Make constant propagation to fold x == x and re-run type propagation for better range analysis.

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 "lib/error.h"
@@ skipping 251 matching lines @@
     case Token::kGTE: return GREATER_EQUAL;
     default:
       UNREACHABLE();
       return OVERFLOW;
   }
 }
 
 
 LocationSummary* EqualityCompareInstr::MakeLocationSummary() const {
   const intptr_t kNumInputs = 2;
-  const bool is_checked_strict_equal =
-      HasICData() && ic_data()->AllTargetsHaveSameOwner(kInstanceCid);
   if (receiver_class_id() == kMintCid) {
     const intptr_t kNumTemps = 1;
     LocationSummary* locs =
         new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
     locs->set_in(0, Location::RequiresFpuRegister());
     locs->set_in(1, Location::RequiresFpuRegister());
     locs->set_temp(0, Location::RequiresRegister());
     locs->set_out(Location::RequiresRegister());
     return locs;
   }
@@ skipping 13 matching lines @@
     locs->set_in(0, Location::RegisterOrConstant(left()));
     // Only one input can be a constant operand. The case of two constant
     // operands should be handled by constant propagation.
     // Only right can be a stack slot.
     locs->set_in(1, locs->in(0).IsConstant()
                         ? Location::RequiresRegister()
                         : Location::RegisterOrConstant(right()));
     locs->set_out(Location::RequiresRegister());
     return locs;
   }
-  if (is_checked_strict_equal) {
+  if (is_checked_strict_equal()) {
     const intptr_t kNumTemps = 1;
     LocationSummary* locs =
         new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
     locs->set_in(0, Location::RequiresRegister());
     locs->set_in(1, Location::RequiresRegister());
     locs->set_temp(0, Location::RequiresRegister());
     locs->set_out(Location::RequiresRegister());
     return locs;
   }
   if (IsPolymorphic()) {
@@ skipping 518 matching lines @@
     return;
   }
   if (receiver_class_id() == kMintCid) {
     EmitUnboxedMintEqualityOp(compiler, *locs(), kind(), kNoBranch);
     return;
   }
   if (receiver_class_id() == kDoubleCid) {
     EmitDoubleComparisonOp(compiler, *locs(), kind(), kNoBranch);
     return;
   }
-  const bool is_checked_strict_equal =
-      HasICData() && ic_data()->AllTargetsHaveSameOwner(kInstanceCid);
-  if (is_checked_strict_equal) {
+  if (is_checked_strict_equal()) {
     EmitCheckedStrictEqual(compiler, *ic_data(), *locs(), kind(), kNoBranch,
                            deopt_id());
     return;
   }
   if (IsPolymorphic()) {
     EmitGenericEqualityCompare(compiler, locs(), kind(), kNoBranch, *ic_data(),
                                deopt_id(), token_pos());
     return;
   }
   Register left = locs()->in(0).reg();
@@ skipping 19 matching lines @@
     return;
   }
   if (receiver_class_id() == kMintCid) {
     EmitUnboxedMintEqualityOp(compiler, *locs(), kind(), branch);
     return;
   }
   if (receiver_class_id() == kDoubleCid) {
     EmitDoubleComparisonOp(compiler, *locs(), kind(), branch);
     return;
   }
-  const bool is_checked_strict_equal =
-      HasICData() && ic_data()->AllTargetsHaveSameOwner(kInstanceCid);
-  if (is_checked_strict_equal) {
+  if (is_checked_strict_equal()) {
     EmitCheckedStrictEqual(compiler, *ic_data(), *locs(), kind(), branch,
                            deopt_id());
     return;
   }
   if (IsPolymorphic()) {
     EmitGenericEqualityCompare(compiler, locs(), kind(), branch, *ic_data(),
                                deopt_id(), token_pos());
     return;
   }
   Register left = locs()->in(0).reg();
@@ skipping 3842 matching lines @@
                          PcDescriptors::kOther,
                          locs());
   __ Drop(2);  // Discard type arguments and receiver.
 }
 
 }  // namespace dart
 
 #undef __
 
 #endif  // defined TARGET_ARCH_IA32