diff options
| author | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2012-08-20 21:39:52 +0000 |
|---|---|---|
| committer | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2012-08-20 21:39:52 +0000 |
| commit | e7fdef420d0c8a825555d246da259342c48bd527 (patch) | |
| tree | 547217afeba3ac83e232e628a24c768f2ab6bf87 /lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp | |
| parent | 2c5a960b0eae0634da6e1854111b35f475e65335 (diff) | |
Don't add CFG edges for redundant conditional branches.
IR that hasn't been through SimplifyCFG can look like this:
br i1 %b, label %r, label %r
Make sure we don't create duplicate Machine CFG edges in this case.
Fix the machine code verifier to accept conditional branches with a
single CFG edge.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162230 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp')
| -rw-r--r-- | lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp index ae2b32969a..f3cf7582be 100644 --- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp +++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp @@ -1601,7 +1601,10 @@ void SelectionDAGBuilder::visitSwitchCase(CaseBlock &CB, // Update successor info addSuccessorWithWeight(SwitchBB, CB.TrueBB, CB.TrueWeight); - addSuccessorWithWeight(SwitchBB, CB.FalseBB, CB.FalseWeight); + // TrueBB and FalseBB are always different unless the incoming IR is + // degenerate. This only happens when running llc on weird IR. + if (CB.TrueBB != CB.FalseBB) + addSuccessorWithWeight(SwitchBB, CB.FalseBB, CB.FalseWeight); // Set NextBlock to be the MBB immediately after the current one, if any. // This is used to avoid emitting unnecessary branches to the next block. |