Author: Serguei Katkov Date: 2021-01-13T10:31:43+07:00 New Revision: f454c9f102a7f0df9d2802e30538192d4fe2f97a
URL: https://github.com/llvm/llvm-project/commit/f454c9f102a7f0df9d2802e30538192d4fe2f97a DIFF: https://github.com/llvm/llvm-project/commit/f454c9f102a7f0df9d2802e30538192d4fe2f97a.diff LOG: [InlineSpiller] Re-tie operands if folding failed InlineSpiller::foldMemoryOperand unties registers before an attempt to fold and does not restore tied-ness in case of failure. I do not have a particular test for demo of invalid behavior. This is something of clean-up. It is better to keep the behavior correct in case some time in future it happens. Reviewers: reames, dantrushin Reviewed By: dantrushin, reames Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D94389 Added: Modified: llvm/lib/CodeGen/InlineSpiller.cpp Removed: ################################################################################ diff --git a/llvm/lib/CodeGen/InlineSpiller.cpp b/llvm/lib/CodeGen/InlineSpiller.cpp index 236a70904690a..1892ca646788f 100644 --- a/llvm/lib/CodeGen/InlineSpiller.cpp +++ b/llvm/lib/CodeGen/InlineSpiller.cpp @@ -853,16 +853,13 @@ foldMemoryOperand(ArrayRef<std::pair<MachineInstr *, unsigned>> Ops, continue; } - if (UntieRegs && MO.isTied()) - MI->untieRegOperand(Idx); - if (!SpillSubRegs && MO.getSubReg()) return false; // We cannot fold a load instruction into a def. if (LoadMI && MO.isDef()) return false; // Tied use operands should not be passed to foldMemoryOperand. - if (!MI->isRegTiedToDefOperand(Idx)) + if (UntieRegs || !MI->isRegTiedToDefOperand(Idx)) FoldOps.push_back(Idx); } @@ -873,11 +870,31 @@ foldMemoryOperand(ArrayRef<std::pair<MachineInstr *, unsigned>> Ops, MachineInstrSpan MIS(MI, MI->getParent()); + SmallVector<std::pair<unsigned, unsigned> > TiedOps; + if (UntieRegs) + for (unsigned Idx : FoldOps) { + MachineOperand &MO = MI->getOperand(Idx); + if (!MO.isTied()) + continue; + unsigned Tied = MI->findTiedOperandIdx(Idx); + if (MO.isUse()) + TiedOps.emplace_back(Tied, Idx); + else { + assert(MO.isDef() && "Tied to not use and def?"); + TiedOps.emplace_back(Idx, Tied); + } + MI->untieRegOperand(Idx); + } + MachineInstr *FoldMI = LoadMI ? TII.foldMemoryOperand(*MI, FoldOps, *LoadMI, &LIS) : TII.foldMemoryOperand(*MI, FoldOps, StackSlot, &LIS, &VRM); - if (!FoldMI) + if (!FoldMI) { + // Re-tie operands. + for (auto Tied : TiedOps) + MI->tieOperands(Tied.first, Tied.second); return false; + } // Remove LIS for any dead defs in the original MI not in FoldMI. for (MIBundleOperands MO(*MI); MO.isValid(); ++MO) { _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
