move CC Lowering stuff to its own public interface

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34655 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 34 insertions, 0 deletions

diff --git a/lib/CodeGen/SelectionDAG/CallingConvLower.cpp b/lib/CodeGen/SelectionDAG/CallingConvLower.cpp
new file mode 100644
index 0000000000..47d08376bb
--- /dev/null
+++ b/lib/CodeGen/SelectionDAG/CallingConvLower.cpp
@@ -0,0 +1,34 @@
+//===-- llvm/CallingConvLower.cpp - Calling Conventions -------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Chris Lattner and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the CCState class, used for lowering and implementing
+// calling conventions.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/CallingConvLower.h"
+#include "llvm/Target/MRegisterInfo.h"
+using namespace llvm;
+
+CCState::CCState(const MRegisterInfo &mri) : MRI(mri) {
+  // No stack is used.
+  StackOffset = 0;
+  
+  UsedRegs.resize(MRI.getNumRegs());
+}
+
+
+/// MarkAllocated - Mark a register and all of its aliases as allocated.
+void CCState::MarkAllocated(unsigned Reg) {
+  UsedRegs[Reg/32] |= 1 << (Reg&31);
+  
+  if (const unsigned *RegAliases = MRI.getAliasSet(Reg))
+    for (; (Reg = *RegAliases); ++RegAliases)
+      UsedRegs[Reg/32] |= 1 << (Reg&31);
+}