Phase 1 of refactoring the MachineRegisterInfo iterators to make them suitable

for use with C++11 range-based for-loops.

The gist of phase 1 is to remove the skipInstruction() and skipBundle()
methods from these iterators, instead splitting each iterator into a version
that walks operands, a version that walks instructions, and a version that
walks bundles.  This has the result of making some "clever" loops in lib/CodeGen
more verbose, but also makes their iterator invalidation characteristics much
more obvious to the casual reader. (Making them concise again in the future is a
good motivating case for a pre-incrementing range adapter!)

Phase 2 of this undertaking with consist of removing the getOperand() method,
and changing operator*() of the operand-walker to return a MachineOperand&.  At
that point, it should be possible to add range views for them that work as one
might expect.

llvm-svn: 203757

1 files changed, 4 insertions, 3 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index cda0b57a159..5d0e2b937df 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -483,9 +483,10 @@ bool SelectionDAGISel::runOnMachineFunction(MachineFunction &mf) {
       // that COPY instructions also need DBG_VALUE, if it is the only
       // user of LDI->second.
       MachineInstr *CopyUseMI = NULL;
-      for (MachineRegisterInfo::use_iterator
-             UI = RegInfo->use_begin(LDI->second);
-           MachineInstr *UseMI = UI.skipInstruction();) {
+      for (MachineRegisterInfo::use_instr_iterator
+           UI = RegInfo->use_instr_begin(LDI->second),
+           E = RegInfo->use_instr_end(); UI != E; ) {
+        MachineInstr *UseMI = &*(UI++);
         if (UseMI->isDebugValue()) continue;
         if (UseMI->isCopy() && !CopyUseMI && UseMI->getParent() == EntryMBB) {
           CopyUseMI = UseMI; continue;