Introduction of improved switch lowering.

src/IceClFlags.cpp

Index: src/IceClFlags.cpp
diff --git a/src/IceClFlags.cpp b/src/IceClFlags.cpp
index f1aebd2dfc42a9fb1724a543f122a702377027ec..22fac2a3dafabe0c78a282ac0d484f57b44351f5 100644
--- a/src/IceClFlags.cpp
+++ b/src/IceClFlags.cpp
@@ -178,6 +178,9 @@ cl::opt<std::string>
 
 cl::opt<bool> UseSandboxing("sandbox", cl::desc("Use sandboxing"));
 
+cl::opt<bool> UseAdvancedSwitchLowering("adv-switch",
+    cl::desc("Use advanced switch lowering"));
+
 cl::opt<std::string> VerboseFocusOn(
     "verbose-focus",
     cl::desc("Temporarily enable full verbosity for a specific function"),
@@ -342,6 +345,7 @@ void ClFlags::resetClFlags(ClFlags &OutFlags) {
   OutFlags.SubzeroTimingEnabled = false;
   OutFlags.TimeEachFunction = false;
   OutFlags.UseSandboxing = false;
+  OutFlags.UseAdvancedSwitchLowering = false;
   // Enum and integer fields.
   OutFlags.Opt = Opt_m1;
   OutFlags.OutFileType = FT_Iasm;
@@ -403,6 +407,7 @@ void ClFlags::getParsedClFlags(ClFlags &OutFlags) {
   OutFlags.setTimingFocusOn(::TimingFocusOn);
   OutFlags.setTranslateOnly(::TranslateOnly);
   OutFlags.setUseSandboxing(::UseSandboxing);
+  OutFlags.setUseAdvancedSwitchLowering(::UseAdvancedSwitchLowering);
   OutFlags.setVerboseFocusOn(::VerboseFocusOn);
   OutFlags.setOutFileType(::OutFileType);
   OutFlags.setMaxNopsPerInstruction(::MaxNopsPerInstruction);