oracle/graal · error · DeserializationException

Register not found

Error message

Register not found

What it means

RegisterSerializer identifies a Register purely by its 'number' field and resolves it by scanning deserializer.getArchitecture().getRegisters() for a matching register.number. DeserializationException('Register not found') means the recorded register number does not exist in the architecture instance the replay session constructed.

Source

Thrown at compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/hotspot/replaycomp/JsonReplayCodec.java:785

        public String tag() {
            return "register";
        }

        @Override
        public void serialize(Object instance, JsonBuilder.ObjectBuilder objectBuilder, RecursiveSerializer serializer) throws IOException {
            Register register = (Register) instance;
            objectBuilder.append("number", register.number);
        }

        @Override
        public Object deserialize(EconomicMap<String, Object> json, RecursiveDeserializer deserializer, CompilationProxies.ProxyFactory proxyFactory) throws DeserializationException {
            int number = (int) json.get("number");
            for (Register register : deserializer.getArchitecture().getRegisters()) {
                if (register.number == number) {
                    return register;
                }
            }
            throw new DeserializationException(this, json, "Register not found");
        }
    }

    private static final class FieldSerializer implements ObjectSerializer {

        @Override
        public Class<?> clazz() {
            return Field.class;
        }

        @Override
        public String tag() {
            return "field";
        }

        @Override
        public void serialize(Object instance, JsonBuilder.ObjectBuilder objectBuilder, RecursiveSerializer serializer) throws IOException {
            Field field = (Field) instance;

View on GitHub (pinned to a66e9ccd1d)

Solutions

1. Replay on the same architecture as the recording (AMD64 file on AMD64, etc.)
2. Verify the architecture entry in the replay file was deserialized before the register entry (the codec calls setArchitecture when it reads the architecture)
3. Re-record the replay file with the same CPU/OS/JVM combination

// Verify the register number exists in the replay architecture before use
int number = (int) json.get("number");
boolean found = Arrays.stream(architecture.getRegisters()).anyMatch(r -> r.number == number);
if (!found) throw new DeserializationException(this, json, "Register " + number + " not in " + architecture);

When it happens

Trigger: Replaying a file recorded on a machine whose register numbering differs from the replaying Architecture object — e.g. an AMD64 file replayed against an AArch64 architecture, or an Architecture constructed with a different feature set that changes the register array.

Common situations: Cross-architecture replay; version skew where register tables changed; the Architecture entry in the replay file was overridden or the architecture was set from the host rather than the file.

Related errors

• Unknown replay register config kind ${kind}
• Unexpected value: ${name}
• Profile file for path %s exists already
• Invalid replay string table index
• Invalid replay string definition index

AI-assisted analysis of oracle/graal@a66e9ccd1d (2026-08-14). Data as JSON: /api/errors/289ed3c7864c6187. Report an issue: GitHub.