[x86] Faster/shorter code for stack checks.

Avoid loading the stack pointer and the stack limit into allocatable
registers first, but generate a cmp rsp,[limit] instead.

R=dcarney@chromium.org

Review URL: https://codereview.chromium.org/989203002

Cr-Commit-Position: refs/heads/master@{#27065}

src/compiler/ia32/code-generator-ia32.cc

@@ -730,6 +730,12 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
     case kCheckedStoreFloat64:
       ASSEMBLE_CHECKED_STORE_FLOAT(movsd);
       break;
+    case kIA32StackCheck: {
+      ExternalReference const stack_limit =
+          ExternalReference::address_of_stack_limit(isolate());
+      __ cmp(esp, Operand::StaticVariable(stack_limit));
+      break;
+    }
   }
 }
 

src/compiler/ia32/instruction-codes-ia32.h

@@ -66,7 +66,8 @@ namespace compiler {
   V(IA32Movsd)                     \
   V(IA32Lea)                       \
   V(IA32Push)                      \
-  V(IA32StoreWriteBarrier)
+  V(IA32StoreWriteBarrier)         \
+  V(IA32StackCheck)
 
 
 // Addressing modes represent the "shape" of inputs to an instruction.

src/compiler/ia32/instruction-selector-ia32.cc

@@ -841,6 +841,26 @@ void VisitWordCompare(InstructionSelector* selector, Node* node,
 
 void VisitWordCompare(InstructionSelector* selector, Node* node,
                       FlagsContinuation* cont) {
+  IA32OperandGenerator g(selector);
+  Int32BinopMatcher m(node);
+  if (m.left().IsLoad() && m.right().IsLoadStackPointer()) {
+    LoadMatcher<ExternalReferenceMatcher> mleft(m.left().node());
+    ExternalReference js_stack_limit =
+        ExternalReference::address_of_stack_limit(selector->isolate());
+    if (mleft.object().Is(js_stack_limit) && mleft.index().Is(0)) {
+      // Compare(Load(js_stack_limit), LoadStackPointer)
+      if (!node->op()->HasProperty(Operator::kCommutative)) cont->Commute();
+      InstructionCode opcode = cont->Encode(kIA32StackCheck);
+      if (cont->IsBranch()) {
+        selector->Emit(opcode, g.NoOutput(), g.Label(cont->true_block()),
+                       g.Label(cont->false_block()))->MarkAsControl();
+      } else {
+        DCHECK(cont->IsSet());
+        selector->Emit(opcode, g.DefineAsRegister(cont->result()));
+      }
+      return;
+    }
+  }
   VisitWordCompare(selector, node, kIA32Cmp, cont);
 }
 

src/compiler/instruction-selector.h

@@ -129,6 +129,8 @@ class InstructionSelector FINAL {
   int GetVirtualRegister(const Node* node);
   const std::map<NodeId, int> GetVirtualRegistersForTesting() const;
 
+  Isolate* isolate() const { return sequence()->isolate(); }
+
  private:
   friend class OperandGenerator;
 

src/compiler/node-matchers.h

@@ -7,6 +7,8 @@
 
 #include <cmath>
 
+// TODO(turbofan): Move ExternalReference out of assembler.h
+#include "src/assembler.h"
 #include "src/compiler/node.h"
 #include "src/compiler/operator.h"
 #include "src/unique.h"
@@ -155,6 +157,32 @@ struct HeapObjectMatcher FINAL
 };
 
 
+// A pattern matcher for external reference constants.
+struct ExternalReferenceMatcher FINAL
+    : public ValueMatcher<ExternalReference, IrOpcode::kExternalConstant> {
+  explicit ExternalReferenceMatcher(Node* node)
+      : ValueMatcher<ExternalReference, IrOpcode::kExternalConstant>(node) {}
+};
+
+
+// For shorter pattern matching code, this struct matches the inputs to
+// machine-level load operations.
+template <typename Object>
+struct LoadMatcher : public NodeMatcher {
+  explicit LoadMatcher(Node* node)
+      : NodeMatcher(node), object_(InputAt(0)), index_(InputAt(1)) {}
+
+  typedef Object ObjectMatcher;
+
+  Object const& object() const { return object_; }
+  IntPtrMatcher const& index() const { return index_; }
+
+ private:
+  Object const object_;
+  IntPtrMatcher const index_;
+};
+
+
 // For shorter pattern matching code, this struct matches both the left and
 // right hand sides of a binary operation and can put constants on the right
 // if they appear on the left hand side of a commutative operation.

src/compiler/raw-machine-assembler.h

@@ -90,6 +90,9 @@ class RawMachineAssembler : public GraphBuilder {
     Unique<HeapObject> val = Unique<HeapObject>::CreateUninitialized(object);
     return NewNode(common()->HeapConstant(val));
   }
+  Node* ExternalConstant(ExternalReference address) {
+    return NewNode(common()->ExternalConstant(address));
+  }
 
   Node* Projection(int index, Node* a) {
     return NewNode(common()->Projection(index), a);
@@ -97,14 +100,14 @@ class RawMachineAssembler : public GraphBuilder {
 
   // Memory Operations.
   Node* Load(MachineType rep, Node* base) {
-    return Load(rep, base, Int32Constant(0));
+    return Load(rep, base, IntPtrConstant(0));
   }
   Node* Load(MachineType rep, Node* base, Node* index) {
     return NewNode(machine()->Load(rep), base, index, graph()->start(),
                    graph()->start());
   }
   void Store(MachineType rep, Node* base, Node* value) {
-    Store(rep, base, Int32Constant(0), value);
+    Store(rep, base, IntPtrConstant(0), value);
   }
   void Store(MachineType rep, Node* base, Node* index, Node* value) {
     NewNode(machine()->Store(StoreRepresentation(rep, kNoWriteBarrier)), base,
@@ -281,6 +284,9 @@ class RawMachineAssembler : public GraphBuilder {
   Node* Int64LessThan(Node* a, Node* b) {
     return NewNode(machine()->Int64LessThan(), a, b);
   }
+  Node* Uint64LessThan(Node* a, Node* b) {
+    return NewNode(machine()->Uint64LessThan(), a, b);
+  }
   Node* Int64LessThanOrEqual(Node* a, Node* b) {
     return NewNode(machine()->Int64LessThanOrEqual(), a, b);
   }
@@ -407,6 +413,9 @@ class RawMachineAssembler : public GraphBuilder {
     return NewNode(machine()->Float64InsertHighWord32(), a, b);
   }
 
+  // Stack operations.
+  Node* LoadStackPointer() { return NewNode(machine()->LoadStackPointer()); }
+
   // Parameters.
   Node* Parameter(size_t index);
 

src/compiler/x64/code-generator-x64.cc

@@ -1051,6 +1051,9 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
     case kCheckedStoreFloat64:
       ASSEMBLE_CHECKED_STORE_FLOAT(movsd);
       break;
+    case kX64StackCheck:
+      __ CompareRoot(rsp, Heap::kStackLimitRootIndex);
+      break;
   }
 }  // NOLINT(readability/fn_size)
 

src/compiler/x64/instruction-codes-x64.h

@@ -87,7 +87,8 @@ namespace compiler {
   V(X64Dec32)                      \
   V(X64Inc32)                      \
   V(X64Push)                       \
-  V(X64StoreWriteBarrier)
+  V(X64StoreWriteBarrier)          \
+  V(X64StackCheck)
 
 
 // Addressing modes represent the "shape" of inputs to an instruction.

src/compiler/x64/instruction-selector-x64.cc

@@ -987,8 +987,10 @@ void InstructionSelector::VisitCall(Node* node, BasicBlock* handler) {
 }
 
 
+namespace {
+
 // Shared routine for multiple compare operations.
-static void VisitCompare(InstructionSelector* selector, InstructionCode opcode,
+void VisitCompare(InstructionSelector* selector, InstructionCode opcode,
                   InstructionOperand left, InstructionOperand right,
                   FlagsContinuation* cont) {
   X64OperandGenerator g(selector);
@@ -1005,7 +1007,7 @@ static void VisitCompare(InstructionSelector* selector, InstructionCode opcode,
 
 
 // Shared routine for multiple compare operations.
-static void VisitCompare(InstructionSelector* selector, InstructionCode opcode,
+void VisitCompare(InstructionSelector* selector, InstructionCode opcode,
                   Node* left, Node* right, FlagsContinuation* cont,
                   bool commutative) {
   X64OperandGenerator g(selector);
@@ -1017,7 +1019,7 @@ static void VisitCompare(InstructionSelector* selector, InstructionCode opcode,
 
 
 // Shared routine for multiple word compare operations.
-static void VisitWordCompare(InstructionSelector* selector, Node* node,
+void VisitWordCompare(InstructionSelector* selector, Node* node,
                       InstructionCode opcode, FlagsContinuation* cont) {
   X64OperandGenerator g(selector);
   Node* const left = node->InputAt(0);
@@ -1036,8 +1038,35 @@ static void VisitWordCompare(InstructionSelector* selector, Node* node,
 }
 
 
+// Shared routine for 64-bit word comparison operations.
+void VisitWord64Compare(InstructionSelector* selector, Node* node,
+                        FlagsContinuation* cont) {
+  X64OperandGenerator g(selector);
+  Int64BinopMatcher m(node);
+  if (m.left().IsLoad() && m.right().IsLoadStackPointer()) {
+    LoadMatcher<ExternalReferenceMatcher> mleft(m.left().node());
+    ExternalReference js_stack_limit =
+        ExternalReference::address_of_stack_limit(selector->isolate());
+    if (mleft.object().Is(js_stack_limit) && mleft.index().Is(0)) {
+      // Compare(Load(js_stack_limit), LoadStackPointer)
+      if (!node->op()->HasProperty(Operator::kCommutative)) cont->Commute();
+      InstructionCode opcode = cont->Encode(kX64StackCheck);
+      if (cont->IsBranch()) {
+        selector->Emit(opcode, g.NoOutput(), g.Label(cont->true_block()),
+                       g.Label(cont->false_block()))->MarkAsControl();
+      } else {
+        DCHECK(cont->IsSet());
+        selector->Emit(opcode, g.DefineAsRegister(cont->result()));
+      }
+      return;
+    }
+  }
+  VisitWordCompare(selector, node, kX64Cmp, cont);
+}
+
+
 // Shared routine for comparison with zero.
-static void VisitCompareZero(InstructionSelector* selector, Node* node,
+void VisitCompareZero(InstructionSelector* selector, Node* node,
                       InstructionCode opcode, FlagsContinuation* cont) {
   X64OperandGenerator g(selector);
   VisitCompare(selector, opcode, g.Use(node), g.TempImmediate(0), cont);
@@ -1045,13 +1074,15 @@ static void VisitCompareZero(InstructionSelector* selector, Node* node,
 
 
 // Shared routine for multiple float64 compare operations (inputs commuted).
-static void VisitFloat64Compare(InstructionSelector* selector, Node* node,
+void VisitFloat64Compare(InstructionSelector* selector, Node* node,
                          FlagsContinuation* cont) {
   Node* const left = node->InputAt(0);
   Node* const right = node->InputAt(1);
   VisitCompare(selector, kSSEFloat64Cmp, right, left, cont, false);
 }
 
+}  // namespace
+
 
 void InstructionSelector::VisitBranch(Node* branch, BasicBlock* tbranch,
                                       BasicBlock* fbranch) {
@@ -1093,16 +1124,16 @@ void InstructionSelector::VisitBranch(Node* branch, BasicBlock* tbranch,
         return VisitWordCompare(this, value, kX64Cmp32, &cont);
       case IrOpcode::kWord64Equal:
         cont.OverwriteAndNegateIfEqual(kEqual);
-        return VisitWordCompare(this, value, kX64Cmp, &cont);
+        return VisitWord64Compare(this, value, &cont);
       case IrOpcode::kInt64LessThan:
         cont.OverwriteAndNegateIfEqual(kSignedLessThan);
-        return VisitWordCompare(this, value, kX64Cmp, &cont);
+        return VisitWord64Compare(this, value, &cont);
       case IrOpcode::kInt64LessThanOrEqual:
         cont.OverwriteAndNegateIfEqual(kSignedLessThanOrEqual);
-        return VisitWordCompare(this, value, kX64Cmp, &cont);
+        return VisitWord64Compare(this, value, &cont);
       case IrOpcode::kUint64LessThan:
         cont.OverwriteAndNegateIfEqual(kUnsignedLessThan);
-        return VisitWordCompare(this, value, kX64Cmp, &cont);
+        return VisitWord64Compare(this, value, &cont);
       case IrOpcode::kFloat64Equal:
         cont.OverwriteAndNegateIfEqual(kUnorderedEqual);
         return VisitFloat64Compare(this, value, &cont);
@@ -1140,7 +1171,7 @@ void InstructionSelector::VisitBranch(Node* branch, BasicBlock* tbranch,
       case IrOpcode::kInt32Sub:
         return VisitWordCompare(this, value, kX64Cmp32, &cont);
       case IrOpcode::kInt64Sub:
-        return VisitWordCompare(this, value, kX64Cmp, &cont);
+        return VisitWord64Compare(this, value, &cont);
       case IrOpcode::kWord32And:
         return VisitWordCompare(this, value, kX64Test32, &cont);
       case IrOpcode::kWord64And:
@@ -1302,7 +1333,7 @@ void InstructionSelector::VisitWord64Equal(Node* const node) {
     if (CanCover(user, value)) {
       switch (value->opcode()) {
         case IrOpcode::kInt64Sub:
-          return VisitWordCompare(this, value, kX64Cmp, &cont);
+          return VisitWord64Compare(this, value, &cont);
         case IrOpcode::kWord64And:
           return VisitWordCompare(this, value, kX64Test, &cont);
         default:
@@ -1311,7 +1342,7 @@ void InstructionSelector::VisitWord64Equal(Node* const node) {
     }
     return VisitCompareZero(this, value, kX64Cmp, &cont);
   }
-  VisitWordCompare(this, node, kX64Cmp, &cont);
+  VisitWord64Compare(this, node, &cont);
 }
 
 
@@ -1337,19 +1368,19 @@ void InstructionSelector::VisitInt32SubWithOverflow(Node* node) {
 
 void InstructionSelector::VisitInt64LessThan(Node* node) {
   FlagsContinuation cont(kSignedLessThan, node);
-  VisitWordCompare(this, node, kX64Cmp, &cont);
+  VisitWord64Compare(this, node, &cont);
 }
 
 
 void InstructionSelector::VisitInt64LessThanOrEqual(Node* node) {
   FlagsContinuation cont(kSignedLessThanOrEqual, node);
-  VisitWordCompare(this, node, kX64Cmp, &cont);
+  VisitWord64Compare(this, node, &cont);
 }
 
 
 void InstructionSelector::VisitUint64LessThan(Node* node) {
   FlagsContinuation cont(kUnsignedLessThan, node);
-  VisitWordCompare(this, node, kX64Cmp, &cont);
+  VisitWord64Compare(this, node, &cont);
 }
 
 

test/unittests/compiler/ia32/instruction-selector-ia32-unittest.cc

@@ -666,6 +666,29 @@ TEST_F(InstructionSelectorTest, Float64BinopArithmetic) {
   }
 }
 
+
+// -----------------------------------------------------------------------------
+// Miscellaneous.
+
+
+TEST_F(InstructionSelectorTest, Uint32LessThanWithLoadAndLoadStackPointer) {
+  StreamBuilder m(this, kMachBool);
+  Node* const sl = m.Load(
+      kMachPtr,
+      m.ExternalConstant(ExternalReference::address_of_stack_limit(isolate())));
+  Node* const sp = m.LoadStackPointer();
+  Node* const n = m.Uint32LessThan(sl, sp);
+  m.Return(n);
+  Stream s = m.Build();
+  ASSERT_EQ(1U, s.size());
+  EXPECT_EQ(kIA32StackCheck, s[0]->arch_opcode());
+  ASSERT_EQ(0U, s[0]->InputCount());
+  ASSERT_EQ(1U, s[0]->OutputCount());
+  EXPECT_EQ(s.ToVreg(n), s.ToVreg(s[0]->Output()));
+  EXPECT_EQ(kFlags_set, s[0]->flags_mode());
+  EXPECT_EQ(kUnsignedGreaterThan, s[0]->flags_condition());
+}
+
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8

test/unittests/compiler/x64/instruction-selector-x64-unittest.cc

@@ -1030,6 +1030,25 @@ TEST_F(InstructionSelectorTest, Float64BinopArithmetic) {
 // Miscellaneous.
 
 
+TEST_F(InstructionSelectorTest, Uint64LessThanWithLoadAndLoadStackPointer) {
+  StreamBuilder m(this, kMachBool);
+  Node* const sl = m.Load(
+      kMachPtr,
+      m.ExternalConstant(ExternalReference::address_of_stack_limit(isolate())));
+  Node* const sp = m.LoadStackPointer();
+  Node* const n = m.Uint64LessThan(sl, sp);
+  m.Return(n);
+  Stream s = m.Build();
+  ASSERT_EQ(1U, s.size());
+  EXPECT_EQ(kX64StackCheck, s[0]->arch_opcode());
+  ASSERT_EQ(0U, s[0]->InputCount());
+  ASSERT_EQ(1U, s[0]->OutputCount());
+  EXPECT_EQ(s.ToVreg(n), s.ToVreg(s[0]->Output()));
+  EXPECT_EQ(kFlags_set, s[0]->flags_mode());
+  EXPECT_EQ(kUnsignedGreaterThan, s[0]->flags_condition());
+}
+
+
 TEST_F(InstructionSelectorTest, Word64ShlWithChangeInt32ToInt64) {
   TRACED_FORRANGE(int64_t, x, 32, 63) {
     StreamBuilder m(this, kMachInt64, kMachInt32);