VM: Improve receiver class check in polymorphic inlining.

runtime/vm/intermediate_language_ia32.cc

 // Copyright (c) 2013, 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_IA32.
 #if defined(TARGET_ARCH_IA32)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/dart_entry.h"
@@ skipping 4563 matching lines @@
 }
 
 
 LocationSummary* CheckClassInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 1;
   const intptr_t kNumTemps = 0;
   LocationSummary* summary =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
   summary->set_in(0, Location::RequiresRegister());
   if (!IsNullCheck()) {
+    if (IsDenseSwitch()) {
+      summary->AddTemp(Location::RegisterLocation(ECX));
+    }
     summary->AddTemp(Location::RequiresRegister());
   }
   return summary;
 }
 
 
 void CheckClassInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   const DeoptReasonId deopt_reason =
       licm_hoisted_ ? kDeoptHoistedCheckClass : kDeoptCheckClass;
   if (IsNullCheck()) {
@@ skipping 14 matching lines @@
   intptr_t cix = 0;
   if (unary_checks().GetReceiverClassIdAt(cix) == kSmiCid) {
     __ testl(value, Immediate(kSmiTagMask));
     __ j(ZERO, &is_ok);
     cix++;  // Skip first check.
   } else {
     __ testl(value, Immediate(kSmiTagMask));
     __ j(ZERO, deopt);
   }
   __ LoadClassId(temp, value);
-  const intptr_t num_checks = unary_checks().NumberOfChecks();
-  const bool use_near_jump = num_checks < 5;
-  for (intptr_t i = cix; i < num_checks; i++) {
-    ASSERT(unary_checks().GetReceiverClassIdAt(i) != kSmiCid);
-    __ cmpl(temp, Immediate(unary_checks().GetReceiverClassIdAt(i)));
-    if (i == (num_checks - 1)) {
-      __ j(NOT_EQUAL, deopt);
-    } else {
-      if (use_near_jump) {
-        __ j(EQUAL, &is_ok, Assembler::kNearJump);
+
+  if (IsDenseSwitch()) {
+    ASSERT(cids_[0] < cids_[cids_.length() - 1]);
+    ASSERT(temp == ECX);
+    Register mask_reg = locs()->temp(1).reg();
+    __ subl(temp, Immediate(cids_[0]));
+    __ cmpl(temp, Immediate(cids_[cids_.length() - 1] - cids_[0]));
+    __ j(ABOVE, deopt);
+    __ movl(mask_reg, Immediate(1));
+    __ shll(mask_reg, temp);
+    intptr_t mask = 0;
+    for (intptr_t i = 0; i < cids_.length(); ++i) {
+      mask |= 1 << (cids_[i] - cids_[0]);
+    }
+    __ andl(mask_reg, Immediate(mask));
+    __ j(ZERO, deopt);
+  } else {
+    const intptr_t num_checks = cids_.length();
+    const bool use_near_jump = num_checks < 5;
+    for (intptr_t i = cix; i < num_checks; i++) {
+      ASSERT(cids_[i] != kSmiCid);
+      __ cmpl(temp, Immediate(cids_[i]));
+      if (i == (num_checks - 1)) {
+        __ j(NOT_EQUAL, deopt);
       } else {
-        __ j(EQUAL, &is_ok);
+        if (use_near_jump) {
+          __ j(EQUAL, &is_ok, Assembler::kNearJump);
+        } else {
+          __ j(EQUAL, &is_ok);
+        }
       }
     }
   }
   __ Bind(&is_ok);
 }
 
 
 LocationSummary* CheckSmiInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 1;
   const intptr_t kNumTemps = 0;
   LocationSummary* summary =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
   summary->set_in(0, Location::RequiresRegister());
   return summary;
 }
 
 
 void CheckSmiInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   Register value = locs()->in(0).reg();
   Label* deopt = compiler->AddDeoptStub(deopt_id(),
                                         kDeoptCheckSmi);
   __ testl(value, Immediate(kSmiTagMask));
   __ j(NOT_ZERO, deopt);
 }
 
 
+LocationSummary* CheckClassIdInstr::MakeLocationSummary(bool opt) const {
+  const intptr_t kNumInputs = 2;
+  const intptr_t kNumTemps = 0;
+  LocationSummary* summary =
+      new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
+  summary->set_in(0, Location::RequiresRegister());
+  summary->set_in(1, Location::RegisterOrSmiConstant(right()));
+  return summary;
+}
+
+
+void CheckClassIdInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  Register left = locs()->in(0).reg();
+  Location right = locs()->in(1);
+  Label* deopt = compiler->AddDeoptStub(deopt_id(), kDeoptCheckClass);
+  if (right.IsRegister()) {
+    __ cmpl(left, right.reg());
+  } else {
+    ASSERT(right.IsConstant());
+    const Object& right_const = Smi::Cast(right.constant());
+    __ cmpl(left, Immediate(reinterpret_cast<int32_t>(right_const.raw())));
+  }
+  __ j(NOT_ZERO, deopt);
+}
+
+
 // Length: register or constant.
 // Index: register, constant or stack slot.
 LocationSummary* CheckArrayBoundInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 2;
   const intptr_t kNumTemps = 0;
   LocationSummary* locs =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
   locs->set_in(kLengthPos, Location::RegisterOrSmiConstant(length()));
   ConstantInstr* index_constant = index()->definition()->AsConstant();
   if (index_constant != NULL) {
@@ skipping 713 matching lines @@
                          PcDescriptors::kOther,
                          locs());
   __ Drop(2);  // Discard type arguments and receiver.
 }
 
 }  // namespace dart
 
 #undef __
 
 #endif  // defined TARGET_ARCH_IA32