COMPMID-1774: Implement CLGEMMReshapeLHSMatrixKernel to reshape the LHS matrix of GEMM/GEMMLowp

Change-Id: I8c5fd4c8bcdffda1522c83158981ed92baa045f4
Reviewed-on: https://review.mlplatform.org/364
Reviewed-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>

15 files changed, 1338 insertions, 3 deletions

diff --git a/arm_compute/core/CL/CLKernels.h b/arm_compute/core/CL/CLKernels.h
index 9d7ec71a32..7bfd44721f 100644
--- a/arm_compute/core/CL/CLKernels.h
+++ b/arm_compute/core/CL/CLKernels.h
@@ -79,6 +79,7 @@
 #include "arm_compute/core/CL/kernels/CLGEMMMatrixAdditionKernel.h"
 #include "arm_compute/core/CL/kernels/CLGEMMMatrixMultiplyKernel.h"
 #include "arm_compute/core/CL/kernels/CLGEMMMatrixVectorMultiplyKernel.h"
+#include "arm_compute/core/CL/kernels/CLGEMMReshapeLHSMatrixKernel.h"
 #include "arm_compute/core/CL/kernels/CLGEMMTranspose1xWKernel.h"
 #include "arm_compute/core/CL/kernels/CLGaussian3x3Kernel.h"
 #include "arm_compute/core/CL/kernels/CLGaussian5x5Kernel.h"
diff --git a/arm_compute/core/CL/kernels/CLGEMMReshapeLHSMatrixKernel.h b/arm_compute/core/CL/kernels/CLGEMMReshapeLHSMatrixKernel.h
new file mode 100644
index 0000000000..77d7494a7f
--- /dev/null
+++ b/arm_compute/core/CL/kernels/CLGEMMReshapeLHSMatrixKernel.h
@@ -0,0 +1,90 @@
+/*
+ * Copyright (c) 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.
+ */
+#ifndef __ARM_COMPUTE_CLGEMMRESHAPELHSMATRIXKERNEL_H__
+#define __ARM_COMPUTE_CLGEMMRESHAPELHSMATRIXKERNEL_H__
+
+#include "arm_compute/core/CL/ICLKernel.h"
+
+namespace arm_compute
+{
+class ICLTensor;
+
+/** OpenCL kernel to reshape the LHS matrix when performing the matrix multiplication.
+ *  In particular, this function splits the input matrix in blocks of size M0xK0 (defined through GEMMLHSInfo) and
+ *  stores each one in the output matrix unrolling the values
+ */
+class CLGEMMReshapeLHSMatrixKernel : public ICLKernel
+{
+public:
+    /** Default constructor */
+    CLGEMMReshapeLHSMatrixKernel();
+    /** Prevent instances of this class from being copied (As this class contains pointers) */
+    CLGEMMReshapeLHSMatrixKernel(const CLGEMMReshapeLHSMatrixKernel &) = delete;
+    /** Prevent instances of this class from being copied (As this class contains pointers) */
+    CLGEMMReshapeLHSMatrixKernel &operator=(const CLGEMMReshapeLHSMatrixKernel &) = delete;
+    /** Allow instances of this class to be moved */
+    CLGEMMReshapeLHSMatrixKernel(CLGEMMReshapeLHSMatrixKernel &&) = default;
+    /** Allow instances of this class to be moved */
+    CLGEMMReshapeLHSMatrixKernel &operator=(CLGEMMReshapeLHSMatrixKernel &&) = default;
+    /** Initialise the kernel's input and output.
+     *
+     * @param[in]  input                   Input tensor. Data types supported: U8/S8/QASYMM8/U16/S16/F16/U32/S32/F32
+     * @param[out] output                  Output tensor. Data type supported: same as @p input
+     * @param[in]  lhs_info                LHS matrix information to be used for reshaping. This object contains all the necessary
+     *                                     information to reshape the input tensor. Only the following values are supported:
+     *                                     lhs_info.m0: 2,3,4,5,6,7,8
+     *                                     lhs_info.k0: 2,4,8,16
+     *                                     lhs_info.v0: greater than 0
+     *                                     lhs_info.transpose: false
+     *                                     lhs_info.interleave: true, false
+     * @param[in]  reinterpret_input_as_3d (Optional) True if the input has to be reinterpreted as 3D tensor
+     */
+    void configure(const ICLTensor *input, ICLTensor *output, const GEMMLHSMatrixInfo &lhs_info, bool reinterpret_input_as_3d = false);
+    /** Static function to check if given info will lead to a valid configuration of @ref CLGEMMReshapeLHSMatrixKernel
+     *
+     * @param[in] input                   Input tensor info. Data types supported: U8/S8/QASYMM8/U16/S16/F16/U32/S32/F32
+     * @param[in] output                  Output tensor info which stores the interleaved matrix. Data type supported: same as @p input.
+     * @param[in] lhs_info                LHS matrix information to be used for reshaping. This object contains all the necessary
+     *                                    information to reshape the input tensor. Only the following values are supported:
+     *                                    lhs_info.m0: 2,3,4,5,6,7,8
+     *                                    lhs_info.k0: 2,4,8,16
+     *                                    lhs_info.v0: greater than 0
+     *                                    lhs_info.transpose: false
+     *                                    lhs_info.interleave: true, false
+     * @param[in] reinterpret_input_as_3d True if the input has to be reinterpreted as 3D tensor
+     *
+     * @return a status
+     */
+    static Status validate(const ITensorInfo *input, const ITensorInfo *output, const GEMMLHSMatrixInfo &lhs_info, bool reinterpret_input_as_3d);
+
+    // Inherited methods overridden
+    void run(const Window &window, cl::CommandQueue &queue) override;
+
+private:
+    const ICLTensor *_input;
+    ICLTensor       *_output;
+    bool             _reinterpret_input_as_3d;
+};
+} // namespace arm_compute
+#endif /* __ARM_COMPUTE_CLGEMMRESHAPELHSMATRIXKERNEL_H__ */
\ No newline at end of file
diff --git a/arm_compute/core/Types.h b/arm_compute/core/Types.h
index 75b38c5cb8..55b0ccb30d 100644
--- a/arm_compute/core/Types.h
+++ b/arm_compute/core/Types.h
@@ -1771,6 +1771,16 @@ struct GEMMLowpOutputStageInfo
     int                     gemmlowp_max_bound{ 0 };               /**< GEMMLowp max value used to saturate down the output result before converting back to QASYMM8 */
 };
 
+/** GEMM LHS (Left Hand Side) matrix information */
+struct GEMMLHSMatrixInfo
+{
+    unsigned int m0{ 1 };            /**< Number of rows processed by the matrix multiplication */
+    unsigned int k0{ 1 };            /**< Number of partial accumulations performed by the matrix multiplication */
+    unsigned int v0{ 1 };            /**< Number of vertical blocks of size (m0xk0) stored on the same output row */
+    bool         transpose{ true };  /**< True if the (m0xk0) block has to be transposed before been stored */
+    bool         interleave{ true }; /**< True if the v0 (m0xk0) blocks have to be interleaved in the output row */
+};
+
 /** GEMM information class. This class stores the necessary information to compute GEMM functions
  *
  * This object also contains the information about how matrix A and matrix B have been reshaped
diff --git a/arm_compute/core/utils/misc/ShapeCalculator.h b/arm_compute/core/utils/misc/ShapeCalculator.h
index c625a07a7f..88ce8d9e7b 100644
--- a/arm_compute/core/utils/misc/ShapeCalculator.h
+++ b/arm_compute/core/utils/misc/ShapeCalculator.h
@@ -101,6 +101,43 @@ inline TensorShape compute_weights_reshaped_shape(const ITensorInfo &weights, bo
     return weights_reshaped;
 }
 
+inline TensorShape compute_lhs_reshaped_shape(const ITensorInfo &a, const GEMMLHSMatrixInfo &lhs_info, bool reinterpret_input_as_3d = false)
+{
+    ARM_COMPUTE_ERROR_ON(lhs_info.m0 == 0);
+    ARM_COMPUTE_ERROR_ON(lhs_info.k0 == 0);
+    ARM_COMPUTE_ERROR_ON(lhs_info.v0 == 0);
+
+    // Input width/height
+    const unsigned int input_width  = a.dimension(0);
+    const unsigned int input_height = reinterpret_input_as_3d ? a.dimension(1) * a.dimension(2) : a.dimension(1);
+
+    // Number of horizontal/vertical blocks in the input tensor
+    const unsigned int num_horiz_blocks = std::ceil(input_width / static_cast<float>(lhs_info.k0));
+    const unsigned int num_vert_blocks  = std::ceil(input_height / static_cast<float>(lhs_info.m0));
+
+    // Block size
+    const unsigned int block_size = lhs_info.m0 * lhs_info.k0;
+
+    // Output width/height
+    const unsigned int output_width  = block_size * num_horiz_blocks * lhs_info.v0;
+    const unsigned int output_height = std::ceil(num_vert_blocks / static_cast<float>(lhs_info.v0));
+
+    TensorShape lhs_shape{ a.tensor_shape() };
+    lhs_shape.set(0, output_width);
+    lhs_shape.set(1, output_height);
+
+    if((reinterpret_input_as_3d) && (lhs_shape.num_dimensions() > 2))
+    {
+        // When the data format is NHWC and the shapes are Nx1x1
+        // the tensor shape num_dimensions is automatically set to 1 instead of 3.
+        // To avoid failures by removing a dimension that doesn't exist
+        // check if the number of dimensions is greater than 2.
+        lhs_shape.remove_dimension(2);
+    }
+
+    return lhs_shape;
+}
+
 inline TensorShape compute_interleaved_shape(const ITensorInfo &a, int mult_interleave4x4_height = 1, bool reinterpret_input_as_3d = false)
 {
     // The interleaved output matrix will have the following shape: [ a_height * W, ceil(a_width / W) ] where W = 4 * mult_interleave4x4_height
diff --git a/src/core/CL/CLKernelLibrary.cpp b/src/core/CL/CLKernelLibrary.cpp
index da85472005..7b98e5ae80 100644
--- a/src/core/CL/CLKernelLibrary.cpp
+++ b/src/core/CL/CLKernelLibrary.cpp
@@ -282,6 +282,7 @@ const std::map<std::string, std::string> CLKernelLibrary::_kernel_program_map =
     { "gemm_mm_floating_point_f32_bifrost_1000", "gemm.cl" },
     { "gemm_lc_vm_f32", "gemm.cl" },
     { "gemm_transpose1xW", "gemm.cl" },
+    { "gemm_reshape_lhs_matrix_nt", "gemm.cl" },
     { "gemmlowp_matrix_a_reduction", "gemmlowp.cl" },
     { "gemmlowp_matrix_a_reduction_dot8", "gemmlowp.cl" },
     { "gemmlowp_matrix_b_reduction", "gemmlowp.cl" },
diff --git a/src/core/CL/cl_kernels/gemm.cl b/src/core/CL/cl_kernels/gemm.cl
index 7de15d018a..cf1e021929 100644
--- a/src/core/CL/cl_kernels/gemm.cl
+++ b/src/core/CL/cl_kernels/gemm.cl
@@ -23,6 +23,235 @@
  */
 #include "helpers.h"
 
+#if defined(M0) && defined(K0) && defined(V0) && defined(DATA_TYPE)
+
+/** This OpenCL kernel reshapes the lhs input matrix. The kernel splits the input matrix in blocks of size M0xK0 and stores each one (not transposed) in
+ *  the output matrix unrolling the values.
+ *
+ * @note The data type must be passed at compile time using -DDATA_TYPE (i.e. -DDATA_TYPE=float)
+ * @note The block's dimensions (M0 and K0) must be passed at compile time using -DM0 and -DK0 (i.e. -DM0=2, -DK0=2).
+ * @note The number of M0xK0 vertical blocks to store on the same output row must be passed at compile time using -DV0 (i.e. -DV0=2)
+ * @note Only the following values for M0, K0 and V0 are supported:
+ *                                      M0: 2,3,4,5,6,7,8
+ *                                      K0: 2,4,8,16
+ *                                      V0: greater than 0
+ * @note In case the input has to be reinterpreted as a 3D tensor (i.e. input of convolution layer 1x1), the following information must be passed at compile time:
+ *       -# REINTERPRET_INPUT_AS_3D: To reinterpret the input as 3D
+ *       -# HEIGHT_GEMM3D: The height of the input in case it has to be reinterpreted as a 3D tensor.
+ *       -# DEPTH_GEMM3D: The depth of the input in case it has to be reinterpreted as a 3D tensor
+ *          (HEIGHT_GEMM3D * DEPTH_GEMM3D) = columns matrix A NOT reshaped
+ * @note If the M0xK0 blocks have to be interleaved, the option -DINTERLEAVE must passed at compile time.
+ *
+ * @param[in]  src_ptr                           Pointer to the source LHS tensor. Supported data types: U8/S8/QASYMM8/U16/S16/F16/U32/S32/F32
+ * @param[in]  src_stride_x                      Stride of the source LHS tensor in X dimension (in bytes)
+ * @param[in]  src_step_x                        src_stride_x * number of elements along X processed per workitem(in bytes)
+ * @param[in]  src_stride_y                      Stride of the source LHS tensor in Y dimension (in bytes)
+ * @param[in]  src_step_y                        src_stride_y * number of elements along Y processed per workitem(in bytes)
+ * @param[in]  src_stride_z                      Stride of the source LHS tensor in Z dimension (in bytes)
+ * @param[in]  src_step_z                        src_stride_z * number of elements along Z processed per workitem(in bytes)
+ * @param[in]  src_offset_first_element_in_bytes The offset of the first element in the source LHS tensor
+ * @param[out] dst_ptr                           Pointer to the destination matrix Supported data types: same as @p src_ptr
+ * @param[in]  dst_stride_x                      Stride of the destination matrix in X dimension (in bytes)
+ * @param[in]  dst_step_x                        dst_stride_x * number of elements along X processed per workitem(in bytes)
+ * @param[in]  dst_stride_y                      Stride of the destination matrix in Y dimension (in bytes)
+ * @param[in]  dst_step_y                        dst_stride_y * number of elements along Y processed per workitem(in bytes)
+ * @param[in]  dst_stride_z                      Stride of the destination tensor in Z dimension (in bytes)
+ * @param[in]  dst_step_z                        dst_stride_z * number of elements along Z processed per workitem(in bytes)
+ * @param[in]  dst_offset_first_element_in_bytes The offset of the first element in the destination matrix
+ * @param[in]  cross_plane_pad                   (Optional) Bottom paddings in unit of elements (only if defined REINTERPRET_INPUT_AS_3D)
+ */
+__kernel void gemm_reshape_lhs_matrix_nt(TENSOR3D_DECLARATION(src),
+                                         TENSOR3D_DECLARATION(dst)
+#if defined(REINTERPRET_INPUT_AS_3D)
+                                         ,
+                                         uint cross_plane_pad
+#endif // REINTERPRET_INPUT_AS_3D
+                                        )
+{
+// Block size
+#define BLOCK_SIZE ((M0) * (K0))
+
+// Output offset X
+#if defined(INTERLEAVE)
+#define OUTPUT_OFFSET_X (K0)
+#else // defined(INTERLEAVE)
+#define OUTPUT_OFFSET_X (BLOCK_SIZE)
+#endif // defined(INTERLEAVE)
+
+// Output step X
+#if defined(INTERLEAVE)
+#define OUTPUT_STEP_X (K0) * (V0)
+#else // Do not interleave
+#define OUTPUT_STEP_X (K0)
+#endif // defined(INTERLEAVE)
+
+    // Compute source and destination addresses
+    uint x = get_global_id(0);
+    uint y = get_global_id(1);
+    uint z = get_global_id(2);
+
+    // ------------------ Compute input/output addresses ---------------------------
+
+    // Compute the input address
+    __global uchar *input_ptr = src_ptr + src_offset_first_element_in_bytes + x * (uint)K0 * sizeof(DATA_TYPE) + y * (uint)M0 * src_stride_y;
+
+    // Compute the output address
+    __global uchar *output_ptr = dst_ptr + dst_offset_first_element_in_bytes + (x * (uint)BLOCK_SIZE * (uint)V0 * sizeof(DATA_TYPE)) + ((y / (uint)V0) * (uint)dst_stride_y) + ((y % V0) *
+                                 (uint)OUTPUT_OFFSET_X * sizeof(DATA_TYPE));
+
+    uint zin0 = 0;
+    uint zin1 = 0;
+    uint zin2 = 0;
+    uint zin3 = 0;
+    uint zin4 = 0;
+    uint zin5 = 0;
+    uint zin6 = 0;
+    uint zin7 = 0;
+
+#if defined(REINTERPRET_INPUT_AS_3D)
+    // Add offset for batched GEMM. The batches will be in the fourth dimension and for this reason we
+    // multiply src_stride_z by DEPTH_GEMM3D
+
+    // Note for the REINTERPRET_INPUT_AS_3D case
+    // Since we load a 2D input tile from a 3D tensor, we need to check when the plane changes across the z dimension
+    // in order to take into account the presence of possible cross plane paddings
+    //
+    //  |                  |
+    //  |      plane0      |
+    //  |                  |
+    //  |__________________|
+    //  |******************|
+    //  |  cross_plane_pad |
+    //  |******************|
+    //  |                  |
+    //  |      plane1      |
+    //  |                  |
+    //  |__________________|
+
+    input_ptr += z * (uint)src_stride_z * DEPTH_GEMM3D;
+
+    // The plane (zin) is calculated dividing M (y * M0) by HEIGHT_GEMM3D
+    zin0 = (0 + (uint)(y * M0)) / (uint)HEIGHT_GEMM3D;
+    zin0 = min((uint)(DEPTH_GEMM3D - 1), zin0);
+    zin0 *= (cross_plane_pad * src_stride_y);
+#if M0 > 1
+    zin1 = (1 + (uint)(y * M0)) / (uint)HEIGHT_GEMM3D;
+    zin1 = min((uint)(DEPTH_GEMM3D - 1), zin1);
+    zin1 *= (cross_plane_pad * src_stride_y);
+#endif // M0 > 1
+#if M0 > 2
+    zin2 = (2 + (uint)(y * M0)) / (uint)HEIGHT_GEMM3D;
+    zin2 = min((uint)(DEPTH_GEMM3D - 1), zin2);
+    zin2 *= (cross_plane_pad * src_stride_y);
+#endif // M0 > 2
+#if M0 > 3
+    zin3 = (3 + (uint)(y * M0)) / (uint)HEIGHT_GEMM3D;
+    zin3 = min((uint)(DEPTH_GEMM3D - 1), zin3);
+    zin3 *= (cross_plane_pad * src_stride_y);
+#endif // M0 > 3
+#if M0 > 4
+    zin4 = (4 + (uint)(y * M0)) / (uint)HEIGHT_GEMM3D;
+    zin4 = min((uint)(DEPTH_GEMM3D - 1), zin4);
+    zin4 *= (cross_plane_pad * src_stride_y);
+#endif // M0 > 4
+#if M0 > 5
+    zin5 = (5 + (uint)(y * M0)) / (uint)HEIGHT_GEMM3D;
+    zin5 = min((uint)(DEPTH_GEMM3D - 1), zin5);
+    zin5 *= (cross_plane_pad * src_stride_y);
+#endif // M0 > 5
+#if M0 > 6
+    zin6 = (6 + (uint)(y * M0)) / (uint)HEIGHT_GEMM3D;
+    zin6 = min((uint)(DEPTH_GEMM3D - 1), zin6);
+    zin6 *= (cross_plane_pad * src_stride_y);
+#endif // M0 > 6
+#if M0 > 6
+    zin7 = (7 + (uint)(y * M0)) / (uint)HEIGHT_GEMM3D;
+    zin7 = min((uint)(DEPTH_GEMM3D - 1), zin7);
+    zin7 *= (cross_plane_pad * src_stride_y);
+#endif // M0 > 7
+
+#else // defined(REINTERPRET_INPUT_AS_3D)
+
+    input_ptr += z * (uint)src_stride_z;
+
+#endif // defined(REINTERPRET_INPUT_AS_3D)
+
+    // Add offset for batched GEMM
+    output_ptr += z * (uint)dst_stride_z;
+
+    // ---------------------------Load input values --------------------------------
+
+    // Load values from the LHS matrix
+    VEC_DATA_TYPE(DATA_TYPE, K0)
+    a0 = VLOAD(K0)(0, (__global DATA_TYPE *)(input_ptr + 0 * src_stride_y + zin0));
+#if M0 > 1
+    VEC_DATA_TYPE(DATA_TYPE, K0)
+    a1 = VLOAD(K0)(0, (__global DATA_TYPE *)(input_ptr + 1 * src_stride_y + zin1));
+#endif // M0 > 1
+#if M0 > 2
+    VEC_DATA_TYPE(DATA_TYPE, K0)
+    a2 = VLOAD(K0)(0, (__global DATA_TYPE *)(input_ptr + 2 * src_stride_y + zin2));
+#endif // M0 > 2
+#if M0 > 3
+    VEC_DATA_TYPE(DATA_TYPE, K0)
+    a3 = VLOAD(K0)(0, (__global DATA_TYPE *)(input_ptr + 3 * src_stride_y + zin3));
+#endif // M0 > 3
+#if M0 > 4
+    VEC_DATA_TYPE(DATA_TYPE, K0)
+    a4 = VLOAD(K0)(0, (__global DATA_TYPE *)(input_ptr + 4 * src_stride_y + zin4));
+#endif // M0 > 4
+#if M0 > 5
+    VEC_DATA_TYPE(DATA_TYPE, K0)
+    a5 = VLOAD(K0)(0, (__global DATA_TYPE *)(input_ptr + 5 * src_stride_y + zin5));
+#endif // M0 > 5
+#if M0 > 6
+    VEC_DATA_TYPE(DATA_TYPE, K0)
+    a6 = VLOAD(K0)(0, (__global DATA_TYPE *)(input_ptr + 6 * src_stride_y + zin6));
+#endif // M0 > 6
+#if M0 > 7
+    VEC_DATA_TYPE(DATA_TYPE, K0)
+    a7 = VLOAD(K0)(0, (__global DATA_TYPE *)(input_ptr + 7 * src_stride_y + zin7));
+#endif // M0 > 7
+
+    // ---------------------------Store output values ------------------------------
+
+    VSTORE(K0)
+    (a0, 0, (__global DATA_TYPE *)(output_ptr + 0 * OUTPUT_STEP_X * sizeof(DATA_TYPE)));
+#if M0 > 1
+    VSTORE(K0)
+    (a1, 0, (__global DATA_TYPE *)(output_ptr + 1 * OUTPUT_STEP_X * sizeof(DATA_TYPE)));
+#endif // M0 > 1
+#if M0 > 2
+    VSTORE(K0)
+    (a2, 0, (__global DATA_TYPE *)(output_ptr + 2 * OUTPUT_STEP_X * sizeof(DATA_TYPE)));
+#endif // M0 > 2
+#if M0 > 3
+    VSTORE(K0)
+    (a3, 0, (__global DATA_TYPE *)(output_ptr + 3 * OUTPUT_STEP_X * sizeof(DATA_TYPE)));
+#endif // M0 > 3
+#if M0 > 4
+    VSTORE(K0)
+    (a4, 0, (__global DATA_TYPE *)(output_ptr + 4 * OUTPUT_STEP_X * sizeof(DATA_TYPE)));
+#endif // M0 > 4
+#if M0 > 5
+    VSTORE(K0)
+    (a5, 0, (__global DATA_TYPE *)(output_ptr + 5 * OUTPUT_STEP_X * sizeof(DATA_TYPE)));
+#endif // M0 > 5
+#if M0 > 6
+    VSTORE(K0)
+    (a6, 0, (__global DATA_TYPE *)(output_ptr + 6 * OUTPUT_STEP_X * sizeof(DATA_TYPE)));
+#endif // M0 > 6
+#if M0 > 7
+    VSTORE(K0)
+    (a7, 0, (__global DATA_TYPE *)(output_ptr + 7 * OUTPUT_STEP_X * sizeof(DATA_TYPE)));
+#endif // M0 > 7
+
+#undef BLOCK_SIZE
+#undef OUTPUT_OFFSET_X
+#undef OUTPUT_STEP_X
+}
+#endif // defined(M0) && defined(K0) && defined(V0) && defined(DATA_TYPE)
+
 #if defined(TRANSPOSE_W) && defined(MULT_TRANSPOSE1XW_WIDTH)
 
 #if ELEMENT_SIZE == 1
@@ -193,7 +422,7 @@ __kernel void gemm_interleave4x4(TENSOR3D_DECLARATION(src),
     vstore4(a1, 0, ((__global DATA_TYPE *)(dst_ptr + dst_addr_in_bytes) + 4 * MULT_INTERLEAVE4X4_HEIGHT));
     vstore4(a2, 0, ((__global DATA_TYPE *)(dst_ptr + dst_addr_in_bytes) + 8 * MULT_INTERLEAVE4X4_HEIGHT));
     vstore4(a3, 0, ((__global DATA_TYPE *)(dst_ptr + dst_addr_in_bytes) + 12 * MULT_INTERLEAVE4X4_HEIGHT));
-#else // defined(UNROLL_BLOCK)
+#else  // defined(UNROLL_BLOCK)
     VEC_DATA_TYPE(DATA_TYPE, 4)
     val0 = (VEC_DATA_TYPE(DATA_TYPE, 4))(a0.s0, a1.s0, a2.s0, a3.s0);
     vstore4(val0, 0, ((__global DATA_TYPE *)(dst_ptr + dst_addr_in_bytes) + 0 * MULT_INTERLEAVE4X4_HEIGHT));
diff --git a/src/core/CL/kernels/CLGEMMReshapeLHSMatrixKernel.cpp b/src/core/CL/kernels/CLGEMMReshapeLHSMatrixKernel.cpp
new file mode 100644
index 0000000000..e0af5801a8
--- /dev/null
+++ b/src/core/CL/kernels/CLGEMMReshapeLHSMatrixKernel.cpp
@@ -0,0 +1,221 @@
+/*
+ * Copyright (c) 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.
+ */
+#include "arm_compute/core/CL/kernels/CLGEMMReshapeLHSMatrixKernel.h"
+
+#include "arm_compute/core/AccessWindowStatic.h"
+#include "arm_compute/core/CL/CLHelpers.h"
+#include "arm_compute/core/CL/CLKernelLibrary.h"
+#include "arm_compute/core/CL/CLValidate.h"
+#include "arm_compute/core/CL/ICLTensor.h"
+#include "arm_compute/core/CL/OpenCL.h"
+#include "arm_compute/core/Error.h"
+#include "arm_compute/core/Helpers.h"
+#include "arm_compute/core/TensorInfo.h"
+#include "arm_compute/core/Types.h"
+#include "arm_compute/core/Utils.h"
+#include "arm_compute/core/Window.h"
+#include "arm_compute/core/utils/misc/ShapeCalculator.h"
+
+using namespace arm_compute;
+using namespace arm_compute::misc::shape_calculator;
+
+namespace
+{
+Status validate_arguments(const ITensorInfo *input, const ITensorInfo *output, const GEMMLHSMatrixInfo &lhs_info, bool reinterpret_input_as_3d)
+{
+    ARM_COMPUTE_RETURN_ERROR_ON(lhs_info.transpose);
+    ARM_COMPUTE_RETURN_ERROR_ON(lhs_info.m0 == 0);
+    ARM_COMPUTE_RETURN_ERROR_ON(lhs_info.k0 == 0);
+    ARM_COMPUTE_RETURN_ERROR_ON(lhs_info.v0 == 0);
+    ARM_COMPUTE_RETURN_ERROR_ON_MSG((lhs_info.k0 & (lhs_info.k0 - 1)), "Only power of two values are allowed for k0");
+    ARM_COMPUTE_RETURN_ERROR_ON(lhs_info.k0 > 16);
+    ARM_COMPUTE_RETURN_ERROR_ON(lhs_info.m0 < 2 || lhs_info.m0 > 8);
+
+    ARM_COMPUTE_RETURN_ERROR_ON_F16_UNSUPPORTED(input);
+    ARM_COMPUTE_RETURN_ERROR_ON_DATA_TYPE_CHANNEL_NOT_IN(input, 1, DataType::QASYMM8, DataType::U8, DataType::S8,
+                                                         DataType::U16, DataType::S16, DataType::U32, DataType::S32,
+                                                         DataType::F16, DataType::F32);
+
+    if(output->total_size() != 0)
+    {
+        ARM_COMPUTE_RETURN_ERROR_ON_MISMATCHING_DIMENSIONS(output->tensor_shape(), compute_lhs_reshaped_shape(*input, lhs_info, reinterpret_input_as_3d));
+        ARM_COMPUTE_RETURN_ERROR_ON_MISMATCHING_DATA_TYPES(input, output);
+    }
+
+    return Status{};
+}
+
+std::pair<Status, Window> validate_and_configure_window(ITensorInfo *input, ITensorInfo *output, const GEMMLHSMatrixInfo &lhs_info, bool reinterpret_input_as_3d)
+{
+    const unsigned int num_elems_processed_per_iteration_x = lhs_info.k0;
+    const unsigned int num_elems_processed_per_iteration_y = lhs_info.m0;
+    bool               window_changed                      = false;
+
+    TensorInfo tmp_info(*input);
+
+    if(reinterpret_input_as_3d)
+    {
+        // Since the input tensor has to be reinterpreted as 3D and the execute window is based on a 2D interleave,
+        // the window needs to be constructed on the 2D collapsed version of the tensor
+        TensorShape tmp_shape(input->tensor_shape());
+        tmp_shape.collapse(2U, 1U);
+        tmp_info.set_tensor_shape(tmp_shape);
+    }
+
+    // Output auto inizialitation if not yet initialized
+    auto_init_if_empty(*output, input->clone()->set_tensor_shape(compute_lhs_reshaped_shape(*input, lhs_info, reinterpret_input_as_3d)));
+
+    // Configure window
+    // Note: bottom paddings are calculated manually as the input can be reinterpreted as 3D tensor
+    // The only way to set properly the paddings, it is to set those explicitly through the AccessWindowStatic
+    const int m          = reinterpret_input_as_3d ? input->tensor_shape()[1] * input->tensor_shape()[2] : input->tensor_shape()[1];
+    const int bottom_pad = ceil_to_multiple(m, num_elems_processed_per_iteration_y) - m;
+
+    Window win    = calculate_max_window(tmp_info, Steps(num_elems_processed_per_iteration_x, num_elems_processed_per_iteration_y));
+    Window win_in = calculate_max_window(*input, Steps(num_elems_processed_per_iteration_x, num_elems_processed_per_iteration_y));
+
+    AccessWindowStatic input_access(input, 0, 0,
+                                    ceil_to_multiple(input->dimension(0), num_elems_processed_per_iteration_x),
+                                    input->dimension(1) + bottom_pad);
+    AccessWindowStatic output_access(output, 0, 0, output->dimension(0), output->dimension(1));
+
+    window_changed = update_window_and_padding(win_in, input_access) || // window used by the execute_window_loop
+                     update_window_and_padding(win, output_access);     // window used to update the padding requirements of output tensor
+    output_access.set_valid_region(win, ValidRegion(Coordinates(0, 0), output->tensor_shape()));
+
+    // Collapse along the Z direction
+    // This collapse needs to be here in order to tune the Z dimension of LWS
+    Window collapsed = win.collapse(win, Window::DimZ);
+
+    Status err = (window_changed) ? ARM_COMPUTE_CREATE_ERROR(ErrorCode::RUNTIME_ERROR, "Insufficient Padding!") : Status{};
+    return std::make_pair(err, collapsed);
+}
+} // namespace
+
+CLGEMMReshapeLHSMatrixKernel::CLGEMMReshapeLHSMatrixKernel()
+    : _input(nullptr), _output(nullptr), _reinterpret_input_as_3d(false)
+{
+}
+
+void CLGEMMReshapeLHSMatrixKernel::configure(const ICLTensor *input, ICLTensor *output, const GEMMLHSMatrixInfo &lhs_info, bool reinterpret_input_as_3d)
+{
+    ARM_COMPUTE_ERROR_ON_NULLPTR(input, output);
+
+    // Perform validate step
+    ARM_COMPUTE_ERROR_THROW_ON(validate_arguments(input->info(), output->info(), lhs_info, reinterpret_input_as_3d));
+
+    _input                   = input;
+    _output                  = output;
+    _reinterpret_input_as_3d = reinterpret_input_as_3d;
+
+    // Create build options
+    CLBuildOptions build_opts;
+    build_opts.add_option("-DM0=" + support::cpp11::to_string(lhs_info.m0));
+    build_opts.add_option("-DK0=" + support::cpp11::to_string(lhs_info.k0));
+    build_opts.add_option("-DV0=" + support::cpp11::to_string(lhs_info.v0));
+    build_opts.add_option_if(lhs_info.interleave, "-DINTERLEAVE");
+    build_opts.add_option_if(_reinterpret_input_as_3d, "-DREINTERPRET_INPUT_AS_3D");
+    build_opts.add_option_if(_reinterpret_input_as_3d, "-DHEIGHT_GEMM3D=" + support::cpp11::to_string(input->info()->dimension(1)));
+    build_opts.add_option_if(_reinterpret_input_as_3d, "-DDEPTH_GEMM3D=" + support::cpp11::to_string(input->info()->dimension(2)));
+
+    switch(input->info()->element_size())
+    {
+        case 1:
+            build_opts.add_option("-DDATA_TYPE=uchar");
+            break;
+        case 2:
+            build_opts.add_option("-DDATA_TYPE=ushort");
+            break;
+        case 4:
+            build_opts.add_option("-DDATA_TYPE=uint");
+            break;
+        default:
+            ARM_COMPUTE_ERROR("Data type not supported");
+    }
+
+    std::string kernel_name("gemm_reshape_lhs_matrix_");
+    kernel_name += lhs_info.transpose ? "t" : "nt";
+
+    // Create kernel
+    _kernel = static_cast<cl::Kernel>(CLKernelLibrary::get().create_kernel(kernel_name, build_opts.options()));
+
+    // Configure kernel window
+    auto win_config = validate_and_configure_window(input->info(), output->info(), lhs_info, reinterpret_input_as_3d);
+    ARM_COMPUTE_ERROR_THROW_ON(win_config.first);
+    ICLKernel::configure_internal(win_config.second);
+
+    // Set config_id for enabling LWS tuning
+    _config_id = "gemm_reshape_lhs_matrix_";
+    _config_id += (_reinterpret_input_as_3d ? "3d_" : "");
+    _config_id += lower_string(string_from_data_type(input->info()->data_type()));
+    _config_id += "_";
+    _config_id += support::cpp11::to_string(output->info()->dimension(0));
+    _config_id += "_";
+    _config_id += support::cpp11::to_string(output->info()->dimension(1));
+    _config_id += "_";
+    _config_id += support::cpp11::to_string(output->info()->dimension(2));
+    _config_id += "_";
+    _config_id += support::cpp11::to_string(lhs_info.m0);
+    _config_id += "_";
+    _config_id += support::cpp11::to_string(lhs_info.k0);
+    _config_id += "_";
+    _config_id += support::cpp11::to_string(lhs_info.v0);
+    _config_id += "_";
+    _config_id += support::cpp11::to_string(lhs_info.interleave);
+    _config_id += "_";
+    _config_id += support::cpp11::to_string(lhs_info.transpose);
+}
+
+Status CLGEMMReshapeLHSMatrixKernel::validate(const ITensorInfo *input, const ITensorInfo *output, const GEMMLHSMatrixInfo &lhs_info, bool reinterpret_input_as_3d)
+{
+    ARM_COMPUTE_RETURN_ON_ERROR(validate_arguments(input, output, lhs_info, reinterpret_input_as_3d));
+    ARM_COMPUTE_RETURN_ON_ERROR(validate_and_configure_window(input->clone().get(), output->clone().get(), lhs_info, reinterpret_input_as_3d).first);
+
+    return Status{};
+}
+
+void CLGEMMReshapeLHSMatrixKernel::run(const Window &window, cl::CommandQueue &queue)
+{
+    ARM_COMPUTE_ERROR_ON_UNCONFIGURED_KERNEL(this);
+    ARM_COMPUTE_ERROR_ON_INVALID_SUBWINDOW(ICLKernel::window(), window);
+
+    Window slice = window.first_slice_window_3D();
+
+    if(_reinterpret_input_as_3d)
+    {
+        // Pass bottom paddings to the kernel if the input has to be reinterpreted as 3D tensor
+        const unsigned int idx0                  = 2 * num_arguments_per_3D_tensor();
+        const unsigned int total_cross_plane_pad = _input->info()->padding().top + _input->info()->padding().bottom;
+        _kernel.setArg<cl_uint>(idx0, static_cast<unsigned int>(total_cross_plane_pad));
+    }
+
+    do
+    {
+        unsigned int idx = 0;
+        add_3D_tensor_argument(idx, _input, slice);
+        add_3D_tensor_argument(idx, _output, slice);
+        enqueue(queue, *this, slice, lws_hint());
+    }
+    while(window.slide_window_slice_3D(slice));
+}
\ No newline at end of file
diff --git a/src/core/CL/kernels/CLReverseKernel.cpp b/src/core/CL/kernels/CLReverseKernel.cpp
index 2859a51ce1..adbdb11c5f 100644
--- a/src/core/CL/kernels/CLReverseKernel.cpp
+++ b/src/core/CL/kernels/CLReverseKernel.cpp
@@ -80,7 +80,20 @@ void CLReverseKernel::configure(const ICLTensor *input, ICLTensor *output, const
     // Set kernel build options
     CLBuildOptions build_opts;
     build_opts.add_option("-DNUM_REVERSE_DIMS=" + support::cpp11::to_string(axis->info()->dimension(0)));
-    build_opts.add_option("-DDATA_TYPE=" + get_cl_type_from_data_type(input->info()->data_type()));
+    switch(input->info()->element_size())
+    {
+        case 1:
+            build_opts.add_option("-DDATA_TYPE=uchar");
+            break;
+        case 2:
+            build_opts.add_option("-DDATA_TYPE=ushort");
+            break;
+        case 4:
+            build_opts.add_option("-DDATA_TYPE=uint");
+            break;
+        default:
+            ARM_COMPUTE_ERROR("Data type not supported");
+    }
 
     // Create kernel
     _kernel = static_cast<cl::Kernel>(CLKernelLibrary::get().create_kernel("reverse", build_opts.options()));
diff --git a/tests/CL/Helper.h b/tests/CL/Helper.h
index 32f9ca00e3..88e716726a 100644
--- a/tests/CL/Helper.h
+++ b/tests/CL/Helper.h
@@ -24,7 +24,13 @@
 #ifndef __ARM_COMPUTE_TEST_CL_HELPER_H__
 #define __ARM_COMPUTE_TEST_CL_HELPER_H__
 
+#include "arm_compute/core/CL/ICLKernel.h"
+#include "arm_compute/core/CL/kernels/CLFillBorderKernel.h"
+#include "arm_compute/core/CL/kernels/CLMemsetKernel.h"
+
+#include "arm_compute/runtime/CL/CLScheduler.h"
 #include "arm_compute/runtime/CL/ICLSimpleFunction.h"
+#include "arm_compute/runtime/IFunction.h"
 #include "support/ToolchainSupport.h"
 
 namespace arm_compute
@@ -77,6 +83,44 @@ public:
         _border_handler.configure(first, BorderSize(bordersize), BorderMode::CONSTANT, PixelValue(0));
     }
 };
+
+/** As above but this also initializes to zero the input tensor */
+template <typename K, int bordersize>
+class CLSynthetizeFunctionInitOutputWithZeroAndWithZeroConstantBorder : public IFunction
+{
+public:
+    /** Configure the kernel.
+     *
+     * @param[in] first  First input argument.
+     * @param[in] second Second input argument.
+     * @param[in] args   Rest of the configuration arguments.
+     */
+    template <typename T, typename... Args>
+    void configure(T first, T second, Args &&... args)
+    {
+        auto k = arm_compute::support::cpp14::make_unique<K>();
+        k->set_target(CLScheduler::get().target());
+        k->configure(first, second, std::forward<Args>(args)...);
+        _kernel = std::move(k);
+        _border_handler.configure(first, BorderSize(bordersize), BorderMode::CONSTANT, PixelValue(0));
+        _memset_kernel.configure(second, PixelValue(0));
+    }
+
+    // Inherited method overridden:
+    void run() override final
+    {
+        ARM_COMPUTE_ERROR_ON_MSG(!_kernel, "The CL kernel or function isn't configured");
+
+        CLScheduler::get().enqueue(_memset_kernel, false);
+        CLScheduler::get().enqueue(_border_handler, false);
+        CLScheduler::get().enqueue(*_kernel);
+    }
+
+private:
+    CLMemsetKernel             _memset_kernel{};  /**< Kernel to initialize the tensor */
+    CLFillBorderKernel         _border_handler{}; /**< Kernel to handle  borders */
+    std::unique_ptr<ICLKernel> _kernel{};         /**< Kernel to run */
+};
 } // namespace test
 } // namespace arm_compute
 #endif /* __ARM_COMPUTE_TEST_CL_HELPER_H__ */
diff --git a/tests/datasets/ShapeDatasets.h b/tests/datasets/ShapeDatasets.h
index f7e7ae26b9..875f7e8ea1 100644
--- a/tests/datasets/ShapeDatasets.h
+++ b/tests/datasets/ShapeDatasets.h
@@ -892,6 +892,62 @@ public:
     {
     }
 };
+
+/** Data set containing small tensor shapes to be used with the GEMM reshaping kernel */
+class SmallGEMMReshape2DShapes final : public ShapeDataset
+{
+public:
+    SmallGEMMReshape2DShapes()
+        : ShapeDataset("Shape",
+    {
+        TensorShape{ 63U, 72U },
+    })
+    {
+    }
+};
+
+/** Data set containing small tensor shapes to be used with the GEMM reshaping kernel when the input has to be reinterpreted as 3D */
+class SmallGEMMReshape3DShapes final : public ShapeDataset
+{
+public:
+    SmallGEMMReshape3DShapes()
+        : ShapeDataset("Shape",
+    {
+        TensorShape{ 63U, 9U, 8U },
+    })
+    {
+    }
+};
+
+/** Data set containing large tensor shapes to be used with the GEMM reshaping kernel */
+class LargeGEMMReshape2DShapes final : public ShapeDataset
+{
+public:
+    LargeGEMMReshape2DShapes()
+        : ShapeDataset("Shape",
+    {
+        TensorShape{ 16U, 27U },
+                     TensorShape{ 533U, 171U },
+                     TensorShape{ 345U, 612U }
+    })
+    {
+    }
+};
+
+/** Data set containing large tensor shapes to be used with the GEMM reshaping kernel when the input has to be reinterpreted as 3D */
+class LargeGEMMReshape3DShapes final : public ShapeDataset
+{
+public:
+    LargeGEMMReshape3DShapes()
+        : ShapeDataset("Shape",
+    {
+        TensorShape{ 16U, 3U, 9U },
+                     TensorShape{ 533U, 19U, 9U },
+                     TensorShape{ 345U, 34U, 18U }
+    })
+    {
+    }
+};
 } // namespace datasets
 } // namespace test
 } // namespace arm_compute
diff --git a/tests/validation/CL/GEMMReshapeLHSMatrix.cpp b/tests/validation/CL/GEMMReshapeLHSMatrix.cpp
new file mode 100644
index 0000000000..ea6589df22
--- /dev/null
+++ b/tests/validation/CL/GEMMReshapeLHSMatrix.cpp
@@ -0,0 +1,335 @@
+/*
+ * Copyright (c) 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.
+ */
+#include "arm_compute/core/CL/kernels/CLGEMMReshapeLHSMatrixKernel.h"
+#include "arm_compute/core/Types.h"
+#include "arm_compute/core/utils/misc/ShapeCalculator.h"
+#include "arm_compute/runtime/CL/CLTensor.h"
+#include "arm_compute/runtime/CL/CLTensorAllocator.h"
+#include "tests/CL/CLAccessor.h"
+#include "tests/CL/Helper.h"
+#include "tests/PaddingCalculator.h"
+#include "tests/datasets/ShapeDatasets.h"
+#include "tests/framework/Asserts.h"
+#include "tests/framework/Macros.h"
+#include "tests/framework/datasets/Datasets.h"
+#include "tests/validation/Validation.h"
+#include "tests/validation/fixtures/GEMMReshapeLHSMatrixFixture.h"
+
+namespace arm_compute
+{
+namespace test
+{
+namespace validation
+{
+namespace
+{
+// *INDENT-OFF*
+// clang-format off
+/** Data types */
+const auto data_types = framework::dataset::make("DataType", { DataType::QASYMM8, DataType::F16, DataType::F32 });
+
+/** Batch size values to test */
+const auto b_values = framework::dataset::make("batchsize", 1, 3);
+
+/** M0 values to test */
+const auto m0_values = framework::dataset::make("M0", 2, 9);
+
+/** K0 values to test */
+const auto k0_values = framework::dataset::make("K0", { 2, 4, 8, 16 });
+
+/** V0 values to test */
+const auto v0_values = framework::dataset::make("V0", 1, 4);
+
+/** Interleave values to test */
+const auto i_values = framework::dataset::make("interleave", { true, false });
+
+/** Transpose values to test */
+const auto t_values = framework::dataset::make("transpose", { false });
+} // namespace
+
+using namespace arm_compute::misc::shape_calculator;
+
+// Initialize the output tensor with zero and fill the border with zero
+using CLGEMMReshapeLHSMatrix = CLSynthetizeFunctionInitOutputWithZeroAndWithZeroConstantBorder<CLGEMMReshapeLHSMatrixKernel, 16>;
+
+template <typename T>
+using CLGEMMReshapeLHSMatrixFixture = GEMMReshapeLHSMatrixValidationFixture<CLTensor, CLAccessor, CLGEMMReshapeLHSMatrix, T, false>;
+
+// Fixture to use when the input has to be reinterpreted as 3D
+template <typename T>
+using CLGEMMReshapeLHSMatrix3DFixture = GEMMReshapeLHSMatrixValidationFixture<CLTensor, CLAccessor, CLGEMMReshapeLHSMatrix, T, true>;
+
+TEST_SUITE(CL)
+TEST_SUITE(GEMMReshapeLHSMatrix)
+
+DATA_TEST_CASE(Configuration, framework::DatasetMode::ALL, combine(combine(combine(combine(combine(combine(combine(datasets::SmallGEMMReshape2DShapes(),
+                                                                   b_values),
+                                                                   data_types),
+                                                                   m0_values),
+                                                                   k0_values),
+                                                                   v0_values),
+                                                                   i_values),
+                                                                   t_values),
+shape_in, b_value, data_type, m0_value, k0_value, v0_value, i_value, t_value)
+{
+    GEMMLHSMatrixInfo lhs_info;
+    lhs_info.m0         = m0_value;
+    lhs_info.k0         = k0_value;
+    lhs_info.v0         = v0_value;
+    lhs_info.interleave = i_value;
+    lhs_info.transpose  = t_value;
+
+    const TensorShape shape_src(shape_in[0], shape_in[1], b_value);
+    const TensorShape shape_dst = compute_lhs_reshaped_shape(TensorInfo(shape_src, 1, data_type), lhs_info, false);
+
+    // Create tensors
+    CLTensor src = create_tensor<CLTensor>(shape_src, data_type);
+    CLTensor dst = create_tensor<CLTensor>(shape_dst, data_type);
+
+    ARM_COMPUTE_EXPECT(src.info()->is_resizable(), framework::LogLevel::ERRORS);
+    ARM_COMPUTE_EXPECT(dst.info()->is_resizable(), framework::LogLevel::ERRORS);
+
+    // Create and configure function
+    CLGEMMReshapeLHSMatrixKernel reshape_lhs;
+    reshape_lhs.configure(&src, &dst, lhs_info, false);
+}
+
+TEST_SUITE(S32)
+FIXTURE_DATA_TEST_CASE(RunSmall, CLGEMMReshapeLHSMatrixFixture<int>, framework::DatasetMode::ALL,
+                combine(combine(combine(combine(combine(combine(combine(datasets::SmallGEMMReshape2DShapes(),
+                                                                   b_values),
+                                                                   framework::dataset::make("DataType", DataType::S32)),
+                                                                   m0_values),
+                                                                   k0_values),
+                                                                   v0_values),
+                                                                   i_values),
+                                                                   t_values))
+{
+    // Validate output
+    validate(CLAccessor(_target), _reference);
+}
+
+FIXTURE_DATA_TEST_CASE(RunLarge, CLGEMMReshapeLHSMatrixFixture<int>, framework::DatasetMode::NIGHTLY,
+                combine(combine(combine(combine(combine(combine(combine(datasets::LargeGEMMReshape2DShapes(),
+                                                                   b_values),
+                                                                   framework::dataset::make("DataType", DataType::S32)),
+                                                                   m0_values),
+                                                                   k0_values),
+                                                                   v0_values),
+                                                                   i_values),
+                                                                   t_values))
+{
+    // Validate output
+    validate(CLAccessor(_target), _reference);
+}
+TEST_SUITE_END() // S32
+
+TEST_SUITE(S16)
+FIXTURE_DATA_TEST_CASE(RunSmall, CLGEMMReshapeLHSMatrixFixture<short>, framework::DatasetMode::ALL,
+                combine(combine(combine(combine(combine(combine(combine(datasets::SmallGEMMReshape2DShapes(),
+                                                                   b_values),
+                                                                   framework::dataset::make("DataType", DataType::S16)),
+                                                                   m0_values),
+                                                                   k0_values),
+                                                                   v0_values),
+                                                                   i_values),
+                                                                   t_values))
+{
+    // Validate output
+    validate(CLAccessor(_target), _reference);
+}
+
+FIXTURE_DATA_TEST_CASE(RunLarge, CLGEMMReshapeLHSMatrixFixture<short>, framework::DatasetMode::NIGHTLY,
+                combine(combine(combine(combine(combine(combine(combine(datasets::LargeGEMMReshape2DShapes(),
+                                                                   b_values),
+                                                                   framework::dataset::make("DataType", DataType::S16)),
+                                                                   m0_values),
+                                                                   k0_values),
+                                                                   v0_values),
+                                                                   i_values),
+                                                                   t_values))
+{
+    // Validate output
+    validate(CLAccessor(_target), _reference);
+}
+TEST_SUITE_END() // S16
+
+TEST_SUITE(S8)
+FIXTURE_DATA_TEST_CASE(RunSmall, CLGEMMReshapeLHSMatrixFixture<char>, framework::DatasetMode::ALL,
+                combine(combine(combine(combine(combine(combine(combine(datasets::SmallGEMMReshape2DShapes(),
+                                                                   b_values),
+                                                                   framework::dataset::make("DataType", DataType::S8)),
+                                                                   m0_values),
+                                                                   k0_values),
+                                                                   v0_values),
+                                                                   i_values),
+                                                                   t_values))
+{
+    // Validate output
+    validate(CLAccessor(_target), _reference);
+}
+
+FIXTURE_DATA_TEST_CASE(RunLarge, CLGEMMReshapeLHSMatrixFixture<char>, framework::DatasetMode::NIGHTLY,
+                combine(combine(combine(combine(combine(combine(combine(datasets::LargeGEMMReshape2DShapes(),
+                                                                   b_values),
+                                                                   framework::dataset::make("DataType", DataType::S8)),
+                                                                   m0_values),
+                                                                   k0_values),
+                                                                   v0_values),
+                                                                   i_values),
+                                                                   t_values))
+{
+    // Validate output
+    validate(CLAccessor(_target), _reference);
+}
+TEST_SUITE_END() // S8
+
+TEST_SUITE(REINTERPRET_INPUT_AS_3D)
+DATA_TEST_CASE(Configuration, framework::DatasetMode::ALL, combine(combine(combine(combine(combine(combine(combine(datasets::SmallGEMMReshape3DShapes(),
+                                                                   b_values),
+                                                                   data_types),
+                                                                   m0_values),
+                                                                   k0_values),
+                                                                   v0_values),
+                                                                   i_values),
+                                                                   t_values),
+shape_in, b_value, data_type, m0_value, k0_value, v0_value, i_value, t_value)
+{
+    GEMMLHSMatrixInfo lhs_info;
+    lhs_info.m0         = m0_value;
+    lhs_info.k0         = k0_value;
+    lhs_info.v0         = v0_value;
+    lhs_info.interleave = i_value;
+    lhs_info.transpose  = t_value;
+
+    const TensorShape shape_src(shape_in[0], shape_in[1], shape_in[2], b_value);
+    const TensorShape shape_dst = compute_lhs_reshaped_shape(TensorInfo(shape_src, 1, data_type), lhs_info, true);
+
+    // Create tensors
+    CLTensor src = create_tensor<CLTensor>(shape_src, data_type);
+    CLTensor dst = create_tensor<CLTensor>(shape_dst, data_type);
+
+    ARM_COMPUTE_EXPECT(src.info()->is_resizable(), framework::LogLevel::ERRORS);
+    ARM_COMPUTE_EXPECT(dst.info()->is_resizable(), framework::LogLevel::ERRORS);
+
+    // Create and configure function
+    CLGEMMReshapeLHSMatrixKernel reshape_lhs;
+    reshape_lhs.configure(&src, &dst, lhs_info, true);
+}
+
+TEST_SUITE(S32)
+FIXTURE_DATA_TEST_CASE(RunSmall, CLGEMMReshapeLHSMatrix3DFixture<int>, framework::DatasetMode::ALL,
+                combine(combine(combine(combine(combine(combine(combine(datasets::SmallGEMMReshape3DShapes(),
+                                                                   b_values),
+                                                                   framework::dataset::make("DataType", DataType::S32)),
+                                                                   m0_values),
+                                                                   k0_values),
+                                                                   v0_values),
+                                                                   i_values),
+                                                                   t_values))
+{
+    // Validate output
+    validate(CLAccessor(_target), _reference);
+}
+
+FIXTURE_DATA_TEST_CASE(RunLarge, CLGEMMReshapeLHSMatrix3DFixture<int>, framework::DatasetMode::NIGHTLY,
+                combine(combine(combine(combine(combine(combine(combine(datasets::LargeGEMMReshape3DShapes(),
+                                                                   b_values),
+                                                                   framework::dataset::make("DataType", DataType::S32)),
+                                                                   m0_values),
+                                                                   k0_values),
+                                                                   v0_values),
+                                                                   i_values),
+                                                                   t_values))
+{
+    // Validate output
+    validate(CLAccessor(_target), _reference);
+}
+TEST_SUITE_END() // S32
+
+TEST_SUITE(S16)
+FIXTURE_DATA_TEST_CASE(RunSmall, CLGEMMReshapeLHSMatrix3DFixture<short>, framework::DatasetMode::ALL,
+                combine(combine(combine(combine(combine(combine(combine(datasets::SmallGEMMReshape3DShapes(),
+                                                                   b_values),
+                                                                   framework::dataset::make("DataType", DataType::S16)),
+                                                                   m0_values),
+                                                                   k0_values),
+                                                                   v0_values),
+                                                                   i_values),
+                                                                   t_values))
+{
+    // Validate output
+    validate(CLAccessor(_target), _reference);
+}
+
+FIXTURE_DATA_TEST_CASE(RunLarge, CLGEMMReshapeLHSMatrix3DFixture<short>, framework::DatasetMode::NIGHTLY,
+                combine(combine(combine(combine(combine(combine(combine(datasets::LargeGEMMReshape3DShapes(),
+                                                                   b_values),
+                                                                   framework::dataset::make("DataType", DataType::S16)),
+                                                                   m0_values),
+                                                                   k0_values),
+                                                                   v0_values),
+                                                                   i_values),
+                                                                   t_values))
+{
+    // Validate output
+    validate(CLAccessor(_target), _reference);
+}
+TEST_SUITE_END() // S16
+
+TEST_SUITE(S8)
+FIXTURE_DATA_TEST_CASE(RunSmall, CLGEMMReshapeLHSMatrix3DFixture<char>, framework::DatasetMode::ALL,
+                combine(combine(combine(combine(combine(combine(combine(datasets::SmallGEMMReshape3DShapes(),
+                                                                   b_values),
+                                                                   framework::dataset::make("DataType", DataType::S8)),
+                                                                   m0_values),
+                                                                   k0_values),
+                                                                   v0_values),
+                                                                   i_values),
+                                                                   t_values))
+{
+    // Validate output
+    validate(CLAccessor(_target), _reference);
+}
+
+FIXTURE_DATA_TEST_CASE(RunLarge, CLGEMMReshapeLHSMatrix3DFixture<char>, framework::DatasetMode::NIGHTLY,
+                combine(combine(combine(combine(combine(combine(combine(datasets::LargeGEMMReshape3DShapes(),
+                                                                   b_values),
+                                                                   framework::dataset::make("DataType", DataType::S8)),
+                                                                   m0_values),
+                                                                   k0_values),
+                                                                   v0_values),
+                                                                   i_values),
+                                                                   t_values))
+{
+    // Validate output
+    validate(CLAccessor(_target), _reference);
+}
+TEST_SUITE_END() // S8
+TEST_SUITE_END() // REINTERPRET_INPUT_AS_3D
+TEST_SUITE_END() // GEMMReshapeLHSMatrix
+TEST_SUITE_END() // CL
+} // namespace validation
+} // namespace test
+} // namespace arm_compute
\ No newline at end of file
diff --git a/tests/validation/Helpers.cpp b/tests/validation/Helpers.cpp
index eab6d5629f..11c454ea67 100644
--- a/tests/validation/Helpers.cpp
+++ b/tests/validation/Helpers.cpp
@@ -207,7 +207,7 @@ void transpose_matrix(const SimpleTensor<T> &in, SimpleTensor<T> &out)
     {
         for(int x = 0; x < width; ++x)
         {
-            const float val = in[x + y * width];
+            const T val = in[x + y * width];
 
             out[x * height + y] = val;
         }
@@ -313,10 +313,16 @@ std::pair<int, int> get_quantized_bounds(const QuantizationInfo &quant_info, flo
 
 template void get_tile(const SimpleTensor<float> &in, SimpleTensor<float> &roi, const Coordinates &coord);
 template void get_tile(const SimpleTensor<half> &in, SimpleTensor<half> &roi, const Coordinates &coord);
+template void get_tile(const SimpleTensor<int> &in, SimpleTensor<int> &roi, const Coordinates &coord);
+template void get_tile(const SimpleTensor<short> &in, SimpleTensor<short> &roi, const Coordinates &coord);
+template void get_tile(const SimpleTensor<char> &in, SimpleTensor<char> &roi, const Coordinates &coord);
 template void zeros(SimpleTensor<float> &in, const Coordinates &anchor, const TensorShape &shape);
 template void zeros(SimpleTensor<half> &in, const Coordinates &anchor, const TensorShape &shape);
 template void transpose_matrix(const SimpleTensor<float> &in, SimpleTensor<float> &out);
 template void transpose_matrix(const SimpleTensor<half> &in, SimpleTensor<half> &out);
+template void transpose_matrix(const SimpleTensor<int> &in, SimpleTensor<int> &out);
+template void transpose_matrix(const SimpleTensor<short> &in, SimpleTensor<short> &out);
+template void transpose_matrix(const SimpleTensor<char> &in, SimpleTensor<char> &out);
 template void matrix_multiply(const SimpleTensor<float> &a, const SimpleTensor<float> &b, SimpleTensor<float> &out);
 template void matrix_multiply(const SimpleTensor<half> &a, const SimpleTensor<half> &b, SimpleTensor<half> &out);
 
diff --git a/tests/validation/fixtures/GEMMReshapeLHSMatrixFixture.h b/tests/validation/fixtures/GEMMReshapeLHSMatrixFixture.h
new file mode 100644
index 0000000000..3a5ab7c5e1
--- /dev/null
+++ b/tests/validation/fixtures/GEMMReshapeLHSMatrixFixture.h
@@ -0,0 +1,137 @@
+/*
+ * Copyright (c) 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.
+ */
+#ifndef ARM_COMPUTE_TEST_GEMMRESHAPELHSMATRIX_FIXTURE
+#define ARM_COMPUTE_TEST_GEMMRESHAPELHSMATRIX_FIXTURE
+
+#include "arm_compute/core/TensorShape.h"
+#include "arm_compute/core/Types.h"
+#include "arm_compute/core/utils/misc/ShapeCalculator.h"
+#include "tests/AssetsLibrary.h"
+#include "tests/Globals.h"
+#include "tests/IAccessor.h"
+#include "tests/framework/Asserts.h"
+#include "tests/framework/Fixture.h"
+#include "tests/validation/Helpers.h"
+#include "tests/validation/reference/GEMMReshapeLHSMatrix.h"
+#include "tests/validation/reference/Utils.h"
+
+#include <random>
+
+namespace arm_compute
+{
+namespace test
+{
+namespace validation
+{
+using namespace arm_compute::misc::shape_calculator;
+
+template <typename TensorType, typename AccessorType, typename FunctionType, typename T, bool reinterpret_input_as_3d = false>
+class GEMMReshapeLHSMatrixValidationFixture : public framework::Fixture
+{
+public:
+    template <typename...>
+    void setup(TensorShape shape_in, unsigned int batch_size, DataType data_type, unsigned int m0, unsigned int k0, unsigned int v0, bool interleave, bool transpose)
+    {
+        GEMMLHSMatrixInfo lhs_info;
+        lhs_info.m0         = m0;
+        lhs_info.k0         = k0;
+        lhs_info.v0         = v0;
+        lhs_info.interleave = interleave;
+        lhs_info.transpose  = transpose;
+
+        // Set the tensor shape
+        const TensorShape shape_src(shape_in[0],
+                                    shape_in[1],
+                                    reinterpret_input_as_3d ? shape_in[2] : batch_size,
+                                    reinterpret_input_as_3d ? batch_size : 1);
+
+        _target    = compute_target(shape_src, data_type, lhs_info);
+        _reference = compute_reference(shape_src, data_type, lhs_info);
+    }
+
+protected:
+    template <typename U>
+    void fill(U &&tensor)
+    {
+        library->fill_tensor_uniform(tensor, 0);
+    }
+
+    TensorType compute_target(TensorShape input_shape, DataType data_type, const GEMMLHSMatrixInfo &lhs_info)
+    {
+        // Create tensors
+        TensorType src = create_tensor<TensorType>(input_shape, data_type, 1);
+        TensorType dst;
+
+        // The output tensor will be auto-initialized within the function
+
+        // Create and configure function
+        FunctionType gemm_lhs_reshape;
+        gemm_lhs_reshape.configure(&src, &dst, lhs_info, reinterpret_input_as_3d);
+
+        ARM_COMPUTE_EXPECT(src.info()->is_resizable(), framework::LogLevel::ERRORS);
+
+        // Allocate tensors
+        src.allocator()->allocate();
+        dst.allocator()->allocate();
+
+        ARM_COMPUTE_EXPECT(!src.info()->is_resizable(), framework::LogLevel::ERRORS);
+        ARM_COMPUTE_EXPECT(!dst.info()->is_resizable(), framework::LogLevel::ERRORS);
+
+        // Fill tensors
+        fill(AccessorType(src));
+
+        // Compute GEMM LHS matrix reshape function
+        gemm_lhs_reshape.run();
+
+        return dst;
+    }
+
+    SimpleTensor<T> compute_reference(const TensorShape &input_shape, DataType data_type, const GEMMLHSMatrixInfo &lhs_info)
+    {
+        TensorShape src_shape = input_shape;
+
+        // If the input has to be reinterpreted as 3D, collapse the second dimension with the 3rd
+        if(reinterpret_input_as_3d)
+        {
+            src_shape.collapse(2U, 1U);
+        }
+
+        // Create reference
+        SimpleTensor<T> src{ src_shape, data_type, 1 };
+
+        // Fill reference
+        fill(src);
+
+        TensorShape output_shape = compute_lhs_reshaped_shape(TensorInfo(input_shape, 1, data_type), lhs_info, reinterpret_input_as_3d);
+
+        return reference::gemm_reshape_lhs_matrix<T>(src, output_shape, lhs_info);
+    }
+
+    TensorType      _target{};
+    SimpleTensor<T> _reference{};
+};
+} // namespace validation
+} // namespace test
+} // namespace arm_compute
+#endif /* ARM_COMPUTE_TEST_GEMMRESHAPELHSMATRIX_FIXTURE */
\ No newline at end of file
diff --git a/tests/validation/reference/GEMMReshapeLHSMatrix.cpp b/tests/validation/reference/GEMMReshapeLHSMatrix.cpp
new file mode 100644
index 0000000000..431d65696e
--- /dev/null
+++ b/tests/validation/reference/GEMMReshapeLHSMatrix.cpp
@@ -0,0 +1,111 @@
+/*
+ * Copyright (c) 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.
+ */
+#include "GEMMReshapeLHSMatrix.h"
+
+#include "arm_compute/core/Types.h"
+
+#include "tests/validation/Helpers.h"
+
+#include <algorithm>
+#include <cmath>
+#include <cstring>
+
+namespace arm_compute
+{
+namespace test
+{
+namespace validation
+{
+namespace reference
+{
+template <typename T>
+SimpleTensor<T> gemm_reshape_lhs_matrix(const SimpleTensor<T> &in, const TensorShape &output_shape, const GEMMLHSMatrixInfo &lhs_info)
+{
+    ARM_COMPUTE_ERROR_ON(in.shape().num_dimensions() > 3);
+
+    SimpleTensor<T> out{ output_shape, in.data_type() };
+
+    // Initialize the output tensor with zero
+    std::memset(&out[0], 0, out.num_elements() * sizeof(T));
+
+    const unsigned int K = in.shape()[0];
+    const unsigned int M = in.shape()[1];
+    const unsigned int B = in.shape()[2];
+
+    const unsigned int num_tiles_x = std::ceil(K / static_cast<float>(lhs_info.k0));
+    const unsigned int num_tiles_y = std::ceil(M / static_cast<float>(lhs_info.m0));
+
+    const TensorShape tile_dims(lhs_info.k0, lhs_info.m0);
+    const TensorShape tile_dims_transposed(lhs_info.m0, lhs_info.k0);
+
+    // Simple tensor for the input tile
+    SimpleTensor<T> src_tile{ tile_dims, in.data_type() };
+
+    // Simple tensor for the input tile
+    SimpleTensor<T> src_tile_transposed{ tile_dims_transposed, in.data_type() };
+
+    // Simple tensor to use when storing the values
+    SimpleTensor<T> *tile_to_use = lhs_info.transpose ? &src_tile_transposed : &src_tile;
+
+    const unsigned int offset_output_x = lhs_info.interleave ? tile_to_use->shape()[0] : tile_to_use->shape()[0] * tile_to_use->shape()[1];
+    const unsigned int step_output_x   = lhs_info.interleave ? tile_to_use->shape()[0] * lhs_info.v0 : tile_to_use->shape()[0];
+
+    for(unsigned int z = 0; z < B; ++z)
+    {
+        for(unsigned int y = 0; y < num_tiles_y; ++y)
+        {
+            for(unsigned int x = 0; x < num_tiles_x; ++x)
+            {
+                // Get the tile from the input tensor
+                get_tile<T>(in, src_tile, Coordinates(x * lhs_info.k0, y * lhs_info.m0, z, 0));
+
+                if(lhs_info.transpose)
+                {
+                    // Transpose matrix
+                    transpose_matrix<T>(src_tile, src_tile_transposed);
+                }
+
+                // Store
+                const unsigned int offset_output = (x * lhs_info.k0 * lhs_info.m0 * lhs_info.v0) + ((y % lhs_info.v0) * offset_output_x) + ((y / lhs_info.v0) * out.shape()[0]) + (z * out.shape()[0] * out.shape()[1]);
+
+                for(unsigned int i = 0; i < tile_to_use->shape()[1]; ++i)
+                {
+                    const unsigned int offset_tile = i * tile_to_use->shape()[0];
+
+                    // Copy per row
+                    std::copy(&(*tile_to_use)[offset_tile], &(*tile_to_use)[offset_tile + tile_to_use->shape()[0]], &out[offset_output + i * step_output_x]);
+                }
+            }
+        }
+    }
+
+    return out;
+}
+template SimpleTensor<int> gemm_reshape_lhs_matrix(const SimpleTensor<int> &in, const TensorShape &output_shape, const GEMMLHSMatrixInfo &lhs_info);
+template SimpleTensor<short> gemm_reshape_lhs_matrix(const SimpleTensor<short> &in, const TensorShape &output_shape, const GEMMLHSMatrixInfo &lhs_info);
+template SimpleTensor<char> gemm_reshape_lhs_matrix(const SimpleTensor<char> &in, const TensorShape &output_shape, const GEMMLHSMatrixInfo &lhs_info);
+} // namespace reference
+} // namespace validation
+} // namespace test
+} // namespace arm_compute
\ No newline at end of file
diff --git a/tests/validation/reference/GEMMReshapeLHSMatrix.h b/tests/validation/reference/GEMMReshapeLHSMatrix.h
new file mode 100644
index 0000000000..c0328dbd51
--- /dev/null
+++ b/tests/validation/reference/GEMMReshapeLHSMatrix.h
@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 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.
+ */
+#ifndef __ARM_COMPUTE_TEST_GEMMRESHAPELHSMATRIX_H__
+#define __ARM_COMPUTE_TEST_GEMMRESHAPELHSMATRIX_H__
+
+#include "tests/SimpleTensor.h"
+#include "tests/validation/Helpers.h"
+
+namespace arm_compute
+{
+namespace test
+{
+namespace validation
+{
+namespace reference
+{
+template <typename T>
+SimpleTensor<T> gemm_reshape_lhs_matrix(const SimpleTensor<T> &in, const TensorShape &output_shape, const GEMMLHSMatrixInfo &lhs_info);
+} // namespace reference
+} // namespace validation
+} // namespace test
+} // namespace arm_compute
+#endif /* __ARM_COMPUTE_TEST_GEMMRESHAPELHSMATRIX_H__ */
\ No newline at end of file