1 //===- SampleProfileMatcher.cpp - Sampling-based Stale Profile Matcher ----===//
10 // profile matching.
22 #define DEBUG_TYPE "sample-profile-matcher"
25     "func-profile-similarity-threshold", cl::Hidden, cl::init(80),
26     cl::desc("Consider a profile matches a function if the similarity of their "
32              "run stale profile call graph matching."));
37              "run stale profile call graph matching."));
45     "salvage-stale-profile-max-callsites", cl::Hidden, cl::init(UINT_MAX),
47              "profile matching will be skipped."));
75   // Extract profile matching anchors in the IR.  in findIRAnchors()
100         // TODO: For line-number based profile(AutoFDO), currently only support  in findIRAnchors()
102         // instructions to extract the line locations for profile matching.  in findIRAnchors()
173   // If IR function doesn't have profile and the profile is unused, try  in functionMatchesProfile()
181          "IR function should be different from profile function to match");  in functionMatchesProfile()
338 // Call target name anchor based profile fuzzy matching.
341 // profile locations, it's the call target name for BodySamples or inlinee's
342 // profile name for CallsiteSamples.
349 // Profile locations: [1, 2, 3(foo), 4, 7, 8(bar), 9]
361   LLVM_DEBUG(dbgs() << "Run stale profile matching for " << F.getName()  in runStaleProfileMatching()
364          "Run stale profile matching only once per function");  in runStaleProfileMatching()
376     LLVM_DEBUG(dbgs() << "Skip stale profile matching for " << F.getName()  in runStaleProfileMatching()
379                       << " and in the profile is "  in runStaleProfileMatching()
385   // between IR and profile.  in runStaleProfileMatching()
390   // For 2), we only consider the anchor functions from IR and profile don't  in runStaleProfileMatching()
409   // in profile only show up when they are hit by samples, i,e. the profile  in runOnFunction()
412   // contexts, aka, the flattened profile to find profile anchors.  in runOnFunction()
415     // Apply the matching in place to find the new function's matched profile.  in runOnFunction()
416     // TODO: For extended profile format, if a function profile is unused and  in runOnFunction()
417     // it's top-level, even if the profile is matched, it's not found in the  in runOnFunction()
418     // profile. This is because sample reader only read the used profile at the  in runOnFunction()
419     // beginning, we need to support loading the profile on-demand in future.  in runOnFunction()
432   // Anchors for profile. It's a map from callsite location to a set of callee  in runOnFunction()
437   // Compute the callsite match states for profile staleness report.  in runOnFunction()
443   // For probe-based profiles, run matching only when profile checksum is  in runOnFunction()
451   // dropped, so we leverage function attribute(profile-checksum-mismatch) to  in runOnFunction()
455     F.addFnAttr("profile-checksum-mismatch");  in runOnFunction()
488     // After fuzzy profile matching, use the matching result to remap the  in recordCallsiteMatchStates()
509   // Check if there are any callsites in the profile that does not match to any  in recordCallsiteMatchStates()
580   // profile, go through it to count the non-inlined callsite samples.  in countMismatchedCallsiteSamples()
615         "Profile matching state is inconsistent");  in countMismatchCallsites()
653   // Count profile mismatches for profile staleness report.  in computeAndReportProfileStaleness()
682              << ") of functions' profile are invalid and ("  in computeAndReportProfileStaleness()
688              << TotalProfiledFunc << ") of functions' profile are matched and ("  in computeAndReportProfileStaleness()
695            << ") of callsites' profile are invalid and ("  in computeAndReportProfileStaleness()
703            << ") of samples are recovered by stale profile matching.\n";  in computeAndReportProfileStaleness()
741   // TODO: Support MD5 profile.  in findFunctionsWithoutProfile()
762     // top-level profile, so check the NameTable which has the all symbol names  in findFunctionsWithoutProfile()
763     // in profile.  in findFunctionsWithoutProfile()
767     // For extended binary, non-profiled function symbols are in the profile  in findFunctionsWithoutProfile()
773                       << " is not in profile or profile symbol list.\n");  in findFunctionsWithoutProfile()
801                         << "(IR) and " << ProfFunc << "(Profile) match.\n");  in functionMatchesProfileHelper()
822   // Use the diff algorithm to find the LCS between IR and profile.  in functionMatchesProfileHelper()
836                     << "(IR) and " << ProfFunc << "(profile) is "  in functionMatchesProfileHelper()
860                       << " matches profile:" << ProfFunc << "\n");  in functionMatchesProfile()
917 // profile with the function name will be set to the same pointer.