Dart VM: Simplify code generation for equality operators.

runtime/vm/stub_code_arm.cc

Index: runtime/vm/stub_code_arm.cc
===================================================================
--- runtime/vm/stub_code_arm.cc	(revision 28079)
+++ runtime/vm/stub_code_arm.cc	(working copy)
@@ -1966,92 +1966,6 @@
 }
 
 
-// Implements equality operator when one of the arguments is null
-// (identity check) and updates ICData if necessary.
-// LR: return address.
-// R1: left argument.
-// R0: right argument.
-// R5: ICData.
-// R0: result.
-// TODO(srdjan): Move to VM stubs once Boolean objects become VM objects.
-void StubCode::GenerateEqualityWithNullArgStub(Assembler* assembler) {
-  __ EnterStubFrame();
-  static const intptr_t kNumArgsTested = 2;
-#if defined(DEBUG)
-  { Label ok;
-    __ ldr(IP, FieldAddress(R5, ICData::num_args_tested_offset()));
-    __ cmp(IP, ShifterOperand(kNumArgsTested));
-    __ b(&ok, EQ);
-    __ Stop("Incorrect ICData for equality");
-    __ Bind(&ok);
-  }
-#endif  // DEBUG
-  // Check IC data, update if needed.
-  // R5: IC data object (preserved).
-  __ ldr(R6, FieldAddress(R5, ICData::ic_data_offset()));
-  // R6: ic_data_array with check entries: classes and target functions.
-  __ AddImmediate(R6, Array::data_offset() - kHeapObjectTag);
-  // R6: points directly to the first ic data array element.
-
-  Label get_class_id_as_smi, no_match, loop, found;
-  __ Bind(&loop);
-  // Check left.
-  __ mov(R2, ShifterOperand(R1));
-  __ bl(&get_class_id_as_smi);
-  __ ldr(R3, Address(R6, 0 * kWordSize));
-  __ cmp(R2, ShifterOperand(R3));  // Class id match?
-  __ b(&no_match, NE);
-  // Check right.
-  __ mov(R2, ShifterOperand(R0));
-  __ bl(&get_class_id_as_smi);
-  __ ldr(R3, Address(R6, 1 * kWordSize));
-  __ cmp(R2, ShifterOperand(R3));  // Class id match?
-  __ b(&found, EQ);
-  __ Bind(&no_match);
-  // Next check group.
-  __ AddImmediate(R6, kWordSize * ICData::TestEntryLengthFor(kNumArgsTested));
-  __ CompareImmediate(R3, Smi::RawValue(kIllegalCid));  // Done?
-  __ b(&loop, NE);
-  Label update_ic_data;
-  __ b(&update_ic_data);
-
-  __ Bind(&found);
-  const intptr_t count_offset =
-      ICData::CountIndexFor(kNumArgsTested) * kWordSize;
-  __ ldr(IP, Address(R6, count_offset));
-  __ adds(IP, IP, ShifterOperand(Smi::RawValue(1)));
-  __ LoadImmediate(IP, Smi::RawValue(Smi::kMaxValue), VS);  // If overflow.
-  __ str(IP, Address(R6, count_offset));
-
-  Label compute_result;
-  __ Bind(&compute_result);
-  __ cmp(R0, ShifterOperand(R1));
-  __ LoadObject(R0, Bool::False(), NE);
-  __ LoadObject(R0, Bool::True(), EQ);
-  __ LeaveStubFrame();
-  __ Ret();
-
-  __ Bind(&get_class_id_as_smi);
-  // Test if Smi -> load Smi class for comparison.
-  __ tst(R2, ShifterOperand(kSmiTagMask));
-  __ mov(R2, ShifterOperand(Smi::RawValue(kSmiCid)), EQ);
-  __ bx(LR, EQ);
-  __ LoadClassId(R2, R2);
-  __ SmiTag(R2);
-  __ bx(LR);
-
-  __ Bind(&update_ic_data);
-  // R5: ICData
-  __ PushList((1 << R0) | (1 << R1));
-  __ PushObject(Symbols::EqualOperator());  // Target's name.
-  __ Push(R5);  // ICData
-  __ CallRuntime(kUpdateICDataTwoArgsRuntimeEntry, 4);  // Clobbers R4, R5.
-  __ Drop(2);
-  __ PopList((1 << R0) | (1 << R1));
-  __ b(&compute_result);
-}
-
-
 // Calls to the runtime to optimize the given function.
 // R6: function to be reoptimized.
 // R4: argument descriptor (preserved).