Fixed an issue on updating profile data when lowering switch statement.

Fixed the issue that when there is an edge from the jump table to the default statement, we should check it directly instead of checking if the sibling of the jump table header is a successor of the jump table header, which may not be the default statment but a successor of it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@248354 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 44f222aeafd5e5adbd62edf5e0a0ff011836a8bc..97caa9d014a963df66e97008738462690def236b 100644 (file)
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -8146,13 +8146,13 @@ void SelectionDAGBuilder::lowerWorkItem(SwitchWorkListItem W, Value *Cond,
         uint32_t JumpWeight = I->Weight;
         uint32_t FallthroughWeight = UnhandledWeights;
 
-        // If Fallthrough is a target of the jump table, we evenly distribute
-        // the weight on the edge to Fallthrough to successors of CurMBB.
-        // Also update the weight on the edge from JumpMBB to Fallthrough.
+        // If the default statement is a target of the jump table, we evenly
+        // distribute the default weight to successors of CurMBB. Also update
+        // the weight on the edge from JumpMBB to Fallthrough.
         for (MachineBasicBlock::succ_iterator SI = JumpMBB->succ_begin(),
                                               SE = JumpMBB->succ_end();
              SI != SE; ++SI) {
-          if (*SI == Fallthrough) {
+          if (*SI == DefaultMBB) {
             JumpWeight += DefaultWeight / 2;
             FallthroughWeight -= DefaultWeight / 2;
             JumpMBB->setSuccWeight(SI, DefaultWeight / 2);