Floating-Point Register (RISC-V)

risc-v

Definition

Floating-Point Register (RISC-V)

A floating-point register is a register used to store floating-point values.

RISC-V provides 32 floating-point registers named f0 to f31. They also have conventional alias names such as ft0, fs0, and fa0.

Register Set

Name	Register Number	Usage
ft0-7	f0-7	Temporary variables
fs0-1	f8-9	Saved variables
fa0-1	f10-11	Function arguments/return values
fa2-7	f12-17	Function arguments
fs2-11	f18-27	Saved variables
ft8-11	f28-31	Temporary variables

Width

The width of a floating-point register is the width of the highest implemented floating-point precision.

If multiple floating-point extensions are implemented, lower-precision values occupy the lower bits of the register.