3 Commits

Author	SHA1	Message	Date
Guozhi Wei	687e80be7f	[MBP] Add whole chain to BlockFilterSet instead of individual BB ... Currently we add individual BB to BlockFilterSet if its frequency satisfies LoopFreq / Freq <= LoopToColdBlockRatio LoopFreq is edge frequency from outside to loop header. LoopToColdBlockRatio is a command line parameter. It doesn't make sense since we always layout whole chain, not individual BBs. It may also cause a tricky problem. Sometimes it is possible that the LoopFreq of an inner loop is smaller than LoopFreq of outer loop. So a BB can be in BlockFilterSet of inner loop, but not in BlockFilterSet of outer loop, like .cold in the test case. So it is added to the chain of inner loop. When work on the outer loop, .cold is not added to BlockFilterSet, so the edge to successor .problem is not counted in UnscheduledPredecessors of .problem chain. But other blocks in the inner loop are added BlockFilterSet, so the whole inner loop chain can be layout, and markChainSuccessors is called to decrease UnscheduledPredecessors of following chains. markChainSuccessors calls markBlockSuccessors for every BB, even it is not in BlockFilterSet, like .cold, so .problem chain's UnscheduledPredecessors is decreased, but this edge was not counted on in fillWorkLists, so .problem chain's UnscheduledPredecessors becomes 0 when it still has an unscheduled predecessor .pred! And it causes problems in following various successor BB selection algorithms. Differential Revision: https://reviews.llvm.org/D89088	2020-12-16 15:45:47 -08:00
Han Shen	e42f6c0ac0	Revert "[MBP] Add whole chain to BlockFilterSet instead of individual BB" ... This reverts commit adfb5415010fbbc009a4a6298cfda7a6ed4fa6d4. This is reverted because it caused an chrome error: https://crbug.com/1140168	2020-10-22 17:31:01 -07:00
Guozhi Wei	adfb541501	[MBP] Add whole chain to BlockFilterSet instead of individual BB ... Currently we add individual BB to BlockFilterSet if its frequency satisfies LoopFreq / Freq <= LoopToColdBlockRatio LoopFreq is edge frequency from outside to loop header. LoopToColdBlockRatio is a command line parameter. It doesn't make sense since we always layout whole chain, not individual BBs. It may also cause a tricky problem. Sometimes it is possible that the LoopFreq of an inner loop is smaller than LoopFreq of outer loop. So a BB can be in BlockFilterSet of inner loop, but not in BlockFilterSet of outer loop, like .cold in the test case. So it is added to the chain of inner loop. When work on the outer loop, .cold is not added to BlockFilterSet, so the edge to successor .problem is not counted in UnscheduledPredecessors of .problem chain. But other blocks in the inner loop are added BlockFilterSet, so the whole inner loop chain can be layout, and markChainSuccessors is called to decrease UnscheduledPredecessors of following chains. markChainSuccessors calls markBlockSuccessors for every BB, even it is not in BlockFilterSet, like .cold, so .problem chain's UnscheduledPredecessors is decreased, but this edge was not counted on in fillWorkLists, so .problem chain's UnscheduledPredecessors becomes 0 when it still has an unscheduled predecessor .pred! And it causes problems in following various successor BB selection algorithms. Differential Revision: https://reviews.llvm.org/D89088	2020-10-14 11:55:10 -07:00