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| author | Evan Cheng <evan.cheng@apple.com> | 2010-08-17 17:43:50 +0000 |
|---|---|---|
| committer | Evan Cheng <evan.cheng@apple.com> | 2010-08-17 17:43:50 +0000 |
| commit | e008384508342a2dec110eafaa87d93614976990 (patch) | |
| tree | 9b55d84fea5b3777135ce41c11bc676ac50e6a43 /lib/CodeGen/MachineBasicBlock.cpp | |
| parent | fc8042a1225790b3a6de434546623babea08496f (diff) | |
| download | llvm-e008384508342a2dec110eafaa87d93614976990.tar.gz llvm-e008384508342a2dec110eafaa87d93614976990.tar.bz2 llvm-e008384508342a2dec110eafaa87d93614976990.tar.xz | |
Move the decision logic whether it's a good idea to split a critical edge to clients. Also fixed an erroneous check. An edge is only a back edge when the from and to blocks are in the same loop.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111256 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/MachineBasicBlock.cpp')
| -rw-r--r-- | lib/CodeGen/MachineBasicBlock.cpp | 10 |
1 files changed, 1 insertions, 9 deletions
diff --git a/lib/CodeGen/MachineBasicBlock.cpp b/lib/CodeGen/MachineBasicBlock.cpp index f506f12050..d351db59e6 100644 --- a/lib/CodeGen/MachineBasicBlock.cpp +++ b/lib/CodeGen/MachineBasicBlock.cpp @@ -439,14 +439,6 @@ MachineBasicBlock::SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P) { if (TII->AnalyzeBranch(*this, TBB, FBB, Cond)) return NULL; - // Avoid splitting backedges of loops. It would introduce small out-of-line - // blocks into the loop which is very bad for code placement. - if (this == Succ) - return NULL; - MachineLoopInfo *MLI = P->getAnalysisIfAvailable<MachineLoopInfo>(); - if (MLI->isLoopHeader(Succ)) - return NULL; - MachineBasicBlock *NMBB = MF->CreateMachineBasicBlock(); MF->insert(llvm::next(MachineFunction::iterator(this)), NMBB); DEBUG(dbgs() << "Splitting critical edge:" @@ -479,7 +471,7 @@ MachineBasicBlock::SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P) { P->getAnalysisIfAvailable<MachineDominatorTree>()) MDT->addNewBlock(NMBB, this); - if (MLI) + if (MachineLoopInfo *MLI = P->getAnalysisIfAvailable<MachineLoopInfo>()) if (MachineLoop *TIL = MLI->getLoopFor(this)) { // If one or the other blocks were not in a loop, the new block is not // either, and thus LI doesn't need to be updated. |