[InstCombine] Allow sinking from unique predecessor with multiple edges

Summary: We can allow sinking if the single user block has only one unique predecessor, regardless of the number of edges. Note that a switch statement with multiple cases can have the same destination.

Reviewers: mcrosier, majnemer, spatel, reames

Subscribers: reames, mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D23722

llvm-svn: 279448

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
index 6424e083bd1..12c42ce6472 100644
--- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -2903,7 +2903,7 @@ bool InstCombiner::run() {
         // If the user is one of our immediate successors, and if that successor
         // only has us as a predecessors (we'd have to split the critical edge
         // otherwise), we can keep going.
-        if (UserIsSuccessor && UserParent->getSinglePredecessor()) {
+        if (UserIsSuccessor && UserParent->getUniquePredecessor()) {
           // Okay, the CFG is simple enough, try to sink this instruction.
           if (TryToSinkInstruction(I, UserParent)) {
             DEBUG(dbgs() << "IC: Sink: " << *I << '\n');