Cleanup: Make CheckClassId instruction more general so it

runtime/vm/il_printer.cc

Index: runtime/vm/il_printer.cc
diff --git a/runtime/vm/il_printer.cc b/runtime/vm/il_printer.cc
index 78821fc699b4385a5f02469d1e4eee5ea799c365..70037272f2085f9ae670c4bf08031bc546971214 100644
--- a/runtime/vm/il_printer.cc
+++ b/runtime/vm/il_printer.cc
@@ -212,7 +212,7 @@ static void PrintTargetsHelper(BufferFormatter* f,
     if (i > 0) {
       f->Print(" | ");
     }
-    if (range.cid_start == range.cid_end) {
+    if (range.IsSingleCid()) {
       const Class& cls =
           Class::Handle(Isolate::Current()->class_table()->At(range.cid_start));
       f->Print("%s", String::Handle(cls.Name()).ToCString());
@@ -249,7 +249,7 @@ static void PrintCidsHelper(BufferFormatter* f,
     const Class& cls =
         Class::Handle(Isolate::Current()->class_table()->At(range.cid_start));
     f->Print("%s etc. ", String::Handle(cls.Name()).ToCString());
-    if (range.cid_start == range.cid_end) {
+    if (range.IsSingleCid()) {
       f->Print(" cid %" Pd, range.cid_start);
     } else {
       f->Print(" cid %" Pd "-%" Pd, range.cid_start, range.cid_end);
@@ -1055,8 +1055,14 @@ void CheckClassIdInstr::PrintOperandsTo(BufferFormatter* f) const {
   value()->PrintTo(f);
 
   const Class& cls =
-      Class::Handle(Isolate::Current()->class_table()->At(cid()));
-  f->Print(", %s", String::Handle(cls.ScrubbedName()).ToCString());
+      Class::Handle(Isolate::Current()->class_table()->At(cids().cid_start));
+  const String& name = String::Handle(cls.ScrubbedName());
+  if (cids().IsSingleCid()) {
+    f->Print(", %s", name.ToCString());
+  } else {
+    f->Print(", cid %" Pd "-%" Pd " %s etc.", cids().cid_start, cids().cid_end,
+             name.ToCString());

[kustermann, 2017/05/18 09:59:45]

Consider either removing the name in this case, or print the name for both ends
of the interval (i.e. "cids().cid_start" and "cids().cid_end")

[erikcorry, 2017/05/18 14:25:30]

Done.

+  }
 }