Don't create a SymbolTable in Function when the LLVMContext discards value names...

The ValueSymbolTable is used to detect name conflict and rename
instructions automatically. This is not needed when the value
names are automatically discarded by the LLVMContext.
No functional change intended, just saving a little bit of memory.

This is a recommit of r281806 after fixing the accessor to return
a pointer instead of a reference and updating all the call-sites.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281813 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/IR/Function.h b/include/llvm/IR/Function.h
index 129ba308004fae7026cb3e25f5791815f6ce8878..44ac826839d0188f543f564dc62e722a7d56ca45 100644 (file)
--- a/include/llvm/IR/Function.h
+++ b/include/llvm/IR/Function.h
@@ -50,7 +50,8 @@ private:
   // Important things that make up a function!
   BasicBlockListType  BasicBlocks;        ///< The basic blocks
   mutable ArgumentListType ArgumentList;  ///< The formal arguments
-  ValueSymbolTable *SymTab;               ///< Symbol table of args/instructions
+  std::unique_ptr<ValueSymbolTable>
+      SymTab;                             ///< Symbol table of args/instructions
   AttributeSet AttributeSets;             ///< Parameter attributes
 
   /*
@@ -493,10 +494,12 @@ public:
   //===--------------------------------------------------------------------===//
   // Symbol Table Accessing functions...
 
-  /// getSymbolTable() - Return the symbol table...
+  /// getSymbolTable() - Return the symbol table if any, otherwise nullptr.
   ///
-  inline       ValueSymbolTable &getValueSymbolTable()       { return *SymTab; }
-  inline const ValueSymbolTable &getValueSymbolTable() const { return *SymTab; }
+  inline ValueSymbolTable *getValueSymbolTable() { return SymTab.get(); }
+  inline const ValueSymbolTable *getValueSymbolTable() const {
+    return SymTab.get();
+  }
 
   //===--------------------------------------------------------------------===//
   // BasicBlock iterator forwarding functions

diff --git a/lib/AsmParser/LLParser.cpp b/lib/AsmParser/LLParser.cpp
index 0e154b265780c754ddb3b32cde0dfd398d1f1e7f..18f5bbe65998abf76ecd3e0464fb38319bfff69b 100644 (file)
--- a/lib/AsmParser/LLParser.cpp
+++ b/lib/AsmParser/LLParser.cpp
@@ -2504,7 +2504,7 @@ bool LLParser::PerFunctionState::FinishFunction() {
 Value *LLParser::PerFunctionState::GetVal(const std::string &Name, Type *Ty,
                                           LocTy Loc) {
   // Look this name up in the normal function symbol table.
-  Value *Val = F.getValueSymbolTable().lookup(Name);
+  Value *Val = F.getValueSymbolTable()->lookup(Name);
 
   // If this is a forward reference for the value, see if we already created a
   // forward ref record.
@@ -2922,7 +2922,7 @@ bool LLParser::ParseValID(ValID &ID, PerFunctionState *PFS) {
         return Error(Label.Loc, "cannot take address of numeric label after "
                                 "the function is defined");
       BB = dyn_cast_or_null<BasicBlock>(
-          F->getValueSymbolTable().lookup(Label.StrVal));
+          F->getValueSymbolTable()->lookup(Label.StrVal));
       if (!BB)
         return Error(Label.Loc, "referenced value is not a basic block");
     }
@@ -6507,7 +6507,7 @@ bool LLParser::ParseUseListOrderBB() {
     return Error(Label.Loc, "invalid numeric label in uselistorder_bb");
   if (Label.Kind != ValID::t_LocalName)
     return Error(Label.Loc, "expected basic block name in uselistorder_bb");
-  Value *V = F->getValueSymbolTable().lookup(Label.StrVal);
+  Value *V = F->getValueSymbolTable()->lookup(Label.StrVal);
   if (!V)
     return Error(Label.Loc, "invalid basic block in uselistorder_bb");
   if (!isa<BasicBlock>(V))

diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp
index da6a89103187c65b06305a1c9691b5e14f1ea003..0fd239f71ccd2e43213ad9887137d10b610f5bf1 100644 (file)
--- a/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -2999,7 +2999,8 @@ void ModuleBitcodeWriter::writeFunction(
     }
 
   // Emit names for all the instructions etc.
-  writeValueSymbolTable(F.getValueSymbolTable());
+  if (auto *Symtab = F.getValueSymbolTable())
+    writeValueSymbolTable(*Symtab);
 
   if (NeedsMetadataAttachment)
     writeFunctionMetadataAttachment(F);

diff --git a/lib/CodeGen/MIRParser/MIParser.cpp b/lib/CodeGen/MIRParser/MIParser.cpp
index 2f4410ba7cd5d82f2836f8abf0ff030ab56973bd..915e1098132b4fc0ec3e7a32c6d1fc50dacb1ee2 100644 (file)
--- a/lib/CodeGen/MIRParser/MIParser.cpp
+++ b/lib/CodeGen/MIRParser/MIParser.cpp
@@ -364,7 +364,7 @@ bool MIParser::parseBasicBlockDefinition(
 
   if (!Name.empty()) {
     BB = dyn_cast_or_null<BasicBlock>(
-        MF.getFunction()->getValueSymbolTable().lookup(Name));
+        MF.getFunction()->getValueSymbolTable()->lookup(Name));
     if (!BB)
       return error(Loc, Twine("basic block '") + Name +
                             "' is not defined in the function '" +
@@ -1383,7 +1383,7 @@ bool MIParser::parseIRBlock(BasicBlock *&BB, const Function &F) {
   switch (Token.kind()) {
   case MIToken::NamedIRBlock: {
     BB = dyn_cast_or_null<BasicBlock>(
-        F.getValueSymbolTable().lookup(Token.stringValue()));
+        F.getValueSymbolTable()->lookup(Token.stringValue()));
     if (!BB)
       return error(Twine("use of undefined IR block '") + Token.range() + "'");
     break;
@@ -1729,7 +1729,7 @@ bool MIParser::parseOperandsOffset(MachineOperand &Op) {
 bool MIParser::parseIRValue(const Value *&V) {
   switch (Token.kind()) {
   case MIToken::NamedIRValue: {
-    V = MF.getFunction()->getValueSymbolTable().lookup(Token.stringValue());
+    V = MF.getFunction()->getValueSymbolTable()->lookup(Token.stringValue());
     break;
   }
   case MIToken::IRValue: {

diff --git a/lib/CodeGen/MIRParser/MIRParser.cpp b/lib/CodeGen/MIRParser/MIRParser.cpp
index 9b0c50996800de7be080471577d5339e42cefe9c..519a08f21981600ef853bc13392028b6211b2dd7 100644 (file)
--- a/lib/CodeGen/MIRParser/MIRParser.cpp
+++ b/lib/CodeGen/MIRParser/MIRParser.cpp
@@ -552,7 +552,7 @@ bool MIRParserImpl::initializeFrameInfo(PerFunctionMIParsingState &PFS,
     const yaml::StringValue &Name = Object.Name;
     if (!Name.Value.empty()) {
       Alloca = dyn_cast_or_null<AllocaInst>(
-          F.getValueSymbolTable().lookup(Name.Value));
+          F.getValueSymbolTable()->lookup(Name.Value));
       if (!Alloca)
         return error(Name.SourceRange.Start,
                      "alloca instruction named '" + Name.Value +

diff --git a/lib/IR/BasicBlock.cpp b/lib/IR/BasicBlock.cpp
index 4640b4f9d413cc4fd238ba88cafd0daf114ca14a..19e784923658392a583ce62d9f6f81f40f87ffec 100644 (file)
--- a/lib/IR/BasicBlock.cpp
+++ b/lib/IR/BasicBlock.cpp
@@ -26,7 +26,7 @@ using namespace llvm;
 
 ValueSymbolTable *BasicBlock::getValueSymbolTable() {
   if (Function *F = getParent())
-    return &F->getValueSymbolTable();
+    return F->getValueSymbolTable();
   return nullptr;
 }
 

diff --git a/lib/IR/Function.cpp b/lib/IR/Function.cpp
index fa34158e9c55eb0b49a506646ae0c8ec9c4d891c..f9f33fef4524d2fb396dc9c79ca5237c56c53d02 100644 (file)
--- a/lib/IR/Function.cpp
+++ b/lib/IR/Function.cpp
@@ -258,7 +258,10 @@ Function::Function(FunctionType *Ty, LinkageTypes Linkage, const Twine &name,
   assert(FunctionType::isValidReturnType(getReturnType()) &&
          "invalid return type");
   setGlobalObjectSubClassData(0);
-  SymTab = new ValueSymbolTable();
+
+  // We only need a symbol table for a function if the context keeps value names
+  if (!getContext().shouldDiscardValueNames())
+    SymTab = make_unique<ValueSymbolTable>();
 
   // If the function has arguments, mark them as lazily built.
   if (Ty->getNumParams())
@@ -279,7 +282,6 @@ Function::~Function() {
 
   // Delete all of the method arguments and unlink from symbol table...
   ArgumentList.clear();
-  delete SymTab;
 
   // Remove the function from the on-the-side GC table.
   clearGC();

diff --git a/lib/IR/Value.cpp b/lib/IR/Value.cpp
index a1dfb37bf90e8ab46ae182a42e1a5a5294737157..451cb09ea9f881ec13575b74dc31bbdc1c1a70a3 100644 (file)
--- a/lib/IR/Value.cpp
+++ b/lib/IR/Value.cpp
@@ -143,16 +143,16 @@ static bool getSymTab(Value *V, ValueSymbolTable *&ST) {
   if (Instruction *I = dyn_cast<Instruction>(V)) {
     if (BasicBlock *P = I->getParent())
       if (Function *PP = P->getParent())
-        ST = &PP->getValueSymbolTable();
+        ST = PP->getValueSymbolTable();
   } else if (BasicBlock *BB = dyn_cast<BasicBlock>(V)) {
     if (Function *P = BB->getParent())
-      ST = &P->getValueSymbolTable();
+      ST = P->getValueSymbolTable();
   } else if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
     if (Module *P = GV->getParent())
       ST = &P->getValueSymbolTable();
   } else if (Argument *A = dyn_cast<Argument>(V)) {
     if (Function *P = A->getParent())
-      ST = &P->getValueSymbolTable();
+      ST = P->getValueSymbolTable();
   } else {
     assert(isa<Constant>(V) && "Unknown value type!");
     return true;  // no name is setable for this.

diff --git a/lib/Transforms/IPO/StripSymbols.cpp b/lib/Transforms/IPO/StripSymbols.cpp
index 51c2103e0e5e19476d64793ef67f85123037a606..5cb8ff56584b2f04fc4909f6b4f0675b575508d2 100644 (file)
--- a/lib/Transforms/IPO/StripSymbols.cpp
+++ b/lib/Transforms/IPO/StripSymbols.cpp
@@ -219,7 +219,8 @@ static bool StripSymbolNames(Module &M, bool PreserveDbgInfo) {
     if (I.hasLocalLinkage() && llvmUsedValues.count(&I) == 0)
       if (!PreserveDbgInfo || !I.getName().startswith("llvm.dbg"))
         I.setName(""); // Internal symbols can't participate in linkage
-    StripSymtab(I.getValueSymbolTable(), PreserveDbgInfo);
+    if (auto *Symtab = I.getValueSymbolTable())
+      StripSymtab(*Symtab, PreserveDbgInfo);
   }
 
   // Remove all names from types.

diff --git a/tools/bugpoint/CrashDebugger.cpp b/tools/bugpoint/CrashDebugger.cpp
index e7367392337e98036ad71d4cff507f4ba0328a5e..cdbf57f90e891ee596ffa96f517a38ef7ddad515 100644 (file)
--- a/tools/bugpoint/CrashDebugger.cpp
+++ b/tools/bugpoint/CrashDebugger.cpp
@@ -461,8 +461,7 @@ bool ReduceCrashingBlocks::TestBlocks(std::vector<const BasicBlock *> &BBs) {
     const ValueSymbolTable &GST = M->getValueSymbolTable();
     for (unsigned i = 0, e = BlockInfo.size(); i != e; ++i) {
       Function *F = cast<Function>(GST.lookup(BlockInfo[i].first));
-      ValueSymbolTable &ST = F->getValueSymbolTable();
-      Value *V = ST.lookup(BlockInfo[i].second);
+      Value *V = F->getValueSymbolTable()->lookup(BlockInfo[i].second);
       if (V && V->getType() == Type::getLabelTy(V->getContext()))
         BBs.push_back(cast<BasicBlock>(V));
     }
@@ -572,8 +571,7 @@ bool ReduceCrashingConditionals::TestBlocks(
     const ValueSymbolTable &GST = M->getValueSymbolTable();
     for (auto &BI : BlockInfo) {
       auto *F = cast<Function>(GST.lookup(BI.first));
-      ValueSymbolTable &ST = F->getValueSymbolTable();
-      Value *V = ST.lookup(BI.second);
+      Value *V = F->getValueSymbolTable()->lookup(BI.second);
       if (V && V->getType() == Type::getLabelTy(V->getContext()))
         BBs.push_back(cast<BasicBlock>(V));
     }
@@ -666,8 +664,7 @@ bool ReduceSimplifyCFG::TestBlocks(std::vector<const BasicBlock *> &BBs) {
     const ValueSymbolTable &GST = M->getValueSymbolTable();
     for (auto &BI : BlockInfo) {
       auto *F = cast<Function>(GST.lookup(BI.first));
-      ValueSymbolTable &ST = F->getValueSymbolTable();
-      Value *V = ST.lookup(BI.second);
+      Value *V = F->getValueSymbolTable()->lookup(BI.second);
       if (V && V->getType() == Type::getLabelTy(V->getContext()))
         BBs.push_back(cast<BasicBlock>(V));
     }