Revert r38116 because of crashes.

runtime/vm/intermediate_language_x64.cc

Index: runtime/vm/intermediate_language_x64.cc
===================================================================
--- runtime/vm/intermediate_language_x64.cc	(revision 38117)
+++ runtime/vm/intermediate_language_x64.cc	(working copy)
@@ -5380,16 +5380,12 @@
 LocationSummary* CheckClassInstr::MakeLocationSummary(Isolate* isolate,
                                                       bool opt) const {
   const intptr_t kNumInputs = 1;
-  const bool need_mask_temp = IsDenseSwitch() && !IsDenseMask(ComputeCidMask());
-  const intptr_t kNumTemps = !IsNullCheck() ? (need_mask_temp ? 2 : 1) : 0;
+  const intptr_t kNumTemps = !IsNullCheck() ? 1 : 0;
   LocationSummary* summary = new(isolate) LocationSummary(
       isolate, kNumInputs, kNumTemps, LocationSummary::kNoCall);
   summary->set_in(0, Location::RequiresRegister());
   if (!IsNullCheck()) {
     summary->set_temp(0, Location::RequiresRegister());
-    if (need_mask_temp) {
-      summary->set_temp(1, Location::RequiresRegister());
-    }
   }
   return summary;
 }
@@ -5422,36 +5418,18 @@
     __ j(ZERO, deopt);
   }
   __ LoadClassId(temp, value);
-
-  if (IsDenseSwitch()) {
-    ASSERT(cids_[0] < cids_[cids_.length() - 1]);
-    __ subq(temp, Immediate(cids_[0]));
-    __ cmpq(temp, Immediate(cids_[cids_.length() - 1] - cids_[0]));
-    __ j(ABOVE, deopt);
-
-    intptr_t mask = ComputeCidMask();
-    if (!IsDenseMask(mask)) {
-      // Only need mask if there are missing numbers in the range.
-      ASSERT(cids_.length() > 2);
-      Register mask_reg = locs()->temp(1).reg();
-      __ movq(mask_reg, Immediate(mask));
-      __ btq(mask_reg, temp);
-      __ j(NOT_CARRY, deopt);
-    }
-  } else {
-    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);
+  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);
       } else {
-        if (use_near_jump) {
-          __ j(EQUAL, &is_ok, Assembler::kNearJump);
-        } else {
-          __ j(EQUAL, &is_ok);
-        }
+        __ j(EQUAL, &is_ok);
       }
     }
   }
@@ -5478,34 +5456,6 @@
 }
 
 
-LocationSummary* CheckClassIdInstr::MakeLocationSummary(Isolate* isolate,
-                                                        bool opt) const {
-  const intptr_t kNumInputs = 2;
-  const intptr_t kNumTemps = 0;
-  LocationSummary* summary = new(isolate) LocationSummary(
-      isolate, 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(), ICData::kDeoptCheckClass);
-  if (right.IsRegister()) {
-    __ cmpq(left, right.reg());
-  } else {
-    ASSERT(right.IsConstant());
-    const Object& right_const = Smi::Cast(right.constant());
-    __ CompareImmediate(
-        left, Immediate(reinterpret_cast<int64_t>(right_const.raw())), PP);
-  }
-  __ j(NOT_ZERO, deopt);
-}
-
-
 LocationSummary* CheckArrayBoundInstr::MakeLocationSummary(Isolate* isolate,
                                                            bool opt) const {
   const intptr_t kNumInputs = 2;