add min max sum

src/ndarray/unary_function-inl.h

@@ -82,6 +82,18 @@ void L2Norm(const TBlob &src,
   mshadow::VectorDot(out, in, in);
   out = mshadow::expr::F<mxnet::op::mshadow_op::square_root>(out);
 }
+
+template<typename xpu, typename Reducer>
+void Reduce(const TBlob &src,
+            TBlob *ret,
+            OpReqType req,
+            RunContext ctx) {
+  mshadow::Stream<xpu> *s = ctx.get_stream<xpu>();
+  mshadow::Tensor<xpu, 1> out = ret->get<xpu, 1, real_t>(s);
+  mshadow::Tensor<xpu, 2> in =
+      src.get_with_shape<xpu, 2, real_t>(mshadow::Shape2(1, src.shape_.Size()), s);
+  out = mshadow::expr::reduce_except_dim<0, Reducer>(in);
+}
 // Register all unary operations here
 // The true means inplace can be enabled.
 // abs
@@ -148,7 +160,24 @@ MXNET_REGISTER_TBLOB_FUN(norm, XPU)
 .set_shape_infer(ScalarShape)
 .describe("Take L2 norm of the src."
           "The result will be ndarray of shape (1,) on the same device.");
-
+// Max
+MXNET_REGISTER_TBLOB_FUN(max, XPU)
+.set_function(XPU::kDevMask, Reduce<XPU, mshadow::red::maximum>, false, false)
+.set_shape_infer(ScalarShape)
+.describe("Take max of the src."
+          "The result will be ndarray of shape (1,) on the same device.");
+// Min
+MXNET_REGISTER_TBLOB_FUN(min, XPU)
+.set_function(XPU::kDevMask, Reduce<XPU, mshadow::red::minimum>, false, false)
+.set_shape_infer(ScalarShape)
+.describe("Take min of the src."
+          "The result will be ndarray of shape (1,) on the same device.");
+// Sum
+MXNET_REGISTER_TBLOB_FUN(sum, XPU)
+.set_function(XPU::kDevMask, Reduce<XPU, mshadow::red::sum>, false, false)
+.set_shape_infer(ScalarShape)
+.describe("Take sum of the src."
+          "The result will be ndarray of shape (1,) on the same device.");
 }  // namespace ndarray
 }  // namespace mxnet
 #endif  // MXNET_NDARRAY_UNARY_FUNCTION_INL_H_