This is a prototype of an experimental register allocation

framework. It's purpose is not to improve register allocation per se,
but to make it easier to develop powerful live range splitting. I call
it the basic allocator because it is as simple as a global allocator
can be but provides the building blocks for sophisticated register
allocation with live range splitting. 

A minimal implementation is provided that trivially spills whenever it
runs out of registers. I'm checking in now to get high-level design
and style feedback. I've only done minimal testing. The next step is
implementing a "greedy" allocation algorithm that does some register
reassignment and makes better splitting decisions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117174 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 6 insertions, 0 deletions

diff --git a/include/llvm/CodeGen/LinkAllCodegenComponents.h b/include/llvm/CodeGen/LinkAllCodegenComponents.h
index 59c0482efc..bc06d43b8f 100644
--- a/include/llvm/CodeGen/LinkAllCodegenComponents.h
+++ b/include/llvm/CodeGen/LinkAllCodegenComponents.h
@@ -34,6 +34,7 @@ namespace {
       (void) llvm::createDeadMachineInstructionElimPass();
 
       (void) llvm::createFastRegisterAllocator();
+      (void) llvm::createBasicRegisterAllocator();
       (void) llvm::createLinearScanRegisterAllocator();
       (void) llvm::createDefaultPBQPRegisterAllocator();
 
diff --git a/include/llvm/CodeGen/Passes.h b/include/llvm/CodeGen/Passes.h
index 7e135617fa..72dd3b8529 100644
--- a/include/llvm/CodeGen/Passes.h
+++ b/include/llvm/CodeGen/Passes.h
@@ -95,6 +95,11 @@ namespace llvm {
   ///
   FunctionPass *createFastRegisterAllocator();
 
+  /// BasicRegisterAllocation Pass - This pass implements a degenerate global
+  /// register allocator using the basic regalloc framework.
+  ///
+  FunctionPass *createBasicRegisterAllocator();
+
   /// LinearScanRegisterAllocation Pass - This pass implements the linear scan
   /// register allocation algorithm, a global register allocator.
   ///