Merge revision 3813 to 3930 from bleeding_edge to partial snapshots branch.

src/x64/fast-codegen-x64.cc

Index: src/x64/fast-codegen-x64.cc
===================================================================
--- src/x64/fast-codegen-x64.cc	(revision 3935)
+++ src/x64/fast-codegen-x64.cc	(working copy)
@@ -35,54 +35,91 @@
 
 #define __ ACCESS_MASM(masm())
 
-void FastCodeGenerator::EmitLoadReceiver(Register reg) {
+Register FastCodeGenerator::accumulator0() { return rax; }
+Register FastCodeGenerator::accumulator1() { return rdx; }
+Register FastCodeGenerator::scratch0() { return rcx; }
+Register FastCodeGenerator::scratch1() { return rdi; }
+Register FastCodeGenerator::receiver_reg() { return rbx; }
+Register FastCodeGenerator::context_reg() { return rsi; }
+
+
+void FastCodeGenerator::EmitLoadReceiver() {
   // Offset 2 is due to return address and saved frame pointer.
   int index = 2 + scope()->num_parameters();
-  __ movq(reg, Operand(rbp, index * kPointerSize));
+  __ movq(receiver_reg(), Operand(rbp, index * kPointerSize));
 }
 
 
-void FastCodeGenerator::EmitReceiverMapCheck() {
-  Comment cmnt(masm(), ";; MapCheck(this)");
-  if (FLAG_print_ir) {
-    PrintF("MapCheck(this)\n");
+void FastCodeGenerator::EmitGlobalVariableLoad(Handle<Object> cell) {
+  ASSERT(!destination().is(no_reg));
+  ASSERT(cell->IsJSGlobalPropertyCell());
+
+  __ Move(destination(), cell);
+  __ movq(destination(),
+          FieldOperand(destination(), JSGlobalPropertyCell::kValueOffset));
+  if (FLAG_debug_code) {
+    __ Cmp(destination(), Factory::the_hole_value());
+    __ Check(not_equal, "DontDelete cells can't contain the hole");
   }
 
-  ASSERT(info()->has_receiver() && info()->receiver()->IsHeapObject());
-  Handle<HeapObject> object = Handle<HeapObject>::cast(info()->receiver());
-  Handle<Map> map(object->map());
-
-  EmitLoadReceiver(rdx);
-  __ CheckMap(rdx, map, bailout(), false);
+  // The loaded value is not known to be a smi.
+  clear_as_smi(destination());
 }
 
 
-void FastCodeGenerator::EmitGlobalMapCheck() {
-  Comment cmnt(masm(), ";; GlobalMapCheck");
-  if (FLAG_print_ir) {
-    PrintF(";; GlobalMapCheck()");
-  }
+void FastCodeGenerator::EmitThisPropertyStore(Handle<String> name) {
+  LookupResult lookup;
+  info()->receiver()->Lookup(*name, &lookup);
 
-  ASSERT(info()->has_global_object());
-  Handle<Map> map(info()->global_object()->map());
+  ASSERT(lookup.holder() == *info()->receiver());
+  ASSERT(lookup.type() == FIELD);
+  Handle<Map> map(Handle<HeapObject>::cast(info()->receiver())->map());
+  int index = lookup.GetFieldIndex() - map->inobject_properties();
+  int offset = index * kPointerSize;
 
-  __ movq(rbx, CodeGenerator::GlobalObject());
-  __ CheckMap(rbx, map, bailout(), true);
-}
+  // We will emit the write barrier unless the stored value is statically
+  // known to be a smi.
+  bool needs_write_barrier = !is_smi(accumulator0());
 
+  // Perform the store.  Negative offsets are inobject properties.
+  if (offset < 0) {
+    offset += map->instance_size();
+    __ movq(FieldOperand(receiver_reg(), offset), accumulator0());
+    if (needs_write_barrier) {
+      // Preserve receiver from write barrier.
+      __ movq(scratch0(), receiver_reg());
+    }
+  } else {
+    offset += FixedArray::kHeaderSize;
+    __ movq(scratch0(),
+            FieldOperand(receiver_reg(), JSObject::kPropertiesOffset));
+    __ movq(FieldOperand(scratch0(), offset), accumulator0());
+  }
 
-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");
+  if (needs_write_barrier) {
+    if (destination().is(no_reg)) {
+      // After RecordWrite accumulator0 is only accidently a smi, but it is
+      // already marked as not known to be one.
+      __ RecordWrite(scratch0(), offset, accumulator0(), scratch1());
+    } else {
+      // Copy the value to the other accumulator to preserve a copy from the
+      // write barrier. One of the accumulators is available as a scratch
+      // register.  Neither is a smi.
+      __ movq(accumulator1(), accumulator0());
+      clear_as_smi(accumulator1());
+      Register value_scratch = other_accumulator(destination());
+      __ RecordWrite(scratch0(), offset, value_scratch, scratch1());
+    }
+  } else if (destination().is(accumulator1())) {
+    __ movq(accumulator1(), accumulator0());
+    // Is a smi because we do not need the write barrier.
+    set_as_smi(accumulator1());
   }
 }
 
 
-void FastCodeGenerator::EmitThisPropertyStore(Handle<String> name) {
+void FastCodeGenerator::EmitThisPropertyLoad(Handle<String> name) {
+  ASSERT(!destination().is(no_reg));
   LookupResult lookup;
   info()->receiver()->Lookup(*name, &lookup);
 
@@ -92,22 +129,62 @@
   int index = lookup.GetFieldIndex() - map->inobject_properties();
   int offset = index * kPointerSize;
 
-  // Negative offsets are inobject properties.
+  // Perform the load.  Negative offsets are inobject properties.
   if (offset < 0) {
     offset += map->instance_size();
-    __ movq(rcx, rdx);  // Copy receiver for write barrier.
+    __ movq(destination(), FieldOperand(receiver_reg(), offset));
   } else {
     offset += FixedArray::kHeaderSize;
-    __ movq(rcx, FieldOperand(rdx, JSObject::kPropertiesOffset));
+    __ movq(scratch0(),
+            FieldOperand(receiver_reg(), JSObject::kPropertiesOffset));
+    __ movq(destination(), FieldOperand(scratch0(), offset));
   }
-  // Perform the store.
-  __ movq(FieldOperand(rcx, offset), rax);
-  // Preserve value from write barrier in case it's needed.
-  __ movq(rbx, rax);
-  __ RecordWrite(rcx, offset, rbx, rdi);
+
+  // The loaded value is not known to be a smi.
+  clear_as_smi(destination());
 }
 
 
+void FastCodeGenerator::EmitBitOr() {
+  if (is_smi(accumulator0()) && is_smi(accumulator1())) {
+    // If both operands are known to be a smi then there is no need to check
+    // the operands or result.
+    if (destination().is(no_reg)) {
+      __ or_(accumulator1(), accumulator0());
+    } else {
+      // Leave the result in the destination register.  Bitwise or is
+      // commutative.
+      __ or_(destination(), other_accumulator(destination()));
+    }
+  } else {
+    // Left is in accumulator1, right in accumulator0.
+    if (destination().is(accumulator0())) {
+      __ movq(scratch0(), accumulator0());
+      __ or_(destination(), accumulator1());  // Or is commutative.
+      Label* bailout =
+          info()->AddBailout(accumulator1(), scratch0());  // Left, right.
+      __ JumpIfNotSmi(destination(), bailout);
+    } else if (destination().is(accumulator1())) {
+      __ movq(scratch0(), accumulator1());
+      __ or_(destination(), accumulator0());
+      Label* bailout = info()->AddBailout(scratch0(), accumulator0());
+      __ JumpIfNotSmi(destination(), bailout);
+    } else {
+      ASSERT(destination().is(no_reg));
+      __ movq(scratch0(), accumulator1());
+      __ or_(scratch0(), accumulator0());
+      Label* bailout = info()->AddBailout(accumulator1(), accumulator0());
+      __ JumpIfNotSmi(scratch0(), bailout);
+    }
+  }
+
+  // If we didn't bailout, the result (in fact, both inputs too) is known to
+  // be a smi.
+  set_as_smi(accumulator0());
+  set_as_smi(accumulator1());
+}
+
+
 void FastCodeGenerator::Generate(CompilationInfo* compilation_info) {
   ASSERT(info_ == NULL);
   info_ = compilation_info;
@@ -121,24 +198,43 @@
   // Note that we keep a live register reference to esi (context) at this
   // point.
 
-  // Receiver (this) is allocated to rdx if there are this properties.
-  if (info()->has_this_properties()) EmitReceiverMapCheck();
+  Label* bailout_to_beginning = info()->AddBailout();
+  // Receiver (this) is allocated to a fixed register.
+  if (info()->has_this_properties()) {
+    Comment cmnt(masm(), ";; MapCheck(this)");
+    if (FLAG_print_ir) {
+      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();
+    __ CheckMap(receiver_reg(), map, bailout_to_beginning, false);
+  }
 
-  // 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();
+  // If there is a global variable access check if the global object is the
+  // same as at lazy-compilation time.
+  if (info()->has_globals()) {
+    Comment cmnt(masm(), ";; MapCheck(GLOBAL)");
+    if (FLAG_print_ir) {
+      PrintF("MapCheck(GLOBAL)\n");
+    }
+    ASSERT(info()->has_global_object());
+    Handle<Map> map(info()->global_object()->map());
+    __ movq(scratch0(), CodeGenerator::GlobalObject());
+    __ CheckMap(scratch0(), map, bailout_to_beginning, true);
+  }
 
   VisitStatements(info()->function()->body());
 
   Comment return_cmnt(masm(), ";; Return(<undefined>)");
+  if (FLAG_print_ir) {
+    PrintF("Return(<undefined>)\n");
+  }
   __ LoadRoot(rax, Heap::kUndefinedValueRootIndex);
-
-  Comment epilogue_cmnt(masm(), ";; Epilogue");
   __ movq(rsp, rbp);
   __ pop(rbp);
   __ ret((scope()->num_parameters() + 1) * kPointerSize);
-
-  __ bind(&bailout_);
 }