[v8-dev] ARM: safepoints frame optimization

src/lithium-allocator.h

Index: src/lithium-allocator.h
diff --git a/src/lithium-allocator.h b/src/lithium-allocator.h
index 8a1476a04bc570759f079c514dc0de656f83d7f1..8c6f229a02b82d8f3085bbbc3e9a51d2b1b4a192 100644
--- a/src/lithium-allocator.h
+++ b/src/lithium-allocator.h
@@ -461,6 +461,12 @@ class LAllocator BASE_EMBEDDED {
   BitVector* assigned_double_registers() {
     return assigned_double_registers_;
   }
+  RegList modified_registers() {
+    return modified_registers_;
+  }
+  RegList modified_double_registers() {
+    return modified_double_registers_;
+  }
 
  private:
   void MeetRegisterConstraints();
@@ -624,6 +630,18 @@ class LAllocator BASE_EMBEDDED {
   BitVector* assigned_registers_;
   BitVector* assigned_double_registers_;
 
+  // modified_registers_ and modified_double_registers_ hold the registers
+  // which are really used by the function. assigned_registers_ and
+  // assigned_double_registers_ hold the registers which are used by the
+  // registers allocator. Each time a function is called, the register
+  // allocator tells that all the allocatable registers are used by this call.
+  // That means that, most of the time assigned_xxx are not relevant (they
+  // hold all the allocatable registers).
+  // TODO(all): check if we can use modified_xxx everywhere instead of
+  // assigned_xxx.
+  RegList modified_registers_;
+  RegList modified_double_registers_;
+
   HGraph* graph_;
 
   bool has_osr_entry_;