Subzero: Speed up VariablesMetadata initialization.

src/IceTargetLoweringX8632.cpp

 //===- subzero/src/IceTargetLoweringX8632.cpp - x86-32 lowering -----------===//
 //
 //                        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 TargetLoweringX8632 class, which
@@ skipping 311 matching lines @@
     return;
   Func->placePhiStores();
   if (Func->hasError())
     return;
   Func->deletePhis();
   if (Func->hasError())
     return;
   Func->dump("After Phi lowering");
 
   // Address mode optimization.
-  Func->getVMetadata()->init();
+  Func->getVMetadata()->init(VMK_SingleDefs);
   Func->doAddressOpt();
 
   // Argument lowering
   Func->doArgLowering();
 
   // Target lowering.  This requires liveness analysis for some parts
   // of the lowering decisions, such as compare/branch fusing.  If
   // non-lightweight liveness analysis is used, the instructions need
   // to be renumbered first.  TODO: This renumbering should only be
   // necessary if we're actually calculating live intervals, which we
@@ skipping 22 matching lines @@
   Func->liveness(Liveness_Intervals);
   if (Func->hasError())
     return;
   // Validate the live range computations.  The expensive validation
   // call is deliberately only made when assertions are enabled.
   assert(Func->validateLiveness());
   ComputedLiveRanges = true;
   // The post-codegen dump is done here, after liveness analysis and
   // associated cleanup, to make the dump cleaner and more useful.
   Func->dump("After initial x8632 codegen");
-  Func->getVMetadata()->init();
+  Func->getVMetadata()->init(VMK_All);
   regAlloc();
   if (Func->hasError())
     return;
   Func->dump("After linear scan regalloc");
 
   // Stack frame mapping.
   Func->genFrame();
   if (Func->hasError())
     return;
   Func->dump("After stack frame mapping");
@@ skipping 4131 matching lines @@
   } else if (IsConstant || IsExternal)
     Str << "\t.zero\t" << Size << "\n";
   // Size is part of .comm.
 
   if (IsConstant || HasInitializer || IsExternal)
     Str << "\t.size\t" << MangledName << ", " << Size << "\n";
   // Size is part of .comm.
 }
 
 } // end of namespace Ice