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The IA-32 Execution Layer (IA-32 EL) is a software emulator in the form of a software driver that improves performance of 32-bit applications running on 64-bit Intel Itanium-based systems, particularly those running Linux and Windows Server 2003 (it is included in Windows 2003 SP1 and later〔(The IA-32 Execution Layer 4.3 Software Driver ) (microsoft.com)〕 and in most Linux distributions for Itanium). The IA-32 EL bypasses the slow x86 hardware emulation which is available on pre-Montecito Itanium models. The IA-32 EL used a two-phase (later three-phase) approach: initially it quickly translated every piece of code at a basic block level, adding certain instrumentation for detecting hot code; then hot code was dynamically optimized at a super-block level, and the optimized translated code replaced cold code on the fly.〔(【引用サイトリンク】title=IA-32 Execution Layer: Technical Whitepaper )〕 Later interpretation engine was added that allowed to avoid altogether translation of code executed just a few times - cold non-optimized translation became thus the second phase, and hot optimized translation became the third phase. IA-32 Execution Layer supported self-modified code, and could even optimize it quite well. Part of the software is under the LGPL and part is under an Intel proprietary license. ==See also== * Itanium * List of Intel Itanium microprocessors 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「IA-32 Execution Layer」の詳細全文を読む スポンサード リンク
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