ReMaterializeTrivialDef need to trim the live interval to the last kill if the copy kills the source register. This fixes uint64tof64.ll after ARM::MOVi is marked as isAsCheapAsAMove.

llvm-svn: 63853

1 files changed, 9 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/SimpleRegisterCoalescing.h b/llvm/lib/CodeGen/SimpleRegisterCoalescing.h
index cce5cebd9e6..9e55c220034 100644
--- a/llvm/lib/CodeGen/SimpleRegisterCoalescing.h
+++ b/llvm/lib/CodeGen/SimpleRegisterCoalescing.h
@@ -196,6 +196,15 @@ namespace llvm {
     bool RemoveCopyByCommutingDef(LiveInterval &IntA, LiveInterval &IntB,
                                   MachineInstr *CopyMI);
 
+    /// TrimLiveIntervalToLastUse - If there is a last use in the same basic
+    /// block as the copy instruction, trim the ive interval to the last use
+    /// and return true.
+    bool TrimLiveIntervalToLastUse(unsigned CopyIdx,
+                                   MachineBasicBlock *CopyMBB,
+                                   LiveInterval &li, const LiveRange *LR);
+
+    /// ReMaterializeTrivialDef - If the source of a copy is defined by a trivial
+    /// computation, replace the copy by rematerialize the definition.
     bool ReMaterializeTrivialDef(LiveInterval &SrcInt, unsigned DstReg,
                                  MachineInstr *CopyMI);