Regs

Regs, short for registers, are small, fast storage locations inside a computer’s processor or microcontroller. They hold operands, addresses, and control information during the execution of instructions. The complete set of registers constitutes the register file, defined by the processor’s instruction set architecture (ISA). Registers are typically faster than main memory and support arithmetic, data movement, addressing, and control flow.

Registers come in several classes. General-purpose registers (GPRs) are used by software for temporary data storage. Special-purpose registers perform fixed functions, such as the program counter (which points to the next instruction), the status or flag register (which holds condition codes), the instruction register (fetch stage), and the stack pointer (managing the call stack). Some architectures also include index or base registers and floating-point or vector registers. The number and naming of registers vary widely between ISAs; modern architectures commonly provide a few dozen general-purpose registers in total when counting architectural and floating-point ones.

In compiler design and computer engineering, reg usage is managed by register allocation and register renaming to optimize performance and avoid hazards in pipelines and speculative execution. The term "regs" is sometimes used colloquially in discussions of assembly language programming and CPU manuals to refer to these registers.

In another field, "regs" is a common abbreviation for regulations or regulatory requirements. In legal, financial, and policy contexts, "regs" denotes the body of rules issued by government agencies that govern behavior, compliance, and reporting.