[turbofan] CheckBounds with Unsigned32 inputs is also supported.

src/compiler/simplified-lowering.cc

Index: src/compiler/simplified-lowering.cc
diff --git a/src/compiler/simplified-lowering.cc b/src/compiler/simplified-lowering.cc
index 58c0bf02a4082188df13d40d47320eac9c417418..f9c2a6d67cc57c2cf10cff43375905c9deca736e 100644
--- a/src/compiler/simplified-lowering.cc
+++ b/src/compiler/simplified-lowering.cc
@@ -1810,8 +1810,14 @@ class RepresentationSelector {
       }
 
       case IrOpcode::kCheckBounds: {
-        VisitBinop(node, UseInfo::CheckedSigned32AsWord32(),
-                   UseInfo::TruncatingWord32(), MachineRepresentation::kWord32);
+        if (BothInputsAreUnsigned32(node)) {

[Jarin, 2016/07/11 12:31:58]

Is not it sufficient to check that the first input is Unsigned32?

I also think you can check TypeOf here. No?

[Benedikt Meurer, 2016/07/11 12:52:00]

Done, thanks.

+          VisitBinop(node, UseInfo::TruncatingWord32(),
+                     MachineRepresentation::kWord32);
+        } else {
+          VisitBinop(node, UseInfo::CheckedSigned32AsWord32(),
+                     UseInfo::TruncatingWord32(),
+                     MachineRepresentation::kWord32);
+        }
         return;
       }
       case IrOpcode::kCheckIf: {