From 0a447add03b5194f83505f31bb31ec9e7fa4f175 Mon Sep 17 00:00:00 2001
From: Nikita Grigorian <nikita.grigorian@intel.com>
Date: Fri, 25 Apr 2025 15:22:49 -0700
Subject: [PATCH 1/2] Update implementations of `real` and `imag`

`imag` uses static constant value of 0 for real inputs and both use sycl complex extension
---
 .../include/kernels/elementwise_functions/imag.hpp  | 13 ++++++++-----
 .../include/kernels/elementwise_functions/real.hpp  |  5 ++++-
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/dpctl/tensor/libtensor/include/kernels/elementwise_functions/imag.hpp b/dpctl/tensor/libtensor/include/kernels/elementwise_functions/imag.hpp
index 89adabff41..2b40d1d0aa 100644
--- a/dpctl/tensor/libtensor/include/kernels/elementwise_functions/imag.hpp
+++ b/dpctl/tensor/libtensor/include/kernels/elementwise_functions/imag.hpp
@@ -31,6 +31,7 @@
 #include <sycl/sycl.hpp>
 #include <type_traits>
 
+#include "sycl_complex.hpp"
 #include "vec_size_util.hpp"
 
 #include "kernels/dpctl_tensor_types.hpp"
@@ -56,11 +57,11 @@ using dpctl::tensor::type_utils::is_complex;
 
 template <typename argT, typename resT> struct ImagFunctor
 {
-
     // is function constant for given argT
-    using is_constant = typename std::false_type;
+    using is_constant =
+        typename std::is_same<is_complex<argT>, std::false_type>;
     // constant value, if constant
-    // constexpr resT constant_value = resT{};
+    static constexpr resT constant_value = resT{0};
     // is function defined for sycl::vec
     using supports_vec = typename std::false_type;
     // do both argTy and resTy support sugroup store/load operation
@@ -70,11 +71,13 @@ template <typename argT, typename resT> struct ImagFunctor
     resT operator()(const argT &in) const
     {
         if constexpr (is_complex<argT>::value) {
-            return std::imag(in);
+            using realT = typename argT::value_type;
+            using sycl_complexT = typename exprm_ns::complex<realT>;
+            return exprm_ns::imag(sycl_complexT(in));
         }
         else {
             static_assert(std::is_same_v<resT, argT>);
-            return resT{0};
+            return constant_value;
         }
     }
 };
diff --git a/dpctl/tensor/libtensor/include/kernels/elementwise_functions/real.hpp b/dpctl/tensor/libtensor/include/kernels/elementwise_functions/real.hpp
index bb22352907..2b661357b7 100644
--- a/dpctl/tensor/libtensor/include/kernels/elementwise_functions/real.hpp
+++ b/dpctl/tensor/libtensor/include/kernels/elementwise_functions/real.hpp
@@ -31,6 +31,7 @@
 #include <sycl/sycl.hpp>
 #include <type_traits>
 
+#include "sycl_complex.hpp"
 #include "vec_size_util.hpp"
 
 #include "kernels/dpctl_tensor_types.hpp"
@@ -70,7 +71,9 @@ template <typename argT, typename resT> struct RealFunctor
     resT operator()(const argT &in) const
     {
         if constexpr (is_complex<argT>::value) {
-            return std::real(in);
+            using realT = typename argT::value_type;
+            using sycl_complexT = typename exprm_ns::complex<realT>;
+            return exprm_ns::real(sycl_complexT(in));
         }
         else {
             static_assert(std::is_same_v<resT, argT>);

From 7564d1c4734c5068aeeebee2adcedebddce6928a Mon Sep 17 00:00:00 2001
From: Nikita Grigorian <nikita.grigorian@intel.com>
Date: Sun, 27 Apr 2025 09:28:04 -0700
Subject: [PATCH 2/2] Use `is_complex_v` in real and imag

---
 .../libtensor/include/kernels/elementwise_functions/imag.hpp   | 3 ++-
 .../libtensor/include/kernels/elementwise_functions/real.hpp   | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/dpctl/tensor/libtensor/include/kernels/elementwise_functions/imag.hpp b/dpctl/tensor/libtensor/include/kernels/elementwise_functions/imag.hpp
index 2b40d1d0aa..0fa432546e 100644
--- a/dpctl/tensor/libtensor/include/kernels/elementwise_functions/imag.hpp
+++ b/dpctl/tensor/libtensor/include/kernels/elementwise_functions/imag.hpp
@@ -54,6 +54,7 @@ using dpctl::tensor::ssize_t;
 namespace td_ns = dpctl::tensor::type_dispatch;
 
 using dpctl::tensor::type_utils::is_complex;
+using dpctl::tensor::type_utils::is_complex_v;
 
 template <typename argT, typename resT> struct ImagFunctor
 {
@@ -70,7 +71,7 @@ template <typename argT, typename resT> struct ImagFunctor
 
     resT operator()(const argT &in) const
     {
-        if constexpr (is_complex<argT>::value) {
+        if constexpr (is_complex_v<argT>) {
             using realT = typename argT::value_type;
             using sycl_complexT = typename exprm_ns::complex<realT>;
             return exprm_ns::imag(sycl_complexT(in));
diff --git a/dpctl/tensor/libtensor/include/kernels/elementwise_functions/real.hpp b/dpctl/tensor/libtensor/include/kernels/elementwise_functions/real.hpp
index 2b661357b7..04ed3a6e49 100644
--- a/dpctl/tensor/libtensor/include/kernels/elementwise_functions/real.hpp
+++ b/dpctl/tensor/libtensor/include/kernels/elementwise_functions/real.hpp
@@ -54,6 +54,7 @@ using dpctl::tensor::ssize_t;
 namespace td_ns = dpctl::tensor::type_dispatch;
 
 using dpctl::tensor::type_utils::is_complex;
+using dpctl::tensor::type_utils::is_complex_v;
 
 template <typename argT, typename resT> struct RealFunctor
 {
@@ -70,7 +71,7 @@ template <typename argT, typename resT> struct RealFunctor
 
     resT operator()(const argT &in) const
     {
-        if constexpr (is_complex<argT>::value) {
+        if constexpr (is_complex_v<argT>) {
             using realT = typename argT::value_type;
             using sycl_complexT = typename exprm_ns::complex<realT>;
             return exprm_ns::real(sycl_complexT(in));