[MSP430][NFC] Remove redundant condition

[baloghadamsoftware]

Summary

Condition NumBytes is checked both in an outer and in an inner if statement in MSP430FrameLowering::emitPrologue(). This patch removes the redundant inner check.

The issue was found using clang-tidy check under review misc-redundant-condition. See https://reviews.llvm.org/D81272.

[asl]

llvm/lib/Target/MSP430/MSP430FrameLowering.cpp

91

Please do not add commented-out code. Thanks!

95

Ditto

[baloghadamsoftware]

Removed commented-out lines.

[baloghadamsoftware]

llvm/lib/Target/MSP430/MSP430FrameLowering.cpp

91

This was already in the code, I did not change it. Now I removed it.

95

Originally, I commented out this, because of the commented-out line above, because they belong together. Now I removed it too.

[asl]

llvm/lib/Target/MSP430/MSP430FrameLowering.cpp

95

Still, there is some commented-out code. And you left obsolete comments which are misleading after removing the code. Will you please remove them while you're there?

[baloghadamsoftware]

Misleading comment deleted together with the last commented-out line.

[baloghadamsoftware]

llvm/lib/Target/MSP430/MSP430FrameLowering.cpp

95

Sorry, I overlooked that line.

[baloghadamsoftware]

Is it OK now, @asl?

[baloghadamsoftware]

Ping. @asl?

llvm/lib/Target/MSP430/MSP430FrameLowering.cpp

while (MBBI != MBB.end() && (MBBI->getOpcode() == MSP430::PUSH16r))
     ++MBBI;
 
   if (MBBI != MBB.end())
     DL = MBBI->getDebugLoc();
 
   if (NumBytes) { // adjust stack pointer: SP -= numbytes
     // If there is an SUB16ri of SP immediately before this instruction, merge
     // the two.
     //NumBytes -= mergeSPUpdates(MBB, MBBI, true);
     // If there is an ADD16ri or SUB16ri of SP immediately after this
     // instruction, merge the two instructions.
     // mergeSPUpdatesDown(MBB, MBBI, &NumBytes);
+    //if (NumBytes) {
 
-    if (NumBytes) {
-      MachineInstr *MI =
-        BuildMI(MBB, MBBI, DL, TII.get(MSP430::SUB16ri), MSP430::SP)
-        .addReg(MSP430::SP).addImm(NumBytes);
-      // The SRW implicit def is dead.
-      MI->getOperand(3).setIsDead();
-    }
-  }
-}
 
 void MSP430FrameLowering::emitEpilogue(MachineFunction &MF,
                                        MachineBasicBlock &MBB) const {
   const MachineFrameInfo &MFI = MF.getFrameInfo();
   MSP430MachineFunctionInfo *MSP430FI = MF.getInfo<MSP430MachineFunctionInfo>();
   const MSP430InstrInfo &TII =
       *static_cast<const MSP430InstrInfo *>(MF.getSubtarget().getInstrInfo());