To ensure that we have more accurate line information for a block
don't elide the branch instruction if it's the only one in the block,
otherwise it's ok.
PR9796 and rdar://11215207
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154417 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/FastISel.cpp b/lib/CodeGen/SelectionDAG/FastISel.cpp
index 5de6667..0c1ac69 100644
--- a/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -821,8 +821,11 @@
/// the CFG.
void
FastISel::FastEmitBranch(MachineBasicBlock *MSucc, DebugLoc DL) {
- if (FuncInfo.MBB->isLayoutSuccessor(MSucc)) {
- // The unconditional fall-through case, which needs no instructions.
+
+ if (FuncInfo.MBB->getBasicBlock()->size() > 1 && FuncInfo.MBB->isLayoutSuccessor(MSucc)) {
+ // For more accurate line information if this is the only instruction
+ // in the block then emit it, otherwise we have the unconditional
+ // fall-through case, which needs no instructions.
} else {
// The unconditional branch case.
TII.InsertBranch(*FuncInfo.MBB, MSucc, NULL,