1 files changed, 51 insertions, 29 deletions

diff --git a/deps/v8/src/compiler/machine-operator-reducer.cc b/deps/v8/src/compiler/machine-operator-reducer.cc
index 0ad20f0684..f7fe19d494 100644
--- a/deps/v8/src/compiler/machine-operator-reducer.cc
+++ b/deps/v8/src/compiler/machine-operator-reducer.cc
@@ -17,9 +17,9 @@ namespace v8 {
 namespace internal {
 namespace compiler {
 
-MachineOperatorReducer::MachineOperatorReducer(JSGraph* jsgraph)
-    : jsgraph_(jsgraph) {}
-
+MachineOperatorReducer::MachineOperatorReducer(JSGraph* jsgraph,
+                                               bool allow_signalling_nan)
+    : jsgraph_(jsgraph), allow_signalling_nan_(allow_signalling_nan) {}
 
 MachineOperatorReducer::~MachineOperatorReducer() {}
 
@@ -50,12 +50,12 @@ Node* MachineOperatorReducer::Float64Mul(Node* lhs, Node* rhs) {
 Node* MachineOperatorReducer::Float64PowHalf(Node* value) {
   value =
       graph()->NewNode(machine()->Float64Add(), Float64Constant(0.0), value);
-  return graph()->NewNode(
-      common()->Select(MachineRepresentation::kFloat64, BranchHint::kFalse),
-      graph()->NewNode(machine()->Float64LessThanOrEqual(), value,
-                       Float64Constant(-V8_INFINITY)),
-      Float64Constant(V8_INFINITY),
-      graph()->NewNode(machine()->Float64Sqrt(), value));
+  Diamond d(graph(), common(),
+            graph()->NewNode(machine()->Float64LessThanOrEqual(), value,
+                             Float64Constant(-V8_INFINITY)),
+            BranchHint::kFalse);
+  return d.Phi(MachineRepresentation::kFloat64, Float64Constant(V8_INFINITY),
+               graph()->NewNode(machine()->Float64Sqrt(), value));
 }
 
 Node* MachineOperatorReducer::Word32And(Node* lhs, Node* rhs) {
@@ -316,14 +316,17 @@ Reduction MachineOperatorReducer::Reduce(Node* node) {
     }
     case IrOpcode::kFloat32Sub: {
       Float32BinopMatcher m(node);
-      if (m.right().Is(0) && (copysign(1.0, m.right().Value()) > 0)) {
+      if (allow_signalling_nan_ && m.right().Is(0) &&
+          (copysign(1.0, m.right().Value()) > 0)) {
         return Replace(m.left().node());  // x - 0 => x
       }
       if (m.right().IsNaN()) {  // x - NaN => NaN
-        return Replace(m.right().node());
+        // Do some calculation to make a signalling NaN quiet.
+        return ReplaceFloat32(m.right().Value() - m.right().Value());
       }
       if (m.left().IsNaN()) {  // NaN - x => NaN
-        return Replace(m.left().node());
+        // Do some calculation to make a signalling NaN quiet.
+        return ReplaceFloat32(m.left().Value() - m.left().Value());
       }
       if (m.IsFoldable()) {  // L - R => (L - R)
         return ReplaceFloat32(m.left().Value() - m.right().Value());
@@ -350,7 +353,8 @@ Reduction MachineOperatorReducer::Reduce(Node* node) {
     case IrOpcode::kFloat64Add: {
       Float64BinopMatcher m(node);
       if (m.right().IsNaN()) {  // x + NaN => NaN
-        return Replace(m.right().node());
+        // Do some calculation to make a signalling NaN quiet.
+        return ReplaceFloat64(m.right().Value() - m.right().Value());
       }
       if (m.IsFoldable()) {  // K + K => K
         return ReplaceFloat64(m.left().Value() + m.right().Value());
@@ -359,14 +363,17 @@ Reduction MachineOperatorReducer::Reduce(Node* node) {
     }
     case IrOpcode::kFloat64Sub: {
       Float64BinopMatcher m(node);
-      if (m.right().Is(0) && (Double(m.right().Value()).Sign() > 0)) {
+      if (allow_signalling_nan_ && m.right().Is(0) &&
+          (Double(m.right().Value()).Sign() > 0)) {
         return Replace(m.left().node());  // x - 0 => x
       }
       if (m.right().IsNaN()) {  // x - NaN => NaN
-        return Replace(m.right().node());
+        // Do some calculation to make a signalling NaN quiet.
+        return ReplaceFloat64(m.right().Value() - m.right().Value());
       }
       if (m.left().IsNaN()) {  // NaN - x => NaN
-        return Replace(m.left().node());
+        // Do some calculation to make a signalling NaN quiet.
+        return ReplaceFloat64(m.left().Value() - m.left().Value());
       }
       if (m.IsFoldable()) {  // L - R => (L - R)
         return ReplaceFloat64(m.left().Value() - m.right().Value());
@@ -392,15 +399,17 @@ Reduction MachineOperatorReducer::Reduce(Node* node) {
     }
     case IrOpcode::kFloat64Mul: {
       Float64BinopMatcher m(node);
+      if (allow_signalling_nan_ && m.right().Is(1))
+        return Replace(m.left().node());  // x * 1.0 => x
       if (m.right().Is(-1)) {  // x * -1.0 => -0.0 - x
         node->ReplaceInput(0, Float64Constant(-0.0));
         node->ReplaceInput(1, m.left().node());
         NodeProperties::ChangeOp(node, machine()->Float64Sub());
         return Changed(node);
       }
-      if (m.right().Is(1)) return Replace(m.left().node());  // x * 1.0 => x
       if (m.right().IsNaN()) {                               // x * NaN => NaN
-        return Replace(m.right().node());
+        // Do some calculation to make a signalling NaN quiet.
+        return ReplaceFloat64(m.right().Value() - m.right().Value());
       }
       if (m.IsFoldable()) {  // K * K => K
         return ReplaceFloat64(m.left().Value() * m.right().Value());
@@ -414,12 +423,16 @@ Reduction MachineOperatorReducer::Reduce(Node* node) {
     }
     case IrOpcode::kFloat64Div: {
       Float64BinopMatcher m(node);
-      if (m.right().Is(1)) return Replace(m.left().node());  // x / 1.0 => x
+      if (allow_signalling_nan_ && m.right().Is(1))
+        return Replace(m.left().node());  // x / 1.0 => x
+      // TODO(ahaas): We could do x / 1.0 = x if we knew that x is not an sNaN.
       if (m.right().IsNaN()) {                               // x / NaN => NaN
-        return Replace(m.right().node());
+        // Do some calculation to make a signalling NaN quiet.
+        return ReplaceFloat64(m.right().Value() - m.right().Value());
       }
       if (m.left().IsNaN()) {  // NaN / x => NaN
-        return Replace(m.left().node());
+        // Do some calculation to make a signalling NaN quiet.
+        return ReplaceFloat64(m.left().Value() - m.left().Value());
       }
       if (m.IsFoldable()) {  // K / K => K
         return ReplaceFloat64(m.left().Value() / m.right().Value());
@@ -664,6 +677,8 @@ Reduction MachineOperatorReducer::Reduce(Node* node) {
     case IrOpcode::kFloat64LessThan:
     case IrOpcode::kFloat64LessThanOrEqual:
       return ReduceFloat64Compare(node);
+    case IrOpcode::kFloat64RoundDown:
+      return ReduceFloat64RoundDown(node);
     default:
       break;
   }
@@ -841,14 +856,13 @@ Reduction MachineOperatorReducer::ReduceInt32Mod(Node* node) {
     if (base::bits::IsPowerOfTwo32(divisor)) {
       uint32_t const mask = divisor - 1;
       Node* const zero = Int32Constant(0);
-      node->ReplaceInput(
-          0, graph()->NewNode(machine()->Int32LessThan(), dividend, zero));
-      node->ReplaceInput(
-          1, Int32Sub(zero, Word32And(Int32Sub(zero, dividend), mask)));
-      node->ReplaceInput(2, Word32And(dividend, mask));
-      NodeProperties::ChangeOp(
-          node,
-          common()->Select(MachineRepresentation::kWord32, BranchHint::kFalse));
+      Diamond d(graph(), common(),
+                graph()->NewNode(machine()->Int32LessThan(), dividend, zero),
+                BranchHint::kFalse);
+      return Replace(
+          d.Phi(MachineRepresentation::kWord32,
+                Int32Sub(zero, Word32And(Int32Sub(zero, dividend), mask)),
+                Word32And(dividend, mask)));
     } else {
       Node* quotient = Int32Div(dividend, divisor);
       DCHECK_EQ(dividend, node->InputAt(0));
@@ -1392,6 +1406,14 @@ Reduction MachineOperatorReducer::ReduceFloat64Compare(Node* node) {
   return NoChange();
 }
 
+Reduction MachineOperatorReducer::ReduceFloat64RoundDown(Node* node) {
+  DCHECK_EQ(IrOpcode::kFloat64RoundDown, node->opcode());
+  Float64Matcher m(node->InputAt(0));
+  if (m.HasValue()) {
+    return ReplaceFloat64(Floor(m.Value()));
+  }
+  return NoChange();
+}
 
 CommonOperatorBuilder* MachineOperatorReducer::common() const {
   return jsgraph()->common();