[CPU] f16 constant folding on cpu plug-in side for MatMul only (#18079)

src/common/transformations/include/transformations/fp16_compression/mark_decompression_convert_constant_folding.hpp

@@ -14,6 +14,7 @@ namespace pass {
 class TRANSFORMATIONS_API EnableDecompressionConvertConstantFolding;
 class TRANSFORMATIONS_API DisableDecompressionConvertConstantFolding;
 class TRANSFORMATIONS_API KeepConstAndDecompression;
+class TRANSFORMATIONS_API KeepConstAndDecompressionForMatMul;
 
 }  // namespace pass
 }  // namespace ov
@@ -47,3 +48,14 @@ public:
     OPENVINO_RTTI("KeepConstAndDecompression", "0");
     KeepConstAndDecompression();
 };
+
+/**
+ * @ingroup ie_transformation_common_api
+ * @brief Disables ConstantFolding for Convert operation (just before MatMul operation only) and prevents conversion
+ * of f16 Consts to f32.
+ */
+class ov::pass::KeepConstAndDecompressionForMatMul : public MatcherPass {
+public:
+    OPENVINO_RTTI("KeepConstAndDecompressionForMatMul", "0");
+    KeepConstAndDecompressionForMatMul();
+};

src/common/transformations/src/transformations/fp16_compression/mark_decompression_convert_constant_folding.cpp

@@ -7,6 +7,7 @@
 #include "itt.hpp"
 #include "openvino/op/constant.hpp"
 #include "openvino/op/convert.hpp"
+#include "openvino/op/matmul.hpp"
 #include "openvino/pass/pattern/op/wrap_type.hpp"
 #include "transformations/rt_info/decompression.hpp"
 #include "transformations/rt_info/disable_constant_folding.hpp"
@@ -61,11 +62,36 @@ pass::KeepConstAndDecompression::KeepConstAndDecompression() {
         disable_constant_folding(node);
 
         if (!is_type<ov::op::v0::Constant>(node->input_value(0).get_node_shared_ptr()))
-            return true;
+            return false;
         enable_keep_fp16_const(node->input_value(0).get_node_shared_ptr());
 
-        return true;
+        return false;
     };
     auto m = std::make_shared<pattern::Matcher>(node_pattern, matcher_name);
     register_matcher(m, callback);
 }
+
+pass::KeepConstAndDecompressionForMatMul::KeepConstAndDecompressionForMatMul() {
+    MATCHER_SCOPE(KeepConstAndDecompressionForMatMul);
+    auto matmul = pass::pattern::wrap_type<ov::op::v0::MatMul>();
+
+    matcher_pass_callback callback = [=](pass::pattern::Matcher& m) {
+        auto node = m.get_match_root();
+
+        // input to matmul is decompression Convert
+        const auto& inp_convert = node->input_value(1).get_node_shared_ptr();
+        if (!is_type<ov::op::v0::Convert>(inp_convert) || !is_decompression(inp_convert))
+            return false;
+
+        disable_constant_folding(inp_convert);
+
+        if (!is_type<ov::op::v0::Constant>(inp_convert->input_value(0).get_node_shared_ptr()))
+            return false;
+        enable_keep_fp16_const(inp_convert->input_value(0).get_node_shared_ptr());
+
+        return false;
+    };
+
+    auto m = std::make_shared<pass::pattern::Matcher>(matmul, matcher_name);
+    this->register_matcher(m, callback);
+}