Enable stub generation using Hydrogen/Lithium (again)

src/arm/lithium-arm.h

Index: src/arm/lithium-arm.h
diff --git a/src/arm/lithium-arm.h b/src/arm/lithium-arm.h
index b45a3e0246fd49dd543ce7fdf0025fe472131598..3a9d10bfbf619ef787cb78445c9a2c6142c118c0 100644
--- a/src/arm/lithium-arm.h
+++ b/src/arm/lithium-arm.h
@@ -255,6 +255,11 @@ class LInstruction: public ZoneObject {
   void MarkAsCall() { is_call_ = true; }
 
   // Interface to the register allocator and iterators.
+  bool ClobbersTemps() const { return is_call_; }
+  bool ClobbersRegisters() const { return is_call_; }
+  bool ClobbersDoubleRegisters() const { return is_call_; }

[Jakob Kummerow, 2012/11/28 16:28:22]

Why doesn't this need " || !CpuFeatures::IsSupported(VFP2);" as ia32 does?

[danno, 2012/11/30 16:23:24]

ia32 needs this because the register allocator must immediately flush the fp
stack after every instruction if it's not immediately used by the next
instruction, because if the value is unused, following instructions could
generate more floating point values, pushing even more of the fp stack, which
would become unbalanced. So it's important to deal with the top-of-stack
immediately. This is not the case on ARM, where the FP register is backed by
real registers that you can overwrite as many times as you want without
side-effect, so they can be treated just like all other registers. 

On 2012/11/28 16:28:22, Jakob wrote:

+
+  // Interface to the register allocator and iterators.
   bool IsMarkedAsCall() const { return is_call_; }
 
   virtual bool HasResult() const = 0;
@@ -2334,8 +2339,9 @@ class LOsrEntry: public LTemplateInstruction<0, 0, 0> {
   // slot, i.e., that must also be restored to the spill slot on OSR entry.
   // NULL if the register has no assigned spill slot.  Indexed by allocation
   // index.
-  LOperand* register_spills_[Register::kNumAllocatableRegisters];
-  LOperand* double_register_spills_[DoubleRegister::kNumAllocatableRegisters];
+  LOperand* register_spills_[Register::kMaxNumAllocatableRegisters];
+  LOperand* double_register_spills_[
+      DoubleRegister::kMaxNumAllocatableRegisters];
 };