Reduce malloc traffic in DwarfAccelTable

- Don't copy offsets into HashData, the underlying vector won't change once the table is finalized.
- Allocate HashData and HashDataContents in a BumpPtrAllocator.
- Allocate string map entries in the same allocator.
- Random cleanups.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154694 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 15 insertions, 22 deletions

diff --git a/lib/CodeGen/AsmPrinter/DwarfAccelTable.h b/lib/CodeGen/AsmPrinter/DwarfAccelTable.h
index 2278d4c784..963b8cdf34 100644
--- a/lib/CodeGen/AsmPrinter/DwarfAccelTable.h
+++ b/lib/CodeGen/AsmPrinter/DwarfAccelTable.h
@@ -15,6 +15,7 @@
 #define CODEGEN_ASMPRINTER_DWARFACCELTABLE_H__
 
 #include "llvm/ADT/StringMap.h"
+#include "llvm/ADT/ArrayRef.h"
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/Support/Dwarf.h"
 #include "llvm/Support/DataTypes.h"
@@ -164,22 +165,12 @@ public:
 
  private:
   struct TableHeaderData {
-    
     uint32_t die_offset_base;
-    std::vector<Atom> Atoms;
+    SmallVector<Atom, 1> Atoms;
+
+    TableHeaderData(ArrayRef<Atom> AtomList, uint32_t offset = 0)
+      : die_offset_base(offset), Atoms(AtomList.begin(), AtomList.end()) { }
 
-    TableHeaderData(std::vector<DwarfAccelTable::Atom> &AtomList,
-                    uint32_t offset = 0) :
-      die_offset_base(offset) {
-      for (size_t i = 0, e = AtomList.size(); i != e; ++i)
-        Atoms.push_back(AtomList[i]);
-    }
-    
-    TableHeaderData(DwarfAccelTable::Atom Atom, uint32_t offset = 0)
-    : die_offset_base(offset) {
-      Atoms.push_back(Atom);
-    }
-    
 #ifndef NDEBUG
     void print (raw_ostream &O) {
       O << "die_offset_base: " << die_offset_base << "\n";
@@ -221,11 +212,11 @@ private:
     StringRef Str;
     uint32_t HashValue;
     MCSymbol *Sym;
-    std::vector<struct HashDataContents*> Data; // offsets
-    HashData(StringRef S) : Str(S) {
+    ArrayRef<HashDataContents*> Data; // offsets
+    HashData(StringRef S, ArrayRef<HashDataContents*> Data)
+      : Str(S), Data(Data) {
       HashValue = DwarfAccelTable::HashDJB(S);
     }
-    void addData(struct HashDataContents *Datum) { Data.push_back(Datum); }
     #ifndef NDEBUG
     void print(raw_ostream &O) {
       O << "Name: " << Str << "\n";
@@ -255,15 +246,18 @@ private:
   void EmitHashes(AsmPrinter *);
   void EmitOffsets(AsmPrinter *, MCSymbol *);
   void EmitData(AsmPrinter *, DwarfDebug *D);
-  
+
+  // Allocator for HashData and HashDataContents.
+  BumpPtrAllocator Allocator;
+
   // Output Variables
   TableHeader Header;
   TableHeaderData HeaderData;
   std::vector<HashData*> Data;
 
   // String Data
-  typedef std::vector<struct HashDataContents*> DataArray;
-  typedef StringMap<DataArray> StringEntries;
+  typedef std::vector<HashDataContents*> DataArray;
+  typedef StringMap<DataArray, BumpPtrAllocator&> StringEntries;
   StringEntries Entries;
 
   // Buckets/Hashes/Offsets
@@ -274,8 +268,7 @@ private:
   
   // Public Implementation
  public:
-  DwarfAccelTable(DwarfAccelTable::Atom);
-  DwarfAccelTable(std::vector<DwarfAccelTable::Atom> &);
+  DwarfAccelTable(ArrayRef<DwarfAccelTable::Atom>);
   ~DwarfAccelTable();
   void AddName(StringRef, DIE*, char = 0);
   void FinalizeTable(AsmPrinter *, const char *);