[NFCI] Factor out block removal from stack of nested loops
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354124 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/LoopSimplifyCFG.cpp b/lib/Transforms/Scalar/LoopSimplifyCFG.cpp
index c623f94..0db5d9e 100644
--- a/lib/Transforms/Scalar/LoopSimplifyCFG.cpp
+++ b/lib/Transforms/Scalar/LoopSimplifyCFG.cpp
@@ -79,6 +79,17 @@
return nullptr;
}
+/// Removes \p BB from all loops from [FirstLoop, LastLoop) in parent chain.
+static void removeBlockFromLoops(BasicBlock *BB, Loop *FirstLoop,
+ Loop *LastLoop = nullptr) {
+ assert((!LastLoop || LastLoop->contains(FirstLoop->getHeader())) &&
+ "First loop is supposed to be inside of last loop!");
+ assert(FirstLoop->contains(BB) && "Must be a loop block!");
+ for (Loop *Current = FirstLoop; Current != LastLoop;
+ Current = Current->getParentLoop())
+ Current->removeBlockFromLoop(BB);
+}
+
namespace {
/// Helper class that can turn branches and switches with constant conditions
/// into unconditional branches.
@@ -371,12 +382,9 @@
// its parents as well). Make the fixup.
if (StillReachable != OuterLoop) {
LI.changeLoopFor(NewPreheader, StillReachable);
- for (Loop *NotContaining = OuterLoop; NotContaining != StillReachable;
- NotContaining = NotContaining->getParentLoop()) {
- NotContaining->removeBlockFromLoop(NewPreheader);
- for (auto *BB : L.blocks())
- NotContaining->removeBlockFromLoop(BB);
- }
+ removeBlockFromLoops(NewPreheader, OuterLoop, StillReachable);
+ for (auto *BB : L.blocks())
+ removeBlockFromLoops(BB, OuterLoop, StillReachable);
OuterLoop->removeChildLoop(&L);
if (StillReachable)
StillReachable->addChildLoop(&L);
