[llvm] r281806 - Don't create a SymbolTable in Function when the LLVMContext discards value names (NFC)

[Mehdi Amini via llvm-commits]

Author: mehdi_amini
Date: Fri Sep 16 22:39:01 2016
New Revision: 281806

URL: http://llvm.org/viewvc/llvm-project?rev=281806&view=rev
Log:
Don't create a SymbolTable in Function when the LLVMContext discards value names (NFC)

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.

Modified:
    llvm/trunk/include/llvm/IR/Function.h
    llvm/trunk/lib/IR/Function.cpp

Modified: llvm/trunk/include/llvm/IR/Function.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/IR/Function.h?rev=281806&r1=281805&r2=281806&view=diff
==============================================================================
--- llvm/trunk/include/llvm/IR/Function.h (original)
+++ llvm/trunk/include/llvm/IR/Function.h Fri Sep 16 22:39:01 2016
@@ -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
 
   /*

Modified: llvm/trunk/lib/IR/Function.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/Function.cpp?rev=281806&r1=281805&r2=281806&view=diff
==============================================================================
--- llvm/trunk/lib/IR/Function.cpp (original)
+++ llvm/trunk/lib/IR/Function.cpp Fri Sep 16 22:39:01 2016
@@ -258,7 +258,10 @@ Function::Function(FunctionType *Ty, Lin
   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();