Make the Integer32 type info only cover the signed 32 bit integers....

src/arm/codegen-arm.cc

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1204 matching lines @@
         __ mov(tos, Operand(tos, LSL, scratch));          // Shift constant.
         deferred->BindExit();
         TypeInfo result = TypeInfo::Integer32();
         frame_->EmitPush(tos, result);
         break;
       }
       // Fall through!
     case Token::SHR:
     case Token::SAR: {
       ASSERT(!reversed);
-      TypeInfo result = TypeInfo::Integer32();
+      TypeInfo result =
+          (op == Token::SAR) ? TypeInfo::Integer32() : TypeInfo::Number();
+      if (!reversed) {
+        if (op == Token::SHR) {
+          if (int_value >= 2) {
+            result = TypeInfo::Smi();
+          } else if (int_value >= 1) {
+            result = TypeInfo::Integer32();
+          }
+        } else {
+          if (int_value >= 1) {
+            result = TypeInfo::Smi();
+          }
+        }
+      }
       Register scratch = VirtualFrame::scratch0();
       Register scratch2 = VirtualFrame::scratch1();
       int shift_value = int_value & 0x1f;  // least significant 5 bits
       DeferredCode* deferred =
         new DeferredInlineSmiOperation(op, shift_value, false, mode, tos);
       uint32_t problematic_mask = kSmiTagMask;
       // For unsigned shift by zero all negative smis are problematic.
       bool skip_smi_test = both_sides_are_smi;
       if (shift_value == 0 && op == Token::SHR) {
         problematic_mask |= 0x80000000;
@@ skipping 10428 matching lines @@
   __ bind(&string_add_runtime);
   __ TailCallRuntime(Runtime::kStringAdd, 2, 1);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM