Subzero ARM: lowerArguments (GPR), basic legalize(), and lowerRet(i32, i64).

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 207 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, Ctx->getFlags().shouldRandomizeRegAlloc());
 }
 
+void TargetLowering::inferTwoAddress() {
+  // Find two-address non-SSA instructions where Dest==Src0, and set
+  // the DestNonKillable flag to keep liveness analysis consistent.
+  for (auto Inst = Context.getCur(), E = Context.getNext(); Inst != E; ++Inst) {
+    if (Inst->isDeleted())
+      continue;
+    if (Variable *Dest = Inst->getDest()) {
+      // TODO(stichnot): We may need to consider all source
+      // operands, not just the first one, if using 3-address
+      // instructions.
+      if (Inst->getSrcSize() > 0 && Inst->getSrc(0) == Dest)
+        Inst->setDestNonKillable();
+    }
+  }
+}
+
 InstCall *TargetLowering::makeHelperCall(const IceString &Name, Variable *Dest,
                                          SizeT MaxSrcs) {
   const bool HasTailCall = false;
   Constant *CallTarget = Ctx->getConstantExternSym(Name);
   InstCall *Call =
       InstCall::create(Func, MaxSrcs, Dest, CallTarget, HasTailCall);
   return Call;
 }
 
 void TargetLowering::emitWithoutPrefix(const ConstantRelocatable *C) const {
@@ skipping 28 matching lines @@
     return std::unique_ptr<TargetDataLowering>(TargetData##X::create(Ctx));
 #include "llvm/Config/SZTargets.def"
 
   llvm_unreachable("Unsupported target data lowering");
   return nullptr;
 }
 
 TargetDataLowering::~TargetDataLowering() {}
 
 } // end of namespace Ice