diff options
| -rw-r--r-- | llvm/lib/CodeGen/MachineBlockPlacement.cpp | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/llvm/lib/CodeGen/MachineBlockPlacement.cpp b/llvm/lib/CodeGen/MachineBlockPlacement.cpp index aa440b2e1ca..b131bbcb3ae 100644 --- a/llvm/lib/CodeGen/MachineBlockPlacement.cpp +++ b/llvm/lib/CodeGen/MachineBlockPlacement.cpp @@ -282,6 +282,11 @@ class MachineBlockPlacement : public MachineFunctionPass { /// \brief A handle to the loop info. MachineLoopInfo *MLI; + /// \brief Preferred loop exit. + /// Member variable for convenience. It may be removed by duplication deep + /// in the call stack. + MachineBasicBlock *PreferredLoopExit; + /// \brief A handle to the target's instruction info. const TargetInstrInfo *TII; @@ -1474,9 +1479,9 @@ void MachineBlockPlacement::buildLoopChains(MachineLoop &L) { // If we selected just the header for the loop top, look for a potentially // profitable exit block in the event that rotating the loop can eliminate // branches by placing an exit edge at the bottom. - MachineBasicBlock *ExitingBB = nullptr; + PreferredLoopExit = nullptr; if (!RotateLoopWithProfile && LoopTop == L.getHeader()) - ExitingBB = findBestLoopExit(L, LoopBlockSet); + PreferredLoopExit = findBestLoopExit(L, LoopBlockSet); BlockChain &LoopChain = *BlockToChain[LoopTop]; @@ -1495,7 +1500,7 @@ void MachineBlockPlacement::buildLoopChains(MachineLoop &L) { if (RotateLoopWithProfile) rotateLoopWithProfile(LoopChain, L, LoopBlockSet); else - rotateLoop(LoopChain, ExitingBB, LoopBlockSet); + rotateLoop(LoopChain, PreferredLoopExit, LoopBlockSet); DEBUG({ // Crash at the end so we get all of the debugging output first. @@ -1928,8 +1933,9 @@ bool MachineBlockPlacement::maybeTailDuplicateBlock( // Remove the block from loop info. MLI->removeBlock(RemBB); + if (RemBB == PreferredLoopExit) + PreferredLoopExit = nullptr; - // TailDuplicator handles removing it from loops. DEBUG(dbgs() << "TailDuplicator deleted block: " << getBlockName(RemBB) << "\n"); }; |
