quickly as possible, second priority to predicting conditional branches based on the sign of the displacement field (backward taken, forward
A.2.3 Improving I-Stream Density — Factor of 3
Compilers should try to use profiles to make sure almost 100% of the bytes brought into an
A.2.4 Instruction Scheduling — Factor of 3
The performance of Alpha programs is sensitive to how carefully the code is scheduled to min- imize
"Result latency" is defined as the number of CPU cycles that must elapse between an instruc- tion that writes a result register and one that uses that register, if
Most Alpha instructions have a
Compilers should try to schedule code to match the above latency rules and also to match the
Implementors should give first priority to minimizing the latency of
A.3 Data-Stream Considerations
The following sections describe considerations for the data stream.
A.3.1 Data Alignment — Factor of 10
Data PSECTs should be at least octaword aligned, so that aggregates (arrays, some records, subroutine stack frames) can be allocated on aligned octaword boundaries to take advantage of any implementations with aligned octaword data paths, and to decrease the number of cache fills in almost all implementations.
Aggregates (arrays, records, common blocks, and so forth) should be allocated on at least