JIT: start working on profile consistency #81936
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Dump flow graph before running post-phase checks so the flow graph visualization can be used in conjunction with the profile checker output to spot profile problems. Various provisional fixes to try and shore up the inevitably inconsistent OSR profile. Add a compensating pseudo-edges to the OSR entry to help explain where the missing flow counts have gone. Relax checking for the OSR entry. Add likelhood when we redirect flow to the OSR entry. Locate the OSR entry and original method entry early so we can special-case them in diagnostics. Defer marking interesting blocks (say for switch peeling) until we've set edge likelihoods, since (someday) those decisions should use edge likelihoods. Disable profile checking after profile incorporation. The plan is to walk this disable back incrementally and fix issues in each succesive phase, ultimately checking them all. But currently we still have a lot of check failures right after this first phase. Contributes to dotnet#46885.
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Tagging subscribers to this area: @JulieLeeMSFT, @jakobbotsch, @kunalspathak Issue DetailsDump flow graph before running post-phase checks so the flow graph visualization can be used in conjunction with the profile checker output to spot profile problems. Various provisional fixes to try and shore up the inevitably inconsistent OSR profile. Add a compensating pseudo-edges to the OSR entry to help explain where the missing flow counts have gone. Relax checking for the OSR entry. Add likelhood when we redirect flow to the OSR entry. Locate the OSR entry and original method entry early so we can special-case them in diagnostics. Defer marking interesting blocks (say for switch peeling) until we've set edge likelihoods, since (someday) those decisions should use edge likelihoods. Disable profile checking after profile incorporation. The plan is to walk this disable back incrementally and fix issues in each succesive phase, ultimately checking them all. But currently we still have a lot of check failures right after this first phase. Contributes to #46885.
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@BruceForstall PTAL Should be no diff, no TP impact. |
| FlowEdge* const edge = fgAddRefPred(fgFirstBB, block); | ||
| edge->setLikelihood(1.0); |
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Presumably fgAddRefPred could set the likelihood to 1.0 automatically if it's the first (and thus only) pred. Do you want callers to always do that work?
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Probably not, but I feel like I will need to work through more of the maintenance issues downstream to see what the best patterns should be.
| @@ -5234,13 +5234,18 @@ bool Compiler::optInvertWhileLoop(BasicBlock* block) | |||
| edgeBlockToAfter->setEdgeWeights(blockToAfterWeight, blockToAfterWeight, bNewCond->bbJumpDest); | |||
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| #ifdef DEBUG | |||
| // Verify profile for the two target blocks is consistent. | |||
| // If we're checkig profile data, see if profile for the two target blocks is consistent. | |||
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| // If we're checkig profile data, see if profile for the two target blocks is consistent. | |
| // If we're checking profile data, see if profile for the two target blocks is consistent. |
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I need a spell check for comments. Will fix this in a subsequent PR.
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Dump flow graph before running post-phase checks so the flow graph visualization can be used in conjunction with the profile checker output to spot profile problems.
Various provisional fixes to try and shore up the inevitably inconsistent OSR profile. Add a compensating pseudo-edges to the OSR entry to help explain where the missing flow counts have gone. Relax checking for the OSR entry. Add likelhood when we redirect flow to the OSR entry. Locate the OSR entry and original method entry early so we can special-case them in diagnostics.
Defer marking interesting blocks (say for switch peeling) until we've set edge likelihoods, since (someday) those decisions should use edge likelihoods.
Disable profile checking after profile incorporation. The plan is to walk this disable back incrementally and fix issues in each succesive phase, ultimately checking them all. But currently we still have a lot of check failures right after this first phase.
Contributes to #46885.