6 files changed, 13 insertions, 23 deletions

diff --git a/lld/ELF/Driver.cpp b/lld/ELF/Driver.cpp
index 208649faf83..2c29c518b4f 100644
--- a/lld/ELF/Driver.cpp
+++ b/lld/ELF/Driver.cpp
@@ -1303,9 +1303,10 @@ template <class ELFT> void LinkerDriver::link(opt::InputArgList &Args) {
 
   // Do size optimizations: garbage collection, merging of SHF_MERGE sections
   // and identical code folding.
+  decompressSections();
+  splitSections();
   markLive<ELFT>();
   demoteSymbols<ELFT>();
-  decompressSections();
   mergeSections();
   if (Config->ICF)
     doIcf<ELFT>();
diff --git a/lld/ELF/InputSection.cpp b/lld/ELF/InputSection.cpp
index 871832a4ef7..7b64621a146 100644
--- a/lld/ELF/InputSection.cpp
+++ b/lld/ELF/InputSection.cpp
@@ -937,10 +937,6 @@ void MergeInputSection::splitIntoPieces() {
   OffsetMap.reserve(Pieces.size());
   for (size_t I = 0, E = Pieces.size(); I != E; ++I)
     OffsetMap[Pieces[I].InputOff] = I;
-
-  if (Config->GcSections && (Flags & SHF_ALLOC))
-    for (uint32_t Off : LiveOffsets)
-      getSectionPiece(Off)->Live = true;
 }
 
 template <class It, class T, class Compare>
diff --git a/lld/ELF/InputSection.h b/lld/ELF/InputSection.h
index 0a1954cdc2e..50ca557a634 100644
--- a/lld/ELF/InputSection.h
+++ b/lld/ELF/InputSection.h
@@ -223,12 +223,6 @@ public:
   static bool classof(const SectionBase *S) { return S->kind() == Merge; }
   void splitIntoPieces();
 
-  // Mark the piece at a given offset live. Used by GC.
-  void markLiveAt(uint64_t Offset) {
-    if (this->Flags & llvm::ELF::SHF_ALLOC)
-      LiveOffsets.insert(Offset);
-  }
-
   // Translate an offset in the input section to an offset in the parent
   // MergeSyntheticSection.
   uint64_t getParentOffset(uint64_t Offset) const;
@@ -259,8 +253,6 @@ public:
 private:
   void splitStrings(ArrayRef<uint8_t> A, size_t Size);
   void splitNonStrings(ArrayRef<uint8_t> A, size_t Size);
-
-  llvm::DenseSet<uint32_t> LiveOffsets;
 };
 
 struct EhSectionPiece {
diff --git a/lld/ELF/MarkLive.cpp b/lld/ELF/MarkLive.cpp
index 6b80e8e77aa..d7cc74e48c1 100644
--- a/lld/ELF/MarkLive.cpp
+++ b/lld/ELF/MarkLive.cpp
@@ -207,7 +207,7 @@ template <class ELFT> static void doGcSections() {
     // (splittable) sections, each piece of data has independent liveness bit.
     // So we explicitly tell it which offset is in use.
     if (auto *MS = dyn_cast<MergeInputSection>(Sec))
-      MS->markLiveAt(Offset);
+      MS->getSectionPiece(Offset)->Live = true;
 
     if (Sec->Live)
       return;
diff --git a/lld/ELF/SyntheticSections.cpp b/lld/ELF/SyntheticSections.cpp
index ac16b858bc4..306bee478ac 100644
--- a/lld/ELF/SyntheticSections.cpp
+++ b/lld/ELF/SyntheticSections.cpp
@@ -2536,9 +2536,16 @@ static MergeSyntheticSection *createMergeSynthetic(StringRef Name,
 
 // Debug sections may be compressed by zlib. Decompress if exists.
 void elf::decompressSections() {
+  parallelForEach(InputSections,
+                  [](InputSectionBase *Sec) { Sec->maybeDecompress(); });
+}
+
+void elf::splitSections() {
+  // splitIntoPieces needs to be called on each MergeInputSection
+  // before calling finalizeContents().
   parallelForEach(InputSections, [](InputSectionBase *Sec) {
-    if (Sec->Live)
-      Sec->maybeDecompress();
+    if (auto *S = dyn_cast<MergeInputSection>(Sec))
+      S->splitIntoPieces();
   });
 }
 
@@ -2550,13 +2557,6 @@ void elf::decompressSections() {
 // that it replaces. It then finalizes each synthetic section in order
 // to compute an output offset for each piece of each input section.
 void elf::mergeSections() {
-  // splitIntoPieces needs to be called on each MergeInputSection
-  // before calling finalizeContents(). Do that first.
-  parallelForEach(InputSections, [](InputSectionBase *Sec) {
-    if (auto *S = dyn_cast<MergeInputSection>(Sec))
-      S->splitIntoPieces();
-  });
-
   std::vector<MergeSyntheticSection *> MergeSections;
   for (InputSectionBase *&S : InputSections) {
     MergeInputSection *MS = dyn_cast<MergeInputSection>(S);
diff --git a/lld/ELF/SyntheticSections.h b/lld/ELF/SyntheticSections.h
index 49080e1601f..bd442a58262 100644
--- a/lld/ELF/SyntheticSections.h
+++ b/lld/ELF/SyntheticSections.h
@@ -834,6 +834,7 @@ private:
 InputSection *createInterpSection();
 MergeInputSection *createCommentSection();
 void decompressSections();
+void splitSections();
 void mergeSections();
 
 Defined *addSyntheticLocal(StringRef Name, uint8_t Type, uint64_t Value,