fix shfl_sync for CUDA8.0

Author: chengduoZH

paddle/cuda/include/hl_base.h

@@ -228,6 +228,21 @@ extern __thread cudaStream_t default_stream;
         << "CUDA error: " << hl_get_device_error_string((size_t)err); \
   }
 
+// __shfl has been deprecated as of CUDA 9.0.
+#if CUDA_VERSION < 9000
+template <typename T>
+__forceinline__ __device__ T
+__shfl_sync(unsigned, T val, int src_line, int width) {
+  return __shfl(val, src_line, width);
+}
+
+#define CREATE_SHFL_MASK(mask, predicate) mask = 0u;
+#else
+#define FULL_WARP_MASK 0xFFFFFFFF
+#define CREATE_SHFL_MASK(mask, predicate) \
+  mask = __ballot_sync(FULL_WARP_MASK, (predicate))
+#endif
+
 #endif /* __NVCC__ */
 
 #endif /* HL_BASE_H_ */

paddle/cuda/src/hl_cuda_lstm.cu

@@ -341,12 +341,15 @@ void hl_lstm_parallel_forward(real *gateValue,
 }
 
 __device__ __forceinline__ void transpose_32x32(real a[], const int idx) {
-  int addr = idx % 32;
+  const int warp_size = 32;
+  int addr = idx % warp_size;
+  unsigned mask = 0u;
+  CREATE_SHFL_MASK(mask, addr < warp_size);
 #pragma unroll
   for (int k = 1; k < 32; k++) {
     // rSrc[k] = __shfl_sync(rSrc[k], (threadIdx.x + k) % 32, 32);
-    addr = __shfl_sync(addr, (idx + 1) % 32, 32);
-    a[k] = __shfl_sync(a[k], addr, 32);
+    addr = __shfl_sync(mask, addr, (idx + 1) % 32, 32);
+    a[k] = __shfl_sync(mask, a[k], addr, 32);
   }
 
 #pragma unroll
@@ -360,10 +363,11 @@ __device__ __forceinline__ void transpose_32x32(real a[], const int idx) {
   }
 
   addr = (32 - idx) % 32;
+  CREATE_SHFL_MASK(mask, idx % 32 < warp_size);
 #pragma unroll
   for (int k = 0; k < 32; k++) {
-    a[k] = __shfl_sync(a[k], addr, 32);
-    addr = __shfl_sync(addr, (idx + 31) % 32, 32);
+    a[k] = __shfl_sync(mask, a[k], addr, 32);
+    addr = __shfl_sync(mask, addr, (idx + 31) % 32, 32);
   }
 }
 

paddle/cuda/src/hl_top_k.cu

@@ -244,13 +244,16 @@ __device__ __forceinline__ void blockReduce(Pair* shTopK,
     if (--beamSize == 0) break;
     __syncthreads();
 
+    unsigned mask = 0u;
+    // CREATE_SHFL_MASK(mask, tid < len);
+
     if (tid == maxId[0]) {
       if (beam < maxLength) {
         shTopK[tid] = topK[beam];
       }
     }
     if (maxId[0] / 32 == warp) {
-      if (__shfl_sync(beam, (maxId[0]) % 32, 32) == maxLength) break;
+      if (__shfl_sync(mask, beam, (maxId[0]) % 32, 32) == maxLength) break;
     }
   }
 }

paddle/fluid/platform/cuda_primitives.h

@@ -74,10 +74,6 @@ __forceinline__ __device__ T __shfl_down_sync(unsigned, T val, int delta) {
 }
 #define CREATE_SHFL_MASK(mask, predicate) mask = 0u;
 #else
-template <typename T>
-__forceinline__ __device__ T __shfl_down_sync(unsigned mask, T val, int delta) {
-  return __shfl_down(mask, val, delta);
-}
 #define FULL_WARP_MASK 0xFFFFFFFF
 #define CREATE_SHFL_MASK(mask, predicate) \
   mask = __ballot_sync(FULL_WARP_MASK, (predicate))