See https://discourse.llvm.org/t/rfc-keep-globalvalue-guids-stable/84801 for context. This is a non-functional change which just changes the interface of GlobalValue, in preparation for future functional changes. This part touches a fair few users, so is split out for ease of review. Future changes to the GlobalValue implementation can then be focused purely on that class. This does the following: * Rename GlobalValue::getGUID(StringRef) to getGUIDAssumingExternalLinkage. This is simply making explicit at the callsite what is currently implicit. * Where possible, migrate users to directly calling getGUID on a GlobalValue instance. * Otherwise, where possible, have them call the newly renamed getGUIDAssumingExternalLinkage, to make the assumption explicit. There are a few cases where neither of the above are possible, as the caller saves and reconstructs the necessary information to compute the GUID themselves. We want to migrate these callers eventually, but for this first step we leave them be.
Clean the unneeded field 'TotalCollectedSamples' and the unnecessary loop. The field seems introduced in:https://reviews.llvm.org/D31952, and its uses were removed in: https://reviews.llvm.org/D19287, but this field and unnecessary calculation were not cleaned up. This patch will remove these unneeded codes.
Tested call-graph matching on some of Meta's large services, it works to reuse some renamed function profiles, no negative perf or significant build speed regression observed. Turned it on by default for CSSPGO mode.
As part of the "RemoveDIs" work to eliminate debug intrinsics, we're replacing methods that use Instruction*'s as positions with iterators. A number of these (such as getFirstNonPHIOrDbg) are sufficiently infrequently used that we can just replace the pointer-returning version with an iterator-returning version, hopefully without much/any disruption. Thus this patch has getFirstNonPHIOrDbg and getFirstNonPHIOrDbgOrLifetime return an iterator, and updates all call-sites. There are no concerns about the iterators returned being converted to Instruction*'s and losing the debug-info bit: because the methods skip debug intrinsics, the iterator head bit is always false anyway.
When using -sample-profile-remove-probe, pseudo probe desc should also be removed and dwarf discriminator for call instruction should be restored.