auto_alias.h

 
#ifndef BACKENDS_TOFINO_BF_P4C_PHV_TRANSFORMS_AUTO_ALIAS_H_
#define BACKENDS_TOFINO_BF_P4C_PHV_TRANSFORMS_AUTO_ALIAS_H_
 
#include "backends/tofino/bf-p4c/phv/phv_fields.h"
#include "backends/tofino/bf-p4c/phv/pragma/pa_alias.h"
#include "backends/tofino/bf-p4c/phv/pragma/pa_no_overlay.h"
#include "lib/bitvec.h"
 
class DetermineCandidateHeaders : public Inspector {
 private:
    const PhvInfo &phv;
    ordered_map<cstring, ordered_set<const IR::MAU::Action *>> headers;
    ordered_set<cstring> headersValidatedInParser;
    ordered_map<cstring, ordered_set<const IR::MAU::Action *>> headersValidatedInMAU;
    ordered_set<cstring> allHeaders;
 
    profile_t init_apply(const IR::Node *root) override;
    bool preorder(const IR::BFN::Extract *extract) override;
    bool preorder(const IR::MAU::Instruction *inst) override;
    void end_apply() override;
 
 public:
    explicit DetermineCandidateHeaders(const PhvInfo &p) : phv(p) {}
 
    const ordered_set<cstring> getCandidateHeaders() const {
        ordered_set<cstring> headerSet;
        for (auto &kv : headers) headerSet.insert(kv.first);
        return headerSet;
    }
 
    bool isCandidateHeader(cstring header) const { return headers.count(header); }
 
    const ordered_set<const IR::MAU::Action *> &getActionsForCandidateHeader(cstring header) const {
        static ordered_set<const IR::MAU::Action *> actions;
        if (!isCandidateHeader(header)) return actions;
        return headers.at(header);
    }
};
 
struct MapDestToInstruction : public Inspector {
    ordered_map<const PHV::Field *, ordered_set<const IR::MAU::Instruction *>> dest_to_inst;
 
    const PhvInfo &phv;
 
    bool preorder(const IR::MAU::Instruction *inst) override {
        if (inst->operands.empty()) return true;
        auto dest = phv.field(inst->operands[0]);
        if (!dest) return true;
        dest_to_inst[dest].insert(inst);
        return true;
    }
 
    explicit MapDestToInstruction(const PhvInfo &p) : phv(p) {}
};
 
class DetermineCandidateFields : public Inspector {
 private:
    const PhvInfo &phv;
    const DetermineCandidateHeaders &headers;
    PragmaAlias &pragma;
    PragmaNoOverlay &no_overlay;
    const MapDestToInstruction &d2i;
 
    ordered_set<const PHV::Field *> initialCandidateSet;
    ordered_map<const PHV::Field *,
                ordered_map<const PHV::Field *, ordered_set<const IR::MAU::Action *>>>
        candidateSources;
 
    inline void dropFromCandidateSet(const PHV::Field *field);
    bool multipleSourcesFound(const PHV::Field *dest, const PHV::Field *src) const;
    bool incompatibleConstraints(const PHV::Field *dest, const PHV::Field *src) const;
 
    profile_t init_apply(const IR::Node *root) override;
    bool preorder(const IR::MAU::Instruction *inst) override;
    void end_apply() override;
 
 public:
    explicit DetermineCandidateFields(const PhvInfo &p, const DetermineCandidateHeaders &h,
                                      PragmaAlias &pa, PragmaNoOverlay &no_ovrl,
                                      const MapDestToInstruction &d)
        : phv(p), headers(h), pragma(pa), no_overlay(no_ovrl), d2i(d) {}
};
 
class AutoAlias : public PassManager {
 private:
    MapDestToInstruction d2i;
 
    DetermineCandidateHeaders headers;
    DetermineCandidateFields fields;
 
 public:
    explicit AutoAlias(const PhvInfo &phv, PragmaAlias &pa, PragmaNoOverlay &no_ovrl)
        : d2i(phv), headers(phv), fields(phv, headers, pa, no_ovrl, d2i) {
        addPasses({&d2i, &headers, &fields});
    }
};
 
#endif /* BACKENDS_TOFINO_BF_P4C_PHV_TRANSFORMS_AUTO_ALIAS_H_ */