Fc fp16 (#44578)

* (modified) fc support fp16

* __CUDA_ARCH__ version

* delete half

* delete half

* add half support

* add half support

* add half support

paddle/phi/kernels/funcs/fc_functor.cu

@@ -36,6 +36,14 @@ struct FcTypeTraits<double> {
   typedef double4 Type;
 };
 
+#if defined(PADDLE_WITH_CUDA)
+#include <cuda_fp16.h>
+
+template <>
+struct FcTypeTraits<float16> {
+  typedef half2 Type;
+};
+#else
 struct float16_4 {
   float16 x, y, z, w;
 };
@@ -44,6 +52,7 @@ template <>
 struct FcTypeTraits<float16> {
   typedef float16_4 Type;
 };
+#endif
 
 template <typename T, bool DoRelu>
 __global__ void bias_relu_v4(const int num, const T* bias, T* data, int K) {
@@ -117,12 +126,109 @@ void AddReluKernel(
   }
 }
 
+#if defined(PADDLE_WITH_CUDA)
+template <bool DoRelu>
+__global__ void bias_relu_v2(const int num,
+                             const half2* bias,
+                             half2* data,
+                             int K) {
+  int tid = blockIdx.x * blockDim.x + threadIdx.x;
+
+  if (tid < num) {
+    int bias_idx = tid % K;
+    const half2 bias_ptr = bias[bias_idx];
+    const half2 in_ptr = data[tid];
+    half2 packed_val;
+#if __CUDA_ARCH__ >= 530
+    packed_val = __hadd2(bias_ptr, in_ptr);
+#else
+    packed_val.x = __hadd(bias_ptr.x, in_ptr.x);
+    packed_val.y = __hadd(bias_ptr.y, in_ptr.y);
+#endif
+    if (DoRelu) {
+#if __CUDA_ARCH__ >= 800
+      packed_val = __hmax2(__half2(0, 0), packed_val);
+#elif __CUDA_ARCH__ >= 530
+      packed_val = __hmul2(__hgt2(__half2(0, 0), packed_val), packed_val);
+#else
+      packed_val.x = static_cast<int>(static_cast<float>(packed_val.x) > 0) *
+                     static_cast<float>(packed_val.x);
+      packed_val.y = static_cast<int>(static_cast<float>(packed_val.y) > 0) *
+                     static_cast<float>(packed_val.y);
+#endif
+    }
+    data[tid] = packed_val;
+  }
+}
+
+template <bool DoRelu, int BlockDim>
+__global__ void InplaceAddReluKernel(const int N,
+                                     const half* bias,
+                                     half* data) {
+  int offset = blockIdx.x * N;
+  for (int i = threadIdx.x; i < N; i += BlockDim) {
+    half temp;
+#if defined(__HIPCC__) || __CUDA_ARCH__ >= 350
+    temp = __hadd(__ldg(data + offset + i), __ldg(bias + i));
+#else
+    temp = __hadd(data[offset + i], bias[i]);
+#endif
+    if (DoRelu) {
+#if __CUDA_ARCH__ >= 800
+      data[offset + i] = __hmax(0, temp);
+#elif __CUDA_ARCH__ >= 530
+      data[offset + i] = __hmul(__hgt(temp, 0), temp);
+#else
+      data[offset + i] = static_cast<int>(static_cast<float>(temp) > 0) *
+                         static_cast<float>(temp);
+#endif
+    } else {
+      data[offset + i] = temp;
+    }
+  }
+}
+
+template <>
+void AddReluKernel(cudaStream_t stream,
+                   const int M,
+                   const int N,
+                   float16* Y,
+                   const float16* B,
+                   bool relu) {
+  if (N % 2 == 0) {
+    const int threads = 256;
+    const int num = M * N / 2;
+    const int blocks = (num + threads - 1) / threads;
+    typedef typename FcTypeTraits<float16>::Type trans_type;
+    auto* bias_ptr_v2 = reinterpret_cast<const trans_type*>(B);
+    auto* data_ptr_v2 = reinterpret_cast<trans_type*>(Y);
+    if (relu) {
+      bias_relu_v2<true><<<blocks, threads, 0, stream>>>(
+          num, bias_ptr_v2, data_ptr_v2, N / 2);
+    } else {
+      bias_relu_v2<false><<<blocks, threads, 0, stream>>>(
+          num, bias_ptr_v2, data_ptr_v2, N / 2);
+    }
+  } else {
+    const int threads = 256;
+    const int blocks = M;
+    auto* halfB = reinterpret_cast<const half*>(B);
+    auto* halfY = reinterpret_cast<half*>(Y);
+    if (relu) {
+      InplaceAddReluKernel<true, threads>
+          <<<blocks, threads, 0, stream>>>(N, halfB, halfY);
+    } else {
+      InplaceAddReluKernel<false, threads>
+          <<<blocks, threads, 0, stream>>>(N, halfB, halfY);
+    }
+  }
+}
+#else
 template <bool DoRelu, int BlockDim>
 __global__ void InplaceAddReluKernel(const int N,
                                      const float16* bias,
                                      float16* data) {
   int offset = blockIdx.x * N;
-
   for (int i = threadIdx.x; i < N; i += BlockDim) {
     float16 temp;
     temp = data[offset + i] + bias[i];
@@ -168,6 +274,7 @@ void AddReluKernel(gpuStream_t stream,
     }
   }
 }
+#endif
 
 template <typename DeviceContext, typename T>
 void FCFunctor<DeviceContext, T>::operator()(const DeviceContext& context,