diff --git a/llvm/include/llvm/CodeGen/RDFGraph.h b/llvm/include/llvm/CodeGen/RDFGraph.h index 8a93afbcb5491..6bb6033a8a2f2 100644 --- a/llvm/include/llvm/CodeGen/RDFGraph.h +++ b/llvm/include/llvm/CodeGen/RDFGraph.h @@ -447,7 +447,7 @@ struct NodeAllocator { AllocatorTy MemPool; }; -using RegisterSet = std::set; +using RegisterSet = std::set; struct TargetOperandInfo { TargetOperandInfo(const TargetInstrInfo &tii) : TII(tii) {} diff --git a/llvm/include/llvm/CodeGen/RDFRegisters.h b/llvm/include/llvm/CodeGen/RDFRegisters.h index 4a9a4063c9e83..82027cad53bdb 100644 --- a/llvm/include/llvm/CodeGen/RDFRegisters.h +++ b/llvm/include/llvm/CodeGen/RDFRegisters.h @@ -199,6 +199,33 @@ struct PhysicalRegisterInfo { std::vector AliasInfos; }; +struct RegisterRefEqualTo { + constexpr RegisterRefEqualTo(const llvm::rdf::PhysicalRegisterInfo &pri) + : PRI(&pri) {} + + bool operator()(llvm::rdf::RegisterRef A, llvm::rdf::RegisterRef B) const { + return PRI->equal_to(A, B); + } + +private: + // Make it a pointer just in case. See comment in `RegisterRefLess` below. + const llvm::rdf::PhysicalRegisterInfo *PRI; +}; + +struct RegisterRefLess { + constexpr RegisterRefLess(const llvm::rdf::PhysicalRegisterInfo &pri) + : PRI(&pri) {} + + bool operator()(llvm::rdf::RegisterRef A, llvm::rdf::RegisterRef B) const { + return PRI->less(A, B); + } + +private: + // Make it a pointer because apparently some versions of MSVC use std::swap + // on the comparator object. + const llvm::rdf::PhysicalRegisterInfo *PRI; +}; + struct RegisterAggr { RegisterAggr(const PhysicalRegisterInfo &pri) : Units(pri.getTRI().getNumRegUnits()), PRI(pri) {} @@ -334,18 +361,6 @@ template <> struct hash { } }; -template <> struct equal_to { - constexpr equal_to(const llvm::rdf::PhysicalRegisterInfo &pri) : PRI(&pri) {} - - bool operator()(llvm::rdf::RegisterRef A, llvm::rdf::RegisterRef B) const { - return PRI->equal_to(A, B); - } - -private: - // Make it a pointer just in case. See comment in `less` below. - const llvm::rdf::PhysicalRegisterInfo *PRI; -}; - template <> struct equal_to { bool operator()(const llvm::rdf::RegisterAggr &A, const llvm::rdf::RegisterAggr &B) const { @@ -353,23 +368,10 @@ template <> struct equal_to { } }; -template <> struct less { - constexpr less(const llvm::rdf::PhysicalRegisterInfo &pri) : PRI(&pri) {} - - bool operator()(llvm::rdf::RegisterRef A, llvm::rdf::RegisterRef B) const { - return PRI->less(A, B); - } - -private: - // Make it a pointer because apparently some versions of MSVC use std::swap - // on the std::less specialization. - const llvm::rdf::PhysicalRegisterInfo *PRI; -}; - } // namespace std namespace llvm::rdf { -using RegisterSet = std::set>; +using RegisterSet = std::set; } // namespace llvm::rdf #endif // LLVM_CODEGEN_RDFREGISTERS_H diff --git a/llvm/lib/CodeGen/RDFLiveness.cpp b/llvm/lib/CodeGen/RDFLiveness.cpp index 318422b46e811..2e1cf499eab41 100644 --- a/llvm/lib/CodeGen/RDFLiveness.cpp +++ b/llvm/lib/CodeGen/RDFLiveness.cpp @@ -652,8 +652,9 @@ void Liveness::computePhiInfo() { // defs, cache the result of subtracting these defs from a given register // ref. using RefHash = std::hash; - using RefEqual = std::equal_to; - using SubMap = std::unordered_map; + using RefEqual = RegisterRefEqualTo; + using SubMap = + std::unordered_map; std::unordered_map Subs; auto ClearIn = [](RegisterRef RR, const RegisterAggr &Mid, SubMap &SM) { if (Mid.empty()) @@ -868,7 +869,7 @@ void Liveness::computeLiveIns() { std::vector LV; for (const MachineBasicBlock::RegisterMaskPair &LI : B.liveins()) LV.push_back(RegisterRef(LI.PhysReg, LI.LaneMask)); - llvm::sort(LV, std::less(PRI)); + llvm::sort(LV, RegisterRefLess(PRI)); dbgs() << printMBBReference(B) << "\t rec = {"; for (auto I : LV) dbgs() << ' ' << Print(I, DFG); @@ -878,7 +879,7 @@ void Liveness::computeLiveIns() { LV.clear(); for (RegisterRef RR : LiveMap[&B].refs()) LV.push_back(RR); - llvm::sort(LV, std::less(PRI)); + llvm::sort(LV, RegisterRefLess(PRI)); dbgs() << "\tcomp = {"; for (auto I : LV) dbgs() << ' ' << Print(I, DFG); diff --git a/llvm/lib/Target/Hexagon/RDFCopy.cpp b/llvm/lib/Target/Hexagon/RDFCopy.cpp index fafdad08909dd..3b1d3bd89680b 100644 --- a/llvm/lib/Target/Hexagon/RDFCopy.cpp +++ b/llvm/lib/Target/Hexagon/RDFCopy.cpp @@ -108,7 +108,7 @@ bool CopyPropagation::scanBlock(MachineBasicBlock *B) { for (NodeAddr IA : BA.Addr->members(DFG)) { if (DFG.IsCode(IA)) { NodeAddr SA = IA; - EqualityMap EM(std::less(DFG.getPRI())); + EqualityMap EM(RegisterRefLess(DFG.getPRI())); if (interpretAsCopy(SA.Addr->getCode(), EM)) recordCopy(SA, EM); } diff --git a/llvm/lib/Target/Hexagon/RDFCopy.h b/llvm/lib/Target/Hexagon/RDFCopy.h index e4fb89892831d..92b2c65982655 100644 --- a/llvm/lib/Target/Hexagon/RDFCopy.h +++ b/llvm/lib/Target/Hexagon/RDFCopy.h @@ -25,8 +25,8 @@ class MachineInstr; namespace rdf { struct CopyPropagation { - CopyPropagation(DataFlowGraph &dfg) : MDT(dfg.getDT()), DFG(dfg), - RDefMap(std::less(DFG.getPRI())) {} + CopyPropagation(DataFlowGraph &dfg) + : MDT(dfg.getDT()), DFG(dfg), RDefMap(RegisterRefLess(DFG.getPRI())) {} virtual ~CopyPropagation() = default; @@ -35,7 +35,7 @@ namespace rdf { bool trace() const { return Trace; } DataFlowGraph &getDFG() { return DFG; } - using EqualityMap = std::map; + using EqualityMap = std::map; virtual bool interpretAsCopy(const MachineInstr *MI, EqualityMap &EM); private: @@ -45,7 +45,7 @@ namespace rdf { bool Trace = false; // map: register -> (map: stmt -> reaching def) - std::map> RDefMap; + std::map, RegisterRefLess> RDefMap; // map: statement -> (map: dst reg -> src reg) std::map CopyMap; std::vector Copies; diff --git a/llvm/unittests/CodeGen/TypeTraitsTest.cpp b/llvm/unittests/CodeGen/TypeTraitsTest.cpp index dde86280cff6a..1c8852fc1f071 100644 --- a/llvm/unittests/CodeGen/TypeTraitsTest.cpp +++ b/llvm/unittests/CodeGen/TypeTraitsTest.cpp @@ -6,13 +6,16 @@ // //===----------------------------------------------------------------------===// +#include "llvm/CodeGen/RDFRegisters.h" #include "llvm/CodeGen/RegisterPressure.h" #include "llvm/CodeGen/ScheduleDAG.h" #include "llvm/CodeGen/SelectionDAGNodes.h" #include "llvm/CodeGen/SlotIndexes.h" #include "llvm/CodeGen/TargetPassConfig.h" #include "gtest/gtest.h" +#include #include +#include using namespace llvm; @@ -23,3 +26,35 @@ static_assert(std::is_trivially_copyable_v, "trivially copyable"); static_assert(std::is_trivially_copyable_v, "trivially copyable"); static_assert(std::is_trivially_copyable_v, "trivially copyable"); + +// https://llvm.org/PR105169 +// Verify that we won't accidently specialize std::less and std::equal_to in a +// wrong way. +// C++17 [namespace.std]/2, C++20/23 [namespace.std]/5: +// A program may explicitly instantiate a template defined in the standard +// library only if the declaration +// - depends on the name of a user-defined type and +// - the instantiation meets the standard library requirements for the +// original template. +template constexpr bool CheckStdCmpRequirements() { + // std::less and std::equal_to are literal, default constructible, and + // copyable classes. + Fn f1; + auto f2 = f1; + auto f3 = std::move(f2); + f2 = f3; + f2 = std::move(f3); + + // Properties held on all known implementations, although not guaranteed by + // the standard. + static_assert(std::is_empty_v); + static_assert(std::is_trivially_default_constructible_v); + static_assert(std::is_trivially_copyable_v); + + return true; +} + +static_assert(CheckStdCmpRequirements>(), + "same as the original template"); +static_assert(CheckStdCmpRequirements>(), + "same as the original template");