Use newly added next() and prior() utility functions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11430 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 5 insertions, 6 deletions

diff --git a/lib/CodeGen/PHIElimination.cpp b/lib/CodeGen/PHIElimination.cpp
index e0025f9e4f..06305826e8 100644
--- a/lib/CodeGen/PHIElimination.cpp
+++ b/lib/CodeGen/PHIElimination.cpp
@@ -20,6 +20,7 @@
 #include "llvm/Target/TargetInstrInfo.h"
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Support/CFG.h"
+#include "Support/STLExtras.h"
 
 namespace llvm {
 
@@ -171,8 +172,7 @@ bool PNE::EliminatePHINodes(MachineFunction &MF, MachineBasicBlock &MBB) {
       bool HaveNotEmitted = true;
       
       if (I != opBlock.begin()) {
-        MachineBasicBlock::iterator PrevInst = I;
-        --PrevInst;
+        MachineBasicBlock::iterator PrevInst = prior(I);
         for (unsigned i = 0, e = PrevInst->getNumOperands(); i != e; ++i) {
           MachineOperand &MO = PrevInst->getOperand(i);
           if (MO.isRegister() && MO.getReg() == IncomingReg)
@@ -253,8 +253,7 @@ bool PNE::EliminatePHINodes(MachineFunction &MF, MachineBasicBlock &MBB) {
           // kills the incoming value!
           //
           if (!ValueIsLive) {
-            MachineBasicBlock::iterator Prev = I;
-            --Prev;
+            MachineBasicBlock::iterator Prev = prior(I);
             LV->addVirtualRegisterKilled(SrcReg, &opBlock, Prev);
           }
         }
diff --git a/lib/CodeGen/TwoAddressInstructionPass.cpp b/lib/CodeGen/TwoAddressInstructionPass.cpp
index 8dc2ffe365..6f1e990140 100644
--- a/lib/CodeGen/TwoAddressInstructionPass.cpp
+++ b/lib/CodeGen/TwoAddressInstructionPass.cpp
@@ -38,6 +38,7 @@
 #include "llvm/Target/TargetMachine.h"
 #include "Support/Debug.h"
 #include "Support/Statistic.h"
+#include "Support/STLExtras.h"
 #include <iostream>
 using namespace llvm;
 
@@ -134,8 +135,7 @@ bool TwoAddressInstructionPass::runOnMachineFunction(MachineFunction &MF) {
                 unsigned Added = MRI.copyRegToReg(*mbbi, mi, regA, regB, rc);
                 numInstrsAdded += Added;
 
-                MachineBasicBlock::iterator prevMi = mi;
-                --prevMi;
+                MachineBasicBlock::iterator prevMi = prior(mi);
                 DEBUG(std::cerr << "\t\tadded instruction: ";
                       prevMi->print(std::cerr, TM));