Memory Opcodes

This section documents the memory operations instructions available in CandleVM.

For operand encodings, see the executable format reference.

Values, modules, globals and resources

Opcode byte	Opcode	Operand bytes	Behavior
9	LoadConst	destination: register, value: tagged value	Loads an immediate Value using the encoding rules and stores it.
10	Mov	destination: register, source: register	Copies a runtime value from one register to another.
11	LoadModule	destination: register, name: string	Looks up the exact module name and stores a ModuleRef; unknown names raise ModuleName.
12	LoadFunction	destination: register, module: register, name: string	Requires a ModuleRef; another value type raises ValueTypeMismatch. It looks up the exact function name and stores a FunctionRef. An invalid module ID raises InvalidModuleRef, and a missing function raises FunctionName.
13	LoadGlobal	destination: register, name: string	Loads the named global. A missing global reads as Null.
14	StoreGlobal	name: string, source: register	Stores a global. Storing Null removes it. A write to an existing read-only global raises ReadOnlyGlobal.
15	LoadResource	destination: register, id: string	Looks up an embedded resource by exact ID, allocates a new buffer containing a copy, and stores its ObjectRef. Missing IDs raise ResourceNotFound.
16	Type	destination: register, source: register	Stores the source value's type discriminator as a byte.
17	ObjectType	destination: register, object: register	Requires a valid ObjectRef and stores its object type discriminator as a byte.

At VM startup, read-only globals include API_VERSION, VM_VERSION, DEBUG, TYPE_NULL, TYPE_BYTE, TYPE_NUMBER, TYPE_BOOL, TYPE_CHAR, TYPE_MODULE_REF, TYPE_FUNCTION_REF, TYPE_OBJECT_REF, and OBJECT_TYPE_ARRAY, OBJECT_TYPE_MAP, OBJECT_TYPE_STRING, OBJECT_TYPE_ERROR, OBJECT_TYPE_BUFFER, OBJECT_TYPE_NATIVE.