DBC: Eager deoptimization and CheckSmi instruction.

runtime/vm/intermediate_language_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 "vm/globals.h"  // Needed here to get TARGET_ARCH_DBC.
 #if defined(TARGET_ARCH_DBC)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/cpu.h"
@@ skipping 90 matching lines @@
   M(ExtractNthOutput)                                                          \
   M(BinaryUint32Op)                                                            \
   M(ShiftUint32Op)                                                             \
   M(UnaryUint32Op)                                                             \
   M(UnboxedIntConverter)                                                       \
   M(GrowRegExpStack)                                                           \
   M(BoxInteger32)                                                              \
   M(UnboxInteger32)                                                            \
   M(CheckedSmiOp)                                                              \
   M(CheckArrayBound)                                                           \
-  M(CheckSmi)                                                                  \
+  M(BinarySmiOp)                                                               \
   M(CheckClassId)                                                              \
   M(CheckClass)                                                                \
-  M(BinarySmiOp)                                                               \
   M(TestSmi)                                                                   \
   M(RelationalOp)                                                              \
   M(EqualityCompare)                                                           \
   M(LoadIndexed)
 
 // Location summaries actually are not used by the unoptimizing DBC compiler
 // because we don't allocate any registers.
 static LocationSummary* CreateLocationSummary(
     Zone* zone,
     intptr_t num_inputs,
@@ skipping 718 matching lines @@
     default:
       UNREACHABLE();
       return kTagged;
   }
 }
 
 
 Representation StoreIndexedInstr::RequiredInputRepresentation(
     intptr_t idx) const {
   // Array can be a Dart object or a pointer to external data.
-  if (idx == 0)  return kNoRepresentation;  // Flexible input representation.
-  if (idx == 1) return kTagged;  // Index is a smi.
+  if (idx == 0) {
+    return kNoRepresentation;  // Flexible input representation.
+  }
+  if (idx == 1) {
+    return kTagged;  // Index is a smi.
+  }
   ASSERT(idx == 2);
   switch (class_id_) {
     case kArrayCid:
     case kOneByteStringCid:
     case kTwoByteStringCid:
     case kExternalOneByteStringCid:
     case kExternalTwoByteStringCid:
     case kTypedDataInt8ArrayCid:
     case kTypedDataUint8ArrayCid:
     case kExternalTypedDataUint8ArrayCid:
@@ skipping 31 matching lines @@
     // environment.
     ASSERT(argc <= values_.length());
     for (intptr_t i = 0; i < argc; i++) {
       ASSERT(values_[values_.length() - i - 1]->definition()->IsPushArgument());
     }
 #endif
     values_.TruncateTo(values_.length() - argc);
 }
 
 
+EMIT_NATIVE_CODE(CheckSmi, 1) {
+  Label* deopt = compiler->AddDeoptStub(deopt_id(),
+                                        ICData::kDeoptCheckSmi,
+                                        licm_hoisted_ ? ICData::kHoisted : 0);
+  __ Push(locs()->in(0).reg());

[zra, 2016/06/07 22:31:28]

Thoughts about adding an instruction for this that just checks the tag?

[Vyacheslav Egorov (Google), 2016/06/08 11:58:53]

Yes, I think this should be just a special bytecode instruction.

[zra, 2016/06/08 17:46:30]

Done.

+  __ LoadClassIdTOS();
+  __ PushConstant(Smi::Handle(Smi::New(kSmiCid)));
+  __ IfNeStrictTOS();
+  __ Jump(deopt);

[Vyacheslav Egorov (Google), 2016/06/08 11:58:53]

__ Jump(deopt) could just be __ Deopt(...)

[zra, 2016/06/08 17:46:30]

Done.

+}
+
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_DBC