Introduction

The AMD64^1.1 architecture^1.2 is an extension of the x86 architecture. Any processor implementing the AMD64 architecture specification will also provide compatiblity modes for previous descendants of the Intel 8086 architecture, including 32-bit processors such as the Intel 386, Intel Pentium, and AMD K6-2 processor. Operating systems conforming to the AMD64 ABI may provide support for executing programs that are designed to execute in these compatiblity modes. The AMD64 ABI does not apply to such prorams; this document applies only programs running in the ``long'' mode provided by the AMD64 architecture.

Except where otherwise noted, the AMD64 architecture ABI follows the conventions described in the Intel386 ABI. Rather than replicate the entire contents of the Intel386 ABI, the AMD64 ABI indicates only those places where changes have been made to the Intel386 ABI.

No attempt has been made to specify an ABI for languages other than C. However, it is assumed that many programming languages will wish to link with code written in C, so that the ABI specifications documented here are relevant.^1.3

Footnotes

... AMD64^1.1

AMD64 has been previously called x86-64. The latter name is used in a number of places out of historical reasons instead of AMD64.

... architecture^1.2

The architecture specification is available on the web at http://www.x86-64.org/documentation.

...^1.3

See section for details on C++ ABI.