[llvm] [BOLT] Use symbol table info in registerFragment (PR #89648)
Amir Ayupov via llvm-commits
llvm-commits at lists.llvm.org
Mon Apr 22 14:04:53 PDT 2024
================
@@ -1417,50 +1418,106 @@ void RewriteInstance::registerFragments() {
if (!BC->HasSplitFunctions)
return;
+ std::vector<std::pair<StringRef, BinaryFunction *>> AmbiguousFragments;
for (auto &BFI : BC->getBinaryFunctions()) {
BinaryFunction &Function = BFI.second;
if (!Function.isFragment())
continue;
- unsigned ParentsFound = 0;
- for (StringRef Name : Function.getNames()) {
+ for (MCSymbol *Symbol : Function.Symbols) {
+ StringRef Name = Symbol->getName();
StringRef BaseName, Suffix;
std::tie(BaseName, Suffix) = Name.split('/');
const size_t ColdSuffixPos = BaseName.find(".cold");
if (ColdSuffixPos == StringRef::npos)
continue;
- // For cold function with local (foo.cold/1) symbol, prefer a parent with
- // local symbol as well (foo/1) over global symbol (foo).
- std::string ParentName = BaseName.substr(0, ColdSuffixPos).str();
+ StringRef ParentName = BaseName.substr(0, ColdSuffixPos);
const BinaryData *BD = BC->getBinaryDataByName(ParentName);
- if (Suffix != "") {
- ParentName.append(Twine("/", Suffix).str());
- const BinaryData *BDLocal = BC->getBinaryDataByName(ParentName);
- if (BDLocal || !BD)
- BD = BDLocal;
- }
- if (!BD) {
- if (opts::Verbosity >= 1)
- BC->outs() << "BOLT-INFO: parent function not found for " << Name
- << "\n";
+ uint64_t NumPossibleLocalParents = NR.getNumDuplicates(ParentName);
+ // The most common case: single local parent fragment.
+ if (!BD && NumPossibleLocalParents == 1) {
+ BD = BC->getBinaryDataByName((Twine(ParentName) + "/1").str());
+ } else if (BD && (!NumPossibleLocalParents || Suffix.empty())) {
+ // Global parent and either no local candidates (second most common), or
+ // the fragment is global as well (uncommon).
+ } else {
+ // Any other case: need to disambiguate using FILE symbols.
+ AmbiguousFragments.emplace_back(ParentName, &Function);
continue;
}
+ assert(BD);
----------------
aaupov wrote:
Switched to exit(1)
https://github.com/llvm/llvm-project/pull/89648
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