Subzero: Emit functions and global initializers in a separate thread.

src/IceTargetLowering.cpp

 //===- subzero/src/IceTargetLowering.cpp - Basic lowering implementation --===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements the skeleton of the TargetLowering class,
@@ skipping 234 matching lines @@
   RegSetMask RegExclude = RegSet_None;
   RegInclude |= RegSet_CallerSave;
   RegInclude |= RegSet_CalleeSave;
   if (hasFramePointer())
     RegExclude |= RegSet_FramePointer;
   LinearScan.init(Kind);
   llvm::SmallBitVector RegMask = getRegisterSet(RegInclude, RegExclude);
   LinearScan.scan(RegMask, RandomizeRegisterAllocation);
 }
 
-TargetDataLowering *TargetDataLowering::createLowering(GlobalContext *Ctx) {
+std::unique_ptr<TargetDataLowering>
+TargetDataLowering::createLowering(GlobalContext *Ctx) {
   // These statements can be #ifdef'd to specialize the code generator
   // to a subset of the available targets.  TODO: use CRTP.
   TargetArch Target = Ctx->getTargetArch();
   if (Target == Target_X8632)
-    return TargetDataX8632::create(Ctx);
+    return std::unique_ptr<TargetDataLowering>(TargetDataX8632::create(Ctx));
 #if 0
   if (Target == Target_X8664)
-    return TargetDataX8664::create(Ctx);
+    return std::unique_ptr<TargetDataLowering>(TargetDataX8664::create(Ctx));
   if (Target == Target_ARM32)
-    return TargetDataARM32::create(Ctx);
+    return std::unique_ptr<TargetDataLowering>(TargetDataARM32::create(Ctx));
   if (Target == Target_ARM64)
-    return TargetDataARM64::create(Ctx);
+    return std::unique_ptr<TargetDataLowering>(TargetDataARM64::create(Ctx));
 #endif
   llvm_unreachable("Unsupported target");
   return nullptr;
 }
 
 TargetDataLowering::~TargetDataLowering() {}
 
 } // end of namespace Ice