Introduce number type information in the virtual frame.

src/x64/virtual-frame-x64.cc

 // 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
@@ skipping 27 matching lines @@
 
 // -------------------------------------------------------------------------
 // VirtualFrame implementation.
 
 // On entry to a function, the virtual frame already contains the receiver,
 // the parameters, and a return address.  All frame elements are in memory.
 VirtualFrame::VirtualFrame()
     : elements_(parameter_count() + local_count() + kPreallocatedElements),
       stack_pointer_(parameter_count() + 1) {  // 0-based index of TOS.
   for (int i = 0; i <= stack_pointer_; i++) {
-    elements_.Add(FrameElement::MemoryElement());
+    elements_.Add(FrameElement::MemoryElement(NumberInfo::kUnknown));
   }
   for (int i = 0; i < RegisterAllocator::kNumRegisters; i++) {
     register_locations_[i] = kIllegalIndex;
   }
 }
 
 
 void VirtualFrame::Enter() {
   // Registers live on entry to a JS frame:
   //   rsp: stack pointer, points to return address from this function.
@@ skipping 127 matching lines @@
 
 
 void VirtualFrame::EmitPop(const Operand& operand) {
   ASSERT(stack_pointer_ == element_count() - 1);
   stack_pointer_--;
   elements_.RemoveLast();
   __ pop(operand);
 }
 
 
-void VirtualFrame::EmitPush(Register reg) {
+void VirtualFrame::EmitPush(Register reg, NumberInfo::Type info) {
   ASSERT(stack_pointer_ == element_count() - 1);
-  elements_.Add(FrameElement::MemoryElement());
+  elements_.Add(FrameElement::MemoryElement(info));
   stack_pointer_++;
   __ push(reg);
 }
 
 
-void VirtualFrame::EmitPush(const Operand& operand) {
+void VirtualFrame::EmitPush(const Operand& operand, NumberInfo::Type info) {
   ASSERT(stack_pointer_ == element_count() - 1);
-  elements_.Add(FrameElement::MemoryElement());
+  elements_.Add(FrameElement::MemoryElement(info));
   stack_pointer_++;
   __ push(operand);
 }
 
 
-void VirtualFrame::EmitPush(Immediate immediate) {
+void VirtualFrame::EmitPush(Immediate immediate, NumberInfo::Type info) {
   ASSERT(stack_pointer_ == element_count() - 1);
-  elements_.Add(FrameElement::MemoryElement());
+  elements_.Add(FrameElement::MemoryElement(info));
   stack_pointer_++;
   __ push(immediate);
 }
 
 
 void VirtualFrame::EmitPush(Smi* smi_value) {
   ASSERT(stack_pointer_ == element_count() - 1);
-  elements_.Add(FrameElement::MemoryElement());
+  elements_.Add(FrameElement::MemoryElement(NumberInfo::kSmi));
   stack_pointer_++;
   __ Push(smi_value);
 }
 
 
 void VirtualFrame::EmitPush(Handle<Object> value) {
   ASSERT(stack_pointer_ == element_count() - 1);
-  elements_.Add(FrameElement::MemoryElement());
+  NumberInfo::Type info = NumberInfo::kUnknown;
+  if (value->IsSmi()) {
+    info = NumberInfo::kSmi;
+  } else if (value->IsHeapNumber()) {
+    info = NumberInfo::kHeapNumber;
+  }
+  elements_.Add(FrameElement::MemoryElement(info));
   stack_pointer_++;
   __ Push(value);
 }
 
 
-void VirtualFrame::EmitPush(Heap::RootListIndex index) {
+void VirtualFrame::EmitPush(Heap::RootListIndex index, NumberInfo::Type info) {
   ASSERT(stack_pointer_ == element_count() - 1);
-  elements_.Add(FrameElement::MemoryElement());
+  elements_.Add(FrameElement::MemoryElement(info));
   stack_pointer_++;
   __ PushRoot(index);
 }
 
 
 void VirtualFrame::Drop(int count) {
   ASSERT(count >= 0);
   ASSERT(height() >= count);
   int num_virtual_elements = (element_count() - 1) - stack_pointer_;
 
@@ skipping 49 matching lines @@
   } else {
     // The original was in a register.
     backing_reg = original.reg();
     set_register_location(backing_reg, new_backing_index);
   }
   // Invalidate the element at index.
   elements_[index] = FrameElement::InvalidElement();
   // Set the new backing element.
   if (elements_[new_backing_index].is_synced()) {
     elements_[new_backing_index] =
-        FrameElement::RegisterElement(backing_reg, FrameElement::SYNCED);
+        FrameElement::RegisterElement(backing_reg,
+                                      FrameElement::SYNCED,
+                                      original.number_info());
   } else {
     elements_[new_backing_index] =
-        FrameElement::RegisterElement(backing_reg, FrameElement::NOT_SYNCED);
+        FrameElement::RegisterElement(backing_reg,
+                                      FrameElement::NOT_SYNCED,
+                                      original.number_info());
   }
   // Update the other copies.
   for (int i = new_backing_index + 1; i < element_count(); i++) {
     if (elements_[i].is_copy() && elements_[i].index() == index) {
       elements_[i].set_index(new_backing_index);
       elements_[new_backing_index].set_copied();
     }
   }
   return new_backing_index;
 }
@@ skipping 10 matching lines @@
   }
 
   switch (original.type()) {
     case FrameElement::MEMORY: {
       // Emit code to load the original element's data into a register.
       // Push that register as a FrameElement on top of the frame.
       Result fresh = cgen()->allocator()->Allocate();
       ASSERT(fresh.is_valid());
       FrameElement new_element =
           FrameElement::RegisterElement(fresh.reg(),
-                                        FrameElement::NOT_SYNCED);
+                                        FrameElement::NOT_SYNCED,
+                                        original.number_info());
       Use(fresh.reg(), element_count());
       elements_.Add(new_element);
       __ movq(fresh.reg(), Operand(rbp, fp_relative(index)));
       break;
     }
     case FrameElement::REGISTER:
       Use(original.reg(), element_count());
       // Fall through.
     case FrameElement::CONSTANT:
     case FrameElement::COPY:
@@ skipping 120 matching lines @@
     ASSERT(top.is_constant());
     elements_[index].clear_sync();
   }
 }
 
 
 void VirtualFrame::MakeMergable() {
   for (int i = 0; i < element_count(); i++) {
     FrameElement element = elements_[i];
 
+    // In all cases we have to reset the number type information
+    // to unknown for a mergable frame because of incoming back edges.
     if (element.is_constant() || element.is_copy()) {
       if (element.is_synced()) {
         // Just spill.
-        elements_[i] = FrameElement::MemoryElement();
+        elements_[i] = FrameElement::MemoryElement(NumberInfo::kUnknown);
       } else {
         // Allocate to a register.
         FrameElement backing_element;  // Invalid if not a copy.
         if (element.is_copy()) {
           backing_element = elements_[element.index()];
         }
         Result fresh = cgen()->allocator()->Allocate();
         ASSERT(fresh.is_valid());  // A register was spilled if all were in use.
         elements_[i] =
             FrameElement::RegisterElement(fresh.reg(),
-                                          FrameElement::NOT_SYNCED);
+                                          FrameElement::NOT_SYNCED,
+                                          NumberInfo::kUnknown);
         Use(fresh.reg(), i);
 
         // Emit a move.
         if (element.is_constant()) {
           __ Move(fresh.reg(), element.handle());
         } else {
           ASSERT(element.is_copy());
           // Copies are only backed by register or memory locations.
           if (backing_element.is_register()) {
             // The backing store may have been spilled by allocating,
             // but that's OK.  If it was, the value is right where we
             // want it.
             if (!fresh.reg().is(backing_element.reg())) {
               __ movq(fresh.reg(), backing_element.reg());
             }
           } else {
             ASSERT(backing_element.is_memory());
             __ movq(fresh.reg(), Operand(rbp, fp_relative(element.index())));
           }
         }
       }
       // No need to set the copied flag --- there are no copies.
     } else {
       // Clear the copy flag of non-constant, non-copy elements.
       // They cannot be copied because copies are not allowed.
       // The copy flag is not relied on before the end of this loop,
       // including when registers are spilled.
       elements_[i].clear_copied();
+      elements_[i].set_number_info(NumberInfo::kUnknown);
     }
   }
 }
 
 
 void VirtualFrame::MergeTo(VirtualFrame* expected) {
   Comment cmnt(masm(), "[ Merge frame");
   // We should always be merging the code generator's current frame to an
   // expected frame.
   ASSERT(cgen()->frame() == this);
@@ skipping 185 matching lines @@
     }
   }
 }
 
 
 Result VirtualFrame::Pop() {
   FrameElement element = elements_.RemoveLast();
   int index = element_count();
   ASSERT(element.is_valid());
 
+  // Get number type information of the result.
+  NumberInfo::Type info;
+  if (!element.is_copy()) {
+    info = element.number_info();
+  } else {
+    info = elements_[element.index()].number_info();
+  }
+
   bool pop_needed = (stack_pointer_ == index);
   if (pop_needed) {
     stack_pointer_--;
     if (element.is_memory()) {
       Result temp = cgen()->allocator()->Allocate();
       ASSERT(temp.is_valid());
       __ pop(temp.reg());
+      temp.set_number_info(info);
       return temp;
     }
 
     __ addq(rsp, Immediate(kPointerSize));
   }
   ASSERT(!element.is_memory());
 
   // The top element is a register, constant, or a copy.  Unuse
   // registers and follow copies to their backing store.
   if (element.is_register()) {
     Unuse(element.reg());
   } else if (element.is_copy()) {
     ASSERT(element.index() < index);
     index = element.index();
     element = elements_[index];
   }
   ASSERT(!element.is_copy());
 
   // The element is memory, a register, or a constant.
   if (element.is_memory()) {
     // Memory elements could only be the backing store of a copy.
     // Allocate the original to a register.
     ASSERT(index <= stack_pointer_);
     Result temp = cgen()->allocator()->Allocate();
     ASSERT(temp.is_valid());
     Use(temp.reg(), index);
     FrameElement new_element =
-        FrameElement::RegisterElement(temp.reg(), FrameElement::SYNCED);
+        FrameElement::RegisterElement(temp.reg(),
+                                      FrameElement::SYNCED,
+                                      element.number_info());
     // Preserve the copy flag on the element.
     if (element.is_copied()) new_element.set_copied();
     elements_[index] = new_element;
     __ movq(temp.reg(), Operand(rbp, fp_relative(index)));
-    return Result(temp.reg());
+    return Result(temp.reg(), info);
   } else if (element.is_register()) {
-    return Result(element.reg());
+    return Result(element.reg(), info);
   } else {
     ASSERT(element.is_constant());
     return Result(element.handle());
   }
 }
 
 
 Result VirtualFrame::RawCallStub(CodeStub* stub) {
   ASSERT(cgen()->HasValidEntryRegisters());
   __ CallStub(stub);
@@ skipping 325 matching lines @@
   // Grow the expression stack by handler size less one (the return
   // address is already pushed by a call instruction).
   Adjust(kHandlerSize - 1);
   __ PushTryHandler(IN_JAVASCRIPT, type);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal