DwarfDebug: emit type units immediately.
Rather than storing type units in a vector and emitting them at the end
of code generation, emit them immediately and destroy them, reclaiming the
memory we were using for their DIEs.
In one benchmark carried out against Chromium's 50 largest (by bitcode
file size) translation units, total peak memory consumption with type units
decreased by median 17%, or by 7% when compared against disabling type units.
Tested using check-{llvm,clang}, the GDB 7.5 test suite (with
'-fdebug-types-section') and by eyeballing llvm-dwarfdump output on those
Chromium translation units with split DWARF both disabled and enabled, and
verifying that the only changes were to addresses and abbreviation ordering.
Differential Revision: http://reviews.llvm.org/D17118
llvm-svn: 260578
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
index 720507a..31303e4 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -235,9 +235,9 @@
/// Holders for the various debug information flags that we might need to
/// have exposed. See accessor functions below for description.
- /// Map from MDNodes for user-defined types to the type units that
- /// describe them.
- DenseMap<const MDNode *, const DwarfTypeUnit *> DwarfTypeUnits;
+ /// Map from MDNodes for user-defined types to their type signatures. Also
+ /// used to keep track of which types we have emitted type units for.
+ DenseMap<const MDNode *, uint64_t> TypeSignatures;
SmallVector<
std::pair<std::unique_ptr<DwarfTypeUnit>, const DICompositeType *>, 1>
@@ -295,7 +295,7 @@
MCDwarfDwoLineTable *getDwoLineTable(const DwarfCompileUnit &);
- const SmallVectorImpl<std::unique_ptr<DwarfUnit>> &getUnits() {
+ const SmallVectorImpl<std::unique_ptr<DwarfCompileUnit>> &getUnits() {
return InfoHolder.getUnits();
}
@@ -391,7 +391,7 @@
/// Initialize common features of skeleton units.
void initSkeletonUnit(const DwarfUnit &U, DIE &Die,
- std::unique_ptr<DwarfUnit> NewU);
+ std::unique_ptr<DwarfCompileUnit> NewU);
/// Construct the split debug info compile unit for the debug info
/// section.