IA-32 Execution Layer: Technical Whitepaper

IA-32 Execution Layer (IA-32 EL) is a new technology that executes IA-32 applications on Intel® Itanium® processor family systems. Currently, support for IA-32 applications on Itanium-based platforms is achieved using hardware circuitry on the Itanium processors. This capability will be enhanced with IA-32 EL-software that will ship with Itanium-based operating systems and will convert IA-32 instructions into Itanium instructions via dynamic translation. In this paper, we describe aspects of the IA-32 Execution Layer technology, including the general two-phase translation architecture and the usage of a single translator for multiple operating systems. The paper provides details of some of the technical challenges such as precise exception, emulation of FP, MMXT, and Intel® Streaming SIMD Extension instructions, and misalignment handling. Finally, the paper presents some performance results.