[Patch][Review Requested][Compilation Time] Recompute LoopDisposition/BlockDisposition every time

[Gurd, Preston]

This patch aims to improve compile time performance by removing getLoopDisposition(), which saves the result of ComputeLoopDisposition(), in favour of just recomputing the loop disposition each time it is needed. Similarly, remove getBlockDisposition in favour of just recomputing the block disposition when needed.

Although at first glance one might think that saving the result of computing a Loop or Block Disposition to avoid re-computing it later should be better than computing the Disposition each time, our benchmark results show a net reduction in back end compile time of ~1%. Only one benchmark (xcsoar) slowed slightly.

Patch by Wan Xiaofei.

PLEASE REVIEW. Thanks!

Preston


--
Preston Gurd <preston.gurd at intel.com>
  Intel Waterloo
  SSG/DPD/ECDL/DMP

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