Virtual Machine Instruction Set

This chapter describes RXVM instructions by functional characteristic. It is a reference for RXAS authors and for readers inspecting compiler output.

Read the assembler guide before writing non-trivial RXAS by hand; many details that look obvious at the instruction level are normally handled by the compiler and linker.

Characteristics of RXVM Instructions

Most RXVM instructions share these properties:

• logical data flow is written from right to left
• comparisons write their boolean result into an explicit register
• there is no separate condition-code register
• constants and symbols are represented through the RXBIN constant pool
• modules carry metadata records for source mapping, imports, classes, interfaces, factories, methods, and linker/runtime support
• typed conversion instructions make representation changes explicit

Instruction Argument Types

Instruction definitions use compact argument-type names. Common ones include:

Type	Description
REG	VM register
ID	label or symbolic identifier
FUNC	global or local callable reference
INT	integer literal or constant-pool integer
FLOAT	floating-point literal or constant-pool float
DECIMAL	decimal literal or constant-pool decimal
STRING	string literal or constant-pool string
BINARY	binary literal or constant-pool binary payload where supported

Related instructions often share a mnemonic and differ by opcode and operand types. The generated instruction tables later in this book are the detailed source for individual opcode forms.