##### 8.15.2.2 Register Names

The 128 integer registers are referred to as r n. The 128 floating-point registers are referred to as f n. The 128 application registers are referred to as ar n. The 128 control registers are referred to as cr n. The 64 one-bit predicate registers are referred to as p n. The 8 branch registers are referred to as b n. In addition, the assembler defines a number of aliases: gp (r1), sp (r12), rp (b0), ret0 (r8), ret1 (r9), ret2 (r10), ret3 (r9), farg n (f8+ n), and fret n (f8+ n).

For convenience, the assembler also defines aliases for all named application and control registers. For example, ar.bsp refers to the register backing store pointer (ar17). Similarly, cr.eoi refers to the end-of-interrupt register (cr67).