Factor out prelowerPhi for 32-bit targets. Disable adv phi lowering for ARM.

src/IceTargetLoweringARM32.cpp

 //===- subzero/src/IceTargetLoweringARM32.cpp - ARM32 lowering ------------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
 /// This file implements the TargetLoweringARM32 class, which consists almost
 /// entirely of the lowering sequence for each high-level instruction.
 ///
 //===----------------------------------------------------------------------===//
 
 #include "IceTargetLoweringARM32.h"
 
 #include "IceCfg.h"
 #include "IceCfgNode.h"
 #include "IceClFlags.h"
 #include "IceDefs.h"
 #include "IceELFObjectWriter.h"
 #include "IceGlobalInits.h"
 #include "IceInstARM32.h"
 #include "IceLiveness.h"
 #include "IceOperand.h"
+#include "IcePhiLoweringImpl.h"
 #include "IceRegistersARM32.h"
 #include "IceTargetLoweringARM32.def"
 #include "IceUtils.h"
 #include "llvm/Support/MathExtras.h"
 
 namespace Ice {
 
 namespace {
 
 void UnimplementedError(const ClFlags &Flags) {
@@ skipping 2366 matching lines @@
     _cmp(Src0Var, Value);
     _br(Inst->getLabel(I), CondARM32::EQ);
   }
   _br(Inst->getLabelDefault());
 }
 
 void TargetARM32::lowerUnreachable(const InstUnreachable * /*Inst*/) {
   _trap();
 }
 
-// Turn an i64 Phi instruction into a pair of i32 Phi instructions, to
-// preserve integrity of liveness analysis.  Undef values are also
-// turned into zeroes, since loOperand() and hiOperand() don't expect
-// Undef input.
 void TargetARM32::prelowerPhis() {
-  UnimplementedError(Func->getContext()->getFlags());
+  PhiLowering::prelowerPhis32Bit<TargetARM32>(this, Context.getNode(), Func);
 }
 
 // Lower the pre-ordered list of assignments into mov instructions.
 // Also has to do some ad-hoc register allocation as necessary.
 void TargetARM32::lowerPhiAssignments(CfgNode *Node,
                                       const AssignList &Assignments) {
   (void)Node;
   (void)Assignments;
   UnimplementedError(Func->getContext()->getFlags());
 }
@@ skipping 338 matching lines @@
       << ".eabi_attribute 68, 1   @ Tag_Virtualization_use\n";
   if (CPUFeatures.hasFeature(TargetARM32Features::HWDivArm)) {
     Str << ".eabi_attribute 44, 2   @ Tag_DIV_use\n";
   }
   // Technically R9 is used for TLS with Sandboxing, and we reserve it.
   // However, for compatibility with current NaCl LLVM, don't claim that.
   Str << ".eabi_attribute 14, 3   @ Tag_ABI_PCS_R9_use: Not used\n";
 }
 
 } // end of namespace Ice