Subzero: Improve the representation and handling of the FakeKill instruction.

src/IceInst.cpp

 //===- subzero/src/IceInst.cpp - High-level instruction 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 Inst class, primarily the various
@@ skipping 436 matching lines @@
 }
 
 InstFakeUse::InstFakeUse(Cfg *Func, Variable *Src)
     : InstHighLevel(Func, Inst::FakeUse, 1, NULL) {
   assert(Src);
   addSource(Src);
 }
 
 InstFakeKill::InstFakeKill(Cfg *Func, const VarList &KilledRegs,
                            const Inst *Linked)
-    : InstHighLevel(Func, Inst::FakeKill, KilledRegs.size(), NULL),
-      Linked(Linked) {
-  for (Variable *Var : KilledRegs)
-    addSource(Var);
-}
+    : InstHighLevel(Func, Inst::FakeKill, 0, NULL), KilledRegs(KilledRegs),
+      Linked(Linked) {}
 
 // ======================== Dump routines ======================== //
 
 void Inst::dumpDecorated(const Cfg *Func) const {
   Ostream &Str = Func->getContext()->getStrDump();
   if (!Func->getContext()->isVerbose(IceV_Deleted) &&
       (isDeleted() || isRedundantAssign()))
     return;
   if (Func->getContext()->isVerbose(IceV_InstNumbers)) {
     char buf[30];
@@ skipping 251 matching lines @@
   Str << ", " << FalseOp->getType() << " ";
   FalseOp->dump(Func);
 }
 
 void InstUnreachable::dump(const Cfg *Func) const {
   Ostream &Str = Func->getContext()->getStrDump();
   Str << "unreachable";
 }
 
 void InstFakeDef::emit(const Cfg *Func) const {
+  // Go ahead and "emit" these for now, since they are relatively
+  // rare.
   Ostream &Str = Func->getContext()->getStrEmit();
   Str << "\t# ";
   getDest()->emit(Func);
   Str << " = def.pseudo ";
   emitSources(Func);
 }
 
 void InstFakeDef::dump(const Cfg *Func) const {
   Ostream &Str = Func->getContext()->getStrDump();
   dumpDest(Func);
   Str << " = def.pseudo ";
   dumpSources(Func);
 }
 
-void InstFakeUse::emit(const Cfg *Func) const {
-  Ostream &Str = Func->getContext()->getStrEmit();
-  Str << "\t# ";
-  Str << "use.pseudo ";
-  emitSources(Func);
-}
+void InstFakeUse::emit(const Cfg *Func) const { (void)Func; }
 
 void InstFakeUse::dump(const Cfg *Func) const {
   Ostream &Str = Func->getContext()->getStrDump();
   Str << "use.pseudo ";
   dumpSources(Func);
 }
 
-void InstFakeKill::emit(const Cfg *Func) const {
-  Ostream &Str = Func->getContext()->getStrEmit();
-  Str << "\t# ";
-  if (Linked->isDeleted())
-    Str << "// ";
-  Str << "kill.pseudo ";
-  emitSources(Func);
-}
+void InstFakeKill::emit(const Cfg *Func) const { (void)Func; }
 
 void InstFakeKill::dump(const Cfg *Func) const {
   Ostream &Str = Func->getContext()->getStrDump();
   if (Linked->isDeleted())
     Str << "// ";
   Str << "kill.pseudo ";
-  dumpSources(Func);
+  bool First = true;
+  for (Variable *Var : KilledRegs) {
+    if (!First)
+      Str << ", ";
+    First = false;
+    Var->dump(Func);
+  }
 }
 
 void InstTarget::dump(const Cfg *Func) const {
   Ostream &Str = Func->getContext()->getStrDump();
   Str << "[TARGET] ";
   Inst::dump(Func);
 }
 
 } // end of namespace Ice