From: Owen Anderson <resistor@mac.com>
Date: Thu, 20 Aug 2009 18:26:03 +0000 (+0000)
Subject: Make the StructType->StructLayout table private to TargetData, allowing us to avoid... 
X-Git-Url: http://plrg.eecs.uci.edu/git/?p=oota-llvm.git;a=commitdiff_plain;h=d9b207122eeb740a3878f8389cb38b81d9388734

Make the StructType->StructLayout table private to TargetData, allowing us to avoid locking on it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79555 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/llvm/Target/TargetData.h b/include/llvm/Target/TargetData.h
index 23775be70f9..b0ea291249a 100644
--- a/include/llvm/Target/TargetData.h
+++ b/include/llvm/Target/TargetData.h
@@ -91,6 +91,9 @@ private:
    */
   static const TargetAlignElem InvalidAlignmentElem;
 
+  /// Opaque pointer for the StructType -> StructLayout map
+  void* LayoutMap;
+
   //! Set/initialize target alignments
   void setAlignment(AlignTypeEnum align_type, unsigned char abi_align,
                     unsigned char pref_align, uint32_t bit_width);
@@ -107,6 +110,9 @@ private:
     return (&align != &InvalidAlignmentElem);
   }
 
+  // DO NOT IMPLEMENT
+  void operator=(const TargetData&);
+  
 public:
   /// Default ctor.
   ///
@@ -118,22 +124,11 @@ public:
   }
 
   /// Constructs a TargetData from a specification string. See init().
-  explicit TargetData(const std::string &TargetDescription)
-    : ImmutablePass(&ID) {
-    init(TargetDescription);
-  }
+  explicit TargetData(const std::string &TargetDescription);
 
   /// Initialize target data from properties stored in the module.
   explicit TargetData(const Module *M);
-
-  TargetData(const TargetData &TD) :
-    ImmutablePass(&ID),
-    LittleEndian(TD.isLittleEndian()),
-    PointerMemSize(TD.PointerMemSize),
-    PointerABIAlign(TD.PointerABIAlign),
-    PointerPrefAlign(TD.PointerPrefAlign),
-    Alignments(TD.Alignments)
-  { }
+  TargetData(const TargetData &TD);
 
   ~TargetData();  // Not virtual, do not subclass this class
 
diff --git a/lib/Target/TargetData.cpp b/lib/Target/TargetData.cpp
index baef9c8fa74..43f0ac8a94d 100644
--- a/lib/Target/TargetData.cpp
+++ b/lib/Target/TargetData.cpp
@@ -24,7 +24,6 @@
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/ManagedStatic.h"
 #include "llvm/Support/ErrorHandling.h"
-#include "llvm/System/Mutex.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/StringExtras.h"
 #include <algorithm>
@@ -132,6 +131,8 @@ const TargetAlignElem TargetData::InvalidAlignmentElem =
 //                       TargetData Class Implementation
 //===----------------------------------------------------------------------===//
 
+typedef DenseMap<const StructType*, StructLayout*> LayoutInfoTy;
+
 /*!
  A TargetDescription string consists of a sequence of hyphen-delimited
  specifiers for target endianness, pointer size and alignments, and various
@@ -170,6 +171,7 @@ const TargetAlignElem TargetData::InvalidAlignmentElem =
  alignment will be used.
  */ 
 void TargetData::init(const std::string &TargetDescription) {
+  LayoutMap = static_cast<void*>(new LayoutInfoTy());
   std::string temp = TargetDescription;
   
   LittleEndian = false;
@@ -234,11 +236,28 @@ void TargetData::init(const std::string &TargetDescription) {
   }
 }
 
+TargetData::TargetData(const std::string &TargetDescription)
+  : ImmutablePass(&ID) {
+  init(TargetDescription);
+}
+
 TargetData::TargetData(const Module *M) 
   : ImmutablePass(&ID) {
   init(M->getDataLayout());
 }
 
+TargetData::TargetData(const TargetData &TD) :
+    ImmutablePass(&ID),
+    LittleEndian(TD.isLittleEndian()),
+    PointerMemSize(TD.PointerMemSize),
+    PointerABIAlign(TD.PointerABIAlign),
+    PointerPrefAlign(TD.PointerPrefAlign),
+    Alignments(TD.Alignments) {
+  LayoutInfoTy *Other = static_cast<LayoutInfoTy*>(TD.LayoutMap);
+  LayoutMap = static_cast<void*>(new LayoutInfoTy(*Other));
+}
+
+
 void
 TargetData::setAlignment(AlignTypeEnum align_type, unsigned char abi_align,
                          unsigned char pref_align, uint32_t bit_width) {
@@ -317,61 +336,26 @@ unsigned TargetData::getAlignmentInfo(AlignTypeEnum AlignType,
                  : Alignments[BestMatchIdx].PrefAlign;
 }
 
-namespace {
-
-/// LayoutInfo - The lazy cache of structure layout information maintained by
-/// TargetData.  Note that the struct types must have been free'd before
-/// llvm_shutdown is called (and thus this is deallocated) because all the
-/// targets with cached elements should have been destroyed.
-///
-typedef std::pair<const TargetData*,const StructType*> LayoutKey;
-
-struct DenseMapLayoutKeyInfo {
-  static inline LayoutKey getEmptyKey() { return LayoutKey(0, 0); }
-  static inline LayoutKey getTombstoneKey() {
-    return LayoutKey((TargetData*)(intptr_t)-1, 0);
-  }
-  static unsigned getHashValue(const LayoutKey &Val) {
-    return DenseMapInfo<void*>::getHashValue(Val.first) ^
-           DenseMapInfo<void*>::getHashValue(Val.second);
-  }
-  static bool isEqual(const LayoutKey &LHS, const LayoutKey &RHS) {
-    return LHS == RHS;
-  }
-
-  static bool isPod() { return true; }
-};
-
-typedef DenseMap<LayoutKey, StructLayout*, DenseMapLayoutKeyInfo> LayoutInfoTy;
-
-}
-
-static ManagedStatic<LayoutInfoTy> LayoutInfo;
-static ManagedStatic<sys::SmartMutex<true> > LayoutLock;
-
 TargetData::~TargetData() {
-  if (!LayoutInfo.isConstructed())
-    return;
-  
-  sys::SmartScopedLock<true> Lock(*LayoutLock);
+  assert(LayoutMap && "LayoutMap not initialized?");
+  LayoutInfoTy &TheMap = *static_cast<LayoutInfoTy*>(LayoutMap);
+
   // Remove any layouts for this TD.
-  LayoutInfoTy &TheMap = *LayoutInfo;
   for (LayoutInfoTy::iterator I = TheMap.begin(), E = TheMap.end(); I != E; ) {
-    if (I->first.first == this) {
-      I->second->~StructLayout();
-      free(I->second);
-      TheMap.erase(I++);
-    } else {
-      ++I;
-    }
+    I->second->~StructLayout();
+    free(I->second);
+    TheMap.erase(I++);
   }
+  
+  delete static_cast<LayoutInfoTy*>(LayoutMap);
+  LayoutMap = 0;
 }
 
 const StructLayout *TargetData::getStructLayout(const StructType *Ty) const {
-  LayoutInfoTy &TheMap = *LayoutInfo;
+  assert(LayoutMap && "LayoutMap not initialized?");
+  LayoutInfoTy &TheMap = *static_cast<LayoutInfoTy*>(LayoutMap);
   
-  sys::SmartScopedLock<true> Lock(*LayoutLock);
-  StructLayout *&SL = TheMap[LayoutKey(this, Ty)];
+  StructLayout *&SL = TheMap[Ty];
   if (SL) return SL;
 
   // Otherwise, create the struct layout.  Because it is variable length, we 
@@ -393,10 +377,9 @@ const StructLayout *TargetData::getStructLayout(const StructType *Ty) const {
 /// removed, this method must be called whenever a StructType is removed to
 /// avoid a dangling pointer in this cache.
 void TargetData::InvalidateStructLayoutInfo(const StructType *Ty) const {
-  if (!LayoutInfo.isConstructed()) return;  // No cache.
-  
-  sys::SmartScopedLock<true> Lock(*LayoutLock);
-  LayoutInfoTy::iterator I = LayoutInfo->find(LayoutKey(this, Ty));
+  assert(LayoutMap && "LayoutMap not initialized?");
+  LayoutInfoTy *LayoutInfo = static_cast<LayoutInfoTy*>(LayoutMap);
+  LayoutInfoTy::iterator I = LayoutInfo->find(Ty);
   if (I == LayoutInfo->end()) return;
   
   I->second->~StructLayout();