Add empty() methods for register def lists.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61890 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/CodeGen/MachineRegisterInfo.h b/include/llvm/CodeGen/MachineRegisterInfo.h
index f477e86554e2be6b443aceb6170b69b7a7bd1f0d..b313fce182f802ae21c8bdd9ebbeec20b9dde058 100644 (file)
--- a/include/llvm/CodeGen/MachineRegisterInfo.h
+++ b/include/llvm/CodeGen/MachineRegisterInfo.h
@@ -81,6 +81,10 @@ public:
   }
   static reg_iterator reg_end() { return reg_iterator(0); }
 
+  /// reg_empty - Return true if there are no instructions using or defining the
+  /// specified register (it may be live-in).
+  bool reg_empty(unsigned RegNo) const { return reg_begin(RegNo) == reg_end(); }
+
   /// def_iterator/def_begin/def_end - Walk all defs of the specified register.
   typedef defusechain_iterator<false,true> def_iterator;
   def_iterator def_begin(unsigned RegNo) const {
@@ -88,6 +92,10 @@ public:
   }
   static def_iterator def_end() { return def_iterator(0); }
 
+  /// def_empty - Return true if there are no instructions defining the
+  /// specified register (it may be live-in).
+  bool def_empty(unsigned RegNo) const { return def_begin(RegNo) == def_end(); }
+
   /// use_iterator/use_begin/use_end - Walk all uses of the specified register.
   typedef defusechain_iterator<true,false> use_iterator;
   use_iterator use_begin(unsigned RegNo) const {