Collect type feedback for fields.

runtime/vm/intermediate_language_x64.cc

Index: runtime/vm/intermediate_language_x64.cc
diff --git a/runtime/vm/intermediate_language_x64.cc b/runtime/vm/intermediate_language_x64.cc
index 06c52785fa222ee67cb0778b8e4a566a4e36b87a..c2b436811a0a87931569f4923858defa3bcac04b 100644
--- a/runtime/vm/intermediate_language_x64.cc
+++ b/runtime/vm/intermediate_language_x64.cc
@@ -13,6 +13,7 @@
 #include "vm/locations.h"
 #include "vm/object_store.h"
 #include "vm/parser.h"
+#include "vm/stack_frame.h"
 #include "vm/stub_code.h"
 #include "vm/symbols.h"
 
@@ -1332,21 +1333,293 @@ void StoreIndexedInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
 }
 
 
+LocationSummary* GuardFieldInstr::MakeLocationSummary() const {
+  const intptr_t kNumInputs = 1;
+  LocationSummary* summary =
+      new LocationSummary(kNumInputs, 0, LocationSummary::kNoCall);
+  summary->set_in(0, Location::RequiresRegister());
+  if (value()->Type()->ToCid() == kDynamicCid) {
+    summary->AddTemp(Location::RequiresRegister());
+  }
+  if (field().guarded_cid() == kIllegalCid) {
+    summary->AddTemp(Location::RequiresRegister());
+  }
+  return summary;
+}
+
+
+static void PushCid(FlowGraphCompiler* compiler, const Immediate& imm) {
+  __ pushq(Immediate(Smi::RawValue(imm.value())));
+}
+
+
+static void PushCid(FlowGraphCompiler* compiler, Register reg) {
+  __ SmiTag(reg);
+  __ pushq(reg);
+}
+
+
+template<typename ValueCidOperandType>
+static void EmitCidGuardInit(FlowGraphCompiler* compiler,
+                                       ValueCidOperandType value_cid,
+                                       const Immediate& field_cid,
+                                       const Immediate& nullability,
+                                       Label* deopt,
+                                       Label* ok) {
+  // nothing to do.
+}
+
+
+template<typename ValueCidOperandType>
+static void EmitCidGuardInit(FlowGraphCompiler* compiler,
+                             ValueCidOperandType value_cid,
+                             const FieldAddress& field_cid,
+                                       const FieldAddress& nullability,
+                                       Label* deopt,
+                                       Label* ok) {
+  // Check if field is initialized for the first time.
+  Label fail;
+  __ cmpq(field_cid, Immediate(kIllegalCid));
+  __ j(NOT_EQUAL, (deopt != NULL) ? deopt : &fail);
+  __ movq(field_cid, value_cid);
+  __ movq(nullability, value_cid);
+  __ jmp(ok);
+  if (deopt == NULL) {
+    __ Bind(&fail);
+  }
+}
+
+
+static void CompareJump(FlowGraphCompiler* compiler,
+                        Condition cond,
+                        const Immediate& left,
+                        const Immediate& right,
+                        Label* target) {
+  if ((left.value() == right.value()) && (cond == EQUAL)) {
+    __ jmp(target);
+  } else if ((left.value() != right.value()) && cond == NOT_EQUAL) {
+    __ jmp(target);
+  }
+}
+
+
+static void CompareJump(FlowGraphCompiler* compiler,
+                        Condition cond,
+                        Immediate left,
+                        Register right,
+                        Label* target) {
+  ASSERT((cond == EQUAL) || (cond == NOT_EQUAL));
+  __ cmpq(right, left);
+  __ j(cond, target);
+}
+
+
+template<typename LeftT, typename RightT>
+static void CompareJump(FlowGraphCompiler* compiler,
+                        Condition cond,
+                        LeftT left,
+                        RightT right,
+                        Label* target) {
+  __ cmpq(left, right);
+  __ j(cond, target);
+}
+
+
+template<typename ValueCidOperandType,
+         typename FieldCidOperandType,
+         typename FieldNullabilityOperandType>
+static void EmitCidGuard(FlowGraphCompiler* compiler,
+                                   const Field& field,
+                                   ValueCidOperandType value_cid,
+                                   FieldCidOperandType field_cid,
+                                   FieldNullabilityOperandType nullability,
+                                   Label* deopt) {
+  Label ok, update;
+  CompareJump(compiler, EQUAL, field_cid, value_cid, &ok);
+  if ((deopt != NULL) && (field.guarded_cid() != kIllegalCid)) {
+    CompareJump(compiler, NOT_EQUAL, nullability, value_cid, deopt);
+  } else {
+    CompareJump(compiler, EQUAL, nullability, value_cid, &ok);
+  }
+
+  EmitCidGuardInit(compiler, value_cid, field_cid, nullability, deopt, &ok);
+
+  if (deopt == NULL) {
+    // Switch field's cid to dynamic and notify runtime.
+    CompareJump(compiler, EQUAL, field_cid, Immediate(kDynamicCid), &ok);
+    __ PushObject(field);
+    PushCid(compiler, value_cid);
+    __ CallRuntime(kUpdateFieldCidRuntimeEntry);
+    __ Drop(2);
+  }
+
+  __ Bind(&ok);
+}
+
+
+template<typename FieldCidOperandType, typename FieldNullabilityOperandType>
+static void EmitCidGuard(FlowGraphCompiler* compiler,
+                                  const Field& field,
+                                   intptr_t value_cid,
+                                   Register value_cid_reg,
+                                   FieldCidOperandType field_cid,
+                                   FieldNullabilityOperandType nullability,
+                                   Label* deopt) {
+  if (value_cid == kDynamicCid) {
+    EmitCidGuard(compiler, field, value_cid_reg, field_cid, nullability, deopt);
+  } else {
+    EmitCidGuard(compiler,
+                 field,
+                 Immediate(value_cid),
+                 field_cid,
+                 nullability,
+                 deopt);
+  }
+}
+
+
+static void EmitFieldGuard(FlowGraphCompiler* compiler,
+                           Register value_reg,
+                           const Field& field,
+                           intptr_t value_cid,
+                           Register value_cid_reg,
+                           intptr_t field_cid,
+                           intptr_t nullability,
+                           Register field_reg,
+                           Label* deopt) {
+  if (value_cid == kDynamicCid) {
+    Label not_smi, cid_loaded;
+    __ testq(value_reg, Immediate(kSmiTagMask));
+    __ j(NOT_ZERO, &not_smi, Assembler::kNearJump);
+    __ movq(value_cid_reg, Immediate(kSmiCid));
+    __ jmp(&cid_loaded);
+    __ Bind(&not_smi);
+    __ LoadClassId(value_cid_reg, value_reg);
+    __ Bind(&cid_loaded);
+  }
+
+  if (field_cid == kIllegalCid) {
+    __ LoadObject(field_reg, Field::ZoneHandle(field.raw()));
+    EmitCidGuard(compiler,
+                 field,
+                 value_cid,
+                 value_cid_reg,
+                 FieldAddress(field_reg, Field::guarded_cid_offset()),
+                 FieldAddress(field_reg, Field::is_nullable_offset()),
+                 deopt);
+  } else {
+    EmitCidGuard(compiler,
+                 field,
+                 value_cid,
+                 value_cid_reg,
+                 Immediate(field_cid),
+                 Immediate(nullability),
+                 deopt);
+  }
+}
+
+
+void GuardFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  const intptr_t value_cid = value()->Type()->ToCid();
+  const intptr_t field_cid = field().guarded_cid();
+  const intptr_t nullability = field().is_nullable() ? kNullCid : kIllegalCid;
+
+  Register value_reg = locs()->in(0).reg();
+
+  Register value_cid_reg = (value_cid == kDynamicCid) ?
+      locs()->temp(0).reg() : kNoRegister;
+
+  Label* deopt = compiler->is_optimizing() && CanDeoptimize() ?
+      compiler->AddDeoptStub(deopt_id(), kDeoptStoreInstanceField) : NULL;
+
+  if ((deopt != NULL) && (field_cid != kIllegalCid)) {
+    if (value_cid != kDynamicCid) {
+      ASSERT(field_cid != value_cid);
+      __ jmp(deopt);
+      return;
+    }
+
+    if (field_cid == kSmiCid) {
+      __ testq(value_reg, Immediate(kSmiTagMask));
+    } else {
+      ASSERT(value_cid_reg != kNoRegister);
+      __ testq(value_reg, Immediate(kSmiTagMask));
+      __ j(ZERO, deopt);
+      __ LoadClassId(value_cid_reg, value_reg);
+      __ cmpq(value_cid_reg, Immediate(field_cid));
+    }
+
+    if (field().is_nullable()) {
+      Label ok;
+      __ j(EQUAL, &ok);
+      const Immediate& raw_null =
+          Immediate(reinterpret_cast<intptr_t>(Object::null()));
+      __ cmpq(value_reg, raw_null);
+      __ j(NOT_EQUAL, deopt);
+      __ Bind(&ok);
+    } else {
+      __ j(NOT_EQUAL, deopt);
+    }
+
+    return;
+  }
+
+  Register field_reg = (field_cid == kIllegalCid) ?
+      locs()->temp(1).reg() : kNoRegister;
+
+  EmitFieldGuard(compiler,
+                 value_reg,
+                 field(),
+                 value_cid, value_cid_reg,
+                 field_cid, nullability, field_reg,
+                 deopt);
+}
+
+
 LocationSummary* StoreInstanceFieldInstr::MakeLocationSummary() const {
   const intptr_t kNumInputs = 2;
   const intptr_t num_temps = 0;
   LocationSummary* summary =
       new LocationSummary(kNumInputs, num_temps, LocationSummary::kNoCall);
   summary->set_in(0, Location::RequiresRegister());
-  summary->set_in(1, ShouldEmitStoreBarrier()
+  summary->set_in(1, (ShouldEmitStoreBarrier() || should_emit_field_guard())
                        ? Location::WritableRegister()
                        : Location::RegisterOrConstant(value()));
+
+  if (should_emit_field_guard()) {
+    summary->AddTemp(Location::RequiresRegister());
+    summary->AddTemp(Location::RequiresRegister());
+  }
+
   return summary;
 }
 
 
 void StoreInstanceFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   Register instance_reg = locs()->in(0).reg();
+
+
+  if (should_emit_field_guard()) {
+    ASSERT(!compiler->is_optimizing());
+    Register value_reg = locs()->in(1).reg();
+    Register value_cid_reg = locs()->temp(0).reg();
+    Register field_reg = locs()->temp(1).reg();
+
+    __ pushq(instance_reg);
+    __ pushq(value_reg);
+    EmitFieldGuard(compiler,
+                   value_reg,
+                   field(),
+                   kDynamicCid,
+                   value_cid_reg,
+                   kIllegalCid,
+                   kIllegalCid,
+                   field_reg,
+                   NULL);
+    __ popq(value_reg);
+    __ popq(instance_reg);
+  }
+
   if (ShouldEmitStoreBarrier()) {
     Register value_reg = locs()->in(1).reg();
     __ StoreIntoObject(instance_reg,
@@ -2680,16 +2953,28 @@ void BranchInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
 
 LocationSummary* CheckClassInstr::MakeLocationSummary() const {
   const intptr_t kNumInputs = 1;
-  const intptr_t kNumTemps = 1;
+  const intptr_t kNumTemps = 0;
   LocationSummary* summary =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
   summary->set_in(0, Location::RequiresRegister());
-  summary->set_temp(0, Location::RequiresRegister());
+  if (!null_check()) {
+    summary->AddTemp(Location::RequiresRegister());
+  }
   return summary;
 }
 
 
 void CheckClassInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  if (null_check()) {
+    Label* deopt = compiler->AddDeoptStub(deopt_id(),
+                                          kDeoptCheckClass);
+    const Immediate& raw_null =
+        Immediate(reinterpret_cast<intptr_t>(Object::null()));
+    __ cmpq(locs()->in(0).reg(), raw_null);
+    __ j(EQUAL, deopt);
+    return;
+  }
+
   ASSERT((unary_checks().GetReceiverClassIdAt(0) != kSmiCid) ||
          (unary_checks().NumberOfChecks() > 1));
   Register value = locs()->in(0).reg();