diff options
Diffstat (limited to 'llvm/lib/CodeGen/MachineOutliner.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/MachineOutliner.cpp | 54 |
1 files changed, 42 insertions, 12 deletions
diff --git a/llvm/lib/CodeGen/MachineOutliner.cpp b/llvm/lib/CodeGen/MachineOutliner.cpp index a3ca27645f7..b072f5ee863 100644 --- a/llvm/lib/CodeGen/MachineOutliner.cpp +++ b/llvm/lib/CodeGen/MachineOutliner.cpp @@ -516,6 +516,10 @@ private: public: + unsigned operator[](const size_t i) const { + return Str[i]; + } + /// \brief Return a substring of the tree with maximum benefit if such a /// substring exists. /// @@ -800,11 +804,13 @@ struct OutlinedFunction { /// The number of instructions this function would save. unsigned Benefit = 0; + bool IsTailCall = false; + OutlinedFunction(size_t Name, size_t OccurrenceCount, const std::vector<unsigned> &Sequence, - unsigned Benefit) + unsigned Benefit, bool IsTailCall) : Name(Name), OccurrenceCount(OccurrenceCount), Sequence(Sequence), - Benefit(Benefit) + Benefit(Benefit), IsTailCall(IsTailCall) {} }; @@ -1009,7 +1015,9 @@ struct MachineOutliner : public ModulePass { /// \returns The length of the longest candidate found. 0 if there are none. unsigned buildCandidateList(std::vector<Candidate> &CandidateList, std::vector<OutlinedFunction> &FunctionList, - SuffixTree &ST, const TargetInstrInfo &TII); + SuffixTree &ST, + InstructionMapper &Mapper, + const TargetInstrInfo &TII); /// \brief Remove any overlapping candidates that weren't handled by the /// suffix tree's pruning method. @@ -1136,7 +1144,8 @@ void MachineOutliner::pruneOverlaps(std::vector<Candidate> &CandidateList, // is being removed. F2.OccurrenceCount--; F2.Benefit = TII.getOutliningBenefit(F2.Sequence.size(), - F2.OccurrenceCount + F2.OccurrenceCount, + F2.IsTailCall ); // Mark C2 as not in the list. @@ -1155,6 +1164,7 @@ unsigned MachineOutliner::buildCandidateList(std::vector<Candidate> &CandidateList, std::vector<OutlinedFunction> &FunctionList, SuffixTree &ST, + InstructionMapper &Mapper, const TargetInstrInfo &TII) { std::vector<unsigned> CandidateSequence; // Current outlining candidate. @@ -1163,7 +1173,8 @@ MachineOutliner::buildCandidateList(std::vector<Candidate> &CandidateList, // Function for maximizing query in the suffix tree. // This allows us to define more fine-grained types of things to outline in // the target without putting target-specific info in the suffix tree. - auto BenefitFn = [&TII](const SuffixTreeNode &Curr, size_t StringLen) { + auto BenefitFn = [&TII, &ST, &Mapper](const SuffixTreeNode &Curr, + size_t StringLen) { // Any leaf whose parent is the root only has one occurrence. if (Curr.Parent->isRoot()) @@ -1180,7 +1191,16 @@ MachineOutliner::buildCandidateList(std::vector<Candidate> &CandidateList, if (Occurrences < 2) return 0u; - return TII.getOutliningBenefit(StringLen, Occurrences); + // Check if the last instruction in the sequence is a return. + MachineInstr *LastInstr = + Mapper.IntegerInstructionMap[ST[Curr.SuffixIdx + StringLen - 1]]; + assert(LastInstr && "Last instruction in sequence was unmapped!"); + + // The only way a terminator could be mapped as legal is if it was safe to + // tail call. + bool IsTailCall = LastInstr->isTerminator(); + + return TII.getOutliningBenefit(StringLen, Occurrences, IsTailCall); }; // Repeatedly query the suffix tree for the substring that maximizes @@ -1204,10 +1224,19 @@ MachineOutliner::buildCandidateList(std::vector<Candidate> &CandidateList, if (CandidateSequence.size() > MaxCandidateLen) MaxCandidateLen = CandidateSequence.size(); + MachineInstr *LastInstr = + Mapper.IntegerInstructionMap[CandidateSequence.back()]; + assert(LastInstr && "Last instruction in sequence was unmapped!"); + + // The only way a terminator could be mapped as legal is if it was safe to + // tail call. + bool IsTailCall = LastInstr->isTerminator(); + // Keep track of the benefit of outlining this candidate in its // OutlinedFunction. unsigned FnBenefit = TII.getOutliningBenefit(CandidateSequence.size(), - Occurrences.size() + Occurrences.size(), + IsTailCall ); assert(FnBenefit > 0 && "Function cannot be unbeneficial!"); @@ -1217,7 +1246,8 @@ MachineOutliner::buildCandidateList(std::vector<Candidate> &CandidateList, FunctionList.size(), // Number of this function. Occurrences.size(), // Number of occurrences. CandidateSequence, // Sequence to outline. - FnBenefit // Instructions saved by outlining this function. + FnBenefit, // Instructions saved by outlining this function. + IsTailCall // Flag set if this function is to be tail called. ); // Save each of the occurrences of the candidate so we can outline them. @@ -1273,7 +1303,7 @@ MachineOutliner::createOutlinedFunction(Module &M, const OutlinedFunction &OF, // Insert the new function into the module. MF.insert(MF.begin(), &MBB); - TII.insertOutlinerPrologue(MBB, MF); + TII.insertOutlinerPrologue(MBB, MF, OF.IsTailCall); // Copy over the instructions for the function using the integer mappings in // its sequence. @@ -1288,7 +1318,7 @@ MachineOutliner::createOutlinedFunction(Module &M, const OutlinedFunction &OF, MBB.insert(MBB.end(), NewMI); } - TII.insertOutlinerEpilogue(MBB, MF); + TII.insertOutlinerEpilogue(MBB, MF, OF.IsTailCall); return &MF; } @@ -1335,7 +1365,7 @@ bool MachineOutliner::outline(Module &M, const TargetInstrInfo &TII = *STI.getInstrInfo(); // Insert a call to the new function and erase the old sequence. - TII.insertOutlinedCall(M, *MBB, StartIt, *MF); + TII.insertOutlinedCall(M, *MBB, StartIt, *MF, OF.IsTailCall); StartIt = Mapper.InstrList[C.StartIdx]; MBB->erase(StartIt, EndIt); @@ -1392,7 +1422,7 @@ bool MachineOutliner::runOnModule(Module &M) { std::vector<OutlinedFunction> FunctionList; unsigned MaxCandidateLen = - buildCandidateList(CandidateList, FunctionList, ST, *TII); + buildCandidateList(CandidateList, FunctionList, ST, Mapper, *TII); pruneOverlaps(CandidateList, FunctionList, MaxCandidateLen, *TII); return outline(M, CandidateList, FunctionList, Mapper); |
