Add a linear scan register allocator to the optimizing compiler.

This is a "by-the-book" implementation. It currently only deals
with allocating registers, with no hint optimizations.

The changes remaining to make it functional are:
- Allocate spill slots.
- Resolution and placements of Move instructions.
- Connect it to the code generator.

Change-Id: Ie0b2f6ba1b98da85425be721ce4afecd6b4012a4

1 files changed, 1 insertions, 0 deletions

diff --git a/compiler/optimizing/nodes.cc b/compiler/optimizing/nodes.cc
index 74ba520..752466b 100644
--- a/compiler/optimizing/nodes.cc
+++ b/compiler/optimizing/nodes.cc
@@ -388,6 +388,7 @@ void HInstructionList::RemoveInstruction(HInstruction* instruction) {
 }
 
 void HInstruction::ReplaceWith(HInstruction* other) {
+  DCHECK(other != nullptr);
   for (HUseIterator<HInstruction> it(GetUses()); !it.Done(); it.Advance()) {
     HUseListNode<HInstruction>* current = it.Current();
     HInstruction* user = current->GetUser();