User Guide

24 General-Purpose Programming

AMD64 Technology 24592—Rev. 3.15—November 2009

Figure 3-1. General-Purpose Programming Registers

3.1.1 Legacy Registers

In legacy and compatibility modes, all of the legacy x86 registers are available. Figure 3-2 on page 25

shows a detailed view of the GPR, flag, and instruction-pointer registers.

513-131.eps

63 31 032

R10

R11

R12

R13

R14

R15

rAX

rBX

rCX

rDX

rBP

rSI

rDI

rSP

63 31 032

rFLAGS

rIP

Available to sofware in all modes

Available to sofware only in 64-bit mode

Ignored by hardware in 64-bit mode

15 0

Segment

Registers

General-Purpose Registers (GPRs)

Flags and Instruction Pointer Registers