Dart VM: Simplify code generation for equality operators.

runtime/vm/stub_code_mips.cc

Index: runtime/vm/stub_code_mips.cc
===================================================================
--- runtime/vm/stub_code_mips.cc	(revision 28079)
+++ runtime/vm/stub_code_mips.cc	(working copy)
@@ -2232,110 +2232,6 @@
 }
 
 
-// Implements equality operator when one of the arguments is null
-// (identity check) and updates ICData if necessary.
-// RA: return address.
-// A1: left argument.
-// A0: right argument.
-// T0: ICData.
-// V0: result.
-// TODO(srdjan): Move to VM stubs once Boolean objects become VM objects.
-void StubCode::GenerateEqualityWithNullArgStub(Assembler* assembler) {
-  __ TraceSimMsg("EqualityWithNullArgStub");
-  __ Comment("EqualityWithNullArgStub");
-  __ EnterStubFrame();
-  static const intptr_t kNumArgsTested = 2;
-#if defined(DEBUG)
-  { Label ok;
-    __ lw(CMPRES1, FieldAddress(T0, ICData::num_args_tested_offset()));
-    __ BranchEqual(CMPRES1, kNumArgsTested, &ok);
-    __ Stop("Incorrect ICData for equality");
-    __ Bind(&ok);
-  }
-#endif  // DEBUG
-  // Check IC data, update if needed.
-  // T0: IC data object (preserved).
-  __ lw(T6, FieldAddress(T0, ICData::ic_data_offset()));
-  // T6: ic_data_array with check entries: classes and target functions.
-  __ AddImmediate(T6, Array::data_offset() - kHeapObjectTag);
-  // T6: points directly to the first ic data array element.
-
-  Label get_class_id_as_smi, no_match, loop, found;
-  __ Bind(&loop);
-  // Check left.
-  __ bal(&get_class_id_as_smi);
-  __ delay_slot()->mov(T2, A1);
-  __ lw(T3, Address(T6, 0 * kWordSize));
-  __ bne(T2, T3, &no_match);  // Class id match?
-
-  // Check right.
-  __ bal(&get_class_id_as_smi);
-  __ delay_slot()->mov(T2, A0);
-  __ lw(T3, Address(T6, 1 * kWordSize));
-  __ beq(T2, T3, &found);  // Class id match?
-  __ Bind(&no_match);
-  // Next check group.
-  intptr_t entry_bytes = kWordSize * ICData::TestEntryLengthFor(kNumArgsTested);
-  if (Utils::IsInt(kImmBits, entry_bytes)) {
-    __ BranchNotEqual(T3, Smi::RawValue(kIllegalCid), &loop);  // Done?
-    __ delay_slot()->addiu(T6, T6, Immediate(entry_bytes));
-  } else {
-    __ AddImmediate(T6, entry_bytes);
-    __ BranchNotEqual(T3, Smi::RawValue(kIllegalCid), &loop);  // Done?
-  }
-
-  Label update_ic_data;
-  __ b(&update_ic_data);
-
-  __ Bind(&found);
-  const intptr_t count_offset =
-      ICData::CountIndexFor(kNumArgsTested) * kWordSize;
-  Label no_overflow;
-  __ lw(T1, Address(T6, count_offset));
-  __ AddImmediateDetectOverflow(T1, T1, Smi::RawValue(1), CMPRES, T5);
-  __ bgez(CMPRES, &no_overflow);
-  __ delay_slot()->sw(T1, Address(T6, count_offset));
-  __ LoadImmediate(TMP1, Smi::RawValue(Smi::kMaxValue));
-  __ sw(TMP1, Address(T6, count_offset));  // If overflow.
-  __ Bind(&no_overflow);
-
-  Label compute_result;
-  __ Bind(&compute_result);
-  __ LoadObject(T4, Bool::True());
-  __ LoadObject(T5, Bool::False());
-  __ subu(CMPRES, A0, A1);
-  __ movz(V0, T4, CMPRES);
-  __ movn(V0, T5, CMPRES);
-  __ LeaveStubFrameAndReturn();
-
-  __ Bind(&get_class_id_as_smi);
-  // Test if Smi -> load Smi class for comparison.
-  Label not_smi;
-  __ andi(CMPRES, T2, Immediate(kSmiTagMask));
-  __ bne(CMPRES, ZR, &not_smi);
-  __ jr(RA);
-  __ delay_slot()->addiu(T2, ZR, Immediate(Smi::RawValue(kSmiCid)));
-  __ Bind(&not_smi);
-  __ LoadClassId(T2, T2);
-  __ jr(RA);
-  __ delay_slot()->SmiTag(T2);
-
-  __ Bind(&update_ic_data);
-  // T0: ICData
-  __ addiu(SP, SP, Immediate(-4 * kWordSize));
-  __ sw(A1, Address(SP, 3 * kWordSize));
-  __ sw(A0, Address(SP, 2 * kWordSize));
-  __ LoadObject(TMP1, Symbols::EqualOperator());  // Target's name.
-  __ sw(TMP1, Address(SP, 1 * kWordSize));
-  __ sw(T0, Address(SP, 0 * kWordSize));  // ICData.
-  __ CallRuntime(kUpdateICDataTwoArgsRuntimeEntry, 4);
-  __ lw(A0, Address(SP, 2 * kWordSize));
-  __ lw(A1, Address(SP, 3 * kWordSize));
-  __ b(&compute_result);
-  __ delay_slot()->addiu(SP, SP, Immediate(4 * kWordSize));
-}
-
-
 // Calls to the runtime to optimize the given function.
 // T0: function to be reoptimized.
 // S4: argument descriptor (preserved).