================
@@ -374,25 +377,40 @@ void DebugNamesDWARFIndex::GetFullyQualifiedType(
m_fallback.GetFullyQualifiedType(context, callback);
}
+bool DebugNamesDWARFIndex::SameAsEntryATName(
+ llvm::StringRef query_name, const DebugNames::Entry &entry) const {
+ auto maybe_dieoffset = entry.getDIEUnitOffset();
+ if (!maybe_dieoffset)
+ return false;
+
+ // [Optimization] instead of parsing the entry from dwo file, we simply
+ // check if the query_name can point to an entry of the same DIE offset.
+ // This greatly reduced number of dwo file parsed and thus improved the
+ // performance.
+ for (const DebugNames::Entry &query_entry :
+ entry.getNameIndex()->equal_range(query_name)) {
+ auto query_dieoffset = query_entry.getDIEUnitOffset();
+ if (!query_dieoffset)
+ continue;
+
+ if (*query_dieoffset == *maybe_dieoffset) {
+ return true;
+ } else if (*query_dieoffset > *maybe_dieoffset) {
+ // The pool entries of the same name are sequentially cluttered together
+ // so if the query name from `query_name` is after the target entry, this
+ // is definitely not the correct one, we can stop searching.
+ return false;
+ }
+ }
+ return false;
+}
+
bool DebugNamesDWARFIndex::SameParentChain(
llvm::ArrayRef<llvm::StringRef> parent_names,
llvm::ArrayRef<DebugNames::Entry> parent_entries) const {
-
if (parent_entries.size() != parent_names.size())
return false;
- auto SameAsEntryATName = [this](llvm::StringRef name,
- const DebugNames::Entry &entry) {
- // Peek at the AT_name of `entry` and test equality to `name`.
- auto maybe_dieoffset = entry.getDIEUnitOffset();
- if (!maybe_dieoffset)
- return false;
- DWARFUnit *unit = GetNonSkeletonUnit(entry);
- if (!unit)
- return false;
- return name == unit->PeekDIEName(unit->GetOffset() + *maybe_dieoffset);
----------------
jeffreytan81 wrote:
Nevermind, I manually strip down the internal target debug info from 7GB =>
400MB so that it can be linked without split dwarf.
Tested with `PeekDIEName()` vs this PR in two different code paths:
```
In the first path:
PeekDIEName 1.2s
This PR: 1.4s
In the second path:
PeekDIEName 1.999s
This PR: 1.720s
```
So they are about the same if not using split dwarf. And majority of the saving
comes from split dwarf which avoiding parsing dwo files really matters.
https://github.com/llvm/llvm-project/pull/108907
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