Add abs functions

Author: joey12300

fastdeploy/function/math.cc

@@ -39,6 +39,7 @@ DEFINE_ACTIVATION_KERNEL(Sqrt, SqrtFunctor)
 DEFINE_ACTIVATION_KERNEL(Log, LogFunctor)
 DEFINE_ACTIVATION_KERNEL(Round, RoundFunctor)
 DEFINE_ACTIVATION_KERNEL(Exp, ExpFunctor)
+DEFINE_ACTIVATION_KERNEL(Abs, AbsFunctor)
 
 void Sqrt(const FDTensor& x, FDTensor* out) {
   FD_VISIT_FLOAT_TYPES(x.dtype, "SqrtKernel",
@@ -60,5 +61,10 @@ void Exp(const FDTensor& x, FDTensor* out) {
                        ([&] { ExpKernel<data_t>(x, out); }));
 }
 
+void Abs(const FDTensor& x, FDTensor* out) {
+  FD_VISIT_FLOAT_TYPES(x.dtype, "AbsKernel",
+                       ([&] { AbsKernel<data_t>(x, out); }));
+}
+
 }  // namespace function
 }  // namespace fastdeploy

fastdeploy/function/math.h

@@ -43,5 +43,11 @@ FASTDEPLOY_DECL void Round(const FDTensor& x, FDTensor* out);
 */
 FASTDEPLOY_DECL void Exp(const FDTensor& x, FDTensor* out);
 
+/** This operator is used to perform elementwise abs for input X. Only for float type FDTensor
+    @param x The input tensor.
+    @param out The output tensor which stores the result.
+*/
+FASTDEPLOY_DECL void Abs(const FDTensor& x, FDTensor* out);
+
 }  // namespace function
 }  // namespace fastdeploy

fastdeploy/function/math_functor.h

@@ -52,5 +52,14 @@ template <typename T> struct SqrtFunctor {
   }
 };
 
+// abs(x) = x if x > 0 else -x
+template <typename T> struct AbsFunctor {
+  template <typename Device, typename X, typename Out>
+  void operator()(Device d, X x, Out out) const {
+    out.device(d) =
+        x.unaryExpr([](T v) { return v > static_cast<T>(0) ? v : -v; });
+  }
+};
+
 }  // namespace function
 }  // namespace fastdeploy

tests/function/test_math.cc

@@ -83,5 +83,18 @@ TEST(fastdeploy, exp_sqrt_round_log) {
              log_result.size());
 }
 
+TEST(fastdeploy, abs) {
+  CheckShape check_shape;
+  CheckData check_data;
+  FDTensor x, y;
+  std::vector<float> test_data = {-1, 2, 3, -5, -4, -6};
+  x.SetExternalData({2, 3}, FDDataType::FP32, test_data.data());
+  std::vector<float> result = {1, 2, 3, 5, 4, 6};
+  Abs(x, &y);
+  check_shape(y.shape, {2, 3});
+  check_data(reinterpret_cast<const float*>(y.Data()), result.data(),
+             result.size());
+}
+
 }  // namespace function
 }  // namespace fastdeploy