It's not necessary to do rounding for alloca operations when the requested
alignment is equal to the stack alignment.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40004 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/IPO/Internalize.cpp b/lib/Transforms/IPO/Internalize.cpp
new file mode 100644
index 0000000..7b5392c
--- /dev/null
+++ b/lib/Transforms/IPO/Internalize.cpp
@@ -0,0 +1,154 @@
+//===-- Internalize.cpp - Mark functions internal -------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This pass loops over all of the functions in the input module, looking for a
+// main function.  If a main function is found, all other functions and all
+// global variables with initializers are marked as internal.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "internalize"
+#include "llvm/Transforms/IPO.h"
+#include "llvm/Pass.h"
+#include "llvm/Module.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/ADT/Statistic.h"
+#include <fstream>
+#include <set>
+using namespace llvm;
+
+STATISTIC(NumFunctions, "Number of functions internalized");
+STATISTIC(NumGlobals  , "Number of global vars internalized");
+
+namespace {
+
+  // APIFile - A file which contains a list of symbols that should not be marked
+  // external.
+  cl::opt<std::string>
+  APIFile("internalize-public-api-file", cl::value_desc("filename"),
+          cl::desc("A file containing list of symbol names to preserve"));
+
+  // APIList - A list of symbols that should not be marked internal.
+  cl::list<std::string>
+  APIList("internalize-public-api-list", cl::value_desc("list"),
+          cl::desc("A list of symbol names to preserve"),
+          cl::CommaSeparated);
+
+  class VISIBILITY_HIDDEN InternalizePass : public ModulePass {
+    std::set<std::string> ExternalNames;
+    bool DontInternalize;
+  public:
+    static char ID; // Pass identification, replacement for typeid
+    InternalizePass(bool InternalizeEverything = true);
+    InternalizePass(const std::vector <const char *>& exportList);
+    void LoadFile(const char *Filename);
+    virtual bool runOnModule(Module &M);
+  };
+  char InternalizePass::ID = 0;
+  RegisterPass<InternalizePass> X("internalize", "Internalize Global Symbols");
+} // end anonymous namespace
+
+InternalizePass::InternalizePass(bool InternalizeEverything) 
+  : ModulePass((intptr_t)&ID), DontInternalize(false){
+  if (!APIFile.empty())           // If a filename is specified, use it
+    LoadFile(APIFile.c_str());
+  else if (!APIList.empty())      // Else, if a list is specified, use it.
+    ExternalNames.insert(APIList.begin(), APIList.end());
+  else if (!InternalizeEverything)
+    // Finally, if we're allowed to, internalize all but main.
+    DontInternalize = true;
+}
+
+InternalizePass::InternalizePass(const std::vector<const char *>&exportList) 
+  : ModulePass((intptr_t)&ID), DontInternalize(false){
+  for(std::vector<const char *>::const_iterator itr = exportList.begin();
+        itr != exportList.end(); itr++) {
+    ExternalNames.insert(*itr);
+  }
+}
+
+void InternalizePass::LoadFile(const char *Filename) {
+  // Load the APIFile...
+  std::ifstream In(Filename);
+  if (!In.good()) {
+    cerr << "WARNING: Internalize couldn't load file '" << Filename << "'!\n";
+    return;   // Do not internalize anything...
+  }
+  while (In) {
+    std::string Symbol;
+    In >> Symbol;
+    if (!Symbol.empty())
+      ExternalNames.insert(Symbol);
+  }
+}
+
+bool InternalizePass::runOnModule(Module &M) {
+  if (DontInternalize) return false;
+  
+  // If no list or file of symbols was specified, check to see if there is a
+  // "main" symbol defined in the module.  If so, use it, otherwise do not
+  // internalize the module, it must be a library or something.
+  //
+  if (ExternalNames.empty()) {
+    Function *MainFunc = M.getFunction("main");
+    if (MainFunc == 0 || MainFunc->isDeclaration())
+      return false;  // No main found, must be a library...
+    
+    // Preserve main, internalize all else.
+    ExternalNames.insert(MainFunc->getName());
+  }
+  
+  bool Changed = false;
+  
+  // Found a main function, mark all functions not named main as internal.
+  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
+    if (!I->isDeclaration() &&         // Function must be defined here
+        !I->hasInternalLinkage() &&  // Can't already have internal linkage
+        !ExternalNames.count(I->getName())) {// Not marked to keep external?
+      I->setLinkage(GlobalValue::InternalLinkage);
+      Changed = true;
+      ++NumFunctions;
+      DOUT << "Internalizing func " << I->getName() << "\n";
+    }
+  
+  // Never internalize the llvm.used symbol.  It is used to implement
+  // attribute((used)).
+  ExternalNames.insert("llvm.used");
+  
+  // Never internalize anchors used by the machine module info, else the info
+  // won't find them.  (see MachineModuleInfo.)
+  ExternalNames.insert("llvm.dbg.compile_units");
+  ExternalNames.insert("llvm.dbg.global_variables");
+  ExternalNames.insert("llvm.dbg.subprograms");
+  ExternalNames.insert("llvm.global_ctors");
+  ExternalNames.insert("llvm.global_dtors");
+      
+  // Mark all global variables with initializers as internal as well.
+  for (Module::global_iterator I = M.global_begin(), E = M.global_end();
+       I != E; ++I)
+    if (!I->isDeclaration() && !I->hasInternalLinkage() &&
+        !ExternalNames.count(I->getName())) {
+      I->setLinkage(GlobalValue::InternalLinkage);
+      Changed = true;
+      ++NumGlobals;
+      DOUT << "Internalized gvar " << I->getName() << "\n";
+    }
+      
+  return Changed;
+}
+
+ModulePass *llvm::createInternalizePass(bool InternalizeEverything) {
+  return new InternalizePass(InternalizeEverything);
+}
+
+ModulePass *llvm::createInternalizePass(const std::vector <const char *> &el) {
+  return new InternalizePass(el);
+}