From 5da1d88492e2487b67c3cf79031b8e273bd6fb35 Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Wed, 26 Oct 2016 15:34:24 +0000
Subject: [PATCH] Reduce the number of allocators.

We used to have one allocator per file, which reduces the advantage of
using an allocator in the first place.

This is a small speed up is most cases. The largest speedup was in
1.014X in chromium no-gc. The largest slowdown was scylla at 1.003X.

llvm-svn: 285205
---
 lld/ELF/Driver.cpp      |  6 +++---
 lld/ELF/InputFiles.cpp  | 29 +++++++++++++++--------------
 lld/ELF/InputFiles.h    | 12 +++++++-----
 lld/ELF/LTO.cpp         |  3 ++-
 lld/ELF/LTO.h           |  1 +
 lld/ELF/SymbolTable.cpp |  8 ++++----
 lld/ELF/Symbols.cpp     | 15 ++++++++-------
 lld/ELF/Symbols.h       |  6 +++---
 8 files changed, 43 insertions(+), 37 deletions(-)

diff --git a/lld/ELF/Driver.cpp b/lld/ELF/Driver.cpp
index 5cb0746..207a2e58 100644
--- a/lld/ELF/Driver.cpp
+++ b/lld/ELF/Driver.cpp
@@ -137,7 +137,7 @@ void LinkerDriver::addFile(StringRef Path) {
   case file_magic::archive:
     if (InWholeArchive) {
       for (MemoryBufferRef MB : getArchiveMembers(MBRef))
-        Files.push_back(createObjectFile(MB, Path));
+        Files.push_back(createObjectFile(Alloc, MB, Path));
       return;
     }
     Files.push_back(new ArchiveFile(MBRef));
@@ -147,13 +147,13 @@ void LinkerDriver::addFile(StringRef Path) {
       error("attempted static link of dynamic object " + Path);
       return;
     }
-    Files.push_back(createSharedFile(MBRef));
+    Files.push_back(createSharedFile(Alloc, MBRef));
     return;
   default:
     if (InLib)
       Files.push_back(new LazyObjectFile(MBRef));
     else
-      Files.push_back(createObjectFile(MBRef));
+      Files.push_back(createObjectFile(Alloc, MBRef));
   }
 }
 
diff --git a/lld/ELF/InputFiles.cpp b/lld/ELF/InputFiles.cpp
index 2dd34f0..507090d 100644
--- a/lld/ELF/InputFiles.cpp
+++ b/lld/ELF/InputFiles.cpp
@@ -140,8 +140,8 @@ template <class ELFT> void ELFFileBase<ELFT>::initStringTable() {
 }
 
 template <class ELFT>
-elf::ObjectFile<ELFT>::ObjectFile(MemoryBufferRef M)
-    : ELFFileBase<ELFT>(Base::ObjectKind, M) {}
+elf::ObjectFile<ELFT>::ObjectFile(BumpPtrAllocator &Alloc, MemoryBufferRef M)
+    : ELFFileBase<ELFT>(Base::ObjectKind, M), Alloc(Alloc) {}
 
 template <class ELFT>
 ArrayRef<SymbolBody *> elf::ObjectFile<ELFT>::getNonLocalSymbols() {
@@ -547,7 +547,7 @@ ArchiveFile::getMember(const Archive::Symbol *Sym) {
 }
 
 template <class ELFT>
-SharedFile<ELFT>::SharedFile(MemoryBufferRef M)
+SharedFile<ELFT>::SharedFile(BumpPtrAllocator &Alloc, MemoryBufferRef M)
     : ELFFileBase<ELFT>(Base::SharedKind, M), AsNeeded(Config->AsNeeded) {}
 
 template <class ELFT>
@@ -793,7 +793,7 @@ void BitcodeFile::parse(DenseSet<CachedHashStringRef> &ComdatGroups) {
 }
 
 template <template <class> class T>
-static InputFile *createELFFile(MemoryBufferRef MB) {
+static InputFile *createELFFile(BumpPtrAllocator &Alloc, MemoryBufferRef MB) {
   unsigned char Size;
   unsigned char Endian;
   std::tie(Size, Endian) = getElfArchType(MB.getBuffer());
@@ -802,13 +802,13 @@ static InputFile *createELFFile(MemoryBufferRef MB) {
 
   InputFile *Obj;
   if (Size == ELFCLASS32 && Endian == ELFDATA2LSB)
-    Obj = new T<ELF32LE>(MB);
+    Obj = new T<ELF32LE>(Alloc, MB);
   else if (Size == ELFCLASS32 && Endian == ELFDATA2MSB)
-    Obj = new T<ELF32BE>(MB);
+    Obj = new T<ELF32BE>(Alloc, MB);
   else if (Size == ELFCLASS64 && Endian == ELFDATA2LSB)
-    Obj = new T<ELF64LE>(MB);
+    Obj = new T<ELF64LE>(Alloc, MB);
   else if (Size == ELFCLASS64 && Endian == ELFDATA2MSB)
-    Obj = new T<ELF64BE>(MB);
+    Obj = new T<ELF64BE>(Alloc, MB);
   else
     fatal("invalid file class: " + MB.getBufferIdentifier());
 
@@ -825,7 +825,7 @@ template <class ELFT> InputFile *BinaryFile::createELF() {
   Buffer = wrapBinaryWithElfHeader<ELFT>(Blob, Filename);
 
   return createELFFile<ObjectFile>(
-      MemoryBufferRef(toStringRef(Buffer), Filename));
+      Alloc, MemoryBufferRef(toStringRef(Buffer), Filename));
 }
 
 static bool isBitcode(MemoryBufferRef MB) {
@@ -833,17 +833,18 @@ static bool isBitcode(MemoryBufferRef MB) {
   return identify_magic(MB.getBuffer()) == file_magic::bitcode;
 }
 
-InputFile *elf::createObjectFile(MemoryBufferRef MB, StringRef ArchiveName,
+InputFile *elf::createObjectFile(BumpPtrAllocator &Alloc, MemoryBufferRef MB,
+                                 StringRef ArchiveName,
                                  uint64_t OffsetInArchive) {
-  InputFile *F =
-      isBitcode(MB) ? new BitcodeFile(MB) : createELFFile<ObjectFile>(MB);
+  InputFile *F = isBitcode(MB) ? new BitcodeFile(MB)
+                               : createELFFile<ObjectFile>(Alloc, MB);
   F->ArchiveName = ArchiveName;
   F->OffsetInArchive = OffsetInArchive;
   return F;
 }
 
-InputFile *elf::createSharedFile(MemoryBufferRef MB) {
-  return createELFFile<SharedFile>(MB);
+InputFile *elf::createSharedFile(BumpPtrAllocator &Alloc, MemoryBufferRef MB) {
+  return createELFFile<SharedFile>(Alloc, MB);
 }
 
 MemoryBufferRef LazyObjectFile::getBuffer() {
diff --git a/lld/ELF/InputFiles.h b/lld/ELF/InputFiles.h
index 3ac390e..ca232fc 100644
--- a/lld/ELF/InputFiles.h
+++ b/lld/ELF/InputFiles.h
@@ -167,7 +167,7 @@ public:
   ArrayRef<SymbolBody *> getLocalSymbols();
   ArrayRef<SymbolBody *> getNonLocalSymbols();
 
-  explicit ObjectFile(MemoryBufferRef M);
+  explicit ObjectFile(llvm::BumpPtrAllocator &Alloc, MemoryBufferRef M);
   void parse(llvm::DenseSet<llvm::CachedHashStringRef> &ComdatGroups);
 
   ArrayRef<InputSectionBase<ELFT> *> getSections() const { return Sections; }
@@ -202,7 +202,7 @@ public:
 
   // SymbolBodies and Thunks for sections in this file are allocated
   // using this buffer.
-  llvm::BumpPtrAllocator Alloc;
+  llvm::BumpPtrAllocator &Alloc;
 
   // Name of source file obtained from STT_FILE symbol value,
   // or empty string if there is no such symbol in object file
@@ -324,7 +324,7 @@ public:
     return F->kind() == Base::SharedKind;
   }
 
-  explicit SharedFile(MemoryBufferRef M);
+  explicit SharedFile(llvm::BumpPtrAllocator &Alloc, MemoryBufferRef M);
 
   void parseSoName();
   void parseRest();
@@ -356,11 +356,13 @@ public:
 
 private:
   std::vector<uint8_t> Buffer;
+  llvm::BumpPtrAllocator Alloc;
 };
 
-InputFile *createObjectFile(MemoryBufferRef MB, StringRef ArchiveName = "",
+InputFile *createObjectFile(llvm::BumpPtrAllocator &Alloc, MemoryBufferRef MB,
+                            StringRef ArchiveName = "",
                             uint64_t OffsetInArchive = 0);
-InputFile *createSharedFile(MemoryBufferRef MB);
+InputFile *createSharedFile(llvm::BumpPtrAllocator &Alloc, MemoryBufferRef MB);
 
 } // namespace elf
 } // namespace lld
diff --git a/lld/ELF/LTO.cpp b/lld/ELF/LTO.cpp
index f819a04..69d0895 100644
--- a/lld/ELF/LTO.cpp
+++ b/lld/ELF/LTO.cpp
@@ -137,7 +137,8 @@ std::vector<InputFile *> BitcodeCompiler::compile() {
       else
         saveBuffer(Buff[I], Config->OutputFile + Twine(I) + ".lto.o");
     }
-    InputFile *Obj = createObjectFile(MemoryBufferRef(Buff[I], "lto.tmp"));
+    InputFile *Obj =
+        createObjectFile(Alloc, MemoryBufferRef(Buff[I], "lto.tmp"));
     Ret.push_back(Obj);
   }
   return Ret;
diff --git a/lld/ELF/LTO.h b/lld/ELF/LTO.h
index 7a91957..e8ef85d 100644
--- a/lld/ELF/LTO.h
+++ b/lld/ELF/LTO.h
@@ -49,6 +49,7 @@ public:
 private:
   std::unique_ptr<llvm::lto::LTO> LtoObj;
   std::vector<SmallString<0>> Buff;
+  llvm::BumpPtrAllocator Alloc;
 };
 }
 }
diff --git a/lld/ELF/SymbolTable.cpp b/lld/ELF/SymbolTable.cpp
index 32eb3c7..6bcf8a9 100644
--- a/lld/ELF/SymbolTable.cpp
+++ b/lld/ELF/SymbolTable.cpp
@@ -293,7 +293,7 @@ Symbol *SymbolTable<ELFT>::addUndefined(StringRef Name, uint8_t Binding,
     // its type. See also comment in addLazyArchive.
     if (S->isWeak())
       L->Type = Type;
-    else if (InputFile *F = L->fetch())
+    else if (InputFile *F = L->fetch(Alloc))
       addFile(F);
   }
   return S;
@@ -510,7 +510,7 @@ void SymbolTable<ELFT>::addLazyArchive(ArchiveFile *F,
   }
   std::pair<MemoryBufferRef, uint64_t> MBInfo = F->getMember(&Sym);
   if (!MBInfo.first.getBuffer().empty())
-    addFile(createObjectFile(MBInfo.first, F->getName(), MBInfo.second));
+    addFile(createObjectFile(Alloc, MBInfo.first, F->getName(), MBInfo.second));
 }
 
 template <class ELFT>
@@ -531,7 +531,7 @@ void SymbolTable<ELFT>::addLazyObject(StringRef Name, LazyObjectFile &Obj) {
   } else {
     MemoryBufferRef MBRef = Obj.getBuffer();
     if (!MBRef.getBuffer().empty())
-      addFile(createObjectFile(MBRef));
+      addFile(createObjectFile(Alloc, MBRef));
   }
 }
 
@@ -539,7 +539,7 @@ void SymbolTable<ELFT>::addLazyObject(StringRef Name, LazyObjectFile &Obj) {
 template <class ELFT> void SymbolTable<ELFT>::scanUndefinedFlags() {
   for (StringRef S : Config->Undefined)
     if (auto *L = dyn_cast_or_null<Lazy>(find(S)))
-      if (InputFile *File = L->fetch())
+      if (InputFile *File = L->fetch(Alloc))
         addFile(File);
 }
 
diff --git a/lld/ELF/Symbols.cpp b/lld/ELF/Symbols.cpp
index f59132a..d508b69 100644
--- a/lld/ELF/Symbols.cpp
+++ b/lld/ELF/Symbols.cpp
@@ -227,10 +227,10 @@ DefinedCommon::DefinedCommon(StringRef N, uint64_t Size, uint64_t Alignment,
   this->File = File;
 }
 
-InputFile *Lazy::fetch() {
+InputFile *Lazy::fetch(BumpPtrAllocator &Alloc) {
   if (auto *S = dyn_cast<LazyArchive>(this))
-    return S->fetch();
-  return cast<LazyObject>(this)->fetch();
+    return S->fetch(Alloc);
+  return cast<LazyObject>(this)->fetch(Alloc);
 }
 
 LazyArchive::LazyArchive(ArchiveFile &File,
@@ -244,21 +244,22 @@ LazyObject::LazyObject(StringRef Name, LazyObjectFile &File, uint8_t Type)
   this->File = &File;
 }
 
-InputFile *LazyArchive::fetch() {
+InputFile *LazyArchive::fetch(BumpPtrAllocator &Alloc) {
   std::pair<MemoryBufferRef, uint64_t> MBInfo = file()->getMember(&Sym);
 
   // getMember returns an empty buffer if the member was already
   // read from the library.
   if (MBInfo.first.getBuffer().empty())
     return nullptr;
-  return createObjectFile(MBInfo.first, file()->getName(), MBInfo.second);
+  return createObjectFile(Alloc, MBInfo.first, file()->getName(),
+                          MBInfo.second);
 }
 
-InputFile *LazyObject::fetch() {
+InputFile *LazyObject::fetch(BumpPtrAllocator &Alloc) {
   MemoryBufferRef MBRef = file()->getBuffer();
   if (MBRef.getBuffer().empty())
     return nullptr;
-  return createObjectFile(MBRef);
+  return createObjectFile(Alloc, MBRef);
 }
 
 bool Symbol::includeInDynsym() const {
diff --git a/lld/ELF/Symbols.h b/lld/ELF/Symbols.h
index 8c2edb2..eda23c1 100644
--- a/lld/ELF/Symbols.h
+++ b/lld/ELF/Symbols.h
@@ -328,7 +328,7 @@ public:
 
   // Returns an object file for this symbol, or a nullptr if the file
   // was already returned.
-  InputFile *fetch();
+  InputFile *fetch(llvm::BumpPtrAllocator &Alloc);
 
 protected:
   Lazy(SymbolBody::Kind K, StringRef Name, uint8_t Type)
@@ -346,7 +346,7 @@ public:
   }
 
   ArchiveFile *file() { return (ArchiveFile *)this->File; }
-  InputFile *fetch();
+  InputFile *fetch(llvm::BumpPtrAllocator &Alloc);
 
 private:
   const llvm::object::Archive::Symbol Sym;
@@ -363,7 +363,7 @@ public:
   }
 
   LazyObjectFile *file() { return (LazyObjectFile *)this->File; }
-  InputFile *fetch();
+  InputFile *fetch(llvm::BumpPtrAllocator &Alloc);
 };
 
 // Some linker-generated symbols need to be created as
-- 
2.7.4