typename To, typename Tr>
+class GemvBatched : public GemmCommon<To, Tr>
+{
+private:
+    UniqueGemmCommon<To, Tr> _subgemm = nullptr;
+
+public:
+    GemvBatched(const CPUInfo &ci, const unsigned int M, const unsigned int N, const unsigned int K,
+                const unsigned int nbatches, const unsigned int nmulti, const bool trA, const bool trB,
+                const To alpha, const To beta, const int maxthreads, const bool pretransposed_hint)
+    {
+        /* Just create a subgemm with batches->M */
+        _subgemm = gemm<To, Tr>(ci, nbatches, N, K, 1, nmulti, trA, trB, alpha, beta, maxthreads, pretransposed_hint);
+    }
+
+    void set_arrays(const To *A, const int lda, const int A_batch_stride, const int A_multi_stride,
+                    const To *B, const int ldb, const int B_multi_stride,
+                    Tr *C, const int ldc, const int C_batch_stride, const int C_multi_stride) override
+    {
+        /* A and C's batch stride becomes their new row stride.  New batch stride is 0 as nbatches for subgemm is always 1. */
+        _subgemm->set_arrays(A, A_batch_stride, 0, A_multi_stride,
+                             B, ldb, B_multi_stride,
+                             C, C_batch_stride, 0, C_multi_stride);
+    }
+
+    unsigned int get_window_size() const override
+    {
+        return _subgemm->get_window_size();
+    }
+
+    void set_nthreads(int nthreads) override
+    {
+        _subgemm->set_nthreads(nthreads);
+    }
+
+    void execute(unsigned int start, unsigned int end, int threadid) override
+    {
+        _subgemm->execute(start, end, threadid);
+    }
+
+    size_t get_working_size() const override
+    {
+        return _subgemm->get_working_size();
+    }
+
+    void set_working_space(void *space) override
+    {
+        _subgemm->set_working_space(space);
+    }
+
+    bool B_is_pretransposed() const override
+    {
+        return _subgemm->B_is_pretransposed();
+    }
+
+    bool B_pretranspose_required() const override
+    {
+        return _subgemm->B_pretranspose_required();
+    }
+
+    size_t get_B_pretransposed_array_size() const override
+    {
+        return _subgemm->get_B_pretransposed_array_size();
+    }
+
+    void pretranspose_B_array(void *buffer, const To *B, const int ldb, const int B_multi_stride) override
+    {
+        _subgemm->pretranspose_B_array(buffer, B, ldb, B_multi_stride);
+    }
+
+    void set_pretransposed_B_data(void *buffer) override
+    {
+        _subgemm->set_pretransposed_B_data(buffer);
+    }
+};
+
+} // namespace arm_gemm