[IR] Value: add replaceUsesWithIf() utility

Summary:
While there is always a `Value::replaceAllUsesWith()`,
sometimes the replacement needs to be conditional.

I have only cleaned a few cases where `replaceUsesWithIf()`
could be used, to both add test coverage,
and show that it is actually useful.

Reviewers: jdoerfert, spatel, RKSimon, craig.topper

Reviewed By: jdoerfert

Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, aheejin, george.burgess.iv, asbirlea, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65528

llvm-svn: 367548

1 files changed, 3 insertions, 6 deletions

diff --git a/llvm/lib/Transforms/Scalar/LoopSink.cpp b/llvm/lib/Transforms/Scalar/LoopSink.cpp
index 975452e13f0..65e0dee0225 100644
--- a/llvm/lib/Transforms/Scalar/LoopSink.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopSink.cpp
@@ -230,12 +230,9 @@ static bool sinkInstruction(Loop &L, Instruction &I,
     IC->setName(I.getName());
     IC->insertBefore(&*N->getFirstInsertionPt());
     // Replaces uses of I with IC in N
-    for (Value::use_iterator UI = I.use_begin(), UE = I.use_end(); UI != UE;) {
-      Use &U = *UI++;
-      auto *I = cast<Instruction>(U.getUser());
-      if (I->getParent() == N)
-        U.set(IC);
-    }
+    I.replaceUsesWithIf(IC, [N](Use &U) {
+      return cast<Instruction>(U.getUser())->getParent() == N;
+    });
     // Replaces uses of I with IC in blocks dominated by N
     replaceDominatedUsesWith(&I, IC, DT, N);
     LLVM_DEBUG(dbgs() << "Sinking a clone of " << I << " To: " << N->getName()