Store a DataLayout in Module.

Now that DataLayout is not a pass, store one in Module.

Since the C API expects to be able to get a char* to the datalayout description,
we have to keep a std::string somewhere. This patch keeps it in Module and also
uses it to represent modules without a DataLayout.

Once DataLayout is mandatory, we should probably move the string to DataLayout
itself since it won't be necessary anymore to represent the special case of a
module without a DataLayout.

llvm-svn: 202190

llvm/include/llvm/IR/Module.h

@@ -16,6 +16,7 @@
 #define LLVM_IR_MODULE_H
 
 #include "llvm/ADT/OwningPtr.h"
+#include "llvm/IR/DataLayout.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/GlobalAlias.h"
 #include "llvm/IR/GlobalVariable.h"
@@ -199,9 +200,16 @@ private:
   OwningPtr<GVMaterializer> Materializer;  ///< Used to materialize GlobalValues
   std::string ModuleID;           ///< Human readable identifier for the module
   std::string TargetTriple;       ///< Platform target triple Module compiled on
-  std::string DataLayout;         ///< Target data description
   void *NamedMDSymTab;            ///< NamedMDNode names.
 
+  // We need to keep the string because the C API expects us to own the string
+  // representation.
+  // Since we have it, we also use an empty string to represent a module without
+  // a DataLayout. If it has a DataLayout, these variables are in sync and the
+  // string is just a cache of getDataLayout()->getStringRepresentation().
+  std::string DataLayoutStr;
+  DataLayout DL;
+
   friend class Constant;
 
 /// @}
@@ -222,10 +230,12 @@ public:
   /// @returns the module identifier as a string
   const std::string &getModuleIdentifier() const { return ModuleID; }
 
-  /// Get the data layout string for the module's target platform.  This encodes
-  /// the type sizes and alignments expected by this module.
-  /// @returns the data layout as a string
-  const std::string &getDataLayout() const { return DataLayout; }
+  /// Get the data layout string for the module's target platform. This is
+  /// equivalent to getDataLayout()->getStringRepresentation().
+  const std::string &getDataLayoutStr() const { return DataLayoutStr; }
+
+  /// Get the data layout for the module's target platform.
+  const DataLayout *getDataLayout() const;
 
   /// Get the target triple which is a string describing the target host.
   /// @returns a string containing the target triple.
@@ -247,7 +257,8 @@ public:
   void setModuleIdentifier(StringRef ID) { ModuleID = ID; }
 
   /// Set the data layout
-  void setDataLayout(StringRef DL) { DataLayout = DL; }
+  void setDataLayout(StringRef Desc);
+  void setDataLayout(const DataLayout *Other);
 
   /// Set the target triple.
   void setTargetTriple(StringRef T) { TargetTriple = T; }

llvm/lib/Bitcode/Writer/BitcodeWriter.cpp

@@ -530,9 +530,9 @@ static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
   if (!M->getTargetTriple().empty())
     WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
                       0/*TODO*/, Stream);
-  if (!M->getDataLayout().empty())
-    WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
-                      0/*TODO*/, Stream);
+  const std::string &DL = M->getDataLayoutStr();
+  if (!DL.empty())
+    WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, DL, 0 /*TODO*/, Stream);
   if (!M->getModuleInlineAsm().empty())
     WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
                       0/*TODO*/, Stream);

llvm/lib/IR/AsmWriter.cpp

@@ -1252,8 +1252,9 @@ void AssemblyWriter::printModule(const Module *M) {
       M->getModuleIdentifier().find('\n') == std::string::npos)
     Out << "; ModuleID = '" << M->getModuleIdentifier() << "'\n";
 
-  if (!M->getDataLayout().empty())
-    Out << "target datalayout = \"" << M->getDataLayout() << "\"\n";
+  const std::string &DL = M->getDataLayoutStr();
+  if (!DL.empty())
+    Out << "target datalayout = \"" << DL << "\"\n";
   if (!M->getTargetTriple().empty())
     Out << "target triple = \"" << M->getTargetTriple() << "\"\n";
 

llvm/lib/IR/Core.cpp

@@ -107,7 +107,7 @@ void LLVMDisposeModule(LLVMModuleRef M) {
 
 /*--.. Data layout .........................................................--*/
 const char * LLVMGetDataLayout(LLVMModuleRef M) {
-  return unwrap(M)->getDataLayout().c_str();
+  return unwrap(M)->getDataLayoutStr().c_str();
 }
 
 void LLVMSetDataLayout(LLVMModuleRef M, const char *Triple) {

llvm/lib/IR/DataLayout.cpp

@@ -344,7 +344,13 @@ void DataLayout::parseSpecifier(StringRef Desc) {
   }
 }
 
-DataLayout::DataLayout(const Module *M) { init(M->getDataLayout()); }
+DataLayout::DataLayout(const Module *M) {
+  const DataLayout *Other = M->getDataLayout();
+  if (Other)
+    *this = *Other;
+  else
+    init("");
+}
 
 void
 DataLayout::setAlignment(AlignTypeEnum align_type, unsigned abi_align,

llvm/lib/IR/Module.cpp

@@ -42,8 +42,8 @@ template class llvm::SymbolTableListTraits<GlobalAlias, Module>;
 // Primitive Module methods.
 //
 
-Module::Module(StringRef MID, LLVMContext& C)
-  : Context(C), Materializer(NULL), ModuleID(MID) {
+Module::Module(StringRef MID, LLVMContext &C)
+    : Context(C), Materializer(NULL), ModuleID(MID), DL("") {
   ValSymTab = new ValueSymbolTable();
   NamedMDSymTab = new StringMap<NamedMDNode *>();
   Context.addModule(this);
@@ -338,6 +338,30 @@ void Module::addModuleFlag(MDNode *Node) {
   getOrInsertModuleFlagsMetadata()->addOperand(Node);
 }
 
+void Module::setDataLayout(StringRef Desc) {
+  if (Desc.empty()) {
+    DataLayoutStr = "";
+  } else {
+    DL.init(Desc);
+    DataLayoutStr = DL.getStringRepresentation();
+  }
+}
+
+void Module::setDataLayout(const DataLayout *Other) {
+  if (!Other) {
+    DataLayoutStr = "";
+  } else {
+    DL = *Other;
+    DataLayoutStr = DL.getStringRepresentation();
+  }
+}
+
+const DataLayout *Module::getDataLayout() const {
+  if (DataLayoutStr.empty())
+    return 0;
+  return &DL;
+}
+
 //===----------------------------------------------------------------------===//
 // Methods to control the materialization of GlobalValues in the Module.
 //

llvm/lib/Linker/LinkModules.cpp

@@ -1200,14 +1200,14 @@ bool ModuleLinker::run() {
 
   // Inherit the target data from the source module if the destination module
   // doesn't have one already.
-  if (DstM->getDataLayout().empty() && !SrcM->getDataLayout().empty())
+  if (!DstM->getDataLayout() && SrcM->getDataLayout())
     DstM->setDataLayout(SrcM->getDataLayout());
 
   // Copy the target triple from the source to dest if the dest's is empty.
   if (DstM->getTargetTriple().empty() && !SrcM->getTargetTriple().empty())
     DstM->setTargetTriple(SrcM->getTargetTriple());
 
-  if (!SrcM->getDataLayout().empty() && !DstM->getDataLayout().empty() &&
+  if (SrcM->getDataLayout() && DstM->getDataLayout() &&
       SrcM->getDataLayout() != DstM->getDataLayout()) {
     if (!SuppressWarnings) {
       errs() << "WARNING: Linking two modules of different data layouts!\n";

llvm/test/CodeGen/X86/pr1462.ll

@@ -1,8 +1,7 @@
 ; RUN: llc < %s
 ; PR1462
 
-target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-
-v64:64:64-v128:128:128-a0:0:64"
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64"
 target triple = "x86_64-unknown-linux-gnu"
 
 define hidden i128 @__addvti3(i128 %a1, i128 %b2) {

llvm/tools/opt/opt.cpp

@@ -429,11 +429,8 @@ int main(int argc, char **argv) {
   Passes.add(TLI);
 
   // Add an appropriate DataLayout instance for this module.
-  DataLayout *DL = 0;
-  const std::string &ModuleDataLayout = M.get()->getDataLayout();
-  if (!ModuleDataLayout.empty())
-    DL = new DataLayout(ModuleDataLayout);
-  else if (!DefaultDataLayout.empty())
+  const DataLayout *DL = M.get()->getDataLayout();
+  if (!DL && !DefaultDataLayout.empty())
     DL = new DataLayout(DefaultDataLayout);
 
   if (DL)