Subzero. Liveness memory management.

src/IceCfg.cpp

 //===- subzero/src/IceCfg.cpp - Control flow graph implementation ---------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 10 matching lines @@
 #include "IceDefs.h"
 #include "IceELFObjectWriter.h"
 #include "IceGlobalInits.h"
 #include "IceInst.h"
 #include "IceInstVarIter.h"
 #include "IceLiveness.h"
 #include "IceLoopAnalyzer.h"
 #include "IceOperand.h"
 #include "IceTargetLowering.h"
 
+#include <memory>
+#include <utility>
+
 namespace Ice {
 
 Cfg::Cfg(GlobalContext *Ctx, uint32_t SequenceNumber)
     : Ctx(Ctx), SequenceNumber(SequenceNumber),
       VMask(Ctx->getFlags().getVerbose()), FunctionName(),
       NextInstNumber(Inst::NumberInitial), Live(nullptr) {
   Allocator.reset(new ArenaAllocator());
   NodeStrings.reset(new StringPool);
   VarStrings.reset(new StringPool);
   CfgLocalAllocatorScope _(this);
@@ skipping 771 matching lines @@
 // convergence.
 void Cfg::livenessLightweight() {
   TimerMarker T(TimerStack::TT_livenessLightweight, this);
   getVMetadata()->init(VMK_Uses);
   for (CfgNode *Node : Nodes)
     Node->livenessLightweight();
 }
 
 void Cfg::liveness(LivenessMode Mode) {
   TimerMarker T(TimerStack::TT_liveness, this);
-  Live.reset(new Liveness(this, Mode));
+  // Destroying the previous (if any) Liveness information clears the Liveness
+  // allocator TLS pointer.
+  Live = nullptr;
+  Live = Liveness::create(this, Mode);
+
   getVMetadata()->init(VMK_Uses);
   Live->init();
+
   // Initialize with all nodes needing to be processed.
   BitVector NeedToProcess(Nodes.size(), true);
   while (NeedToProcess.any()) {
     // Iterate in reverse topological order to speed up convergence.
     for (CfgNode *Node : reverse_range(Nodes)) {
       if (NeedToProcess[Node->getIndex()]) {
         NeedToProcess[Node->getIndex()] = false;
         bool Changed = Node->liveness(getLiveness());
         if (Changed) {
           // If the beginning-of-block liveness changed since the last
@@ skipping 312 matching lines @@
     }
   }
   // Print each basic block
   for (CfgNode *Node : Nodes)
     Node->dump(this);
   if (isVerbose(IceV_Instructions))
     Str << "}\n";
 }
 
 } // end of namespace Ice