Copy of Issue 231383002 after hard disk crash: First step in improving instance of test for a fixed…

runtime/vm/intermediate_language_x64.cc

Index: runtime/vm/intermediate_language_x64.cc
===================================================================
--- runtime/vm/intermediate_language_x64.cc	(revision 35442)
+++ runtime/vm/intermediate_language_x64.cc	(working copy)
@@ -529,6 +529,78 @@
 }
 
 
+
+LocationSummary* TestCidsInstr::MakeLocationSummary(bool opt) const {
+  const intptr_t kNumInputs = 1;
+  const intptr_t kNumTemps = 1;
+  LocationSummary* locs =
+      new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
+  locs->set_in(0, Location::RequiresRegister());
+  locs->set_temp(0, Location::RequiresRegister());
+  locs->set_out(0, Location::RequiresRegister());
+  return locs;
+}
+
+
+Condition TestCidsInstr::EmitComparisonCode(FlowGraphCompiler* compiler,
+                                            BranchLabels labels) {
+  ASSERT((kind() == Token::kIS) || (kind() == Token::kISNOT));
+  Register val_reg = locs()->in(0).reg();
+  Register cid_reg = locs()->temp(0).reg();
+
+  Label* deopt = CanDeoptimize() ?
+      compiler->AddDeoptStub(deopt_id(), kDeoptTestCids) : NULL;
+
+  const intptr_t true_result = (kind() == Token::kIS) ? 1 : 0;
+  const ZoneGrowableArray<intptr_t>& data = cid_results();
+  ASSERT(data[0] == kSmiCid);
+  bool result = data[1] == true_result;
+  __ testq(val_reg, Immediate(kSmiTagMask));
+  __ j(ZERO, result ? labels.true_label : labels.false_label);
+  __ LoadClassId(cid_reg, val_reg);
+  for (intptr_t i = 2; i < data.length(); i += 2) {
+    const intptr_t test_cid = data[i];
+    ASSERT(test_cid != kSmiCid);
+    result = data[i + 1] == true_result;
+    __ cmpq(cid_reg,  Immediate(test_cid));
+    __ j(EQUAL, result ? labels.true_label : labels.false_label);
+  }
+  // No match found, deoptimize or false.
+  if (deopt == NULL) {
+    Label* target = result ? labels.false_label : labels.true_label;
+    if (target != labels.fall_through) {
+      __ jmp(target);
+    }
+  } else {
+    __ jmp(deopt);
+  }
+  // Dummy result as the last instruction is a jump, any conditional
+  // branch using the result will therefore be skipped.
+  return ZERO;
+}
+
+
+void TestCidsInstr::EmitBranchCode(FlowGraphCompiler* compiler,
+                                   BranchInstr* branch) {
+  BranchLabels labels = compiler->CreateBranchLabels(branch);
+  EmitComparisonCode(compiler, labels);
+}
+
+
+void TestCidsInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  Register result_reg = locs()->out(0).reg();
+  Label is_true, is_false, done;
+  BranchLabels labels = { &is_true, &is_false, &is_false };
+  EmitComparisonCode(compiler, labels);
+  __ Bind(&is_false);
+  __ LoadObject(result_reg, Bool::False(), PP);
+  __ jmp(&done, Assembler::kNearJump);
+  __ Bind(&is_true);
+  __ LoadObject(result_reg, Bool::True(), PP);
+  __ Bind(&done);
+}
+
+
 LocationSummary* RelationalOpInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 2;
   const intptr_t kNumTemps = 0;