diff options
Diffstat (limited to 'llvm/lib/CodeGen/ShrinkWrap.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/ShrinkWrap.cpp | 30 |
1 files changed, 24 insertions, 6 deletions
diff --git a/llvm/lib/CodeGen/ShrinkWrap.cpp b/llvm/lib/CodeGen/ShrinkWrap.cpp index f8ec1f358c4..261b8402bc0 100644 --- a/llvm/lib/CodeGen/ShrinkWrap.cpp +++ b/llvm/lib/CodeGen/ShrinkWrap.cpp @@ -309,12 +309,30 @@ void ShrinkWrap::updateSaveRestorePoints(MachineBasicBlock &MBB) { // Fix (C). if (Save && Restore && Save != Restore && MLI->getLoopFor(Save) != MLI->getLoopFor(Restore)) { - if (MLI->getLoopDepth(Save) > MLI->getLoopDepth(Restore)) - // Push Save outside of this loop. - Save = FindIDom<>(*Save, Save->predecessors(), *MDT); - else - // Push Restore outside of this loop. - Restore = FindIDom<>(*Restore, Restore->successors(), *MPDT); + if (MLI->getLoopDepth(Save) > MLI->getLoopDepth(Restore)) { + // Push Save outside of this loop if immediate dominator is different + // from save block. If immediate dominator is not different, bail out. + MachineBasicBlock *IDom = FindIDom<>(*Save, Save->predecessors(), *MDT); + if (IDom != Save) + Save = IDom; + else { + Save = nullptr; + break; + } + } + else { + // Push Restore outside of this loop if immediate post-dominator is + // different from restore block. If immediate post-dominator is not + // different, bail out. + MachineBasicBlock *IPdom = + FindIDom<>(*Restore, Restore->successors(), *MPDT); + if (IPdom != Restore) + Restore = IPdom; + else { + Restore = nullptr; + break; + } + } } } } |
