diff options
Diffstat (limited to 'lib/CodeGen/TailDuplication.cpp')
| -rw-r--r-- | lib/CodeGen/TailDuplication.cpp | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/lib/CodeGen/TailDuplication.cpp b/lib/CodeGen/TailDuplication.cpp index ce4b1be854..15aed3436c 100644 --- a/lib/CodeGen/TailDuplication.cpp +++ b/lib/CodeGen/TailDuplication.cpp @@ -465,9 +465,12 @@ TailDuplicatePass::TailDuplicate(MachineBasicBlock *TailBB, MachineFunction &MF, MaxDuplicateCount = TailDuplicateSize; if (PreRegAlloc) { - // Pre-regalloc tail duplication hurts compile time and doesn't help - // much except for indirect branches. - if (TailBB->empty() || !TailBB->back().getDesc().isIndirectBranch()) + if (TailBB->empty()) + return false; + const TargetInstrDesc &TID = TailBB->back().getDesc(); + // Pre-regalloc tail duplication hurts compile time and doesn't help + // much except for indirect branches and returns. + if (!TID.isIndirectBranch() && !TID.isReturn()) return false; // If the target has hardware branch prediction that can handle indirect // branches, duplicating them can often make them predictable when there @@ -502,7 +505,7 @@ TailDuplicatePass::TailDuplicate(MachineBasicBlock *TailBB, MachineFunction &MF, } // Heuristically, don't tail-duplicate calls if it would expand code size, // as it's less likely to be worth the extra cost. - if (InstrCount > 1 && HasCall) + if (InstrCount > 1 && (PreRegAlloc && HasCall)) return false; DEBUG(dbgs() << "\n*** Tail-duplicating BB#" << TailBB->getNumber() << '\n'); |