[NFC] BasicBlock: refactor changePhiUses() out of replacePhiUsesWith(), use it

Summary:
It is a common thing to loop over every `PHINode` in some `BasicBlock`
and change old `BasicBlock` incoming block to a new `BasicBlock` incoming block.
`replaceSuccessorsPhiUsesWith()` already had code to do that,
it just wasn't a function.
So outline it into a new function, and use it.

Reviewers: chandlerc, craig.topper, spatel, danielcdh

Reviewed By: craig.topper

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61013

llvm-svn: 359996

1 files changed, 2 insertions, 4 deletions

diff --git a/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp b/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
index 92e3e9a0496..64a97f86a21 100644
--- a/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
+++ b/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
@@ -1325,8 +1325,7 @@ LoopConstrainer::RewrittenRangeInfo LoopConstrainer::changeIterationSpaceEnd(
 
   // The latch exit now has a branch from `RRI.ExitSelector' instead of
   // `LS.Latch'.  The PHI nodes need to be updated to reflect that.
-  for (PHINode &PN : LS.LatchExit->phis())
-    PN.replaceIncomingBlockWith(LS.Latch, RRI.ExitSelector);
+  LS.LatchExit->replacePhiUsesWith(LS.Latch, RRI.ExitSelector);
 
   return RRI;
 }
@@ -1349,8 +1348,7 @@ BasicBlock *LoopConstrainer::createPreheader(const LoopStructure &LS,
   BasicBlock *Preheader = BasicBlock::Create(Ctx, Tag, &F, LS.Header);
   BranchInst::Create(LS.Header, Preheader);
 
-  for (PHINode &PN : LS.Header->phis())
-    PN.replaceIncomingBlockWith(OldPreheader, Preheader);
+  LS.Header->replacePhiUsesWith(OldPreheader, Preheader);
 
   return Preheader;
 }