================ @@ -6765,12 +6765,256 @@ llvm::Value *CGOpenMPRuntime::emitNumThreadsForTargetDirective( namespace { LLVM_ENABLE_BITMASK_ENUMS_IN_NAMESPACE(); +/// Utility to compare expression locations. +/// Returns true if expr-loc of LHS is less-than that of RHS. +/// This function asserts that both expressions have valid expr-locations. +static bool compareExprLocs(const Expr *LHS, const Expr *RHS) { + // Assert that neither LHS nor RHS can be null + assert(LHS && "LHS expression cannot be null"); + assert(RHS && "RHS expression cannot be null"); + + // Get source locations + SourceLocation LocLHS = LHS->getExprLoc(); + SourceLocation LocRHS = RHS->getExprLoc(); + + // Assert that we have valid source locations + assert(LocLHS.isValid() && "LHS expression must have valid source location"); + assert(LocRHS.isValid() && "RHS expression must have valid source location"); + + // Compare source locations for deterministic ordering + bool result = LocLHS < LocRHS; + return result; +} + // Utility to handle information from clauses associated with a given // construct that use mappable expressions (e.g. 'map' clause, 'to' clause). // It provides a convenient interface to obtain the information and generate // code for that information. class MappableExprsHandler { public: + /// Custom comparator for attach-pointer expressions that compares them by + /// complexity (i.e. their component-depth) first, then by their expr-locs if + /// they are semantically different. + struct AttachPtrExprComparator { + const MappableExprsHandler *Handler; + // Cache of previous equality comparison results. + mutable llvm::DenseMap<std::pair<const Expr *, const Expr *>, bool> + CachedEqualityComparisons; + + AttachPtrExprComparator(const MappableExprsHandler *H) : Handler(H) {} + + // Return true iff LHS is "less than" RHS. + bool operator()(const Expr *LHS, const Expr *RHS) const { + if (LHS == RHS) + return false; + + // First, compare by complexity (depth) + auto ItLHS = Handler->AttachPtrComponentDepthMap.find(LHS); + auto ItRHS = Handler->AttachPtrComponentDepthMap.find(RHS); + + std::optional<size_t> DepthLHS = + (ItLHS != Handler->AttachPtrComponentDepthMap.end()) ? ItLHS->second + : std::nullopt; + std::optional<size_t> DepthRHS = + (ItRHS != Handler->AttachPtrComponentDepthMap.end()) ? ItRHS->second + : std::nullopt; + + // std::nullopt (no attach pointer) has lowest complexity + if (!DepthLHS.has_value() && !DepthRHS.has_value()) { + // Both have same complexity, now check semantic equality + if (areEqual(LHS, RHS)) + return false; + // Different semantically, compare by location + return compareExprLocs(LHS, RHS); + } + if (!DepthLHS.has_value()) + return true; // LHS has lower complexity + if (!DepthRHS.has_value()) + return false; // RHS has lower complexity + + // Both have values, compare by depth (lower depth = lower complexity) + if (DepthLHS.value() != DepthRHS.value()) + return DepthLHS.value() < DepthRHS.value(); + + // Same complexity, now check semantic equality + if (areEqual(LHS, RHS)) + return false; + // Different semantically, compare by location + return compareExprLocs(LHS, RHS); + } + + public: + /// Return true if \p LHS and \p RHS are semantically equal. Uses pre-cached + /// results, if available, otherwise does a recursive semantic comparison. + bool areEqual(const Expr *LHS, const Expr *RHS) const { + // Check cache first for faster lookup + auto CachedResultIt = CachedEqualityComparisons.find({LHS, RHS}); + if (CachedResultIt != CachedEqualityComparisons.end()) + return CachedResultIt->second; + + bool ComparisonResult = areSemanticallyEqual(LHS, RHS); + + // Cache the result for future lookups (both orders since semantic + // equality is commutative) + CachedEqualityComparisons[{LHS, RHS}] = ComparisonResult; + CachedEqualityComparisons[{RHS, LHS}] = ComparisonResult; + return ComparisonResult; + } + + private: + /// Helper function to compare attach-pointer expressions semantically. + /// This function handles various expression types that can be part of an + /// attach-pointer. + /// TODO: Not urgent, but we should ideally return true when comparing + /// `p[10]`, `*(p + 10)`, `*(p + 5 + 5)`, `p[10:1]` etc. + bool areSemanticallyEqual(const Expr *LHS, const Expr *RHS) const { ---------------- abhinavgaba wrote:
@alexey-bataev, is there a cleaner/less expensive way to compare two exprs? I am trying to cache the results so that we don't do this for the same two exprs repeatedly, but the first one comparison would involve this recursive check. https://github.com/llvm/llvm-project/pull/155625 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits