Справочник Пользователя для AMD 250
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Instruction-Decoding Optimizations
Chapter 4
25112
Rev. 3.06
September 2005
Software Optimization Guide for AMD64 Processors
4.3
Branch Targets in Program Hot Spots
Optimization
In program “hot spots” (as determined by either profiling or loop-nesting analysis), branch targets
should be placed at or near the beginning of code windows that are 16-byte aligned. The smaller the
basic block, the more beneficial this optimization will be.
should be placed at or near the beginning of code windows that are 16-byte aligned. The smaller the
basic block, the more beneficial this optimization will be.
Application
This optimization applies to:
•
32-bit software
•
64-bit software
Rationale
Aligning branch targets maximizes the number of instructions in the pick window and preserves
instruction-cache space in branch-intensive code outside such hot spots.
instruction-cache space in branch-intensive code outside such hot spots.