Merge commit 'bc4021f31eaa97ee52655828da3e3de14a39e4a6'

Conflicts:
	lib/MC/MCAssembler.cpp
	lib/Target/ARM/ARMISelDAGToDAG.cpp
	lib/Target/Mips/MipsInstrFPU.td
	lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp
	lib/Target/X86/X86ISelLowering.h

1 files changed, 22 insertions, 0 deletions

diff --git a/include/llvm/CodeGen/MachineBasicBlock.h b/include/llvm/CodeGen/MachineBasicBlock.h
index 77ea4d03ea..97c39458d9 100644
--- a/include/llvm/CodeGen/MachineBasicBlock.h
+++ b/include/llvm/CodeGen/MachineBasicBlock.h
@@ -547,6 +547,28 @@ public:
     return findDebugLoc(MBBI.getInstrIterator());
   }
 
+  /// Possible outcome of a register liveness query to computeRegisterLiveness()
+  enum LivenessQueryResult {
+    LQR_Live,            ///< Register is known to be live.
+    LQR_OverlappingLive, ///< Register itself is not live, but some overlapping
+                         ///< register is.
+    LQR_Dead,            ///< Register is known to be dead.
+    LQR_Unknown          ///< Register liveness not decidable from local
+                         ///< neighborhood.
+  };
+
+  /// computeRegisterLiveness - Return whether (physical) register \c Reg
+  /// has been <def>ined and not <kill>ed as of just before \c MI.
+  /// 
+  /// Search is localised to a neighborhood of
+  /// \c Neighborhood instructions before (searching for defs or kills) and
+  /// Neighborhood instructions after (searching just for defs) MI.
+  ///
+  /// \c Reg must be a physical register.
+  LivenessQueryResult computeRegisterLiveness(const TargetRegisterInfo *TRI,
+                                              unsigned Reg, MachineInstr *MI,
+                                              unsigned Neighborhood=10);
+
   // Debugging methods.
   void dump() const;
   void print(raw_ostream &OS, SlotIndexes* = 0) const;