Allow dispatch to use a range of Class-ids in tests

runtime/vm/simulator_dbc.cc

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include <setjmp.h>  // NOLINT
 #include <stdlib.h>
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_DBC)
 
@@ skipping 1840 matching lines @@
         *++SP = target;
         pc++;
         break;
       }
     }
     pc += 2 * cids_length;
     DISPATCH();
   }
 
   {
+    BYTECODE(PushPolymorphic3InstanceCall, A_D);
+    const uint8_t argc = rA;
+    const intptr_t cids_length = rD;
+    RawObject** args = SP - argc + 1;
+    const intptr_t receiver_cid = SimulatorHelpers::GetClassId(args[0]);
+    for (intptr_t i = 0; i < 3 * cids_length; i += 3) {
+      // Note unsigned types to get an unsigned range compare.
+      const uintptr_t cid_start = Bytecode::DecodeD(*(pc + i));
+      const uintptr_t cids = Bytecode::DecodeD(*(pc + i + 1));
+      if (receiver_cid - cid_start < cids) {
+        RawFunction* target =
+            RAW_CAST(Function, LOAD_CONSTANT(Bytecode::DecodeD(*(pc + i + 2))));
+        *++SP = target;
+        pc++;
+        break;
+      }
+    }
+    pc += 3 * cids_length;
+    DISPATCH();
+  }
+
+  {
     BYTECODE(NativeBootstrapCall, 0);
     RawFunction* function = FrameFunction(FP);
     RawObject** incoming_args =
         (function->ptr()->num_optional_parameters_ == 0)
             ? FrameArguments(FP, function->ptr()->num_fixed_parameters_)
             : FP;
 
     SimulatorBootstrapNativeCall native_target =
         reinterpret_cast<SimulatorBootstrapNativeCall>(SP[-1]);
     intptr_t argc_tag = reinterpret_cast<intptr_t>(SP[-0]);
@@ skipping 1330 matching lines @@
       }
       pc += cids_length;
     } else {
       pc += cids_length;
       pc += (may_be_smi ? 1 : 0);
     }
     DISPATCH();
   }
 
   {
+    BYTECODE(CheckCids2, A_B_C);
+    const intptr_t raw_value = reinterpret_cast<intptr_t>(FP[rA]);
+    const bool is_smi = ((raw_value & kSmiTagMask) == kSmiTag);
+    const bool may_be_smi = (rB == 1);
+    const intptr_t cids_length = rC;
+    if (LIKELY(!is_smi)) {
+      const intptr_t cid = SimulatorHelpers::GetClassId(FP[rA]);
+      for (intptr_t i = 0; i < cids_length; i += 2) {
+        // Note unsigned type to get unsigned range check below.
+        const uintptr_t cid_start = Bytecode::DecodeD(*(pc + i));
+        const uintptr_t cids = Bytecode::DecodeD(*(pc + i + 1));
+        if (cid - cid_start < cids) {
+          pc++;
+          break;
+        }
+      }
+      pc += cids_length;
+    } else {
+      pc += cids_length;
+      pc += (may_be_smi ? 1 : 0);
+    }
+    DISPATCH();
+  }
+
+  {
     BYTECODE(IfEqStrictTOS, 0);
     SP -= 2;
     if (SP[1] != SP[2]) {
       pc++;
     }
     DISPATCH();
   }
 
   {
     BYTECODE(IfNeStrictTOS, 0);
@@ skipping 544 matching lines @@
     pc_ = pc;
   }
 
   buf->Longjmp();
   UNREACHABLE();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_DBC