/* Copyright (c) 2018 PaddlePaddle Authors. All Rights Reserved.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at
 
 http://www.apache.org/licenses/LICENSE-2.0
 
 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License. */

#include <metal_stdlib>
using namespace metal;

kernel void batchnorm(texture2d_array<float, access::read> inTexture [[texture(0)]],
                      texture2d_array<float, access::write> outTexture [[texture(1)]],
                      const device float4 * nscale [[buffer(0)]],
                      const device float4 * nbias [[buffer(1)]],
                      uint3 gid [[thread_position_in_grid]]) {
    if (gid.x >= outTexture.get_width() ||
        gid.y >= outTexture.get_height() ||
        gid.z >= outTexture.get_array_size()) return;
    const float4 input = inTexture.read(gid.xy, gid.z);
    float4 output = input * nscale[gid.z] + nbias[gid.z];
    outTexture.write(output, gid.xy, gid.z);
}

kernel void batchnorm_half(texture2d_array<half, access::read> inTexture [[texture(0)]],
                           texture2d_array<half, access::write> outTexture [[texture(1)]],
                           const device half4 * newScale [[buffer(0)]],
                           const device half4 * newBias [[buffer(1)]],
                           uint3 gid [[thread_position_in_grid]]) {
    if (gid.x >= outTexture.get_width() ||
        gid.y >= outTexture.get_height() ||
        gid.z >= outTexture.get_array_size()) return;
    const half4 input = inTexture.read(gid.xy, gid.z);
    half4 output = input * newScale[gid.z] + newBias[gid.z];
    outTexture.write(output, gid.xy, gid.z);
}
