Some cleanup of the toplevel code generator:...

src/x64/fast-codegen-x64.cc

Index: src/x64/fast-codegen-x64.cc
===================================================================
--- src/x64/fast-codegen-x64.cc	(revision 3576)
+++ src/x64/fast-codegen-x64.cc	(working copy)
@@ -202,57 +202,106 @@
 }
 
 
-void FastCodeGenerator::Move(Expression::Context context, Register source) {
+void FastCodeGenerator::Apply(Expression::Context context,
+                              Slot* slot,
+                              Register scratch) {
   switch (context) {
     case Expression::kUninitialized:
       UNREACHABLE();
     case Expression::kEffect:
       break;
+    case Expression::kValue: {
+      MemOperand location = EmitSlotSearch(slot, scratch);
+      __ push(location);
+      break;
+    }
+    case Expression::kTest:
+    case Expression::kValueTest:
+    case Expression::kTestValue:
+      Move(scratch, slot);
+      Apply(context, scratch);
+      break;
+  }
+}
+
+
+void FastCodeGenerator::Apply(Expression::Context context, Literal* lit) {
+  switch (context) {
+    case Expression::kUninitialized:
+      UNREACHABLE();
+    case Expression::kEffect:
+      break;
     case Expression::kValue:
-      __ push(source);
+      __ Push(lit->handle());
       break;
     case Expression::kTest:
-      TestAndBranch(source, true_label_, false_label_);
+    case Expression::kValueTest:
+    case Expression::kTestValue:
+      __ Move(rax, lit->handle());
+      Apply(context, rax);
       break;
+  }
+}
+
+
+void FastCodeGenerator::ApplyTOS(Expression::Context context) {
+  switch (context) {
+    case Expression::kUninitialized:
+      UNREACHABLE();
+    case Expression::kEffect:
+      __ Drop(1);
+      break;
+    case Expression::kValue:
+      break;
+    case Expression::kTest:
+      __ pop(rax);
+      TestAndBranch(rax, true_label_, false_label_);
+      break;
     case Expression::kValueTest: {
       Label discard;
-      __ push(source);
-      TestAndBranch(source, true_label_, &discard);
+      __ movq(rax, Operand(rsp, 0));
+      TestAndBranch(rax, true_label_, &discard);
       __ bind(&discard);
-      __ addq(rsp, Immediate(kPointerSize));
+      __ Drop(1);
       __ jmp(false_label_);
       break;
     }
     case Expression::kTestValue: {
       Label discard;
-      __ push(source);
-      TestAndBranch(source, &discard, false_label_);
+      __ movq(rax, Operand(rsp, 0));
+      TestAndBranch(rax, &discard, false_label_);
       __ bind(&discard);
-      __ addq(rsp, Immediate(kPointerSize));
+      __ Drop(1);
       __ jmp(true_label_);
-      break;
     }
   }
 }
 
 
-void FastCodeGenerator::MoveTOS(Expression::Context context) {
+void FastCodeGenerator::DropAndApply(int count,
+                                     Expression::Context context,
+                                     Register reg) {
+  ASSERT(count > 0);
+  ASSERT(!reg.is(rsp));
   switch (context) {
     case Expression::kUninitialized:
       UNREACHABLE();
     case Expression::kEffect:
-      __ Drop(1);
+      __ Drop(count);
       break;
     case Expression::kValue:
+      if (count > 1) __ Drop(count - 1);
+      __ movq(Operand(rsp, 0), reg);
       break;
     case Expression::kTest:
-      __ pop(rax);
-      TestAndBranch(rax, true_label_, false_label_);
+      __ Drop(count);
+      TestAndBranch(reg, true_label_, false_label_);
       break;
     case Expression::kValueTest: {
       Label discard;
-      __ movq(rax, Operand(rsp, 0));
-      TestAndBranch(rax, true_label_, &discard);
+      if (count > 1) __ Drop(count - 1);
+      __ movq(Operand(rsp, 0), reg);
+      TestAndBranch(reg, true_label_, &discard);
       __ bind(&discard);
       __ Drop(1);
       __ jmp(false_label_);
@@ -260,11 +309,13 @@
     }
     case Expression::kTestValue: {
       Label discard;
-      __ movq(rax, Operand(rsp, 0));
-      TestAndBranch(rax, &discard, false_label_);
+      if (count > 1) __ Drop(count - 1);
+      __ movq(Operand(rsp, 0), reg);
+      TestAndBranch(reg, &discard, false_label_);
       __ bind(&discard);
       __ Drop(1);
       __ jmp(true_label_);
+      break;
     }
   }
 }
@@ -295,48 +346,6 @@
 }
 
 
-void FastCodeGenerator::Move(Expression::Context context,
-                             Slot* source,
-                             Register scratch) {
-  switch (context) {
-    case Expression::kUninitialized:
-      UNREACHABLE();
-    case Expression::kEffect:
-      break;
-    case Expression::kValue: {
-      MemOperand location = EmitSlotSearch(source, scratch);
-      __ push(location);
-      break;
-    }
-    case Expression::kTest:
-    case Expression::kValueTest:
-    case Expression::kTestValue:
-      Move(scratch, source);
-      Move(context, scratch);
-      break;
-  }
-}
-
-
-void FastCodeGenerator::Move(Expression::Context context, Literal* expr) {
-  switch (context) {
-    case Expression::kUninitialized:
-      UNREACHABLE();
-    case Expression::kEffect:
-      break;
-    case Expression::kValue:
-      __ Push(expr->handle());
-      break;
-    case Expression::kTest:
-    case Expression::kValueTest:
-    case Expression::kTestValue:
-      __ Move(rax, expr->handle());
-      Move(context, rax);
-      break;
-  }
-}
-
-
 void FastCodeGenerator::Move(Slot* dst,
                              Register src,
                              Register scratch1,
@@ -353,52 +362,6 @@
 }
 
 
-void FastCodeGenerator::DropAndMove(Expression::Context context,
-                                    Register source,
-                                    int drop_count) {
-  ASSERT(drop_count > 0);
-  switch (context) {
-    case Expression::kUninitialized:
-      UNREACHABLE();
-    case Expression::kEffect:
-      __ addq(rsp, Immediate(drop_count * kPointerSize));
-      break;
-    case Expression::kValue:
-      if (drop_count > 1) {
-        __ addq(rsp, Immediate((drop_count - 1) * kPointerSize));
-      }
-      __ movq(Operand(rsp, 0), source);
-      break;
-    case Expression::kTest:
-      ASSERT(!source.is(rsp));
-      __ addq(rsp, Immediate(drop_count * kPointerSize));
-      TestAndBranch(source, true_label_, false_label_);
-      break;
-    case Expression::kValueTest: {
-      Label discard;
-      if (drop_count > 1) {
-        __ addq(rsp, Immediate((drop_count - 1) * kPointerSize));
-      }
-      __ movq(Operand(rsp, 0), source);
-      TestAndBranch(source, true_label_, &discard);
-      __ bind(&discard);
-      __ addq(rsp, Immediate(kPointerSize));
-      __ jmp(false_label_);
-      break;
-    }
-    case Expression::kTestValue: {
-      Label discard;
-      __ movq(Operand(rsp, 0), source);
-      TestAndBranch(source, &discard, false_label_);
-      __ bind(&discard);
-      __ addq(rsp, Immediate(kPointerSize));
-      __ jmp(true_label_);
-      break;
-    }
-  }
-}
-
-
 void FastCodeGenerator::TestAndBranch(Register source,
                                       Label* true_label,
                                       Label* false_label) {
@@ -528,7 +491,7 @@
 
       // Value in rax is ignored (declarations are statements).  Receiver
       // and key on stack are discarded.
-      __ addq(rsp, Immediate(2 * kPointerSize));
+      __ Drop(2);
     }
   }
 }
@@ -558,7 +521,7 @@
   __ push(rsi);
   __ Push(boilerplate);
   __ CallRuntime(Runtime::kNewClosure, 2);
-  Move(expr->context(), rax);
+  Apply(expr->context(), rax);
 }
 
 
@@ -585,7 +548,7 @@
     // is no test rax instruction here.
     __ nop();
 
-    DropAndMove(context, rax);
+    DropAndApply(1, context, rax);
   } else if (rewrite->AsSlot() != NULL) {
     Slot* slot = rewrite->AsSlot();
     if (FLAG_debug_code) {
@@ -604,41 +567,43 @@
           break;
       }
     }
-    Move(context, slot, rax);
+    Apply(context, slot, rax);
   } else {
-    // A variable has been rewritten into an explicit access to
-    // an object property.
+    Comment cmnt(masm_, "Variable rewritten to property");
+    // A variable has been rewritten into an explicit access to an object
+    // property.
     Property* property = rewrite->AsProperty();
     ASSERT_NOT_NULL(property);
 
-    // Currently the only parameter expressions that can occur are
-    // on the form "slot[literal]".
+    // The only property expressions that can occur are of the form
+    // "slot[literal]".
 
-    // Check that the object is in a slot.
+    // Assert that the object is in a slot.
     Variable* object = property->obj()->AsVariableProxy()->AsVariable();
     ASSERT_NOT_NULL(object);
     Slot* object_slot = object->slot();
     ASSERT_NOT_NULL(object_slot);
 
     // Load the object.
-    Move(Expression::kValue, object_slot, rax);
+    MemOperand object_loc = EmitSlotSearch(object_slot, rax);
+    __ push(object_loc);
 
-    // Check that the key is a smi.
+    // Assert that the key is a smi.
     Literal* key_literal = property->key()->AsLiteral();
     ASSERT_NOT_NULL(key_literal);
     ASSERT(key_literal->handle()->IsSmi());
 
     // Load the key.
-    Move(Expression::kValue, key_literal);
+    __ Push(key_literal->handle());
 
-    // Do a KEYED property load.
+    // Do a keyed property load.
     Handle<Code> ic(Builtins::builtin(Builtins::KeyedLoadIC_Initialize));
     __ call(ic, RelocInfo::CODE_TARGET);
-    // Notice: We must not have a "test rax, ..." instruction after
-    // the call. It is treated specially by the LoadIC code.
+    // Notice: We must not have a "test rax, ..." instruction after the
+    // call. It is treated specially by the LoadIC code.
 
     // Drop key and object left on the stack by IC, and push the result.
-    DropAndMove(context, rax, 2);
+    DropAndApply(2, context, rax);
   }
 }
 
@@ -666,7 +631,7 @@
   __ CallRuntime(Runtime::kMaterializeRegExpLiteral, 4);
   // Label done:
   __ bind(&done);
-  Move(expr->context(), rax);
+  Apply(expr->context(), rax);
 }
 
 
@@ -742,7 +707,7 @@
     case Expression::kUninitialized:
       UNREACHABLE();
     case Expression::kEffect:
-      if (result_saved) __ addq(rsp, Immediate(kPointerSize));
+      if (result_saved) __ Drop(1);
       break;
     case Expression::kValue:
       if (!result_saved) __ push(rax);
@@ -756,7 +721,7 @@
       if (!result_saved) __ push(rax);
       TestAndBranch(rax, true_label_, &discard);
       __ bind(&discard);
-      __ addq(rsp, Immediate(kPointerSize));
+      __ Drop(1);
       __ jmp(false_label_);
       break;
     }
@@ -765,7 +730,7 @@
       if (!result_saved) __ push(rax);
       TestAndBranch(rax, &discard, false_label_);
       __ bind(&discard);
-      __ addq(rsp, Immediate(kPointerSize));
+      __ Drop(1);
       __ jmp(true_label_);
       break;
     }
@@ -821,7 +786,7 @@
     case Expression::kUninitialized:
       UNREACHABLE();
     case Expression::kEffect:
-      if (result_saved) __ addq(rsp, Immediate(kPointerSize));
+      if (result_saved) __ Drop(1);
       break;
     case Expression::kValue:
       if (!result_saved) __ push(rax);
@@ -835,7 +800,7 @@
       if (!result_saved) __ push(rax);
       TestAndBranch(rax, true_label_, &discard);
       __ bind(&discard);
-      __ addq(rsp, Immediate(kPointerSize));
+      __ Drop(1);
       __ jmp(false_label_);
       break;
     }
@@ -844,7 +809,7 @@
       if (!result_saved) __ push(rax);
       TestAndBranch(rax, &discard, false_label_);
       __ bind(&discard);
-      __ addq(rsp, Immediate(kPointerSize));
+      __ Drop(1);
       __ jmp(true_label_);
       break;
     }
@@ -859,7 +824,7 @@
   __ Move(rcx, key->handle());
   Handle<Code> ic(Builtins::builtin(Builtins::LoadIC_Initialize));
   __ Call(ic, RelocInfo::CODE_TARGET);
-  Move(context, rax);
+  Apply(context, rax);
 }
 
 
@@ -868,7 +833,7 @@
   SetSourcePosition(prop->position());
   Handle<Code> ic(Builtins::builtin(Builtins::KeyedLoadIC_Initialize));
   __ Call(ic, RelocInfo::CODE_TARGET);
-  Move(context, rax);
+  Apply(context, rax);
 }
 
 
@@ -878,7 +843,7 @@
                            NO_OVERWRITE,
                            NO_GENERIC_BINARY_FLAGS);
   __ CallStub(&stub);
-  Move(context, rax);
+  Apply(context, rax);
 }
 
 
@@ -896,7 +861,7 @@
     Handle<Code> ic(Builtins::builtin(Builtins::StoreIC_Initialize));
     __ Call(ic, RelocInfo::CODE_TARGET);
     // Overwrite the global object on the stack with the result if needed.
-    DropAndMove(context, rax);
+    DropAndApply(1, context, rax);
 
   } else if (var->slot() != NULL) {
     Slot* slot = var->slot();
@@ -928,7 +893,7 @@
             __ movq(target, rax);
             TestAndBranch(rax, true_label_, &discard);
             __ bind(&discard);
-            __ addq(rsp, Immediate(kPointerSize));
+            __ Drop(1);
             __ jmp(false_label_);
             break;
           }
@@ -938,7 +903,7 @@
             __ movq(target, rax);
             TestAndBranch(rax, &discard, false_label_);
             __ bind(&discard);
-            __ addq(rsp, Immediate(kPointerSize));
+            __ Drop(1);
             __ jmp(true_label_);
             break;
           }
@@ -959,9 +924,8 @@
         }
         int offset = FixedArray::kHeaderSize + slot->index() * kPointerSize;
         __ RecordWrite(rcx, offset, rax, rbx);
-        if (context != Expression::kEffect &&
-            context != Expression::kValue) {
-          Move(context, rdx);
+        if (context != Expression::kEffect && context != Expression::kValue) {
+          Apply(context, rdx);
         }
         break;
       }
@@ -1005,7 +969,7 @@
     __ pop(rax);
   }
 
-  DropAndMove(expr->context(), rax);
+  DropAndApply(1, expr->context(), rax);
 }
 
 
@@ -1038,15 +1002,13 @@
   }
 
   // Receiver and key are still on stack.
-  __ addq(rsp, Immediate(2 * kPointerSize));
-  Move(expr->context(), rax);
+  DropAndApply(2, expr->context(), rax);
 }
 
 
 void FastCodeGenerator::VisitProperty(Property* expr) {
   Comment cmnt(masm_, "[ Property");
   Expression* key = expr->key();
-  uint32_t dummy;
 
   // Record the source position for the property load.
   SetSourcePosition(expr->position());
@@ -1054,29 +1016,27 @@
   // Evaluate receiver.
   Visit(expr->obj());
 
-
-  if (key->AsLiteral() != NULL && key->AsLiteral()->handle()->IsSymbol() &&
-      !String::cast(*(key->AsLiteral()->handle()))->AsArrayIndex(&dummy)) {
-    // Do a NAMED property load.
-    // The IC expects the property name in rcx and the receiver on the stack.
+  if (key->IsPropertyName()) {
+    // Do a named property load.  The IC expects the property name in rcx
+    // and the receiver on the stack.
     __ Move(rcx, key->AsLiteral()->handle());
     Handle<Code> ic(Builtins::builtin(Builtins::LoadIC_Initialize));
     __ call(ic, RelocInfo::CODE_TARGET);
     // By emitting a nop we make sure that we do not have a "test rax,..."
     // instruction after the call it is treated specially by the LoadIC code.
     __ nop();
+    DropAndApply(1, expr->context(), rax);
   } else {
-    // Do a KEYED property load.
+    // Do a keyed property load.
     Visit(expr->key());
     Handle<Code> ic(Builtins::builtin(Builtins::KeyedLoadIC_Initialize));
     __ call(ic, RelocInfo::CODE_TARGET);
-    // Notice: We must not have a "test rax, ..." instruction after
-    // the call. It is treated specially by the LoadIC code.
-
-    // Drop key left on the stack by IC.
-    __ addq(rsp, Immediate(kPointerSize));
+    // Notice: We must not have a "test rax, ..." instruction after the
+    // call. It is treated specially by the LoadIC code.
+    __ nop();
+    // Drop key and receiver left on the stack by IC.
+    DropAndApply(2, expr->context(), rax);
   }
-  DropAndMove(expr->context(), rax);
 }
 
 
@@ -1099,7 +1059,7 @@
   // Restore context register.
   __ movq(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
   // Discard the function left on TOS.
-  DropAndMove(expr->context(), rax);
+  DropAndApply(1, expr->context(), rax);
 }
 
 
@@ -1117,7 +1077,7 @@
   // Restore context register.
   __ movq(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
   // Discard the function left on TOS.
-  DropAndMove(expr->context(), rax);
+  DropAndApply(1, expr->context(), rax);
 }
 
 
@@ -1161,7 +1121,7 @@
       // instruction after the call it is treated specially by the LoadIC code.
       __ nop();
       // Drop key left on the stack by IC.
-      __ addq(rsp, Immediate(kPointerSize));
+      __ Drop(1);
       // Pop receiver.
       __ pop(rbx);
       // Push result (function).
@@ -1230,7 +1190,7 @@
   __ Call(construct_builtin, RelocInfo::CONSTRUCT_CALL);
 
   // Replace function on TOS with result in rax, or pop it.
-  DropAndMove(expr->context(), rax);
+  DropAndApply(1, expr->context(), rax);
 }
 
 
@@ -1260,10 +1220,10 @@
     // Restore context register.
     __ movq(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
     // Discard the function left on TOS.
-    DropAndMove(expr->context(), rax);
+    DropAndApply(1, expr->context(), rax);
   } else {
     __ CallRuntime(expr->function(), arg_count);
-    Move(expr->context(), rax);
+    Apply(expr->context(), rax);
   }
 }
 
@@ -1386,7 +1346,7 @@
       }
 
       __ CallRuntime(Runtime::kTypeof, 1);
-      Move(expr->context(), rax);
+      Apply(expr->context(), rax);
       break;
     }
 
@@ -1486,7 +1446,7 @@
         // For all contexts except kEffect: We have the result on
         // top of the stack.
         if (expr->context() != Expression::kEffect) {
-          MoveTOS(expr->context());
+          ApplyTOS(expr->context());
         }
       } else {
         EmitVariableAssignment(expr->expression()->AsVariableProxy()->var(),
@@ -1503,10 +1463,10 @@
       if (expr->is_postfix()) {
         __ Drop(1);  // Result is on the stack under the receiver.
         if (expr->context() != Expression::kEffect) {
-          MoveTOS(expr->context());
+          ApplyTOS(expr->context());
         }
       } else {
-        DropAndMove(expr->context(), rax);
+        DropAndApply(1, expr->context(), rax);
       }
       break;
     }
@@ -1519,10 +1479,10 @@
       if (expr->is_postfix()) {
         __ Drop(2);  // Result is on the stack under the key and the receiver.
         if (expr->context() != Expression::kEffect) {
-          MoveTOS(expr->context());
+          ApplyTOS(expr->context());
         }
       } else {
-        DropAndMove(expr->context(), rax, 2);
+        DropAndApply(2, expr->context(), rax);
       }
       break;
     }
@@ -1564,7 +1524,7 @@
                                NO_OVERWRITE,
                                NO_GENERIC_BINARY_FLAGS);
       __ CallStub(&stub);
-      Move(expr->context(), rax);
+      Apply(expr->context(), rax);
 
       break;
     }
@@ -1732,7 +1692,7 @@
 
 void FastCodeGenerator::VisitThisFunction(ThisFunction* expr) {
   __ movq(rax, Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
-  Move(expr->context(), rax);
+  Apply(expr->context(), rax);
 }