A group of optimizations known as loop transformation optimizations and software pipelining with its associated additional software dependence analysis are enabled by using the /optimize:5 option. In certain cases, this improves run-time performance.
The loop transformation optimizations apply to array references within loops and can apply to multiple nested loops. These optimizations can improve the performance of the memory system.
On ia64 systems, software pipelining applies instruction scheduling to certain innermost loops, allowing instructions within a loop to "wrap around" and execute in a different iteration of the loop. This can reduce the impact of long-latency operations, resulting in faster loop execution.
Software pipelining also enables the prefetching of data to reduce the impact of cache misses.
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