From: Saleem Abdulrasool <compnerd@compnerd.org>
Date: Sun, 8 Jan 2017 19:14:15 +0000 (+0000)
Subject: llvm-objdump: speed up -objc-meta-data
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=8204fd73206682998c8d78f7e4c0e351f1b79ca4;p=llvm

llvm-objdump: speed up -objc-meta-data

Running a Debug build of objdump -objc-meta-data with a large Mach-O file is
currently unnecessarily slow.

With some local test input, this change reduces the run time from 75-85s down
to 15-20s.

The two changes are:
  Assert on pointer equality not array equality
  Replace vector<pair<address, symbol>> with DenseMap<address, symbol>

Additionally, use a std::unique_ptr rather than handling the memory manually.

Patch by Dave Lee!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291398 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Object/MachOObjectFile.cpp b/lib/Object/MachOObjectFile.cpp
index 40105000c56..5b018676eba 100644
--- a/lib/Object/MachOObjectFile.cpp
+++ b/lib/Object/MachOObjectFile.cpp
@@ -2823,7 +2823,11 @@ StringRef MachORebaseEntry::typeName() const {
 }
 
 bool MachORebaseEntry::operator==(const MachORebaseEntry &Other) const {
+#ifdef EXPENSIVE_CHECKS
   assert(Opcodes == Other.Opcodes && "compare iterators of different files");
+#else
+  assert(Opcodes.data() == Other.Opcodes.data() && "compare iterators of different files");
+#endif
   return (Ptr == Other.Ptr) &&
          (RemainingLoopCount == Other.RemainingLoopCount) &&
          (Done == Other.Done);
@@ -3073,7 +3077,11 @@ uint32_t MachOBindEntry::flags() const { return Flags; }
 int MachOBindEntry::ordinal() const { return Ordinal; }
 
 bool MachOBindEntry::operator==(const MachOBindEntry &Other) const {
+#ifdef EXPENSIVE_CHECKS
   assert(Opcodes == Other.Opcodes && "compare iterators of different files");
+#else
+  assert(Opcodes.data() == Other.Opcodes.data() && "compare iterators of different files");
+#endif
   return (Ptr == Other.Ptr) &&
          (RemainingLoopCount == Other.RemainingLoopCount) &&
          (Done == Other.Done);
diff --git a/tools/llvm-objdump/MachODump.cpp b/tools/llvm-objdump/MachODump.cpp
index c43ccc21181..563084856f6 100644
--- a/tools/llvm-objdump/MachODump.cpp
+++ b/tools/llvm-objdump/MachODump.cpp
@@ -1780,10 +1780,6 @@ void llvm::ParseInputMachO(StringRef Filename) {
   llvm_unreachable("Input object can't be invalid at this point");
 }
 
-typedef std::pair<uint64_t, const char *> BindInfoEntry;
-typedef std::vector<BindInfoEntry> BindTable;
-typedef BindTable::iterator bind_table_iterator;
-
 // The block of info used by the Symbolizer call backs.
 struct DisassembleInfo {
   bool verbose;
@@ -1797,7 +1793,7 @@ struct DisassembleInfo {
   char *demangled_name;
   uint64_t adrp_addr;
   uint32_t adrp_inst;
-  BindTable *bindtable;
+  std::unique_ptr<SymbolAddressMap> bindtable;
   uint32_t depth;
 };
 
@@ -5311,9 +5307,6 @@ static void printObjc2_64bit_MetaData(MachOObjectFile *O, bool verbose) {
     II = get_section(O, "__DATA", "__objc_imageinfo");
   info.S = II;
   print_image_info64(II, &info);
-
-  if (info.bindtable != nullptr)
-    delete info.bindtable;
 }
 
 static void printObjc2_32bit_MetaData(MachOObjectFile *O, bool verbose) {
@@ -6841,14 +6834,10 @@ static void DisassembleMachO(StringRef Filename, MachOObjectFile *MachOOF,
       free(SymbolizerInfo.method);
     if (SymbolizerInfo.demangled_name != nullptr)
       free(SymbolizerInfo.demangled_name);
-    if (SymbolizerInfo.bindtable != nullptr)
-      delete SymbolizerInfo.bindtable;
     if (ThumbSymbolizerInfo.method != nullptr)
       free(ThumbSymbolizerInfo.method);
     if (ThumbSymbolizerInfo.demangled_name != nullptr)
       free(ThumbSymbolizerInfo.demangled_name);
-    if (ThumbSymbolizerInfo.bindtable != nullptr)
-      delete ThumbSymbolizerInfo.bindtable;
   }
 }
 
@@ -9427,7 +9416,7 @@ void llvm::printMachOWeakBindTable(const object::MachOObjectFile *Obj) {
 static const char *get_dyld_bind_info_symbolname(uint64_t ReferenceValue,
                                                  struct DisassembleInfo *info) {
   if (info->bindtable == nullptr) {
-    info->bindtable = new (BindTable);
+    info->bindtable = llvm::make_unique<SymbolAddressMap>();
     SegInfo sectionTable(info->O);
     for (const llvm::object::MachOBindEntry &Entry : info->O->bindTable()) {
       uint32_t SegIndex = Entry.segmentIndex();
@@ -9435,21 +9424,11 @@ static const char *get_dyld_bind_info_symbolname(uint64_t ReferenceValue,
       if (!sectionTable.isValidSegIndexAndOffset(SegIndex, OffsetInSeg))
         continue;
       uint64_t Address = sectionTable.address(SegIndex, OffsetInSeg);
-      const char *SymbolName = nullptr;
       StringRef name = Entry.symbolName();
       if (!name.empty())
-        SymbolName = name.data();
-      info->bindtable->push_back(std::make_pair(Address, SymbolName));
-    }
-  }
-  for (bind_table_iterator BI = info->bindtable->begin(),
-                           BE = info->bindtable->end();
-       BI != BE; ++BI) {
-    uint64_t Address = BI->first;
-    if (ReferenceValue == Address) {
-      const char *SymbolName = BI->second;
-      return SymbolName;
+        (*info->bindtable)[Address] = name;
     }
   }
-  return nullptr;
+  auto name = info->bindtable->lookup(ReferenceValue);
+  return !name.empty() ? name.data() : nullptr;
 }