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

src/IceClFlags.cpp

 //===- subzero/src/IceClFlags.cpp - Command line flags and parsing --------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 372 matching lines @@
   OutFlags.setDefaultFunctionPrefix(::DefaultFunctionPrefix);
   OutFlags.setDefaultGlobalPrefix(::DefaultGlobalPrefix);
   OutFlags.setDisableInternal(::DisableInternal);
   OutFlags.setDisableIRGeneration(::DisableIRGeneration);
   OutFlags.setDisableTranslation(::DisableTranslation);
   OutFlags.setDumpStats(::DumpStats);
   OutFlags.setEnableBlockProfile(::EnableBlockProfile);
   OutFlags.setFunctionSections(::FunctionSections);
   OutFlags.setNumTranslationThreads(::NumThreads);
   OutFlags.setOptLevel(::OLevel);
-  OutFlags.setPhiEdgeSplit(::EnablePhiEdgeSplit);
+  if (::TargetArch == Target_ARM32) {
+    // TODO(jvoung): We need lowerPhiAssignments to handle spilling
+    // more than one register, since some ARM lowerAssign sequences
+    // may require more than one register. For now, disable PhiEdgeSplit
+    // to avoid requiring lowerPhiAssignments.
+    OutFlags.setPhiEdgeSplit(false);
+  } else {
+    OutFlags.setPhiEdgeSplit(::EnablePhiEdgeSplit);
+  }
   OutFlags.setRandomSeed(::RandomSeed);
   OutFlags.setShouldDoNopInsertion(::ShouldDoNopInsertion);
   OutFlags.setShouldRandomizeRegAlloc(::RandomizeRegisterAllocation);
   OutFlags.setSkipUnimplemented(::SkipUnimplemented);
   OutFlags.setSubzeroTimingEnabled(::SubzeroTimingEnabled);
   OutFlags.setTargetArch(::TargetArch);
   OutFlags.setTargetInstructionSet(::TargetInstructionSet);
   OutFlags.setTestPrefix(::TestPrefix);
   OutFlags.setTimeEachFunction(::TimeEachFunction);
   OutFlags.setTimingFocusOn(::TimingFocusOn);
@@ skipping 28 matching lines @@
   OutFlagsExtra.setGenerateBuildAtts(GenerateBuildAtts);
   OutFlagsExtra.setLLVMVerboseErrors(LLVMVerboseErrors);
   OutFlagsExtra.setAppName(AppName);
   OutFlagsExtra.setInputFileFormat(InputFileFormat);
   OutFlagsExtra.setIRFilename(IRFilename);
   OutFlagsExtra.setLogFilename(LogFilename);
   OutFlagsExtra.setOutputFilename(OutputFilename);
 }
 
 } // end of namespace Ice