Bug fixed.

1. CPU Support for Gather function.
2. Fix the bugs in GPU Gather.
2. Minor error fixed.

source/tensor/core/movement/Gather.cpp

@@ -43,14 +43,43 @@ void _Gather(const XTensor * s, XTensor * t, XTensor * srcIndex, int dim)
     CheckNTErrors((s && t), "Invalid tensors!");
     CheckNTErrors(s->devID == t->devID, "the data must be kept on the same device!");
     CheckNTErrors((t->unitSize == srcIndex->unitSize), "Unmatched tensors!");
+    CheckNTErrors((srcIndex->dataType == X_INT), "The index tensor should be INT type!");
+    CheckNTErrors((srcIndex->order == s->order), "index's order should be the same with source's");
 #ifdef USE_CUDA
     if (s->devID >= 0 && t->devID >= 0) {
         _CudaGather(s, t, srcIndex, dim);
         return;
     }
 #endif
-    ShowNTErrors("TODO!");
-    return;
+    int stride = 1;
+    int blockNum = 1;
+    for (int i = dim + 1; i < s->order; ++i)
+    {
+        stride *= s->GetDim(i);
+    }
+    for (int i = 0; i < dim; ++i)
+    {
+        blockNum *= s->GetDim(i);
+    }
+    int indexStrideNum = srcIndex->GetDim(dim);
+    int srcStrideNum = stride * s->GetDim(dim);
+    int tgtBlockSize = stride * indexStrideNum;
+
+    DTYPE * sData = (DTYPE*)s->data;
+    DTYPE * tData = (DTYPE*)t->data;
+    int * sIndexData = (int*)srcIndex->data;
+    for (int blockIndex = 0; blockIndex < blockNum; ++blockIndex)
+    {
+        for (int i = 0; i < indexStrideNum; i++) {
+            for (int j = 0; j < stride; j++)
+            {
+                int sIndex = sIndexData[i * stride + blockIndex * indexStrideNum + j] * stride + blockIndex * srcStrideNum + j;
+                CheckNTErrors(sIndex < s->unitNum, "Wrong index!");
+                int tIndex = i * stride + blockIndex * tgtBlockSize + j;
+                tData[tIndex] = sData[sIndex];
+            }
+        }
+    }
 }
 
 /*

source/tensor/core/movement/Gather.cu

@@ -77,7 +77,7 @@ gather indexed sub-tensors(cuda version)
 >> blockNum - block size of data
 */
 __global__
-void KernelGather(DTYPE * sData, DTYPE * tData, int * sIndex, int stride, int strideNum, int blockNum)
+void KernelGather(DTYPE * sData, DTYPE * tData, int * sIndex, int stride, int strideNum, int blockNum, int srcStrideNum)
 {
     int idx = blockDim.x * blockIdx.x + threadIdx.x;
     int idy = blockDim.y * blockIdx.y + threadIdx.y;
@@ -90,7 +90,7 @@ void KernelGather(DTYPE * sData, DTYPE * tData, int * sIndex, int stride, int st
     for (int i = idx * stride + stride * strideNum * blockIndex + offsetInBlock;
         i < stride * strideNum * blockIndex + offsetInBlock + stride * strideNum && i < size;
         i += stride * blockDim.x) {
-        tData[i] = sData[sIndex[i]];
+        tData[i] = sData[sIndex[i] * stride + stride * srcStrideNum * blockIndex + offsetInBlock];
     }
 }
 
@@ -179,6 +179,7 @@ void _CudaGather(const XTensor * s, XTensor * t, XTensor * srcIndex, int dim)
     int blockNum = 1;
     int indexSize = srcIndex->unitNum;
     int strideNum = srcIndex->dimSize[dim];
+    int srcStrideNum = s->dimSize[dim];
     for (int i = 0; i < dim; i++)
         blockNum *= srcIndex->dimSize[i];
     for (int i = dim + 1; i < srcIndex->order; i++)
@@ -186,19 +187,33 @@ void _CudaGather(const XTensor * s, XTensor * t, XTensor * srcIndex, int dim)
 
     int * sIndex = NULL;
     if (srcIndex->devID < 0) {
+        int * sIndexData = (int*)srcIndex->data;
+        for (int i = 0; i < indexSize; i++) {
+            int srcIndexValue = sIndexData[i] * stride;
+            CheckNTErrors(srcIndexValue < s->unitNum, "Wrong index!");
+        }
+
         sIndex = mem != NULL ?
-            (int*)mem->AllocBuf(mem->devID, sizeof(int) * indexSize) :
-            (int*)XMemAlloc(mem->devID, sizeof(int) * indexSize);
+                  (int*)mem->AllocBuf(mem->devID, sizeof(int) * indexSize) :
+                  (int*)XMemAlloc(mem->devID, sizeof(int) * indexSize);
         XMemCopy(sIndex, devID, srcIndex, -1, sizeof(int) * indexSize);
     }
-    else
+    else {
+        int * sIndexData = new int[sizeof(int) * indexSize];
+        XMemCopy(sIndexData, -1, srcIndex->data, srcIndex->devID, sizeof(int) * indexSize);
+        for (int i = 0; i < indexSize; i++) {
+            int srcIndexValue = sIndexData[i] * stride;
+            CheckNTErrors(srcIndexValue < s->unitNum, "Wrong index!");
+        }
+
         sIndex = (int *)srcIndex->data;
+	   delete[] sIndexData;
+    }
 
     int cudaGrids[3];
     int cudaBlocks[3];
     GDevs.GetCudaThread2D(devID, max(32, strideNum), stride*blockNum, MAX_INT, cudaGrids, cudaBlocks);
-
-    KernelGather << <dim3(cudaGrids[0], cudaGrids[1]), dim3(cudaBlocks[0], cudaBlocks[1]) >> > ((DTYPE *)s->data, (DTYPE *)t->data, sIndex, stride, strideNum, blockNum);
+    KernelGather << <dim3(cudaGrids[0], cudaGrids[1]), dim3(cudaBlocks[0], cudaBlocks[1]) >> > ((DTYPE *)s->data, (DTYPE *)t->data, sIndex, stride, strideNum, blockNum, srcStrideNum);
 }
 #endif // USE_CUDA
 

source/tensor/test/TSpread.cpp

@@ -32,7 +32,7 @@ spread a collection tensor to source tensor.
 */
 bool TestSpread1()
 {
-    /* a input tensor of size (2, 4, 3) */
+    /* a input tensor of size (4, 4, 3) */
     int sOrder = 3;
     int * sDimSize = new int[sOrder];
     sDimSize[0] = 4;