[foldMemoryOperand()] Pass LiveIntervals to enable liveness check.

SystemZ (and probably other targets as well) can fold a memory operand
by changing the opcode into a new instruction that as a side-effect
also clobbers the CC-reg.

In order to do this, liveness of that reg must first be checked. When
LIS is passed, getRegUnit() can be called on it and the right
LiveRange is computed on demand.

Reviewed by Matthias Braun.
http://reviews.llvm.org/D19861

llvm-svn: 269026

1 files changed, 4 insertions, 2 deletions

diff --git a/llvm/lib/Target/X86/X86InstrInfo.h b/llvm/lib/Target/X86/X86InstrInfo.h
index d72589604ae..5a82c161b27 100644
--- a/llvm/lib/Target/X86/X86InstrInfo.h
+++ b/llvm/lib/Target/X86/X86InstrInfo.h
@@ -370,7 +370,8 @@ public:
   MachineInstr *foldMemoryOperandImpl(MachineFunction &MF, MachineInstr *MI,
                                       ArrayRef<unsigned> Ops,
                                       MachineBasicBlock::iterator InsertPt,
-                                      int FrameIndex) const override;
+                                      int FrameIndex,
+                                      LiveIntervals *LIS = nullptr) const override;
 
   /// foldMemoryOperand - Same as the previous version except it allows folding
   /// of any load and store from / to any address, not just from a specific
@@ -378,7 +379,8 @@ public:
   MachineInstr *foldMemoryOperandImpl(MachineFunction &MF, MachineInstr *MI,
                                       ArrayRef<unsigned> Ops,
                                       MachineBasicBlock::iterator InsertPt,
-                                      MachineInstr *LoadMI) const override;
+                                      MachineInstr *LoadMI,
+                                      LiveIntervals *LIS = nullptr) const override;
 
   /// unfoldMemoryOperand - Separate a single instruction which folded a load or
   /// a store or a load and a store into two or more instruction. If this is