diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2a46f47..b8dd450 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -20,6 +20,7 @@ set(LIB_SOURCES
     src/iss/arch/tgc5c.cpp
     src/vm/interp/vm_tgc5c.cpp
     src/vm/fp_functions.cpp
+    src/vm/instruction_decoder.cpp
     src/iss/semihosting/semihosting.cpp
 )
 
diff --git a/src/vm/instruction_decoder.cpp b/src/vm/instruction_decoder.cpp
new file mode 100644
index 0000000..b975d81
--- /dev/null
+++ b/src/vm/instruction_decoder.cpp
@@ -0,0 +1,103 @@
+/*******************************************************************************
+ * Copyright (C) 2024 MINRES Technologies GmbH
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Contributors:
+ *       alex@minres.com - initial implementation
+ ******************************************************************************/
+
+#include <algorithm>
+#include <cassert>
+#include <cstddef>
+#include <cstdint>
+#include <limits>
+#include <numeric>
+#include <vector>
+#include <vm/instruction_decoder.h>
+
+decoder::decoder(std::vector<generic_instruction_descriptor> instr_list) {
+    for(auto instr : instr_list) {
+        root.instrs.push_back(instr);
+    }
+    populate_decoding_tree(root);
+}
+
+void decoder::populate_decoding_tree(decoding_tree_node& parent) {
+    // create submask
+    parent.submask =
+        std::accumulate(parent.instrs.begin(), parent.instrs.end(), std::numeric_limits<uint32_t>::max(),
+                        [](int current_submask, const generic_instruction_descriptor& instr) { return current_submask & instr.mask; });
+    //  put each instr according to submask&encoding into children
+    for(auto instr : parent.instrs) {
+        bool foundMatch = false;
+        for(auto& child : parent.children) {
+            // use value as identifying trait
+            if(child.value == (instr.value & parent.submask)) {
+                child.instrs.push_back(instr);
+                foundMatch = true;
+            }
+        }
+        if(!foundMatch) {
+            decoding_tree_node child = decoding_tree_node(instr.value & parent.submask);
+            child.instrs.push_back(instr);
+            parent.children.push_back(child);
+        }
+    }
+    parent.instrs.clear();
+    // call populate_decoding_tree for all children
+    if(parent.children.size() > 1)
+        for(auto& child : parent.children) {
+            populate_decoding_tree(child);
+        }
+    else {
+        // sort instrs by value of the mask, so we have the least restrictive mask last
+        std::sort(parent.children[0].instrs.begin(), parent.children[0].instrs.end(),
+                  [](const generic_instruction_descriptor& instr1, const generic_instruction_descriptor& instr2) {
+                      return instr1.mask > instr2.mask;
+                  });
+    }
+}
+uint32_t decoder::decode_instr(uint32_t word) { return _decode_instr(this->root, word); }
+uint32_t decoder::_decode_instr(decoding_tree_node const& node, uint32_t word) {
+    if(!node.children.size()) {
+        if(node.instrs.size() == 1)
+            return node.instrs[0].index;
+        for(auto instr : node.instrs) {
+            if((instr.mask & word) == instr.value)
+                return instr.index;
+        }
+    } else {
+        for(auto child : node.children) {
+            if(child.value == (node.submask & word)) {
+                return _decode_instr(child, word);
+            }
+        }
+    }
+    return std::numeric_limits<uint32_t>::max();
+}
diff --git a/src/vm/instruction_decoder.h b/src/vm/instruction_decoder.h
new file mode 100644
index 0000000..c1e8aac
--- /dev/null
+++ b/src/vm/instruction_decoder.h
@@ -0,0 +1,63 @@
+/*******************************************************************************
+ * Copyright (C) 2024 MINRES Technologies GmbH
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Contributors:
+ *       alex@minres.com - initial implementation
+ ******************************************************************************/
+
+#include <cstddef>
+#include <cstdint>
+#include <limits>
+#include <vector>
+
+struct generic_instruction_descriptor {
+    uint32_t value;
+    uint32_t mask;
+    uint32_t index;
+};
+
+struct decoding_tree_node {
+    std::vector<generic_instruction_descriptor> instrs;
+    std::vector<decoding_tree_node> children;
+    uint32_t submask = std::numeric_limits<uint32_t>::max();
+    uint32_t value;
+    decoding_tree_node(uint32_t value)
+    : value(value) {}
+};
+class decoder {
+public:
+    decoder(std::vector<generic_instruction_descriptor> instr_list);
+    uint32_t decode_instr(uint32_t word);
+
+private:
+    decoding_tree_node root{decoding_tree_node(std::numeric_limits<uint32_t>::max())};
+    void populate_decoding_tree(decoding_tree_node& root);
+    uint32_t _decode_instr(decoding_tree_node const& node, uint32_t word);
+};
\ No newline at end of file