Fast compiler: Load globals variables directly from property cells.

This is a first step towards loading globals directly from property cells instead
of going through a load IC.

This change supports only properties with the DontDelete attribute since
we are only able to bailout into the generic code generated by the secondary 
code generator the beginning of a function. The resulting fast-case code is 
specialized for a specific context. When invoked with a different global object, 
it will always bailout to the secondary code.

When loading a property that does not exist at compile-time or a property
that is deleteable we still generate the generic load IC.

Review URL: http://codereview.chromium.org/565034

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3808 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/fast-codegen-arm.cc

@@ -48,42 +48,48 @@ void FastCodeGenerator::EmitReceiverMapCheck() {
     PrintF("MapCheck(this)\n");
   }
 
+  ASSERT(info()->has_receiver() && info()->receiver()->IsHeapObject());
+  Handle<HeapObject> object = Handle<HeapObject>::cast(info()->receiver());
+  Handle<Map> map(object->map());
+
   EmitLoadReceiver(r1);
-  __ BranchOnSmi(r1, bailout());
+  __ CheckMap(r1, r3, map, bailout(), false);
+}
 
-  ASSERT(has_receiver() && receiver()->IsHeapObject());
-  Handle<HeapObject> object = Handle<HeapObject>::cast(receiver());
-  Handle<Map> map(object->map());
-  __ ldr(r3, FieldMemOperand(r1, HeapObject::kMapOffset));
-  __ mov(ip, Operand(map));
-  __ cmp(r3, ip);
-  __ b(ne, bailout());
+
+void FastCodeGenerator::EmitGlobalMapCheck() {
+  Comment cmnt(masm(), ";; GlobalMapCheck");
+  if (FLAG_print_ir) {
+    PrintF(";; GlobalMapCheck()");
+  }
+
+  ASSERT(info()->has_global_object());
+  Handle<Map> map(info()->global_object()->map());
+
+  __ ldr(r3, CodeGenerator::GlobalObject());
+  __ CheckMap(r3, r3, map, bailout(), true);
 }
 
 
-void FastCodeGenerator::EmitGlobalVariableLoad(Handle<String> name) {
-  // Compile global variable accesses as load IC calls.  The only live
-  // registers are cp (context) and possibly r1 (this).  Both are also saved
-  // in the stack and cp is preserved by the call.
-  __ ldr(ip, CodeGenerator::GlobalObject());
-  __ push(ip);
-  __ mov(r2, Operand(name));
-  Handle<Code> ic(Builtins::builtin(Builtins::LoadIC_Initialize));
-  __ Call(ic, RelocInfo::CODE_TARGET_CONTEXT);
-  if (has_this_properties()) {
-    // Restore this.
-    EmitLoadReceiver(r1);
+void FastCodeGenerator::EmitGlobalVariableLoad(Handle<Object> cell) {
+  ASSERT(cell->IsJSGlobalPropertyCell());
+  __ mov(r0, Operand(cell));
+  __ ldr(r0, FieldMemOperand(r0, JSGlobalPropertyCell::kValueOffset));
+  if (FLAG_debug_code) {
+    __ mov(ip, Operand(Factory::the_hole_value()));
+    __ cmp(r0, ip);
+    __ Check(ne, "DontDelete cells can't contain the hole");
   }
 }
 
 
 void FastCodeGenerator::EmitThisPropertyStore(Handle<String> name) {
   LookupResult lookup;
-  receiver()->Lookup(*name, &lookup);
+  info()->receiver()->Lookup(*name, &lookup);
 
-  ASSERT(lookup.holder() == *receiver());
+  ASSERT(lookup.holder() == *info()->receiver());
   ASSERT(lookup.type() == FIELD);
-  Handle<Map> map(Handle<HeapObject>::cast(receiver())->map());
+  Handle<Map> map(Handle<HeapObject>::cast(info()->receiver())->map());
   int index = lookup.GetFieldIndex() - map->inobject_properties();
   int offset = index * kPointerSize;
 
@@ -102,9 +108,9 @@ void FastCodeGenerator::EmitThisPropertyStore(Handle<String> name) {
 }
 
 
-void FastCodeGenerator::Generate(CompilationInfo* info) {
+void FastCodeGenerator::Generate(CompilationInfo* compilation_info) {
   ASSERT(info_ == NULL);
-  info_ = info;
+  info_ = compilation_info;
 
   // Save the caller's frame pointer and set up our own.
   Comment prologue_cmnt(masm(), ";; Prologue");
@@ -114,7 +120,11 @@ void FastCodeGenerator::Generate(CompilationInfo* info) {
   // this point.
 
   // Receiver (this) is allocated to r1 if there are this properties.
-  if (has_this_properties()) EmitReceiverMapCheck();
+  if (info()->has_this_properties()) EmitReceiverMapCheck();
+
+  // If there is a global variable access check if the global object
+  // is the same as at lazy-compilation time.
+  if (info()->has_globals()) EmitGlobalMapCheck();
 
   VisitStatements(function()->body());
 

src/arm/macro-assembler-arm.cc

@@ -1064,6 +1064,21 @@ void MacroAssembler::CompareInstanceType(Register map,
 }
 
 
+void MacroAssembler::CheckMap(Register obj,
+                              Register scratch,
+                              Handle<Map> map,
+                              Label* fail,
+                              bool is_heap_object) {
+  if (!is_heap_object) {
+    BranchOnSmi(obj, fail);
+  }
+  ldr(scratch, FieldMemOperand(obj, HeapObject::kMapOffset));
+  mov(ip, Operand(map));
+  cmp(scratch, ip);
+  b(ne, fail);
+}
+
+
 void MacroAssembler::TryGetFunctionPrototype(Register function,
                                              Register result,
                                              Register scratch,

src/arm/macro-assembler-arm.h

@@ -270,6 +270,15 @@ class MacroAssembler: public Assembler {
                            InstanceType type);
 
 
+  // Check if the map of an object is equal to a specified map and
+  // branch to label if not. Skip the smi check if not required
+  // (object is known to be a heap object)
+  void CheckMap(Register obj,
+                Register scratch,
+                Handle<Map> map,
+                Label* fail,
+                bool is_heap_object);
+
   // Load and check the instance type of an object for being a string.
   // Loads the type into the second argument register.
   // Returns a condition that will be enabled if the object was a string.

src/compiler.h

@@ -121,6 +121,14 @@ class CompilationInfo BASE_EMBEDDED {
   bool has_this_properties() { return has_this_properties_; }
   void set_has_this_properties(bool flag) { has_this_properties_ = flag; }
 
+  bool has_global_object() {
+    return !closure().is_null() && (closure()->context()->global() != NULL);
+  }
+
+  GlobalObject* global_object() {
+    return has_global_object() ? closure()->context()->global() : NULL;
+  }
+
   bool has_globals() { return has_globals_; }
   void set_has_globals(bool flag) { has_globals_ = flag; }
 

src/data-flow.cc

@@ -163,6 +163,10 @@ void AstLabeler::VisitSlot(Slot* expr) {
 
 void AstLabeler::VisitVariableProxy(VariableProxy* expr) {
   expr->set_num(next_number_++);
+  Variable* var = expr->var();
+  if (var->is_global() && !var->is_this()) {
+    info_->set_has_globals(true);
+  }
 }
 
 

src/fast-codegen.cc

@@ -214,7 +214,16 @@ void FastCodeGenSyntaxChecker::VisitSlot(Slot* expr) {
 void FastCodeGenSyntaxChecker::VisitVariableProxy(VariableProxy* expr) {
   // Only global variable references are supported.
   Variable* var = expr->var();
-  if (!var->is_global()) BAILOUT("Non-global variable");
+  if (!var->is_global() || var->is_this()) BAILOUT("Non-global variable");
+
+  // Check if the global variable is existing and non-deletable.
+  if (info()->has_global_object()) {
+    LookupResult lookup;
+    info()->global_object()->Lookup(*expr->name(), &lookup);
+    if (!lookup.IsValid() || !lookup.IsDontDelete()) {
+      BAILOUT("Non-existing or deletable global variable");
+    }
+  }
 }
 
 
@@ -485,7 +494,16 @@ void FastCodeGenerator::VisitVariableProxy(VariableProxy* expr) {
     SmartPointer<char> name = expr->name()->ToCString();
     PrintF("%d: t%d = Global(%s)\n", expr->num(), expr->num(), *name);
   }
-  EmitGlobalVariableLoad(expr->name());
+
+  // Check if we can compile a global variable load directly from the cell.
+  ASSERT(info()->has_global_object());
+  LookupResult lookup;
+  info()->global_object()->Lookup(*expr->name(), &lookup);
+  // We only support DontDelete properties for now.
+  ASSERT(lookup.IsValid());
+  ASSERT(lookup.IsDontDelete());
+  Handle<Object> cell(info()->global_object()->GetPropertyCell(&lookup));
+  EmitGlobalVariableLoad(cell);
 }
 
 

src/fast-codegen.h

@@ -69,15 +69,13 @@ class FastCodeGenerator: public AstVisitor {
 
   static Handle<Code> MakeCode(CompilationInfo* info);
 
-  void Generate(CompilationInfo* info);
+  void Generate(CompilationInfo* compilation_info);
 
  private:
   MacroAssembler* masm() { return masm_; }
+  CompilationInfo* info() { return info_; }
   Label* bailout() { return &bailout_; }
 
-  bool has_receiver() { return !info_->receiver().is_null(); }
-  Handle<Object> receiver() { return info_->receiver(); }
-  bool has_this_properties() { return info_->has_this_properties(); }
   FunctionLiteral* function() { return info_->function(); }
   Scope* scope() { return info_->scope(); }
 
@@ -94,11 +92,13 @@ class FastCodeGenerator: public AstVisitor {
   // arm-r1}.  Emit a branch to the (single) bailout label if check fails.
   void EmitReceiverMapCheck();
 
-  // Emit code to load a global variable value into {is32-eax, x64-rax,
-  // arm-r0}.  Register {ia32-edx, x64-rdx, arm-r1} is preserved if it is
-  // holding the receiver and {is32-ecx, x64-rcx, arm-r2} is always
-  // clobbered.
-  void EmitGlobalVariableLoad(Handle<String> name);
+  // Emit code to check that the global object has the same map as the
+  // global object seen at compile time.
+  void EmitGlobalMapCheck();
+
+  // Emit code to load a global variable directly from a global
+  // property cell into {ia32-eax, x64-rax, arm-r0}.
+  void EmitGlobalVariableLoad(Handle<Object> cell);
 
   // Emit a store to an own property of this.  The stored value is expected
   // in {ia32-eax, x64-rax, arm-r0} and the receiver in {is32-edx, x64-rdx,

src/ia32/fast-codegen-ia32.cc

@@ -48,42 +48,47 @@ void FastCodeGenerator::EmitReceiverMapCheck() {
     PrintF("MapCheck(this)\n");
   }
 
+  ASSERT(info()->has_receiver() && info()->receiver()->IsHeapObject());
+  Handle<HeapObject> object = Handle<HeapObject>::cast(info()->receiver());
+  Handle<Map> map(object->map());
+
   EmitLoadReceiver(edx);
-  __ test(edx, Immediate(kSmiTagMask));
-  __ j(zero, bailout());
+  __ CheckMap(edx, map, bailout(), false);
+}
 
-  ASSERT(has_receiver() && receiver()->IsHeapObject());
-  Handle<HeapObject> object = Handle<HeapObject>::cast(receiver());
-  Handle<Map> map(object->map());
-  __ cmp(FieldOperand(edx, HeapObject::kMapOffset), Immediate(map));
-  __ j(not_equal, bailout());
+
+void FastCodeGenerator::EmitGlobalMapCheck() {
+  Comment cmnt(masm(), ";; GlobalMapCheck");
+  if (FLAG_print_ir) {
+    PrintF(";; GlobalMapCheck()");
+  }
+
+  ASSERT(info()->has_global_object());
+  Handle<Map> map(info()->global_object()->map());
+
+  __ mov(ebx, CodeGenerator::GlobalObject());
+  __ CheckMap(ebx, map, bailout(), true);
 }
 
 
-void FastCodeGenerator::EmitGlobalVariableLoad(Handle<String> name) {
-  // Compile global variable accesses as load IC calls.  The only live
-  // registers are esi (context) and possibly edx (this).  Both are also
-  // saved in the stack and esi is preserved by the call.
-  __ push(CodeGenerator::GlobalObject());
-  __ mov(ecx, name);
-  Handle<Code> ic(Builtins::builtin(Builtins::LoadIC_Initialize));
-  __ call(ic, RelocInfo::CODE_TARGET_CONTEXT);
-  if (has_this_properties()) {
-    // Restore this.
-    EmitLoadReceiver(edx);
-  } else {
-    __ nop();  // Not test eax, indicates IC has no inlined code at call site.
+void FastCodeGenerator::EmitGlobalVariableLoad(Handle<Object> cell) {
+  ASSERT(cell->IsJSGlobalPropertyCell());
+  __ mov(eax, Immediate(cell));
+  __ mov(eax, FieldOperand(eax, JSGlobalPropertyCell::kValueOffset));
+  if (FLAG_debug_code) {
+    __ cmp(eax, Factory::the_hole_value());
+    __ Check(not_equal, "DontDelete cells can't contain the hole");
   }
 }
 
 
 void FastCodeGenerator::EmitThisPropertyStore(Handle<String> name) {
   LookupResult lookup;
-  receiver()->Lookup(*name, &lookup);
+  info()->receiver()->Lookup(*name, &lookup);
 
-  ASSERT(lookup.holder() == *receiver());
+  ASSERT(lookup.holder() == *info()->receiver());
   ASSERT(lookup.type() == FIELD);
-  Handle<Map> map(Handle<HeapObject>::cast(receiver())->map());
+  Handle<Map> map(Handle<HeapObject>::cast(info()->receiver())->map());
   int index = lookup.GetFieldIndex() - map->inobject_properties();
   int offset = index * kPointerSize;
 
@@ -103,9 +108,9 @@ void FastCodeGenerator::EmitThisPropertyStore(Handle<String> name) {
 }
 
 
-void FastCodeGenerator::Generate(CompilationInfo* info) {
+void FastCodeGenerator::Generate(CompilationInfo* compilation_info) {
   ASSERT(info_ == NULL);
-  info_ = info;
+  info_ = compilation_info;
 
   // Save the caller's frame pointer and set up our own.
   Comment prologue_cmnt(masm(), ";; Prologue");
@@ -117,7 +122,11 @@ void FastCodeGenerator::Generate(CompilationInfo* info) {
   // point.
 
   // Receiver (this) is allocated to edx if there are this properties.
-  if (has_this_properties()) EmitReceiverMapCheck();
+  if (info()->has_this_properties()) EmitReceiverMapCheck();
+
+  // If there is a global variable access check if the global object
+  // is the same as at lazy-compilation time.
+  if (info()->has_globals()) EmitGlobalMapCheck();
 
   VisitStatements(function()->body());
 

src/ia32/macro-assembler-ia32.cc

@@ -338,6 +338,19 @@ void MacroAssembler::CmpInstanceType(Register map, InstanceType type) {
 }
 
 
+void MacroAssembler::CheckMap(Register obj,
+                              Handle<Map> map,
+                              Label* fail,
+                              bool is_heap_object) {
+  if (!is_heap_object) {
+    test(obj, Immediate(kSmiTagMask));
+    j(zero, fail);
+  }
+  cmp(FieldOperand(obj, HeapObject::kMapOffset), Immediate(map));
+  j(not_equal, fail);
+}
+
+
 Condition MacroAssembler::IsObjectStringType(Register heap_object,
                                              Register map,
                                              Register instance_type) {

src/ia32/macro-assembler-ia32.h

@@ -141,6 +141,14 @@ class MacroAssembler: public Assembler {
   // Compare instance type for map.
   void CmpInstanceType(Register map, InstanceType type);
 
+  // Check if the map of an object is equal to a specified map and
+  // branch to label if not. Skip the smi check if not required
+  // (object is known to be a heap object)
+  void CheckMap(Register obj,
+                Handle<Map> map,
+                Label* fail,
+                bool is_heap_object);
+
   // Check if the object in register heap_object is a string. Afterwards the
   // register map contains the object map and the register instance_type
   // contains the instance_type. The registers map and instance_type can be the

src/x64/fast-codegen-x64.cc

@@ -48,41 +48,47 @@ void FastCodeGenerator::EmitReceiverMapCheck() {
     PrintF("MapCheck(this)\n");
   }
 
+  ASSERT(info()->has_receiver() && info()->receiver()->IsHeapObject());
+  Handle<HeapObject> object = Handle<HeapObject>::cast(info()->receiver());
+  Handle<Map> map(object->map());
+
   EmitLoadReceiver(rdx);
-  __ JumpIfSmi(rdx, bailout());
+  __ CheckMap(rdx, map, bailout(), false);
+}
 
-  ASSERT(has_receiver() && receiver()->IsHeapObject());
-  Handle<HeapObject> object = Handle<HeapObject>::cast(receiver());
-  Handle<Map> map(object->map());
-  __ Cmp(FieldOperand(rdx, HeapObject::kMapOffset), map);
-  __ j(not_equal, bailout());
+
+void FastCodeGenerator::EmitGlobalMapCheck() {
+  Comment cmnt(masm(), ";; GlobalMapCheck");
+  if (FLAG_print_ir) {
+    PrintF(";; GlobalMapCheck()");
+  }
+
+  ASSERT(info()->has_global_object());
+  Handle<Map> map(info()->global_object()->map());
+
+  __ movq(rbx, CodeGenerator::GlobalObject());
+  __ CheckMap(rbx, map, bailout(), true);
 }
 
 
-void FastCodeGenerator::EmitGlobalVariableLoad(Handle<String> name) {
-  // Compile global variable accesses as load IC calls.  The only live
-  // registers are rsi (context) and possibly rdx (this).  Both are also
-  // saved in the stack and rsi is preserved by the call.
-  __ push(CodeGenerator::GlobalObject());
-  __ Move(rcx, name);
-  Handle<Code> ic(Builtins::builtin(Builtins::LoadIC_Initialize));
-  __ Call(ic, RelocInfo::CODE_TARGET_CONTEXT);
-  if (has_this_properties()) {
-    // Restore this.
-    EmitLoadReceiver(rdx);
-  } else {
-    __ nop();  // Not test rax, indicates IC has no inlined code at call site.
+void FastCodeGenerator::EmitGlobalVariableLoad(Handle<Object> cell) {
+  ASSERT(cell->IsJSGlobalPropertyCell());
+  __ Move(rax, cell);
+  __ movq(rax, FieldOperand(rax, JSGlobalPropertyCell::kValueOffset));
+  if (FLAG_debug_code) {
+    __ Cmp(rax, Factory::the_hole_value());
+    __ Check(not_equal, "DontDelete cells can't contain the hole");
   }
 }
 
 
 void FastCodeGenerator::EmitThisPropertyStore(Handle<String> name) {
   LookupResult lookup;
-  receiver()->Lookup(*name, &lookup);
+  info()->receiver()->Lookup(*name, &lookup);
 
-  ASSERT(lookup.holder() == *receiver());
+  ASSERT(lookup.holder() == *info()->receiver());
   ASSERT(lookup.type() == FIELD);
-  Handle<Map> map(Handle<HeapObject>::cast(receiver())->map());
+  Handle<Map> map(Handle<HeapObject>::cast(info()->receiver())->map());
   int index = lookup.GetFieldIndex() - map->inobject_properties();
   int offset = index * kPointerSize;
 
@@ -102,9 +108,9 @@ void FastCodeGenerator::EmitThisPropertyStore(Handle<String> name) {
 }
 
 
-void FastCodeGenerator::Generate(CompilationInfo* info) {
+void FastCodeGenerator::Generate(CompilationInfo* compilation_info) {
   ASSERT(info_ == NULL);
-  info_ = info;
+  info_ = compilation_info;
 
   // Save the caller's frame pointer and set up our own.
   Comment prologue_cmnt(masm(), ";; Prologue");
@@ -116,9 +122,13 @@ void FastCodeGenerator::Generate(CompilationInfo* info) {
   // point.
 
   // Receiver (this) is allocated to rdx if there are this properties.
-  if (has_this_properties()) EmitReceiverMapCheck();
+  if (info()->has_this_properties()) EmitReceiverMapCheck();
+
+  // If there is a global variable access check if the global object
+  // is the same as at lazy-compilation time.
+  if (info()->has_globals()) EmitGlobalMapCheck();
 
-  VisitStatements(info->function()->body());
+  VisitStatements(info()->function()->body());
 
   Comment return_cmnt(masm(), ";; Return(<undefined>)");
   __ LoadRoot(rax, Heap::kUndefinedValueRootIndex);

src/x64/macro-assembler-x64.cc

@@ -1585,6 +1585,18 @@ void MacroAssembler::CmpInstanceType(Register map, InstanceType type) {
 }
 
 
+void MacroAssembler::CheckMap(Register obj,
+                              Handle<Map> map,
+                              Label* fail,
+                              bool is_heap_object) {
+  if (!is_heap_object) {
+    JumpIfSmi(obj, fail);
+  }
+  Cmp(FieldOperand(obj, HeapObject::kMapOffset), map);
+  j(not_equal, fail);
+}
+
+
 Condition MacroAssembler::IsObjectStringType(Register heap_object,
                                              Register map,
                                              Register instance_type) {

src/x64/macro-assembler-x64.h

@@ -460,6 +460,14 @@ class MacroAssembler: public Assembler {
   // Always use unsigned comparisons: above and below, not less and greater.
   void CmpInstanceType(Register map, InstanceType type);
 
+  // Check if the map of an object is equal to a specified map and
+  // branch to label if not. Skip the smi check if not required
+  // (object is known to be a heap object)
+  void CheckMap(Register obj,
+                Handle<Map> map,
+                Label* fail,
+                bool is_heap_object);
+
   // Check if the object in register heap_object is a string. Afterwards the
   // register map contains the object map and the register instance_type
   // contains the instance_type. The registers map and instance_type can be the

test/mjsunit/compiler/simple-global-access.js

+// Copyright 2010 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Flags: --fast-compiler
+
+// Test global variable loads with the fast compiler.
+var g1 = 42;
+var g2 = 43;
+var g3 = 44;
+
+function f1() { this.x = this.y = this.z = g1; }
+function f2() { this.x = g1; this.y = g2; this.z = g3; }
+
+var o = {x:0, y:0, z:0, m1:f1, m2:f2}
+
+o.m1();
+
+assertEquals(42, o.x);
+assertEquals(42, o.y);
+assertEquals(42, o.z);
+
+
+o.m2();
+
+assertEquals(42, o.x);
+assertEquals(43, o.y);
+assertEquals(44, o.z);

test/mjsunit/typeof.js

@@ -25,7 +25,7 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-// Flags: --nofast-compiler
+// Flags: --nofull-compiler
 
 // The type of a regular expression should be 'function', including in
 // the context of string equality comparisons.