Implement fast load and call of arguments in the presence of eval.

Load the arguments object from the context if there are no extensions
objects on the way. Then load the argument with a keyed load ic.

Review URL: http://codereview.chromium.org/2033004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4633 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/codegen-arm.cc

@@ -2776,22 +2776,15 @@ void CodeGenerator::LoadFromSlot(Slot* slot, TypeofState typeof_state) {
     // containing the eval.
     if (slot->var()->mode() == Variable::DYNAMIC_GLOBAL) {
       LoadFromGlobalSlotCheckExtensions(slot, typeof_state, &slow);
-      // If there was no control flow to slow, we can exit early.
-      if (!slow.is_linked()) {
-        frame_->EmitPush(r0);
-        return;
-      }
       frame_->SpillAll();
-
       done.Jump();
 
     } else if (slot->var()->mode() == Variable::DYNAMIC_LOCAL) {
       frame_->SpillAll();
       Slot* potential_slot = slot->var()->local_if_not_shadowed()->slot();
-      // Only generate the fast case for locals that rewrite to slots.
-      // This rules out argument loads because eval forces arguments
-      // access to be through the arguments object.
+      Expression* rewrite = slot->var()->local_if_not_shadowed()->rewrite();
       if (potential_slot != NULL) {
+        // Generate fast case for locals that rewrite to slots.
         __ ldr(r0,
                ContextSlotOperandCheckExtensions(potential_slot,
                                                  r1,
@@ -2802,10 +2795,32 @@ void CodeGenerator::LoadFromSlot(Slot* slot, TypeofState typeof_state) {
           __ cmp(r0, ip);
           __ LoadRoot(r0, Heap::kUndefinedValueRootIndex, eq);
         }
-        // There is always control flow to slow from
-        // ContextSlotOperandCheckExtensions so we have to jump around
-        // it.
         done.Jump();
+      } else if (rewrite != NULL) {
+        // Generate fast case for argument loads.
+        Property* property = rewrite->AsProperty();
+        if (property != NULL) {
+          VariableProxy* obj_proxy = property->obj()->AsVariableProxy();
+          Literal* key_literal = property->key()->AsLiteral();
+          if (obj_proxy != NULL &&
+              key_literal != NULL &&
+              obj_proxy->IsArguments() &&
+              key_literal->handle()->IsSmi()) {
+            // Load arguments object if there are no eval-introduced
+            // variables. Then load the argument from the arguments
+            // object using keyed load.
+            __ ldr(r0,
+                   ContextSlotOperandCheckExtensions(obj_proxy->var()->slot(),
+                                                     r1,
+                                                     r2,
+                                                     &slow));
+            frame_->EmitPush(r0);
+            __ mov(r1, Operand(key_literal->handle()));
+            frame_->EmitPush(r1);
+            EmitKeyedLoad();
+            done.Jump();
+          }
+        }
       }
     }
 
@@ -3708,12 +3723,12 @@ void CodeGenerator::VisitCall(Call* node) {
     // ----------------------------------
     // JavaScript examples:
     //
-    //  with (obj) foo(1, 2, 3)  // foo is in obj
+    //  with (obj) foo(1, 2, 3)  // foo may be in obj.
     //
     //  function f() {};
     //  function g() {
     //    eval(...);
-    //    f();  // f could be in extension object
+    //    f();  // f could be in extension object.
     //  }
     // ----------------------------------
 
@@ -3735,10 +3750,9 @@ void CodeGenerator::VisitCall(Call* node) {
 
     } else if (var->mode() == Variable::DYNAMIC_LOCAL) {
       Slot* potential_slot = var->local_if_not_shadowed()->slot();
-      // Only generate the fast case for locals that rewrite to slots.
-      // This rules out argument loads because eval forces arguments
-      // access to be through the arguments object.
+      Expression* rewrite = var->local_if_not_shadowed()->rewrite();
       if (potential_slot != NULL) {
+        // Generate fast case for locals that rewrite to slots.
         __ ldr(r0,
                ContextSlotOperandCheckExtensions(potential_slot,
                                                  r1,
@@ -3752,6 +3766,33 @@ void CodeGenerator::VisitCall(Call* node) {
         frame_->EmitPush(r0);
         LoadGlobalReceiver(r1);
         done.Jump();
+      } else if (rewrite != NULL) {
+        // Generate fast case for calls of an argument function.
+        Property* property = rewrite->AsProperty();
+        if (property != NULL) {
+          VariableProxy* obj_proxy = property->obj()->AsVariableProxy();
+          Literal* key_literal = property->key()->AsLiteral();
+          if (obj_proxy != NULL &&
+              key_literal != NULL &&
+              obj_proxy->IsArguments() &&
+              key_literal->handle()->IsSmi()) {
+            // Load arguments object if there are no eval-introduced
+            // variables. Then load the argument from the arguments
+            // object using keyed load.
+            __ ldr(r0,
+                   ContextSlotOperandCheckExtensions(obj_proxy->var()->slot(),
+                                                     r1,
+                                                     r2,
+                                                     &slow));
+            frame_->EmitPush(r0);
+            __ mov(r1, Operand(key_literal->handle()));
+            frame_->EmitPush(r1);
+            EmitKeyedLoad();
+            frame_->EmitPush(r0);
+            LoadGlobalReceiver(r1);
+            done.Jump();
+          }
+        }
       }
     }
 

src/ia32/codegen-ia32.cc

@@ -4731,16 +4731,13 @@ Result CodeGenerator::LoadFromSlot(Slot* slot, TypeofState typeof_state) {
     // containing the eval.
     if (slot->var()->mode() == Variable::DYNAMIC_GLOBAL) {
       result = LoadFromGlobalSlotCheckExtensions(slot, typeof_state, &slow);
-      // If there was no control flow to slow, we can exit early.
-      if (!slow.is_linked()) return result;
       done.Jump(&result);
 
     } else if (slot->var()->mode() == Variable::DYNAMIC_LOCAL) {
       Slot* potential_slot = slot->var()->local_if_not_shadowed()->slot();
-      // Only generate the fast case for locals that rewrite to slots.
-      // This rules out argument loads because eval forces arguments
-      // access to be through the arguments object.
+      Expression* rewrite = slot->var()->local_if_not_shadowed()->rewrite();
       if (potential_slot != NULL) {
+        // Generate fast case for locals that rewrite to slots.
         // Allocate a fresh register to use as a temp in
         // ContextSlotOperandCheckExtensions and to hold the result
         // value.
@@ -4755,10 +4752,32 @@ Result CodeGenerator::LoadFromSlot(Slot* slot, TypeofState typeof_state) {
           done.Branch(not_equal, &result);
           __ mov(result.reg(), Factory::undefined_value());
         }
-        // There is always control flow to slow from
-        // ContextSlotOperandCheckExtensions so we have to jump around
-        // it.
         done.Jump(&result);
+      } else if (rewrite != NULL) {
+        // Generate fast case for argument loads.
+        Property* property = rewrite->AsProperty();
+        if (property != NULL) {
+          VariableProxy* obj_proxy = property->obj()->AsVariableProxy();
+          Literal* key_literal = property->key()->AsLiteral();
+          if (obj_proxy != NULL &&
+              key_literal != NULL &&
+              obj_proxy->IsArguments() &&
+              key_literal->handle()->IsSmi()) {
+            // Load arguments object if there are no eval-introduced
+            // variables. Then load the argument from the arguments
+            // object using keyed load.
+            Result arguments = allocator()->Allocate();
+            ASSERT(arguments.is_valid());
+            __ mov(arguments.reg(),
+                   ContextSlotOperandCheckExtensions(obj_proxy->var()->slot(),
+                                                     arguments,
+                                                     &slow));
+            frame_->Push(&arguments);
+            frame_->Push(key_literal->handle());
+            result = EmitKeyedLoad();
+            done.Jump(&result);
+          }
+        }
       }
     }
 
@@ -5765,12 +5784,12 @@ void CodeGenerator::VisitCall(Call* node) {
     // ----------------------------------
     // JavaScript examples:
     //
-    //  with (obj) foo(1, 2, 3)  // foo is in obj
+    //  with (obj) foo(1, 2, 3)  // foo may be in obj.
     //
     //  function f() {};
     //  function g() {
     //    eval(...);
-    //    f();  // f could be in extension object
+    //    f();  // f could be in extension object.
     //  }
     // ----------------------------------
 
@@ -5782,9 +5801,8 @@ void CodeGenerator::VisitCall(Call* node) {
     // introducing variables.  In those cases, we do not want to
     // perform a runtime call for all variables in the scope
     // containing the eval.
-    Result function;
     if (var->mode() == Variable::DYNAMIC_GLOBAL) {
-      function = LoadFromGlobalSlotCheckExtensions(var->slot(),
+      Result function = LoadFromGlobalSlotCheckExtensions(var->slot(),
                                                           NOT_INSIDE_TYPEOF,
                                                           &slow);
       frame_->Push(&function);
@@ -5793,14 +5811,13 @@ void CodeGenerator::VisitCall(Call* node) {
 
     } else if (var->mode() == Variable::DYNAMIC_LOCAL) {
       Slot* potential_slot = var->local_if_not_shadowed()->slot();
-      // Only generate the fast case for locals that rewrite to slots.
-      // This rules out argument loads because eval forces arguments
-      // access to be through the arguments object.
+      Expression* rewrite = var->local_if_not_shadowed()->rewrite();
       if (potential_slot != NULL) {
+        // Generate fast case for locals that rewrite to slots.
         // Allocate a fresh register to use as a temp in
         // ContextSlotOperandCheckExtensions and to hold the result
         // value.
-        function = allocator()->Allocate();
+        Result function = allocator()->Allocate();
         ASSERT(function.is_valid());
         __ mov(function.reg(),
                ContextSlotOperandCheckExtensions(potential_slot,
@@ -5816,6 +5833,33 @@ void CodeGenerator::VisitCall(Call* node) {
         frame_->Push(&function);
         LoadGlobalReceiver();
         done.Jump();
+      } else if (rewrite != NULL) {
+        // Generate fast case for calls of an argument function.
+        Property* property = rewrite->AsProperty();
+        if (property != NULL) {
+          VariableProxy* obj_proxy = property->obj()->AsVariableProxy();
+          Literal* key_literal = property->key()->AsLiteral();
+          if (obj_proxy != NULL &&
+              key_literal != NULL &&
+              obj_proxy->IsArguments() &&
+              key_literal->handle()->IsSmi()) {
+            // Load arguments object if there are no eval-introduced
+            // variables. Then load the argument from the arguments
+            // object using keyed load.
+            Result arguments = allocator()->Allocate();
+            ASSERT(arguments.is_valid());
+            __ mov(arguments.reg(),
+                   ContextSlotOperandCheckExtensions(obj_proxy->var()->slot(),
+                                                     arguments,
+                                                     &slow));
+            frame_->Push(&arguments);
+            frame_->Push(key_literal->handle());
+            Result value = EmitKeyedLoad();
+            frame_->Push(&value);
+            LoadGlobalReceiver();
+            done.Jump();
+          }
+        }
       }
     }
 

src/x64/codegen-x64.cc

@@ -2867,12 +2867,12 @@ void CodeGenerator::VisitCall(Call* node) {
     // ----------------------------------
     // JavaScript examples:
     //
-    //  with (obj) foo(1, 2, 3)  // foo is in obj
+    //  with (obj) foo(1, 2, 3)  // foo may be in obj.
     //
     //  function f() {};
     //  function g() {
     //    eval(...);
-    //    f();  // f could be in extension object
+    //    f();  // f could be in extension object.
     //  }
     // ----------------------------------
 
@@ -2895,10 +2895,9 @@ void CodeGenerator::VisitCall(Call* node) {
 
     } else if (var->mode() == Variable::DYNAMIC_LOCAL) {
       Slot* potential_slot = var->local_if_not_shadowed()->slot();
-      // Only generate the fast case for locals that rewrite to slots.
-      // This rules out argument loads because eval forces arguments
-      // access to be through the arguments object.
+      Expression* rewrite = var->local_if_not_shadowed()->rewrite();
       if (potential_slot != NULL) {
+        // Generate fast case for locals that rewrite to slots.
         // Allocate a fresh register to use as a temp in
         // ContextSlotOperandCheckExtensions and to hold the result
         // value.
@@ -2918,6 +2917,34 @@ void CodeGenerator::VisitCall(Call* node) {
         frame_->Push(&function);
         LoadGlobalReceiver();
         done.Jump();
+      } else if (rewrite != NULL) {
+        // Generate fast case for calls of an argument function.
+        Property* property = rewrite->AsProperty();
+        if (property != NULL) {
+          VariableProxy* obj_proxy = property->obj()->AsVariableProxy();
+          Literal* key_literal = property->key()->AsLiteral();
+          if (obj_proxy != NULL &&
+              key_literal != NULL &&
+              obj_proxy->IsArguments() &&
+              key_literal->handle()->IsSmi()) {
+            // Load arguments object if there are no eval-introduced
+            // variables. Then load the argument from the arguments
+            // object using keyed load.
+            Result arguments = allocator()->Allocate();
+            ASSERT(arguments.is_valid());
+            __ movq(arguments.reg(),
+                    ContextSlotOperandCheckExtensions(obj_proxy->var()->slot(),
+                                                      arguments,
+                                                      &slow));
+            frame_->Push(&arguments);
+            frame_->Push(key_literal->handle());
+            Result value = EmitKeyedLoad(false);
+            frame_->Drop(2);  // Drop key and receiver.
+            frame_->Push(&value);
+            LoadGlobalReceiver();
+            done.Jump();
+          }
+        }
       }
     }
 
@@ -5342,20 +5369,13 @@ void CodeGenerator::LoadFromSlot(Slot* slot, TypeofState typeof_state) {
     // containing the eval.
     if (slot->var()->mode() == Variable::DYNAMIC_GLOBAL) {
       value = LoadFromGlobalSlotCheckExtensions(slot, typeof_state, &slow);
-      // If there was no control flow to slow, we can exit early.
-      if (!slow.is_linked()) {
-        frame_->Push(&value);
-        return;
-      }
-
       done.Jump(&value);
 
     } else if (slot->var()->mode() == Variable::DYNAMIC_LOCAL) {
       Slot* potential_slot = slot->var()->local_if_not_shadowed()->slot();
-      // Only generate the fast case for locals that rewrite to slots.
-      // This rules out argument loads because eval forces arguments
-      // access to be through the arguments object.
+      Expression* rewrite = slot->var()->local_if_not_shadowed()->rewrite();
       if (potential_slot != NULL) {
+        // Generate fast case for locals that rewrite to slots.
         // Allocate a fresh register to use as a temp in
         // ContextSlotOperandCheckExtensions and to hold the result
         // value.
@@ -5370,10 +5390,33 @@ void CodeGenerator::LoadFromSlot(Slot* slot, TypeofState typeof_state) {
           done.Branch(not_equal, &value);
           __ LoadRoot(value.reg(), Heap::kUndefinedValueRootIndex);
         }
-        // There is always control flow to slow from
-        // ContextSlotOperandCheckExtensions so we have to jump around
-        // it.
         done.Jump(&value);
+      } else if (rewrite != NULL) {
+        // Generate fast case for argument loads.
+        Property* property = rewrite->AsProperty();
+        if (property != NULL) {
+          VariableProxy* obj_proxy = property->obj()->AsVariableProxy();
+          Literal* key_literal = property->key()->AsLiteral();
+          if (obj_proxy != NULL &&
+              key_literal != NULL &&
+              obj_proxy->IsArguments() &&
+              key_literal->handle()->IsSmi()) {
+            // Load arguments object if there are no eval-introduced
+            // variables. Then load the argument from the arguments
+            // object using keyed load.
+            Result arguments = allocator()->Allocate();
+            ASSERT(arguments.is_valid());
+            __ movq(arguments.reg(),
+                    ContextSlotOperandCheckExtensions(obj_proxy->var()->slot(),
+                                                      arguments,
+                                                      &slow));
+            frame_->Push(&arguments);
+            frame_->Push(key_literal->handle());
+            value = EmitKeyedLoad(false);
+            frame_->Drop(2);  // Drop key and receiver.
+            done.Jump(&value);
+          }
+        }
       }
     }
 

test/mjsunit/arguments-load-across-eval.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.
+
+// Tests loading of aguments across eval calls.
+
+// Test loading across an eval call that does not shadow variables.
+function testNoShadowing(x, h) {
+  function f() {
+    eval('1');
+    assertEquals(1, x);
+    assertEquals(2, h());
+    function g() {
+      assertEquals(1, x);
+      assertEquals(2, h());
+    }
+    g();
+  }
+  f();
+}
+
+testNoShadowing(1, function() { return 2; });
+
+// Test loading across eval calls that do not shadow variables.
+function testNoShadowing2(x, h) {
+  eval('1');
+  function f() {
+    eval('1');
+    assertEquals(1, x);
+    assertEquals(2, h());
+    function g() {
+      assertEquals(1, x);
+      assertEquals(2, h());
+    }
+    g();
+  }
+  f();
+}
+
+testNoShadowing2(1, function() { return 2; });
+
+// Test loading across an eval call that shadows variables.
+function testShadowing(x, h) {
+  function f() {
+    assertEquals(1, x);
+    assertEquals(2, h());
+    eval('var x = 3; var h = function() { return 4; };');
+    assertEquals(3, x);
+    assertEquals(4, h());
+    function g() {
+      assertEquals(3, x);
+      assertEquals(4, h());
+    }
+    g();
+  }
+  f();
+  assertEquals(1, x);
+  assertEquals(2, h());
+}
+
+testShadowing(1, function() { return 2; });
+
+

test/mjsunit/property-load-across-eval.js

@@ -41,6 +41,7 @@ function testNoShadowing() {
   function f() {
     eval('1');
     assertEquals(1, x);
+    try { typeof(asdf); } catch(e) { assertUnreachable(); }
     assertEquals(2, y);
     assertEquals('global', global_function());
     assertEquals('local', local_function());
@@ -60,6 +61,7 @@ function testNoShadowing() {
     assertEquals('const_local', local_const_initialized());
     function g() {
       assertEquals(1, x);
+      try { typeof(asdf); } catch(e) { assertUnreachable(); }
       assertEquals(2, y);
       assertEquals('global', global_function());
       assertEquals('local', local_function());