From 665aa6efcc3ea940e5f95159409766e67123d1db Mon Sep 17 00:00:00 2001 From: Jakob Stoklund Olesen Date: Thu, 30 Sep 2010 19:44:31 +0000 Subject: When isel is emitting instructions for an x86 target without CMOV, the CFG is edited during emission. If the basic block ends in a switch that gets lowered to a jump table, any phis at the default edge were getting updated wrong. The jump table data structure keeps a pointer to the header blocks that wasn't getting updated after the MBB is split. This bug was exposed on 32-bit Linux when disabling critical edge splitting in codegen prepare. The fix is to uipdate stale MBB pointers whenever a block is split during emission. llvm-svn: 115191 --- llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp') diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp index c316ef6c54a..adc225b94bc 100644 --- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp @@ -2207,6 +2207,19 @@ size_t SelectionDAGBuilder::Clusterify(CaseVector& Cases, return numCmps; } +void SelectionDAGBuilder::UpdateSplitBlock(MachineBasicBlock *First, + MachineBasicBlock *Last) { + // Update JTCases. + for (unsigned i = 0, e = JTCases.size(); i != e; ++i) + if (JTCases[i].first.HeaderBB == First) + JTCases[i].first.HeaderBB = Last; + + // Update BitTestCases. + for (unsigned i = 0, e = BitTestCases.size(); i != e; ++i) + if (BitTestCases[i].Parent == First) + BitTestCases[i].Parent = Last; +} + void SelectionDAGBuilder::visitSwitch(const SwitchInst &SI) { MachineBasicBlock *SwitchMBB = FuncInfo.MBB; -- cgit v1.2.3