Dart VM: Simplify code generation for equality operators.

runtime/vm/intermediate_language_arm.cc

Index: runtime/vm/intermediate_language_arm.cc
===================================================================
--- runtime/vm/intermediate_language_arm.cc	(revision 28079)
+++ runtime/vm/intermediate_language_arm.cc	(working copy)
@@ -361,14 +361,6 @@
   const Array& kNoArgumentNames = Object::null_array();
   const int kNumArgumentsChecked = 2;
 
-  Label check_identity;
-  __ LoadImmediate(IP, reinterpret_cast<intptr_t>(Object::null()));
-  __ ldm(IA, SP, (1 << R0) | (1 << R1));
-  __ cmp(R1, ShifterOperand(IP));
-  __ b(&check_identity, EQ);
-  __ cmp(R0, ShifterOperand(IP));
-  __ b(&check_identity, EQ);
-
   ICData& equality_ic_data = ICData::ZoneHandle();
   if (compiler->is_optimizing() && FLAG_propagate_ic_data) {
     ASSERT(!original_ic_data.IsNull());
@@ -395,42 +387,12 @@
                                  kNoArgumentNames,
                                  locs,
                                  equality_ic_data);
-  Label check_ne;
-  __ b(&check_ne);
-
-  __ Bind(&check_identity);
-  Label equality_done;
-  if (compiler->is_optimizing()) {
-    // No need to update IC data.
-    __ PopList((1 << R0) | (1 << R1));
-    __ cmp(R0, ShifterOperand(R1));
-    __ LoadObject(R0, Bool::Get(kind != Token::kEQ), NE);
-    __ LoadObject(R0, Bool::Get(kind == Token::kEQ), EQ);
-    if (kind == Token::kNE) {
-      // Skip not-equal result conversion.
-      __ b(&equality_done);
-    }
-  } else {
-    // Call stub, load IC data in register. The stub will update ICData if
-    // necessary.
-    Register ic_data_reg = locs->temp(0).reg();
-    ASSERT(ic_data_reg == R5);  // Stub depends on it.
-    __ LoadObject(ic_data_reg, equality_ic_data);
-    // Pass left in R1 and right in R0.
-    compiler->GenerateCall(token_pos,
-                           &StubCode::EqualityWithNullArgLabel(),
-                           PcDescriptors::kRuntimeCall,
-                           locs);
-    __ Drop(2);
-  }
-  __ Bind(&check_ne);
   if (kind == Token::kNE) {
     // Negate the condition: true label returns false and vice versa.
     __ CompareObject(R0, Bool::True());
     __ LoadObject(R0, Bool::True(), NE);
     __ LoadObject(R0, Bool::False(), EQ);
   }
-  __ Bind(&equality_done);
 }
 
 
@@ -612,35 +574,11 @@
   ASSERT(!ic_data.IsNull() && (ic_data.NumberOfChecks() > 0));
   Register left = locs->in(0).reg();
   Register right = locs->in(1).reg();
-  Label done, identity_compare, non_null_compare;
-  __ LoadImmediate(IP, reinterpret_cast<intptr_t>(Object::null()));
-  __ cmp(right, ShifterOperand(IP));
-  __ b(&identity_compare, EQ);
-  __ cmp(left, ShifterOperand(IP));
-  __ b(&non_null_compare, NE);
-  // Comparison with NULL is "===".
-  __ Bind(&identity_compare);
-  __ cmp(left, ShifterOperand(right));
-  Condition cond = TokenKindToSmiCondition(kind);
-  if (branch != NULL) {
-    branch->EmitBranchOnCondition(compiler, cond);
-  } else {
-    Register result = locs->out().reg();
-    Label load_true;
-    __ b(&load_true, cond);
-    __ LoadObject(result, Bool::False());
-    __ b(&done);
-    __ Bind(&load_true);
-    __ LoadObject(result, Bool::True());
-  }
-  __ b(&done);
-  __ Bind(&non_null_compare);  // Receiver is not null.
   ASSERT(left == R1);
   ASSERT(right == R0);
   __ PushList((1 << R0) | (1 << R1));
   EmitEqualityAsPolymorphicCall(compiler, ic_data, locs, branch, kind,
                                 deopt_id, token_pos);
-  __ Bind(&done);
 }