move MergeBasicBlockIntoOnlyPred to Transforms/Utils.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60162 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/JumpThreading.cpp b/lib/Transforms/Scalar/JumpThreading.cpp
index b6d8ff6..eb4a873 100644
--- a/lib/Transforms/Scalar/JumpThreading.cpp
+++ b/lib/Transforms/Scalar/JumpThreading.cpp
@@ -156,37 +156,6 @@
return Size;
}
-/// MergeBasicBlockIntoOnlyPred - DestBB is a block with one predecessor and its
-/// predecessor is known to have one successor (DestBB!). Eliminate the edge
-/// between them, moving the instructions in the predecessor into DestBB and
-/// deleting the predecessor block.
-///
-/// FIXME: Move to TransformUtils to share with simplifycfg and codegenprepare.
-static void MergeBasicBlockIntoOnlyPred(BasicBlock *DestBB) {
- // If BB has single-entry PHI nodes, fold them.
- while (PHINode *PN = dyn_cast<PHINode>(DestBB->begin())) {
- Value *NewVal = PN->getIncomingValue(0);
- // Replace self referencing PHI with undef, it must be dead.
- if (NewVal == PN) NewVal = UndefValue::get(PN->getType());
- PN->replaceAllUsesWith(NewVal);
- PN->eraseFromParent();
- }
-
- BasicBlock *PredBB = DestBB->getSinglePredecessor();
- assert(PredBB && "Block doesn't have a single predecessor!");
-
- // Splice all the instructions from PredBB to DestBB.
- PredBB->getTerminator()->eraseFromParent();
- DestBB->getInstList().splice(DestBB->begin(), PredBB->getInstList());
-
- // Anything that branched to PredBB now branches to DestBB.
- PredBB->replaceAllUsesWith(DestBB);
-
- // Nuke BB.
- PredBB->eraseFromParent();
-}
-
-
/// ProcessBlock - If there are any predecessors whose control can be threaded
/// through to a successor, transform them now.
bool JumpThreading::ProcessBlock(BasicBlock *BB) {
diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp
index ed67c5e..efb9022 100644
--- a/lib/Transforms/Utils/Local.cpp
+++ b/lib/Transforms/Utils/Local.cpp
@@ -200,3 +200,36 @@
}
return false;
}
+
+//===----------------------------------------------------------------------===//
+// Control Flow Graph Restructuring...
+//
+
+/// MergeBasicBlockIntoOnlyPred - DestBB is a block with one predecessor and its
+/// predecessor is known to have one successor (DestBB!). Eliminate the edge
+/// between them, moving the instructions in the predecessor into DestBB and
+/// deleting the predecessor block.
+///
+void llvm::MergeBasicBlockIntoOnlyPred(BasicBlock *DestBB) {
+ // If BB has single-entry PHI nodes, fold them.
+ while (PHINode *PN = dyn_cast<PHINode>(DestBB->begin())) {
+ Value *NewVal = PN->getIncomingValue(0);
+ // Replace self referencing PHI with undef, it must be dead.
+ if (NewVal == PN) NewVal = UndefValue::get(PN->getType());
+ PN->replaceAllUsesWith(NewVal);
+ PN->eraseFromParent();
+ }
+
+ BasicBlock *PredBB = DestBB->getSinglePredecessor();
+ assert(PredBB && "Block doesn't have a single predecessor!");
+
+ // Splice all the instructions from PredBB to DestBB.
+ PredBB->getTerminator()->eraseFromParent();
+ DestBB->getInstList().splice(DestBB->begin(), PredBB->getInstList());
+
+ // Anything that branched to PredBB now branches to DestBB.
+ PredBB->replaceAllUsesWith(DestBB);
+
+ // Nuke BB.
+ PredBB->eraseFromParent();
+}