Volume 3: General-Purpose and System Instructions - Stanford ...

24594 Rev. 3.10 February 2005 AMD64 Technology1.7.3 Address-SizePrefix and RIP-Relative AddressingRIP-relative addressing is enabled by 64-bit mode, not by a 64-bit address-size. Conversely, use of the address-size prefix(“Address-Size Override Prefix” on page 6) does not disableRIP-relative addressing. The effect of the address-size prefix isto truncate and zero-extend the computed effective address to32 bits, like any other addressing mode.Chapter 1: Instruction Formats 25