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, 2 insertions, 2 deletions

diff --git a/llvm/lib/Target/Mips/MipsFrameLowering.cpp b/llvm/lib/Target/Mips/MipsFrameLowering.cpp
index 2db0b9b..c53b96c 100644
--- a/llvm/lib/Target/Mips/MipsFrameLowering.cpp
+++ b/llvm/lib/Target/Mips/MipsFrameLowering.cpp
@@ -143,7 +143,7 @@ uint64_t MipsFrameLowering::estimateStackSize(const MachineFunction &MF) const {
 }
 
 // Eliminate ADJCALLSTACKDOWN, ADJCALLSTACKUP pseudo instructions
-void MipsFrameLowering::
+MachineBasicBlock::iterator MipsFrameLowering::
 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
                               MachineBasicBlock::iterator I) const {
   unsigned SP = STI.getABI().IsN64() ? Mips::SP_64 : Mips::SP;
@@ -156,5 +156,5 @@ eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
     STI.getInstrInfo()->adjustStackPtr(SP, Amount, MBB, I);
   }
 
-  MBB.erase(I);
+  return MBB.erase(I);
 }