Change eliminateCallFramePseudoInstr() to return an iterator

This will become necessary in a subsequent change to make this method
merge adjacent stack adjustments, i.e. it might erase the previous
and/or next instruction.

It also greatly simplifies the calls to this function from Prolog-
EpilogInserter. Previously, that had a bunch of logic to resume iteration
after the call; now it just continues with the returned iterator.

Note that this changes the behaviour of PEI a little. Previously,
it attempted to re-visit the new instruction created by
eliminateCallFramePseudoInstr(). That code was added in r36625,
but I can't see any reason for it: the new instructions will obviously
not be pseudo instructions, they will not have FrameIndex operands,
and we have already accounted for the stack adjustment.

Differential Revision: http://reviews.llvm.org/D18627

llvm-svn: 265036

1 files changed, 4 insertions, 4 deletions

diff --git a/llvm/lib/Target/MSP430/MSP430FrameLowering.cpp b/llvm/lib/Target/MSP430/MSP430FrameLowering.cpp
index eb720809e47..2df5b962cfe 100644
--- a/llvm/lib/Target/MSP430/MSP430FrameLowering.cpp
+++ b/llvm/lib/Target/MSP430/MSP430FrameLowering.cpp
@@ -224,9 +224,9 @@ MSP430FrameLowering::restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
   return true;
 }
 
-void MSP430FrameLowering::
-eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
-                              MachineBasicBlock::iterator I) const {
+MachineBasicBlock::iterator MSP430FrameLowering::eliminateCallFramePseudoInstr(
+    MachineFunction &MF, MachineBasicBlock &MBB,
+    MachineBasicBlock::iterator I) const {
   const MSP430InstrInfo &TII =
       *static_cast<const MSP430InstrInfo *>(MF.getSubtarget().getInstrInfo());
   unsigned StackAlign = getStackAlignment();
@@ -283,7 +283,7 @@ eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
     }
   }
 
-  MBB.erase(I);
+  return MBB.erase(I);
 }
 
 void