Reland "Add DoubleTestOp instruction"

runtime/vm/intermediate_language_arm64.cc

Index: runtime/vm/intermediate_language_arm64.cc
diff --git a/runtime/vm/intermediate_language_arm64.cc b/runtime/vm/intermediate_language_arm64.cc
index 1eabe23055f10867cae5ef623d5ba392d905b47c..3503a991b702d8f84a328d78d3ff4809f4b816ef 100644
--- a/runtime/vm/intermediate_language_arm64.cc
+++ b/runtime/vm/intermediate_language_arm64.cc
@@ -3482,6 +3482,41 @@ void BinaryDoubleOpInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
 }
 
 
+LocationSummary* DoubleTestOpInstr::MakeLocationSummary(Zone* zone,
+                                                        bool opt) const {
+  const intptr_t kNumInputs = 1;
+  const intptr_t kNumTemps = 0;
+  LocationSummary* summary = new(zone) LocationSummary(
+      zone, kNumInputs, kNumTemps, LocationSummary::kNoCall);
+  summary->set_in(0, Location::RequiresFpuRegister());
+  summary->set_out(0, Location::RequiresRegister());
+  return summary;
+}
+
+
+void DoubleTestOpInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  ASSERT(compiler->is_optimizing());
+  const VRegister value = locs()->in(0).fpu_reg();
+  const Register result = locs()->out(0).reg();
+  if (op_kind() == MethodRecognizer::kDouble_getIsNaN) {
+    __ fcmpd(value, value);
+    __ LoadObject(result, Bool::False());
+    __ LoadObject(TMP, Bool::True());
+    __ csel(result, TMP, result, VS);
+  } else {
+    ASSERT(op_kind() == MethodRecognizer::kDouble_getIsInfinite);
+    __ vmovrd(result, value, 0);
+    // Mask off the sign.
+    __ AndImmediate(result, result, 0x7FFFFFFFFFFFFFFFLL);
+    // Compare with +infinity.
+    __ CompareImmediate(result, 0x7FF0000000000000LL);
+    __ LoadObject(result, Bool::False());
+    __ LoadObject(TMP, Bool::True());
+    __ csel(result, TMP, result, EQ);
+  }
+}
+
+
 LocationSummary* BinaryFloat32x4OpInstr::MakeLocationSummary(Zone* zone,
                                                              bool opt) const {
   const intptr_t kNumInputs = 2;