[turbofan] Prevent storing signalling NaNs into holey double arrays.

src/compiler/instruction-selector.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/instruction-selector.h"
 
 #include <limits>
 
 #include "src/base/adapters.h"
 #include "src/compiler/instruction-selector-impl.h"
@@ skipping 1017 matching lines @@
     case IrOpcode::kChangeFloat32ToFloat64:
       return MarkAsFloat64(node), VisitChangeFloat32ToFloat64(node);
     case IrOpcode::kChangeInt32ToFloat64:
       return MarkAsFloat64(node), VisitChangeInt32ToFloat64(node);
     case IrOpcode::kChangeUint32ToFloat64:
       return MarkAsFloat64(node), VisitChangeUint32ToFloat64(node);
     case IrOpcode::kChangeFloat64ToInt32:
       return MarkAsWord32(node), VisitChangeFloat64ToInt32(node);
     case IrOpcode::kChangeFloat64ToUint32:
       return MarkAsWord32(node), VisitChangeFloat64ToUint32(node);
+    case IrOpcode::kFloat64SilenceNaN:
+      MarkAsFloat64(node);
+      if (CanProduceSignalingNaN(node->InputAt(0))) {
+        return VisitFloat64SilenceNaN(node);
+      } else {
+        return EmitIdentity(node);
+      }
     case IrOpcode::kTruncateFloat64ToUint32:
       return MarkAsWord32(node), VisitTruncateFloat64ToUint32(node);
     case IrOpcode::kTruncateFloat32ToInt32:
       return MarkAsWord32(node), VisitTruncateFloat32ToInt32(node);
     case IrOpcode::kTruncateFloat32ToUint32:
       return MarkAsWord32(node), VisitTruncateFloat32ToUint32(node);
     case IrOpcode::kTryTruncateFloat32ToInt64:
       return MarkAsWord64(node), VisitTryTruncateFloat32ToInt64(node);
     case IrOpcode::kTryTruncateFloat64ToInt64:
       return MarkAsWord64(node), VisitTryTruncateFloat64ToInt64(node);
@@ skipping 246 matching lines @@
 void InstructionSelector::VisitStackSlot(Node* node) {
   int size = 1 << ElementSizeLog2Of(StackSlotRepresentationOf(node->op()));
   int slot = frame_->AllocateSpillSlot(size);
   OperandGenerator g(this);
 
   Emit(kArchStackSlot, g.DefineAsRegister(node),
        sequence()->AddImmediate(Constant(slot)), 0, nullptr);
 }
 
 void InstructionSelector::VisitBitcastWordToTagged(Node* node) {
-  OperandGenerator g(this);
-  Node* value = node->InputAt(0);
-  Emit(kArchNop, g.DefineSameAsFirst(node), g.Use(value));
+  EmitIdentity(node);
 }
 
 // 32 bit targets do not implement the following instructions.
 #if V8_TARGET_ARCH_32_BIT
 
 void InstructionSelector::VisitWord64And(Node* node) { UNIMPLEMENTED(); }
 
 
 void InstructionSelector::VisitWord64Or(Node* node) { UNIMPLEMENTED(); }
 
@@ skipping 151 matching lines @@
 
 void InstructionSelector::VisitInt32PairMul(Node* node) { UNIMPLEMENTED(); }
 
 void InstructionSelector::VisitWord32PairShl(Node* node) { UNIMPLEMENTED(); }
 
 void InstructionSelector::VisitWord32PairShr(Node* node) { UNIMPLEMENTED(); }
 
 void InstructionSelector::VisitWord32PairSar(Node* node) { UNIMPLEMENTED(); }
 #endif  // V8_TARGET_ARCH_64_BIT
 
-void InstructionSelector::VisitFinishRegion(Node* node) {
-  OperandGenerator g(this);
-  Node* value = node->InputAt(0);
-  Emit(kArchNop, g.DefineSameAsFirst(node), g.Use(value));
-}
-
+void InstructionSelector::VisitFinishRegion(Node* node) { EmitIdentity(node); }
 
 void InstructionSelector::VisitParameter(Node* node) {
   OperandGenerator g(this);
   int index = ParameterIndexOf(node->op());
   InstructionOperand op =
       linkage()->ParameterHasSecondaryLocation(index)
           ? g.DefineAsDualLocation(
                 node, linkage()->GetParameterLocation(index),
                 linkage()->GetParameterSecondaryLocation(index))
           : g.DefineAsLocation(
@@ skipping 305 matching lines @@
       sequence()->AddFrameStateDescriptor(descriptor);
   args.push_back(g.TempImmediate(state_id.ToInt()));
   StateObjectDeduplicator deduplicator(instruction_zone());
   AddInputsToFrameStateDescriptor(descriptor, frame_state, &g, &deduplicator,
                                   &args, FrameStateInputKind::kAny,
                                   instruction_zone());
   return Emit(opcode, output_count, outputs, args.size(), &args.front(), 0,
               nullptr);
 }
 
+void InstructionSelector::EmitIdentity(Node* node) {
+  OperandGenerator g(this);
+  Node* value = node->InputAt(0);
+  Emit(kArchNop, g.DefineSameAsFirst(node), g.Use(value));
+}
+
 void InstructionSelector::VisitDeoptimize(DeoptimizeKind kind, Node* value) {
   InstructionCode opcode = kArchDeoptimize;
   switch (kind) {
     case DeoptimizeKind::kEager:
       opcode |= MiscField::encode(Deoptimizer::EAGER);
       break;
     case DeoptimizeKind::kSoft:
       opcode |= MiscField::encode(Deoptimizer::SOFT);
       break;
   }
@@ skipping 10 matching lines @@
   OperandGenerator g(this);
   Emit(kArchDebugBreak, g.NoOutput());
 }
 
 void InstructionSelector::VisitComment(Node* node) {
   OperandGenerator g(this);
   InstructionOperand operand(g.UseImmediate(node));
   Emit(kArchComment, 0, nullptr, 1, &operand);
 }
 
+bool InstructionSelector::CanProduceSignalingNaN(Node* node) {
+  // TODO(jarin) Improve the heuristic here.
+  if (node->opcode() == IrOpcode::kFloat64Add ||
+      node->opcode() == IrOpcode::kFloat64Sub ||
+      node->opcode() == IrOpcode::kFloat64Mul) {
+    return false;
+  }
+  return true;
+}
+
 FrameStateDescriptor* InstructionSelector::GetFrameStateDescriptor(
     Node* state) {
   DCHECK(state->opcode() == IrOpcode::kFrameState);
   DCHECK_EQ(kFrameStateInputCount, state->InputCount());
   FrameStateInfo state_info = OpParameter<FrameStateInfo>(state);
 
   int parameters = static_cast<int>(
       StateValuesAccess(state->InputAt(kFrameStateParametersInput)).size());
   int locals = static_cast<int>(
       StateValuesAccess(state->InputAt(kFrameStateLocalsInput)).size());
@@ skipping 12 matching lines @@
   return new (instruction_zone()) FrameStateDescriptor(
       instruction_zone(), state_info.type(), state_info.bailout_id(),
       state_info.state_combine(), parameters, locals, stack,
       state_info.shared_info(), outer_state);
 }
 
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8