CodeGen: Use mop_iterator instead of MIOperands/ConstMIOperands

MIOperands/ConstMIOperands are classes iterating over the MachineOperand
of a MachineInstr, however MachineInstr::mop_iterator does the same
thing.

I assume these two iterators exist to have a uniform interface to
iterate over the operands of a machine instruction bundle and a single
machine instruction. However in practice I find it more confusing to have 2
different iterator classes, so this patch transforms (nearly all) the
code to use mop_iterators.

The only exception being MIOperands::anlayzePhysReg() and
MIOperands::analyzeVirtReg() still needing an equivalent, I leave that
as an exercise for the next patch.

Differential Revision: http://reviews.llvm.org/D9932

This version is slightly modified from the proposed revision in that it
introduces MachineInstr::getOperandNo to avoid the extra counting
variable in the few loops that previously used MIOperands::getOperandNo.

llvm-svn: 238539

1 files changed, 4 insertions, 4 deletions

diff --git a/llvm/lib/Target/ARM/Thumb2ITBlockPass.cpp b/llvm/lib/Target/ARM/Thumb2ITBlockPass.cpp
index b62ae2e..68736bc 100644
--- a/llvm/lib/Target/ARM/Thumb2ITBlockPass.cpp
+++ b/llvm/lib/Target/ARM/Thumb2ITBlockPass.cpp
@@ -94,12 +94,12 @@ static void TrackDefUses(MachineInstr *MI,
 /// conservatively remove more kill flags than are necessary, but removing them
 /// is safer than incorrect kill flags remaining on instructions.
 static void ClearKillFlags(MachineInstr *MI, SmallSet<unsigned, 4> &Uses) {
-  for (MIOperands MO(MI); MO.isValid(); ++MO) {
-    if (!MO->isReg() || MO->isDef() || !MO->isKill())
+  for (MachineOperand &MO : MI->operands()) {
+    if (!MO.isReg() || MO.isDef() || !MO.isKill())
       continue;
-    if (!Uses.count(MO->getReg()))
+    if (!Uses.count(MO.getReg()))
       continue;
-    MO->setIsKill(false);
+    MO.setIsKill(false);
   }
 }