DBC: CheckClassInstr

runtime/vm/intermediate_language_dbc.cc

Index: runtime/vm/intermediate_language_dbc.cc
diff --git a/runtime/vm/intermediate_language_dbc.cc b/runtime/vm/intermediate_language_dbc.cc
index d28bbb2c30aff544c47e1e37ad46739edb5d8879..624109c75162901c42aae6502dc36b9b28604ac0 100644
--- a/runtime/vm/intermediate_language_dbc.cc
+++ b/runtime/vm/intermediate_language_dbc.cc
@@ -105,7 +105,6 @@ DECLARE_FLAG(int, optimization_counter_threshold);
   M(UnboxInteger32)                                                            \
   M(CheckedSmiOp)                                                              \
   M(CheckArrayBound)                                                           \
-  M(CheckClass)                                                                \
   M(TestSmi)                                                                   \
   M(RelationalOp)                                                              \
   M(EqualityCompare)                                                           \
@@ -481,6 +480,13 @@ void BranchInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
 
 
 EMIT_NATIVE_CODE(Goto, 0) {
+  if (!compiler->is_optimizing()) {
+    // Add a deoptimization descriptor for deoptimizing instructions that
+    // may be inserted before this instruction.
+    compiler->AddCurrentDescriptor(RawPcDescriptors::kDeopt,
+                                   GetDeoptId(),
+                                   TokenPosition::kNoSource);
+  }
   if (HasParallelMove()) {
     compiler->parallel_move_resolver()->EmitNativeCode(parallel_move());
   }
@@ -945,6 +951,52 @@ EMIT_NATIVE_CODE(CheckClassId, 1) {
 }
 
 
+EMIT_NATIVE_CODE(CheckClass, 1) {
+  const Register value = locs()->in(0).reg();
+  if (IsNullCheck()) {
+    ASSERT(DeoptIfNull() || DeoptIfNotNull());
+    if (DeoptIfNull()) {
+      __ IfEqNull(value);
+    } else {
+      __ IfNeNull(value);
+    }
+  } else {
+    ASSERT((unary_checks().GetReceiverClassIdAt(0) != kSmiCid) ||
+           (unary_checks().NumberOfChecks() > 1));
+    const intptr_t may_be_smi =
+        (unary_checks().GetReceiverClassIdAt(0) == kSmiCid) ? 1 : 0;
+    if (IsDenseSwitch()) {
+      ASSERT(cids_[0] < cids_[cids_.length() - 1]);
+      __ CheckDenseSwitch(value, may_be_smi);
+      __ Nop(__ AddConstant(Smi::Handle(Smi::New(cids_[0]))));
+      __ Nop(__ AddConstant(Smi::Handle(Smi::New(ComputeCidMask()))));
+    } else {
+      GrowableArray<CidTarget> sorted_ic_data;
+      FlowGraphCompiler::SortICDataByCount(unary_checks(),
+                                           &sorted_ic_data,
+                                           /* drop_smi = */ true);
+      ASSERT(sorted_ic_data.length() >= 1);
+      if (sorted_ic_data.length() == 1) {
+        __ CheckCid(value, may_be_smi);
+        __ Nop(__ AddConstant(Smi::Handle(Smi::New(sorted_ic_data[0].cid))));
+      } else {
+        const Array& sorted_smi_cids =
+            Array::Handle(Array::New(sorted_ic_data.length(), Heap::kOld));
+        for (intptr_t i = 0; i < sorted_ic_data.length(); i++) {
+          sorted_smi_cids.SetAt(i,
+              Smi::Handle(Smi::New(sorted_ic_data[i].cid)));
+        }
+        __ CheckCids(value, may_be_smi);
+        __ Nop(__ AddConstant(sorted_smi_cids));

[Vyacheslav Egorov (Google), 2016/06/29 17:11:06]

I suggest just embedding them into the code instead of having an array on the
side. 

I don't think we are saving any memory by doing this. 

Embed CIDs by truncating them to 16bits.

You can have a helper that bails out of optimized compilation if CID is not
16bit.

[zra, 2016/06/29 22:19:18]

Done.

+      }
+    }
+  }
+  compiler->EmitDeopt(deopt_id(),
+                  ICData::kDeoptCheckClass,

[Vyacheslav Egorov (Google), 2016/06/29 17:11:06]

indentation

[zra, 2016/06/29 22:19:17]

Done.

+                  licm_hoisted_ ? ICData::kHoisted : 0);
+}
+
+
 EMIT_NATIVE_CODE(BinarySmiOp, 2, Location::RequiresRegister()) {
   const Register left = locs()->in(0).reg();
   const Register right = locs()->in(1).reg();
@@ -998,7 +1050,7 @@ EMIT_NATIVE_CODE(BinarySmiOp, 2, Location::RequiresRegister()) {
   if (can_deopt) {
     compiler->EmitDeopt(deopt_id(), ICData::kDeoptBinarySmiOp);
   } else if (needs_nop) {
-    __ Nop();
+    __ Nop(0);
   }
 }