DBC: Implement TestCids instruction.

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 2040 matching lines @@
     BYTECODE(TestSmi, A_D);
     intptr_t left = reinterpret_cast<intptr_t>(RAW_CAST(Smi, FP[rA]));
     intptr_t right = reinterpret_cast<intptr_t>(RAW_CAST(Smi, FP[rD]));
     if ((left & right) != 0) {
       pc++;
     }
     DISPATCH();
   }
 
   {
+    BYTECODE(TestCids, A_D);
+    intptr_t cid = SimulatorHelpers::GetClassId(FP[rA]);

[Vyacheslav Egorov (Google), 2016/07/07 17:08:28]

const 

[rmacnak, 2016/07/08 00:54:21]

Done.

+    intptr_t num_cases = rD;

[Vyacheslav Egorov (Google), 2016/07/07 17:08:28]

const 

[rmacnak, 2016/07/08 00:54:21]

Done.

+    for (intptr_t i = 0; i < num_cases; i++) {
+      ASSERT(Bytecode::DecodeOpcode(pc[i]) == Bytecode::kNop);
+      intptr_t test_target = Bytecode::DecodeA(pc[i]);
+      intptr_t test_cid = Bytecode::DecodeD(pc[i]);
+      if (cid == test_cid) {
+        if (test_target != 0) {
+          pc += num_cases + 1;  // Match true.

[Vyacheslav Egorov (Google), 2016/07/07 17:08:28]

pc += 1

+        } else {
+          pc += num_cases + 2;  // Match false.

[Vyacheslav Egorov (Google), 2016/07/07 17:08:28]

pc += 2

+        }
+        goto TestCidsOk;

[Vyacheslav Egorov (Google), 2016/07/07 17:08:28]

break

then there is no need for goto.

[rmacnak, 2016/07/08 00:54:21]

Yes, I like that better.

+      }
+    }
+    pc += num_cases;  // No match.
+
+  TestCidsOk:
+    DISPATCH();
+  }
+
+  {
     BYTECODE(CheckSmi, 0);
     intptr_t obj = reinterpret_cast<intptr_t>(FP[rA]);
     if ((obj & kSmiTagMask) == kSmiTag) {
       pc++;
     }
     DISPATCH();
   }
 
   {
     BYTECODE(CheckClassId, A_D);
@@ skipping 383 matching lines @@
   special_[kExceptionSpecialIndex] = raw_exception;
   special_[kStacktraceSpecialIndex] = raw_stacktrace;
   buf->Longjmp();
   UNREACHABLE();
 }
 
 }  // namespace dart
 
 
 #endif  // defined TARGET_ARCH_DBC