[C++11] Add two range adaptor views to User: operands and

operand_values. The first provides a range view over operand Use
objects, and the second provides a range view over the Value*s being
used by those operands.

The naming is "STL-style" rather than "LLVM-style" because we have
historically named iterator methods STL-style, and range methods seem to
have far more in common with their iterator counterparts than with
"normal" APIs. Feel free to bikeshed on this one if you want, I'm happy
to change these around if people feel strongly.

I've switched code in SROA and LCG to exercise these mostly to ensure
they work correctly -- we don't really have an easy way to unittest this
and they're trivial.

llvm-svn: 202687

1 files changed, 5 insertions, 6 deletions

diff --git a/llvm/lib/Transforms/Scalar/SROA.cpp b/llvm/lib/Transforms/Scalar/SROA.cpp
index 1cb76696f18..3c245e4bd5e 100644
--- a/llvm/lib/Transforms/Scalar/SROA.cpp
+++ b/llvm/lib/Transforms/Scalar/SROA.cpp
@@ -3447,9 +3447,8 @@ bool SROA::runOnAlloca(AllocaInst &AI) {
                                         DE = S.dead_user_end();
        DI != DE; ++DI) {
     // Free up everything used by this instruction.
-    for (User::op_iterator DOI = (*DI)->op_begin(), DOE = (*DI)->op_end();
-         DOI != DOE; ++DOI)
-      clobberUse(*DOI);
+    for (Use &DeadOp : (*DI)->operands())
+      clobberUse(DeadOp);
 
     // Now replace the uses of this instruction.
     (*DI)->replaceAllUsesWith(UndefValue::get((*DI)->getType()));
@@ -3498,10 +3497,10 @@ void SROA::deleteDeadInstructions(SmallPtrSet<AllocaInst*, 4> &DeletedAllocas) {
 
     I->replaceAllUsesWith(UndefValue::get(I->getType()));
 
-    for (User::op_iterator OI = I->op_begin(), E = I->op_end(); OI != E; ++OI)
-      if (Instruction *U = dyn_cast<Instruction>(*OI)) {
+    for (Use &Operand : I->operands())
+      if (Instruction *U = dyn_cast<Instruction>(Operand)) {
         // Zero out the operand and see if it becomes trivially dead.
-        *OI = 0;
+        Operand = 0;
         if (isInstructionTriviallyDead(U))
           DeadInsts.insert(U);
       }