From 23a0e32ce3a1b153fb10f91f0d85dfeb54fd0283 Mon Sep 17 00:00:00 2001
From: "Raasz, Pawel" <pawel.raasz@intel.com>
Date: Sun, 17 Mar 2024 07:27:06 +0000
Subject: [PATCH] Correct NF4 <-> floating point deduction

---
 .../include/openvino/reference/convert.hpp    | 24 +++++++++++--------
 1 file changed, 14 insertions(+), 10 deletions(-)

diff --git a/src/core/reference/include/openvino/reference/convert.hpp b/src/core/reference/include/openvino/reference/convert.hpp
index 479e89c6f2e5b3..19872a427f17f5 100644
--- a/src/core/reference/include/openvino/reference/convert.hpp
+++ b/src/core/reference/include/openvino/reference/convert.hpp
@@ -13,6 +13,15 @@
 #include "openvino/core/type/nf4.hpp"
 
 namespace ov {
+
+template <class ElementIter>
+constexpr bool is_nf4_iterator() {
+    using it = typename std::decay<ElementIter>::type;
+    using T = fundamental_type_for<element::nf4>;
+    return std::is_same<it, element::Iterator<element::nf4, const T>>::value ||
+           std::is_same<it, element::Iterator<element::nf4, T>>::value;
+}
+
 namespace reference {
 namespace detail {
 
@@ -33,15 +42,10 @@ void convert(InputIt arg, OutputIt out, const size_t count) {
     using OUT_T = typename std::iterator_traits<OutputIt>::value_type;
 
     // Deduce types for NF4 <-> floating point conversion to use quantization.
-    using From =
-        typename std::conditional<std::is_same<InputIt, element::Iterator<element::nf4, const int8_t>>::value &&
-                                      !std::is_integral<OUT_T>::value,
-                                  const float,
-                                  IN_T>::type;
-    using To = typename std::conditional<std::is_same<OutputIt, element::Iterator<element::nf4, int8_t>>::value &&
-                                             !std::is_integral<IN_T>::value,
-                                         float,
-                                         OUT_T>::type;
+    using From = typename std::
+        conditional<is_nf4_iterator<InputIt>() && !std::is_integral<OUT_T>::value, const float, IN_T>::type;
+    using To =
+        typename std::conditional<is_nf4_iterator<OutputIt>() && !std::is_integral<IN_T>::value, float, OUT_T>::type;
 
     std::transform(arg, arg + count, out, detail::convert<From, To>);
 }
@@ -69,7 +73,7 @@ void convert<float16, int8_t>(const float16* arg, int8_t* out, size_t count);
 // Count how many f32 values is out of normal finite numbers range when converted to f16
 size_t count_out_of_f16_range(const float* arg, size_t count);
 
-// Convert values from f32 to f16 with claming to f16 min/max when value is out of normal finite numbers range
+// Convert values from f32 to f16 with clamping to f16 min/max when value is out of normal finite numbers range
 void convert_from_f32_to_f16_with_clamp(const float* arg, float16* out, size_t count);
 }  // namespace reference
 }  // namespace ov