Move the data layout computation to TargetParser so clang can use it

Author: rnk

llvm/benchmarks/RuntimeLibcalls.cpp

@@ -54,10 +54,7 @@ static std::vector<std::string> readSymbolsFromFile(StringRef InputFile) {
   // Hackily figure out if there's a prefix on the symbol names - llvm-nm
   // appears to not have a flag to skip this.
   llvm::Triple HostTriple(LLVM_HOST_TRIPLE);
-  std::string DummyDatalayout = "e";
-  DummyDatalayout += DataLayout::getManglingComponent(HostTriple);
-
-  DataLayout DL(DummyDatalayout);
+  DataLayout DL(HostTriple.computeDataLayout());
   char GlobalPrefix = DL.getGlobalPrefix();
 
   std::vector<std::string> Lines;

llvm/include/llvm/IR/DataLayout.h

@@ -194,12 +194,6 @@ class DataLayout {
   /// description on failure.
   LLVM_ABI static Expected<DataLayout> parse(StringRef LayoutString);
 
-  /// Given an LLVM target triple, compute the well-known datalayout string.
-  /// TODO: Create a static factor helper version of this method and refactor
-  /// the TargetMachine callers to use it.
-  LLVM_ABI static std::string computeStringForTriple(const Triple &T,
-                                                     StringRef ABIName = "");
-
   /// Layout endianness...
   bool isLittleEndian() const { return !BigEndian; }
   bool isBigEndian() const { return BigEndian; }
@@ -309,8 +303,6 @@ class DataLayout {
     llvm_unreachable("invalid mangling mode");
   }
 
-  LLVM_ABI static const char *getManglingComponent(const Triple &T);
-
   /// Returns true if the specified type fits in a native integer type
   /// supported by the CPU.
   ///

llvm/include/llvm/TargetParser/Triple.h

@@ -1327,6 +1327,10 @@ class Triple {
                                            const VersionTuple &Version);
 
   LLVM_ABI ExceptionHandling getDefaultExceptionHandling() const;
+
+  /// Compute the LLVM IR data layout string based on the triple. Some targets
+  /// customize the layout based on the ABIName string.
+  LLVM_ABI std::string computeDataLayout(StringRef ABIName = "") const;
 };
 
 } // End llvm namespace