// If the destination block has a single pred, then this is a trivial edge,
// just collapse it.
if (BasicBlock *SinglePred = DestBB->getSinglePredecessor()) {
- // Remember if SinglePred was the entry block of the function. If so, we
- // will need to move BB back to the entry position.
- bool isEntry = SinglePred == &SinglePred->getParent()->getEntryBlock();
- MergeBasicBlockIntoOnlyPred(DestBB);
-
- if (isEntry && BB != &BB->getParent()->getEntryBlock())
- BB->moveBefore(&BB->getParent()->getEntryBlock());
-
- DOUT << "AFTER:\n" << *DestBB << "\n\n\n";
- return;
+ if (SinglePred != DestBB) {
+ // Remember if SinglePred was the entry block of the function. If so, we
+ // will need to move BB back to the entry position.
+ bool isEntry = SinglePred == &SinglePred->getParent()->getEntryBlock();
+ MergeBasicBlockIntoOnlyPred(DestBB);
+
+ if (isEntry && BB != &BB->getParent()->getEntryBlock())
+ BB->moveBefore(&BB->getParent()->getEntryBlock());
+
+ DOUT << "AFTER:\n" << *DestBB << "\n\n\n";
+ return;
+ }
}
// Otherwise, we have multiple predecessors of BB. Update the PHIs in DestBB
// because now the condition in this block can be threaded through
// predecessors of our predecessor block.
if (BasicBlock *SinglePred = BB->getSinglePredecessor())
- if (SinglePred->getTerminator()->getNumSuccessors() == 1) {
+ if (SinglePred->getTerminator()->getNumSuccessors() == 1 &&
+ SinglePred != BB) {
// Remember if SinglePred was the entry block of the function. If so, we
// will need to move BB back to the entry position.
bool isEntry = SinglePred == &SinglePred->getParent()->getEntryBlock();
--- /dev/null
+; RUN: llvm-as < %s | opt -jump-threading | llvm-dis
+
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
+target triple = "i386-apple-darwin9.5"
+ %struct.decContext = type { i32 }
+ %struct.decNumber = type { i32, i32 }
+
+define i32 @decNumberPower(%struct.decNumber* %res, %struct.decNumber* %lhs, %struct.decNumber* %rhs, %struct.decContext* %set) nounwind {
+entry:
+ br i1 true, label %decDivideOp.exit, label %bb7.i
+
+bb7.i: ; preds = %bb7.i, %entry
+ br label %bb7.i
+
+decDivideOp.exit: ; preds = %entry
+ ret i32 undef
+}