[loop-unroll] Factor out code to update LoopInfo (NFC).
Move the code to update LoopInfo for cloned basic blocks to
addClonedBlockToLoopInfo, as suggested in
https://reviews.llvm.org/D28482.
llvm-svn: 291614
diff --git a/llvm/lib/Transforms/Utils/LoopUnroll.cpp b/llvm/lib/Transforms/Utils/LoopUnroll.cpp
index e551e4b..f9a602b 100644
--- a/llvm/lib/Transforms/Utils/LoopUnroll.cpp
+++ b/llvm/lib/Transforms/Utils/LoopUnroll.cpp
@@ -172,6 +172,36 @@
return false;
}
+/// Adds ClonedBB to LoopInfo, creates a new loop for ClonedBB if necessary
+/// and adds a mapping from the original loop to the new loop to NewLoops.
+/// Returns nullptr if no new loop was created and a pointer to the
+/// original loop OriginalBB was part of otherwise.
+const Loop* llvm::addClonedBlockToLoopInfo(BasicBlock *OriginalBB,
+ BasicBlock *ClonedBB, LoopInfo *LI,
+ NewLoopsMap &NewLoops) {
+ // Figure out which loop New is in.
+ const Loop *OldLoop = LI->getLoopFor(OriginalBB);
+ assert(OldLoop && "Should (at least) be in the loop being unrolled!");
+
+ Loop *&NewLoop = NewLoops[OldLoop];
+ if (!NewLoop) {
+ // Found a new sub-loop.
+ assert(OriginalBB == OldLoop->getHeader() &&
+ "Header should be first in RPO");
+
+ Loop *NewLoopParent = NewLoops.lookup(OldLoop->getParentLoop());
+ assert(NewLoopParent &&
+ "Expected parent loop before sub-loop in RPO");
+ NewLoop = new Loop;
+ NewLoopParent->addChildLoop(NewLoop);
+ NewLoop->addBasicBlockToLoop(ClonedBB, *LI);
+ return OldLoop;
+ } else {
+ NewLoop->addBasicBlockToLoop(ClonedBB, *LI);
+ return nullptr;
+ }
+}
+
/// Unroll the given loop by Count. The loop must be in LCSSA form. Returns true
/// if unrolling was successful, or false if the loop was unmodified. Unrolling
/// can only fail when the loop's latch block is not terminated by a conditional
@@ -428,28 +458,14 @@
assert(LI->getLoopFor(*BB) == L && "Header should not be in a sub-loop");
L->addBasicBlockToLoop(New, *LI);
} else {
- // Figure out which loop New is in.
- const Loop *OldLoop = LI->getLoopFor(*BB);
- assert(OldLoop && "Should (at least) be in the loop being unrolled!");
-
- Loop *&NewLoop = NewLoops[OldLoop];
- if (!NewLoop) {
- // Found a new sub-loop.
- assert(*BB == OldLoop->getHeader() &&
- "Header should be first in RPO");
-
- Loop *NewLoopParent = NewLoops.lookup(OldLoop->getParentLoop());
- assert(NewLoopParent &&
- "Expected parent loop before sub-loop in RPO");
- NewLoop = new Loop;
- NewLoopParent->addChildLoop(NewLoop);
- LoopsToSimplify.insert(NewLoop);
+ const Loop *OldLoop = addClonedBlockToLoopInfo(*BB, New, LI, NewLoops);
+ if (OldLoop) {
+ LoopsToSimplify.insert(NewLoops[OldLoop]);
// Forget the old loop, since its inputs may have changed.
if (SE)
SE->forgetLoop(OldLoop);
}
- NewLoop->addBasicBlockToLoop(New, *LI);
}
if (*BB == Header)