Fix PHIElimination optimization that uses MBB->getBasicBlock.
The BasicBlock associated with a MachineBasicBlock does not necessarily
correspond to the code in the MBB.
Don't insert a new IR BasicBlock when splitting critical edges. We are not
supposed to modify the IR during codegen, and we should be able to do just
fine with a NULL BB.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@88707 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/PHIElimination.h b/lib/CodeGen/PHIElimination.h
index edc2d36..94716ee 100644
--- a/lib/CodeGen/PHIElimination.h
+++ b/lib/CodeGen/PHIElimination.h
@@ -110,11 +110,12 @@
MachineBasicBlock *SplitCriticalEdge(MachineBasicBlock *A,
MachineBasicBlock *B);
- // FindCopyInsertPoint - Find a safe place in MBB to insert a copy from
- // SrcReg. This needs to be after any def or uses of SrcReg, but before
- // any subsequent point where control flow might jump out of the basic
- // block.
+ /// FindCopyInsertPoint - Find a safe place in MBB to insert a copy from
+ /// SrcReg when following the CFG edge to SuccMBB. This needs to be after
+ /// any def of SrcReg, but before any subsequent point where control flow
+ /// might jump out of the basic block.
MachineBasicBlock::iterator FindCopyInsertPoint(MachineBasicBlock &MBB,
+ MachineBasicBlock &SuccMBB,
unsigned SrcReg);
// SkipPHIsAndLabels - Copies need to be inserted after phi nodes and