DBC: Eager deoptimization and CheckSmi instruction.

runtime/vm/constants_dbc.h

 // 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.
 
 #ifndef VM_CONSTANTS_DBC_H_
 #define VM_CONSTANTS_DBC_H_
 
 #include "platform/globals.h"
 #include "platform/assert.h"
 #include "platform/utils.h"
@@ skipping 305 matching lines @@
 //
 //  - AssertAssignable D
 //
 //    Assert that SP[-3] is assignable to variable named SP[0] of type
 //    SP[-1] with type arguments SP[-2] using SubtypeTestCache PP[D].
 //
 //  - AssertBoolean A
 //
 //    Assert that TOS is a boolean (A = 1) or that TOS is not null (A = 0).
 //
+//  - CheckSmi rA
+//
+//    If FP[rA] is a Smi, then skip the next instruction.
+//
 //  - CheckStack
 //
 //    Compare SP against isolate stack limit and call StackOverflow handler if
 //    necessary.
 //
 //  - DebugStep, DebugBreak A
 //
 //    Debugger support. DebugBreak is bytecode that can be patched into the
 //    instruction stream to trigger in place breakpoint.
 //
@@ skipping 16 matching lines @@
 //    If D == 0 then trigger lazy deoptimization.
 //
 //    The meaning of operand ArgC (encoded as A operand) matches that of an
 //    ArgC operand in call instructions. This is needed because we could
 //    potentially patch calls instructions with a lazy deopt and we need to
 //    ensure that any Return/ReturnTOS instructions
 //    returning from the patched calls will continue to function,
 //    e.g. in bytecode sequences like
 //
 //    InstanceCall ... <- lazy deopt inside first call
-//    InstanceCall ... <- patches seconds call with Deopt
+//    InstanceCall ... <- patches second call with Deopt
 //
 // BYTECODE LIST FORMAT
 //
 // Bytecode list below is specified using the following format:
 //
 //     V(BytecodeName, OperandForm, Op1, Op2, Op3)
 //
 // - OperandForm specifies operand encoding and should be one of 0, A, T, A_D,
 //   A_X, X, D (see ENCODING section above).
 //
@@ skipping 73 matching lines @@
   V(EntryOptimized,                A_D, num, num, ___) \
   V(Frame,                           D, num, ___, ___) \
   V(SetFrame,                        A, num, ___, num) \
   V(AllocateContext,                 D, num, ___, ___) \
   V(CloneContext,                    0, ___, ___, ___) \
   V(MoveSpecial,                   A_D, reg, num, ___) \
   V(InstantiateType,                 D, lit, ___, ___) \
   V(InstantiateTypeArgumentsTOS,   A_D, num, lit, ___) \
   V(AssertAssignable,                D, num, lit, ___) \
   V(AssertBoolean,                   A, num, ___, ___) \
+  V(CheckSmi,                        A, reg, ___, ___) \
   V(CheckStack,                      0, ___, ___, ___) \
   V(DebugStep,                       0, ___, ___, ___) \
   V(DebugBreak,                      A, num, ___, ___) \
   V(Deopt,                         A_D, num, num, ___) \
 
 typedef uint32_t Instr;
 
 class Bytecode {
  public:
   enum Opcode {
@@ skipping 102 matching lines @@
   kNumberOfDummyFpuRegisters,
 };
 const FpuRegister FpuTMP = kFakeFpuRegister;
 const intptr_t kNumberOfFpuRegisters = 1;
 
 enum Condition { EQ, NE };
 
 }  // namespace dart
 
 #endif  // VM_CONSTANTS_DBC_H_