[X86] Remove mergeSPUpdatesUp()

X86FrameLowering has both a mergeSPUpdates() that accepts a direction, and an
mergeSPUpdatesUp(), which seem to do the same thing, except for a slightly 
different interface. Removed the less general function.
NFC.

Differential Revision: http://reviews.llvm.org/D11510

llvm-svn: 243396

llvm/lib/Target/X86/X86FrameLowering.cpp

@@ -343,30 +343,6 @@ MachineInstrBuilder X86FrameLowering::BuildStackAdjustment(
   return MI;
 }
 
-/// mergeSPUpdatesUp - Merge two stack-manipulating instructions upper iterator.
-static
-void mergeSPUpdatesUp(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
-                      unsigned StackPtr, uint64_t *NumBytes = nullptr) {
-  if (MBBI == MBB.begin()) return;
-
-  MachineBasicBlock::iterator PI = std::prev(MBBI);
-  unsigned Opc = PI->getOpcode();
-  if ((Opc == X86::ADD64ri32 || Opc == X86::ADD64ri8 ||
-       Opc == X86::ADD32ri || Opc == X86::ADD32ri8 ||
-       Opc == X86::LEA32r || Opc == X86::LEA64_32r) &&
-      PI->getOperand(0).getReg() == StackPtr) {
-    if (NumBytes)
-      *NumBytes += PI->getOperand(2).getImm();
-    MBB.erase(PI);
-  } else if ((Opc == X86::SUB64ri32 || Opc == X86::SUB64ri8 ||
-              Opc == X86::SUB32ri || Opc == X86::SUB32ri8) &&
-             PI->getOperand(0).getReg() == StackPtr) {
-    if (NumBytes)
-      *NumBytes -= PI->getOperand(2).getImm();
-    MBB.erase(PI);
-  }
-}
-
 int X86FrameLowering::mergeSPUpdates(MachineBasicBlock &MBB,
                                      MachineBasicBlock::iterator &MBBI,
                                      bool doMergeWithPrevious) const {
@@ -1074,7 +1050,7 @@ void X86FrameLowering::emitEpilogue(MachineFunction &MF,
   // If there is an ADD32ri or SUB32ri of ESP immediately before this
   // instruction, merge the two instructions.
   if (NumBytes || MFI->hasVarSizedObjects())
-    mergeSPUpdatesUp(MBB, MBBI, StackPtr, &NumBytes);
+    NumBytes += mergeSPUpdates(MBB, MBBI, true);
 
   // If dynamic alloca is used, then reset esp to point to the last callee-saved
   // slot before popping them off! Same applies for the case, when stack was