Add DoubleTestOp instruction

runtime/vm/intermediate_language_mips.cc

Index: runtime/vm/intermediate_language_mips.cc
diff --git a/runtime/vm/intermediate_language_mips.cc b/runtime/vm/intermediate_language_mips.cc
index e824df18862e5c411a9bf1cc4128604139ea1d92..d61337d52f38a965917fbdb336448c81a91d5052 100644
--- a/runtime/vm/intermediate_language_mips.cc
+++ b/runtime/vm/intermediate_language_mips.cc
@@ -3692,6 +3692,51 @@ 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 DRegister value = locs()->in(0).fpu_reg();
+  const Register result = locs()->out(0).reg();
+  if (op_kind() == MethodRecognizer::kDouble_getIsNaN) {
+    Label is_not_nan;
+    __ LoadObject(result, Bool::False());
+    __ cund(value, value);
+    __ bc1f(&is_not_nan);
+    __ LoadObject(result, Bool::True());
+    __ Bind(&is_not_nan);
+  } else {
+    ASSERT(op_kind() == MethodRecognizer::kDouble_getIsInfinite);
+    Label not_inf, done;
+    __ mfc1(TMP, EvenFRegisterOf(value));
+    __ mfc1(result, OddFRegisterOf(value));
+    // If the low word isn't zero, then it isn't infinity.
+    __ bne(TMP, ZR, &not_inf);
+    // Mask off the sign bit.
+    __ AndImmediate(result, result, 0x7FFFFFFF);
+    // Compare with +infinity.
+    __ BranchNotEqual(result, Immediate(0x7FF00000), &not_inf);
+
+    __ LoadObject(result, Bool::True());
+    __ b(&done);
+
+    __ Bind(&not_inf);
+    __ LoadObject(result, Bool::False());
+    __ Bind(&done);
+  }
+}
+
+
 LocationSummary* BinaryFloat32x4OpInstr::MakeLocationSummary(Zone* zone,
                                                              bool opt) const {
   UNIMPLEMENTED();
@@ -4536,10 +4581,10 @@ static void InvokeDoublePow(FlowGraphCompiler* compiler,
   __ Bind(&try_sqrt);
   // Before calling pow, check if we could use sqrt instead of pow.
   __ LoadImmediate(result, kPosInfinity);
-  // base == -Infinity -> call pow;
+  // base == Infinity -> call pow;
   __ ceqd(base, result);
   Label do_pow;
-  __ b(&do_pow);
+  __ bc1t(&do_pow);
 
   // exponent == 0.5 ?
   __ LoadImmediate(result, 0.5);