dpdkAsmOpt.h

/*
Copyright 2020 Intel Corp.
 
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
 
    http://www.apache.org/licenses/LICENSE-2.0
 
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
 
#ifndef BACKENDS_DPDK_DPDKASMOPT_H_
#define BACKENDS_DPDK_DPDKASMOPT_H_
 
#include <fstream>
 
#include "dpdkUtils.h"
#include "frontends/common/constantFolding.h"
#include "frontends/common/resolveReferences/referenceMap.h"
#include "frontends/p4/coreLibrary.h"
#include "frontends/p4/enumInstance.h"
#include "frontends/p4/evaluator/evaluator.h"
#include "frontends/p4/methodInstance.h"
#include "frontends/p4/simplify.h"
#include "frontends/p4/typeMap.h"
#include "frontends/p4/unusedDeclarations.h"
#include "ir/ir.h"
#include "lib/big_int_util.h"
#include "lib/json.h"
 
#define DPDK_TABLE_MAX_KEY_SIZE 64 * 8
 
namespace DPDK {
 
using namespace P4::literals;
 
class RemoveRedundantLabel : public Transform {
 public:
    const IR::IndexedVector<IR::DpdkAsmStatement> *removeRedundantLabel(
        const IR::IndexedVector<IR::DpdkAsmStatement> &s);
 
    const IR::Node *postorder(IR::DpdkListStatement *l) override {
        const IR::IndexedVector<IR::DpdkAsmStatement> *newStmts;
        newStmts = removeRedundantLabel(l->statements);
        l->statements = *newStmts;
        return l;
    }
 
    const IR::Node *postorder(IR::DpdkAction *l) override {
        const IR::IndexedVector<IR::DpdkAsmStatement> *newStmts;
        newStmts = removeRedundantLabel(l->statements);
        l->statements = *newStmts;
        return l;
    }
};
 
 
class RemoveConsecutiveJmpAndLabel : public Transform {
 public:
    const IR::IndexedVector<IR::DpdkAsmStatement> *removeJmpAndLabel(
        const IR::IndexedVector<IR::DpdkAsmStatement> &s);
    const IR::Node *postorder(IR::DpdkListStatement *l) override {
        const IR::IndexedVector<IR::DpdkAsmStatement> *newStmts;
        newStmts = removeJmpAndLabel(l->statements);
        l->statements = *newStmts;
        return l;
    }
 
    const IR::Node *postorder(IR::DpdkAction *l) override {
        const IR::IndexedVector<IR::DpdkAsmStatement> *newStmts;
        newStmts = removeJmpAndLabel(l->statements);
        l->statements = *newStmts;
        return l;
    }
};
 
 
class ThreadJumps : public Transform {
 public:
    const IR::IndexedVector<IR::DpdkAsmStatement> *threadJumps(
        const IR::IndexedVector<IR::DpdkAsmStatement> &s);
 
    const IR::Node *postorder(IR::DpdkListStatement *l) override {
        const IR::IndexedVector<IR::DpdkAsmStatement> *newStmts;
        newStmts = threadJumps(l->statements);
        l->statements = *newStmts;
        return l;
    }
 
    const IR::Node *postorder(IR::DpdkAction *l) override {
        const IR::IndexedVector<IR::DpdkAsmStatement> *newStmts;
        newStmts = threadJumps(l->statements);
        l->statements = *newStmts;
        return l;
    }
};
 
 
class RemoveLabelAfterLabel : public Transform {
 public:
    const IR::IndexedVector<IR::DpdkAsmStatement> *removeLabelAfterLabel(
        const IR::IndexedVector<IR::DpdkAsmStatement> &s);
 
    const IR::Node *postorder(IR::DpdkListStatement *l) override {
        const IR::IndexedVector<IR::DpdkAsmStatement> *newStmts;
        newStmts = removeLabelAfterLabel(l->statements);
        l->statements = *newStmts;
        return l;
    }
 
    const IR::Node *postorder(IR::DpdkAction *l) override {
        const IR::IndexedVector<IR::DpdkAsmStatement> *newStmts;
        newStmts = removeLabelAfterLabel(l->statements);
        l->statements = *newStmts;
        return l;
    }
};
 
class CollectUsedMetadataField : public Inspector {
    ordered_set<cstring> &used_fields;
 
 public:
    explicit CollectUsedMetadataField(ordered_set<cstring> &used_fields)
        : used_fields(used_fields) {}
    bool preorder(const IR::Member *m) override {
        // metadata struct field used like m.<field_name> in expressions
        if (m->expr->toString() == "m") used_fields.insert(m->member.toString());
        return true;
    }
};
 
class RemoveUnusedMetadataFields : public Transform {
    ordered_set<cstring> &used_fields;
 
 public:
    explicit RemoveUnusedMetadataFields(ordered_set<cstring> &used_fields)
        : used_fields(used_fields) {}
    const IR::Node *preorder(IR::DpdkAsmProgram *p) override;
    bool isByteSizeField(const IR::Type *field_type);
};
 
class ShortenTokenLength : public Transform {
    ordered_map<cstring, cstring> &newNameMap;
    static size_t count;
    cstring shortenString(cstring str, size_t allowedLength = 60) {
        if (str.size() <= allowedLength) return str;
        auto itr = newNameMap.find(str);
        if (itr != newNameMap.end()) return itr->second;
        // make sure new string length less or equal allowedLength
        cstring newStr = str.substr(0, allowedLength - std::to_string(count).size());
        newStr += std::to_string(count);
        count++;
        newNameMap.insert(std::pair<cstring, cstring>(str, newStr));
        origNameMap.insert(std::pair<cstring, cstring>(newStr, str));
        return newStr;
    }
 
    cstring dropSuffixIfNoAction(IR::ID name) {
        if (name.originalName == "NoAction") return name.originalName;
        return name.name;
    }
 
 public:
    explicit ShortenTokenLength(ordered_map<cstring, cstring> &newNameMap)
        : newNameMap(newNameMap) {}
    static ordered_map<cstring, cstring> origNameMap;
 
    const IR::Node *preorder(IR::Member *m) override {
        if (m->toString().startsWith("m.") || m->toString().startsWith("t."))
            m->member = shortenString(m->member);
        else
            m->member = shortenString(m->member, 30);
        return m;
    }
 
    const IR::Node *preorder(IR::DpdkStructType *s) override {
        if (s->getAnnotations()->getSingle("__packet_data__"_cs)) {
            s->name = shortenString(s->name);
            IR::IndexedVector<IR::StructField> changedFields;
            for (auto field : s->fields) {
                IR::StructField *f = new IR::StructField(field->name, field->type);
                f->name = shortenString(f->name, 30);
                changedFields.push_back(f);
            }
            return new IR::DpdkStructType(s->srcInfo, s->name, s->annotations, changedFields);
        } else {
            s->name = shortenString(s->name);
            IR::IndexedVector<IR::StructField> changedFields;
            for (auto field : s->fields) {
                IR::StructField *f = new IR::StructField(field->name, field->type);
                f->name = shortenString(f->name);
                changedFields.push_back(f);
            }
            return new IR::DpdkStructType(s->srcInfo, s->name, s->annotations, changedFields);
        }
        return s;
    }
 
    const IR::Node *preorder(IR::DpdkHeaderType *h) override {
        h->name = shortenString(h->name);
        IR::IndexedVector<IR::StructField> changedFields;
        for (auto field : h->fields) {
            IR::StructField *f = new IR::StructField(field->name, field->type);
            f->name = shortenString(f->name, 30);
            changedFields.push_back(f);
        }
        return new IR::DpdkHeaderType(h->srcInfo, h->name, h->annotations, changedFields);
    }
 
    const IR::Node *preorder(IR::DpdkExternDeclaration *e) override {
        e->name = shortenString(e->name);
        return e;
    }
 
    const IR::Node *preorder(IR::Declaration *g) override {
        g->name = shortenString(g->name);
        return g;
    }
 
    void shortenParamTypeName(IR::ParameterList &pl) {
        IR::IndexedVector<IR::Parameter> new_pl;
        for (auto p : pl.parameters) {
            auto newType0 = p->type->to<IR::Type_Name>();
            auto path0 = newType0->path->clone();
            path0->name = shortenString(path0->name);
            new_pl.push_back(new IR::Parameter(p->srcInfo, p->name, p->annotations, p->direction,
                                               new IR::Type_Name(newType0->srcInfo, path0),
                                               p->defaultValue));
        }
        pl = IR::ParameterList{new_pl};
    }
 
    const IR::Node *preorder(IR::DpdkAction *a) override {
        a->name = shortenString(dropSuffixIfNoAction(a->name));
        shortenParamTypeName(a->para);
        return a;
    }
 
    const IR::Node *preorder(IR::ActionList *al) override {
        IR::IndexedVector<IR::ActionListElement> new_al;
        for (auto ale : al->actionList) {
            auto methodCallExpr = ale->expression->to<IR::MethodCallExpression>();
            auto pathExpr = methodCallExpr->method->to<IR::PathExpression>();
            auto path0 = pathExpr->path->clone();
            path0->name = shortenString(dropSuffixIfNoAction(path0->name));
            new_al.push_back(new IR::ActionListElement(
                ale->srcInfo, ale->annotations,
                new IR::MethodCallExpression(
                    methodCallExpr->srcInfo, methodCallExpr->type,
                    new IR::PathExpression(pathExpr->srcInfo, pathExpr->type, path0),
                    methodCallExpr->typeArguments, methodCallExpr->arguments)));
        }
        return new IR::ActionList(al->srcInfo, new_al);
    }
 
    const IR::Node *preorder(IR::DpdkTable *t) override {
        t->name = shortenString(t->name);
        auto methodCallExpr = t->default_action->to<IR::MethodCallExpression>();
        auto pathExpr = methodCallExpr->method->to<IR::PathExpression>();
        auto path0 = pathExpr->path->clone();
        path0->name = shortenString(dropSuffixIfNoAction(path0->name));
        t->default_action = new IR::MethodCallExpression(
            methodCallExpr->srcInfo, methodCallExpr->type,
            new IR::PathExpression(pathExpr->srcInfo, pathExpr->type, path0),
            methodCallExpr->typeArguments, methodCallExpr->arguments);
        return t;
    }
 
    const IR::Node *preorder(IR::DpdkLearner *l) override {
        l->name = shortenString(l->name);
        return l;
    }
 
    const IR::Node *preorder(IR::DpdkSelector *s) override {
        s->name = shortenString(s->name);
        return s;
    }
 
    const IR::Node *preorder(IR::DpdkLearnStatement *ls) override {
        ls->action = shortenString(dropSuffixIfNoAction(ls->action));
        return ls;
    }
 
    const IR::Node *preorder(IR::DpdkApplyStatement *as) override {
        as->table = shortenString(as->table);
        return as;
    }
 
    const IR::Node *preorder(IR::DpdkJmpStatement *j) override {
        j->label = shortenString(j->label);
        return j;
    }
 
    const IR::Node *preorder(IR::DpdkLabelStatement *ls) override {
        ls->label = shortenString(ls->label);
        return ls;
    }
 
    const IR::Node *preorder(IR::DpdkJmpActionStatement *jas) override {
        jas->action = shortenString(dropSuffixIfNoAction(jas->action));
        return jas;
    }
};
 
class CollectUseDefInfo : public Inspector {
    P4::TypeMap *typeMap;
 
 public:
    std::unordered_map<cstring /*member expresion as string */, int> usesInfo;
    std::unordered_map<cstring, int> defInfo;
    std::unordered_map<cstring /*def*/, const IR::Expression * /*use*/> replacementMap;
    std::unordered_map<cstring, bool> dontEliminate;
 
    explicit CollectUseDefInfo(P4::TypeMap *typeMap) : typeMap(typeMap) {
        dontEliminate["m.pna_main_output_metadata_output_port"_cs] = true;
        dontEliminate["m.psa_ingress_output_metadata_drop"_cs] = true;
        dontEliminate["m.psa_ingress_output_metadata_egress_port"_cs] = true;
    }
 
    bool preorder(const IR::DpdkJmpCondStatement *b) override {
        usesInfo[b->src1->toString()]++;
        usesInfo[b->src2->toString()]++;
        return false;
    }
 
    bool preorder(const IR::DpdkLearnStatement *b) override {
        usesInfo[b->timeout->toString()]++;
        dontEliminate[b->timeout->toString()] = true;
        if (b->argument) {
            usesInfo[b->argument->toString()]++;
            // dpdk expect all action argument to be contiguous starting from first argument
            // passed to learner action
            dontEliminate[b->argument->toString()] = true;
        }
        return false;
    }
 
    bool preorder(const IR::DpdkUnaryStatement *u) override {
        usesInfo[u->src->toString()]++;
        defInfo[u->dst->toString()]++;
        // do not eliminate the destination
        dontEliminate[u->dst->toString()] = true;
        return false;
    }
 
    bool preorder(const IR::DpdkBinaryStatement *b) override {
        usesInfo[b->src1->toString()]++;
        usesInfo[b->src2->toString()]++;
        defInfo[b->dst->toString()]++;
        // dst and src1 can not be eliminated, because both are same
        // and dpdk does not allow src1 to be constant
        dontEliminate[b->dst->toString()] = true;
        dontEliminate[b->src1->toString()] = true;
        return false;
    }
 
    bool preorder(const IR::DpdkMovStatement *mv) override {
        defInfo[mv->dst->toString()]++;
        usesInfo[mv->src->toString()]++;
        replacementMap[mv->dst->toString()] = mv->src;
        return false;
    }
 
    bool preorder(const IR::DpdkCastStatement *c) override {
        usesInfo[c->src->toString()]++;
        defInfo[c->dst->toString()]++;
        replacementMap[c->dst->toString()] = c->src;
        return false;
    }
 
    bool preorder(const IR::DpdkMirrorStatement *m) override {
        usesInfo[m->slotId->toString()]++;
        usesInfo[m->sessionId->toString()]++;
        // dpdk expect it as metadata struct member
        dontEliminate[m->slotId->toString()] = true;
        dontEliminate[m->sessionId->toString()] = true;
        return false;
    }
 
    bool preorder(const IR::DpdkEmitStatement *e) override {
        auto type = typeMap->getType(e->header)->to<IR::Type_Header>();
        if (type)
            for (auto f : type->fields) {
                cstring name = e->header->toString() + "." + f->name.toString();
                usesInfo[name]++;
            }
        return false;
    }
 
    bool preorder(const IR::DpdkExtractStatement *e) override {
        auto type = typeMap->getType(e->header)->to<IR::Type_Header>();
        if (type)
            for (auto f : type->fields) {
                cstring name = e->header->toString() + "." + f->name.toString();
                defInfo[name]++;
            }
        if (e->length) {
            usesInfo[e->length->toString()]++;
            // dpdk expect length to be metadata struct member
            dontEliminate[e->length->toString()] = true;
        }
        return false;
    }
 
    bool preorder(const IR::DpdkLookaheadStatement *l) override {
        auto type = typeMap->getType(l->header)->to<IR::Type_Header>();
        if (type)
            for (auto f : type->fields) {
                cstring name = l->header->toString() + "." + f->name.toString();
                defInfo[name]++;
            }
        return false;
    }
 
    bool preorder(const IR::DpdkRxStatement *r) override {
        usesInfo[r->port->toString()]++;
        // always required
        dontEliminate[r->port->toString()] = true;
        return false;
    }
 
    bool preorder(const IR::DpdkTxStatement *t) override {
        usesInfo[t->port->toString()]++;
        // always required
        dontEliminate[t->port->toString()] = true;
        return false;
    }
 
    bool preorder(const IR::DpdkRecircidStatement *t) override {
        usesInfo[t->pass->toString()]++;
        // uses standard metadata fields
        dontEliminate[t->pass->toString()] = true;
        return false;
    }
 
    bool preorder(const IR::DpdkRearmStatement *r) override {
        if (r->timeout) {
            usesInfo[r->timeout->toString()]++;
            // dpdk requires it in metadata struct
            dontEliminate[r->timeout->toString()] = true;
        }
        return false;
    }
 
    bool preorder(const IR::DpdkChecksumAddStatement *c) override {
        usesInfo[c->field->toString()]++;
        // dpdk requires it in header
        if (auto m = c->field->to<IR::Member>())
            if (m->expr->is<IR::Type_Header>()) dontEliminate[c->field->toString()] = true;
        return false;
    }
 
    bool preorder(const IR::DpdkChecksumSubStatement *c) override {
        usesInfo[c->field->toString()]++;
        // dpdk requires it in header
        if (auto m = c->field->to<IR::Member>())
            if (m->expr->is<IR::Type_Header>()) dontEliminate[c->field->toString()] = true;
        return false;
    }
 
    bool preorder(const IR::DpdkGetHashStatement *c) override {
        usesInfo[c->dst->toString()]++;
        // dpdk requires it in metadata struct
        dontEliminate[c->dst->toString()] = true;
        return false;
    }
 
    bool preorder(const IR::DpdkVerifyStatement *v) override {
        usesInfo[v->condition->toString()]++;
        usesInfo[v->error->toString()]++;
        // dpdk requires it in metadata struct
        dontEliminate[v->condition->toString()] = true;
        dontEliminate[v->error->toString()] = true;
        return false;
    }
 
    bool preorder(const IR::DpdkMeterDeclStatement *c) override {
        usesInfo[c->size->toString()]++;
        return false;
    }
 
    bool preorder(const IR::DpdkMeterExecuteStatement *e) override {
        usesInfo[e->index->toString()]++;
        if (e->length) usesInfo[e->length->toString()]++;
        usesInfo[e->color_in->toString()]++;
        usesInfo[e->color_out->toString()]++;
        return false;
    }
 
    bool preorder(const IR::DpdkCounterCountStatement *c) override {
        usesInfo[c->index->toString()]++;
        if (c->incr) usesInfo[c->incr->toString()]++;
        return false;
    }
 
    bool preorder(const IR::DpdkRegisterDeclStatement *r) override {
        usesInfo[r->size->toString()]++;
        return false;
    }
 
    bool preorder(const IR::DpdkRegisterReadStatement *r) override {
        usesInfo[r->index->toString()]++;
        defInfo[r->dst->toString()]++;
        return false;
    }
 
    bool preorder(const IR::DpdkRegisterWriteStatement *r) override {
        usesInfo[r->index->toString()]++;
        return false;
    }
 
    bool preorder(const IR::DpdkTable *t) override {
        auto keys = t->match_keys;
        if (keys)
            for (auto ke : keys->keyElements) {
                dontEliminate[ke->expression->toString()] = true;
            }
        return false;
    }
 
    bool haveSingleUseDef(cstring str) { return defInfo[str] == 1 && usesInfo[str] == 1; }
};
 
class CopyPropagationAndElimination : public Transform {
    std::unordered_map<cstring, int> newUsesInfo;
    P4::TypeMap *typeMap;
    CollectUseDefInfo *collectUseDef;
 
 public:
    explicit CopyPropagationAndElimination(P4::TypeMap *typeMap) : typeMap(typeMap) {}
 
    const IR::Expression *getIrreplaceableExpr(cstring str, bool allowConst);
    const IR::Expression *replaceIfCopy(const IR::Expression *expr, bool allowConst = true);
    const IR::DpdkAsmStatement *elimCastOrMov(const IR::DpdkAsmStatement *stmt);
    IR::IndexedVector<IR::DpdkAsmStatement> copyPropAndDeadCodeElim(
        IR::IndexedVector<IR::DpdkAsmStatement> stmts);
 
    CollectUseDefInfo *calculateUseDef() {
        collectUseDef = new CollectUseDefInfo(typeMap);
        collectUseDef->setCalledBy(this);
        return collectUseDef;
    }
    const IR::Node *preorder(IR::DpdkAction *a) override {
        a->apply(*calculateUseDef());
        return a;
    }
 
    const IR::Node *preorder(IR::DpdkListStatement *l) override {
        l->apply(*calculateUseDef());
        return l;
    }
 
    const IR::Node *postorder(IR::DpdkAction *a) override {
        a->statements = copyPropAndDeadCodeElim(a->statements);
        return a;
    }
 
    const IR::Node *postorder(IR::DpdkListStatement *l) override {
        return new IR::DpdkListStatement(copyPropAndDeadCodeElim(l->statements));
    }
};
 
class EmitDpdkTableConfig : public Inspector {
    P4::ReferenceMap *refMap;
    P4::TypeMap *typeMap;
    ordered_map<cstring, cstring> &newNameMap;
    std::ofstream dpdkTableConfigFile;
 
    void addExact(const IR::Expression *k, int keyWidth, P4::TypeMap *typeMap);
    void addLpm(const IR::Expression *k, int keyWidth, P4::TypeMap *typeMap);
    void addTernary(const IR::Expression *k, int keyWidth, P4::TypeMap *typeMap);
    void addRange(const IR::Expression *k, int keyWidth, P4::TypeMap *typeMap);
    void addOptional(const IR::Expression *k, int keyWidth, P4::TypeMap *typeMap);
    void addMatchKey(const IR::DpdkTable *table, const IR::ListExpression *keyset,
                     P4::TypeMap *typeMap);
    void addAction(const IR::Expression *actionRef, P4::ReferenceMap *refMap, P4::TypeMap *typeMap);
    int getTypeWidth(const IR::Type *type, P4::TypeMap *typeMap);
    cstring getKeyMatchType(const IR::KeyElement *ke, P4::ReferenceMap *refMap);
    const IR::EntriesList *getEntries(const IR::DpdkTable *dt);
    const IR::Key *getKey(const IR::DpdkTable *dt);
    big_int convertSimpleKeyExpressionToBigInt(const IR::Expression *k, int keyWidth,
                                               P4::TypeMap *typeMap);
    bool tableNeedsPriority(const IR::DpdkTable *table, P4::ReferenceMap *refMap);
    bool isAllKeysDefaultExpression(const IR::ListExpression *keyset);
    void print(std::string_view str, std::string_view sep = "");
    void print(big_int, std::string_view sep = "");
 
 public:
    EmitDpdkTableConfig(P4::ReferenceMap *refMap, P4::TypeMap *typeMap,
                        ordered_map<cstring, cstring> &newNameMap)
        : refMap(refMap), typeMap(typeMap), newNameMap(newNameMap) {}
    void postorder(const IR::DpdkTable *table) override;
};
 
class DpdkAsmOptimization : public PassRepeated {
 private:
 public:
    DpdkAsmOptimization() {
        passes.push_back(new RemoveRedundantLabel);
        auto r = new PassRepeated{new RemoveLabelAfterLabel};
        passes.push_back(r);
        passes.push_back(new RemoveConsecutiveJmpAndLabel);
        passes.push_back(new RemoveRedundantLabel);
        passes.push_back(r);
        passes.push_back(new ThreadJumps);
    }
};
 
}  // namespace DPDK
#endif /* BACKENDS_DPDK_DPDKASMOPT_H_ */