Allow some reloads to be folded in multi-use cases. Specifically testl r, r -> cmpl [mem], 0.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44479 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 18 insertions, 1 deletions

diff --git a/include/llvm/CodeGen/LiveIntervalAnalysis.h b/include/llvm/CodeGen/LiveIntervalAnalysis.h
index 725beb708c..5ada1ad149 100644
--- a/include/llvm/CodeGen/LiveIntervalAnalysis.h
+++ b/include/llvm/CodeGen/LiveIntervalAnalysis.h
@@ -275,7 +275,8 @@ namespace llvm {
     /// returns true.
     bool tryFoldMemoryOperand(MachineInstr* &MI, VirtRegMap &vrm,
                               MachineInstr *DefMI, unsigned InstrIdx,
-                              unsigned OpIdx, unsigned NumUses,
+                              unsigned OpIdx,
+                              SmallVector<unsigned, 2> &UseOps,
                               bool isSS, int Slot, unsigned Reg);
 
     /// anyKillInMBBAfterIdx - Returns true if there is a kill of the specified
diff --git a/include/llvm/Target/MRegisterInfo.h b/include/llvm/Target/MRegisterInfo.h
index bff74de882..ecbee642f4 100644
--- a/include/llvm/Target/MRegisterInfo.h
+++ b/include/llvm/Target/MRegisterInfo.h
@@ -543,6 +543,14 @@ public:
     return 0;
   }
 
+  /// foldMemoryOperand - Same as previous except it tries to fold instruction
+  /// with multiple uses of the same register.
+  virtual MachineInstr* foldMemoryOperand(MachineInstr* MI,
+                                          SmallVectorImpl<unsigned> &UseOps,
+                                          int FrameIndex) const {
+    return 0;
+  }
+
   /// foldMemoryOperand - Same as the previous version except it allows folding
   /// of any load and store from / to any address, not just from a specific
   /// stack slot.
@@ -552,6 +560,14 @@ public:
     return 0;
   }
 
+  /// foldMemoryOperand - Same as previous except it tries to fold instruction
+  /// with multiple uses of the same register.
+  virtual MachineInstr* foldMemoryOperand(MachineInstr* MI,
+                                          SmallVectorImpl<unsigned> &UseOps,
+                                          MachineInstr* LoadMI) const {
+    return 0;
+  }
+
   /// getOpcodeAfterMemoryFold - Returns the opcode of the would be new
   /// instruction after load / store is folded into an instruction of the
   /// specified opcode. It returns zero if the specified unfolding is not