Initial bypass of JumpTarget::ComputeEntryFrame for deferred code...

src/arm/jump-target-arm.cc

 // Copyright 2008 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 34 matching lines @@
   // which are still live in the C++ code.
   ASSERT(cgen_->HasValidEntryRegisters());
 
   if (is_bound()) {
     // Backward jump.  There is an expected frame to merge to.
     ASSERT(direction_ == BIDIRECTIONAL);
     cgen_->frame()->MergeTo(entry_frame_);
     cgen_->DeleteFrame();
     __ jmp(&entry_label_);
   } else {
+    // Preconfigured entry frame is not used on ARM.
+    ASSERT(entry_frame_ == NULL);
     // Forward jump.  The current frame is added to the end of the list
     // of frames reaching the target block and a jump to the merge code
     // is emitted.
     AddReachingFrame(cgen_->frame());
     RegisterFile empty;
     cgen_->SetFrame(NULL, &empty);
     __ jmp(&merge_labels_.last());
   }
 
   is_linked_ = !is_bound_;
@@ skipping 43 matching lines @@
     // around the merge code on the fall through path.
     Label original_fall_through;
     __ b(NegateCondition(cc), &original_fall_through);
     cgen_->frame()->MergeTo(entry_frame_);
     cgen_->DeleteFrame();
     __ b(&entry_label_);
     cgen_->SetFrame(fall_through_frame, &non_frame_registers);
     __ bind(&original_fall_through);
 
   } else {
+    // Preconfigured entry frame is not used on ARM.
+    ASSERT(entry_frame_ == NULL);
     // Forward branch.  A copy of the current frame is added to the end
     // of the list of frames reaching the target block and a branch to
     // the merge code is emitted.
     AddReachingFrame(new VirtualFrame(cgen_->frame()));
     __ b(cc, &merge_labels_.last());
     is_linked_ = true;
   }
 }
 
 
 void JumpTarget::Call() {
   // Call is used to push the address of the catch block on the stack as
   // a return address when compiling try/catch and try/finally.  We
   // fully spill the frame before making the call.  The expected frame
   // at the label (which should be the only one) is the spilled current
   // frame plus an in-memory return address.  The "fall-through" frame
   // at the return site is the spilled current frame.
   ASSERT(cgen_ != NULL);
   ASSERT(cgen_->has_valid_frame());
   // There are no non-frame references across the call.
   ASSERT(cgen_->HasValidEntryRegisters());
   ASSERT(!is_linked());
 
   cgen_->frame()->SpillAll();
   VirtualFrame* target_frame = new VirtualFrame(cgen_->frame());
   target_frame->Adjust(1);
+  // We do not expect a call with a preconfigured entry frame.
+  ASSERT(entry_frame_ == NULL);
   AddReachingFrame(target_frame);
   __ bl(&merge_labels_.last());
 
   is_linked_ = !is_bound_;
 }
 
 
 void JumpTarget::DoBind(int mergable_elements) {
   ASSERT(cgen_ != NULL);
   ASSERT(!is_bound());
@@ skipping 44 matching lines @@
       is_bound_ = true;
       return;
     }
   }
 
   // If there is a current frame, record it as the fall-through.  It
   // is owned by the reaching frames for now.
   bool had_fall_through = false;
   if (cgen_->has_valid_frame()) {
     had_fall_through = true;
-    AddReachingFrame(cgen_->frame());
+    AddReachingFrame(cgen_->frame());  // Return value ignored.
     RegisterFile empty;
     cgen_->SetFrame(NULL, &empty);
   }
 
   // Compute the frame to use for entry to the block.
-  ComputeEntryFrame(mergable_elements);
+  if (entry_frame_ == NULL) {
+    ComputeEntryFrame(mergable_elements);
+  }
 
   // Some moves required to merge to an expected frame require purely
   // frame state changes, and do not require any code generation.
   // Perform those first to increase the possibility of finding equal
   // frames below.
   for (int i = 0; i < reaching_frames_.length(); i++) {
     if (reaching_frames_[i] != NULL) {
       reaching_frames_[i]->PrepareMergeTo(entry_frame_);
     }
   }
@@ skipping 101 matching lines @@
   }
 
   is_linked_ = false;
   is_bound_ = true;
 }
 
 #undef __
 
 
 } }  // namespace v8::internal