/* vim: set ts=4 sw=4 tw=99 et:

  *

  * Copyright (C) 2012 David Anderson

  *

  * This file is part of JITCraft.

  *

  * JITCraft is free software: you can redistribute it and/or modify it under

  * the terms of the GNU General Public License as published by the Free

  * Software Foundation, either version 3 of the License, or (at your option)

  * any later version.

  * 

  * Foobar is distributed in the hope that it will be useful, but WITHOUT ANY

  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS

  * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

  *

  * You should have received a copy of the GNU General Public License along with

  * JITCraft. If not, see http://www.gnu.org/licenses/.

  */

 #include "AST.h"

 #include "HIR.h"

 #include "BytecodeEmitter.h"

 #include "../Strings.h"

 #include "../Heap-inl.h"

 #include "../Handles-inl.h"

 using namespace ke;

 class HIRTranslator : public HIRVisitor

 {

   public:

     HIRTranslator(Zone *zone, BytecodeEmitter &emitter)

       : zone_(zone),

         emitter_(emitter)

     {

     }

     void translate(HIR *hir) {

         hir->accept(this);

     }

     void visitFloat(HFloat *hir);

     void visitInteger(HInteger *hir);

     void visitArray(HArray *hir);

     void visitCall(HCall *call);

     void visitStore(HStore *store);

     void visitBinary(HBinary *binary);

     void visitLocal(HLocal *local);

     void visitGlobal(HGlobal *global);

     void visitConvert(HConvert *convert);

     void visitIndex(HIndex *index);

     void visitPostIncDec(HPostIncDec *hir);

     void visitToRef(HToRef *hir);

   private:

     Zone *zone_;

     BytecodeEmitter &emitter_;

 };

 #define __ emitter_.

 void

 HIRTranslator::visitFloat(HFloat *hir)

 {

     __ float_(hir->value());

 }

 void

 HIRTranslator::visitInteger(HInteger *hir)

 {

     __ int_(hir->value());

 }

 void

 HIRTranslator::visitArray(HArray *hir)

 {

     __ object(hir->array());

     if (!hir->type()->isConst()) {

         // If the type isn't const, we have to assume a consumer may modify

         // the array, and therefore we have to duplicate it here.

         __ duparray(); 

     }

 }

 void

 HIRTranslator::visitCall(HCall *call)

 {

     Local<FunctionType> fun(zone_, FunctionType::cast(call->callee()->type()));

     assert(call->args()->length() == fun->parameters()->length());

     __ note_position(call->node()->pos());

     unsigned argc = call->args()->length();

     for (size_t i = call->args()->length() - 1; i < call->args()->length(); i--) {

         HIR *hir = call->args()->at(i);

         hir->accept(this);

     }

     call->callee()->accept(this);

     __ call(fun, argc);

 }

 void

 HGlobal::bind(HIRVisitor *visitor, BytecodeEmitter &emitter_)

 {

 }

 void

 HGlobal::hold(BytecodeEmitter &emitter_)

 {

 }

 void

 HGlobal::swapAndPick(BytecodeEmitter &emitter_)

 {

     __ dup();

 }

 void

 HGlobal::store(BytecodeEmitter &emitter_)

 {

     __ setglobal(sym_);

 }

 void

 HGlobal::load(BytecodeEmitter &emitter_)

 {

     __ getglobal(sym_);

 }

 bool

 HGlobal::ref(BytecodeEmitter &emitter_)

 {

     return false;

 }

 static inline Type *

 MaybeDereference(Type *type)

 {

     if (type->isReference())

         return ReferenceType::cast(type)->contained();

     return type;

 }

 HLocal::HLocal(AstNode *node, VariableSymbol *sym)

   : HLValue(node, MaybeDereference(sym->type())),

     sym_(sym)

 {

 }

 void

 HLocal::bind(HIRVisitor *visitor, BytecodeEmitter &emitter_)

 {

     if (sym_->type()->isReference()) {

         if (sym_->storage() == VariableSymbol::Local)

             __ getlocal(sym_);

         else if (sym_->storage() == VariableSymbol::Arg)

             __ getarg(sym_);

         else

             assert(false);

     }

 }

 void

 HLocal::hold(BytecodeEmitter &emitter_)

 {

     if (sym_->type()->isReference())

         __ dup();

 }

 void

 HLocal::swapAndPick(BytecodeEmitter &emitter_)

 {

     if (sym_->type()->isReference()) {

         __ swap();

         __ pick2();

     } else {

         __ dup();

     }

 }

 void

 HLocal::store(BytecodeEmitter &emitter_)

 {

     if (sym_->type()->isReference()) {

         __ setref(ReferenceType::cast(sym_->type())->contained());

     } else {

         if (sym_->storage() == VariableSymbol::Local)

             __ setlocal(sym_);

         else if (sym_->storage() == VariableSymbol::Arg)

             __ setarg(sym_);

         else

             assert(false);

     }

 }

 void

 HLocal::load(BytecodeEmitter &emitter_)

 {

     if (sym_->type()->isReference())

         __ getref(ReferenceType::cast(sym_->type())->contained());

     else if (sym_->storage() == VariableSymbol::Local)

         __ getlocal(sym_);

     else if (sym_->storage() == VariableSymbol::Arg)

         __ getarg(sym_);

     else

         assert(false);

 }

 bool

 HLocal::ref(BytecodeEmitter &emitter_)

 {

     if (sym_->storage() == VariableSymbol::Heap) {

         // Closing over a reference should never pass SemA.

         assert(!sym_->type()->isReference());

         // We don't support direct references to heap-allocated locals. This

         // should probably be banned in SemA? But for now, just assert. :TODO:

         assert(false);

         return false;

     }

     if (sym_->type()->isReference()) {

         if (sym_->storage() == VariableSymbol::Local)

             __ getlocal(sym_);

         else if (sym_->storage() == VariableSymbol::Arg)

             __ getarg(sym_);

         else

             assert(false);

     } else {

         __ newref(sym_);

     }

     return true;

 }

 void

 HIndex::bind(HIRVisitor *visitor, BytecodeEmitter &emitter_)

 {

     __ note_position(node()->pos());

     left_->accept(visitor);

     right_->accept(visitor);

 }

 void

 HIndex::hold(BytecodeEmitter &emitter_)

 {

     __ dup2();

 }

 void

 HIndex::swapAndPick(BytecodeEmitter &emitter_)

 {

     // BASE INDEX VALUE

     __ roll3();         // INDEX VALUE BASE

     __ roll3();         // VALUE BASE INDEX

     __ pick3();         // VALUE BASE INDEX VALUE

 }

 void

 HIndex::store(BytecodeEmitter &emitter_)

 {

     __ setelem(type());

 }

 void

 HIndex::load(BytecodeEmitter &emitter_)

 {

     __ getelem(type());

 }

 bool

 HIndex::ref(BytecodeEmitter &emitter_)

 {

     return false;

 }

 void

 HIRTranslator::visitLocal(HLocal *local)

 {

     local->bind(this, emitter_);

     local->load(emitter_);

 }

 void

 HIRTranslator::visitIndex(HIndex *index)

 {

     index->bind(this, emitter_);

     index->load(emitter_);

 }

 void

 HIRTranslator::visitGlobal(HGlobal *global)

 {

     global->bind(this, emitter_);

     global->load(emitter_);

 }

 static inline Opcode

 TokenToOpcode(TokenKind kind)

 {

     switch (kind) {

       case TOK_PLUS:

       case TOK_ASSIGN_ADD:

       case TOK_INCREMENT:

         return OP_ADD;

       case TOK_MINUS:

       case TOK_ASSIGN_SUB:

       case TOK_DECREMENT:

         return OP_SUB;

       case TOK_STAR:

       case TOK_ASSIGN_MUL:

         return OP_MUL;

       case TOK_SLASH:

       case TOK_ASSIGN_DIV:

         return OP_DIV;

       case TOK_PERCENT:

       case TOK_ASSIGN_MOD:

         return OP_MOD;

       case TOK_SHR:

       case TOK_ASSIGN_SHR:

         return OP_SHR;

       case TOK_USHR:

       case TOK_ASSIGN_USHR:

         return OP_USHR;

       case TOK_SHL:

       case TOK_ASSIGN_SHL:

         return OP_SHL;

       case TOK_BITAND:

       case TOK_ASSIGN_BITAND:

         return OP_BITAND;

       case TOK_BITOR:

       case TOK_ASSIGN_BITOR:

         return OP_BITOR;

       case TOK_GT:

           return OP_GT;

       case TOK_GE:

           return OP_GE;

       case TOK_LT:

           return OP_LT;

       case TOK_LE:

           return OP_LE;

       case TOK_EQUALS:

           return OP_EQ;

       case TOK_NOTEQUALS:

           return OP_NE;

       default:

         assert(kind == TOK_BITXOR);

         return OP_BITXOR;

     }

 }

 void

 HIRTranslator::visitStore(HStore *store)

 {

     store->lval()->bind(this, emitter_);

     if (store->kind() == TOK_ASSIGN) {

         store->rval()->accept(this);

     } else {

         // Advanced case: dup the ref, load, op, store.

         store->lval()->hold(emitter_);

         store->lval()->load(emitter_);

         store->rval()->accept(this);

         __ binary(TokenToOpcode(store->kind()));

     }

     store->lval()->store(emitter_);

 }

 void

 HIRTranslator::visitPostIncDec(HPostIncDec *hir)

 {

     hir->lval()->bind(this, emitter_);

     hir->lval()->hold(emitter_);

     hir->lval()->load(emitter_);

     hir->lval()->swapAndPick(emitter_);

     hir->rval()->accept(this);

     __ binary(TokenToOpcode(hir->kind()));

     hir->lval()->store(emitter_);

     __ pop();

 }

 void

 HIRTranslator::visitBinary(HBinary *binary)

 {

     binary->left()->accept(this);

     binary->right()->accept(this);

     // We define three sets of math operators:

     //

     //  (1) ADD, SUB, MUL, DIV, MOD, which take two equal types and produce

     //      the same type.

     //  (2) LT, LE, GE, GT, EQ, NE, which take two equal types and produce

     //      a boolean.

     //  (3) SHL, SR, USHR, BITAND, BITOR, BITXOR, BITNOT, which take two

     //      equal integer types and return that integer type.

     //

     Opcode op = TokenToOpcode(binary->token());

     if (op == OP_DIV)

         __ note_position(binary->node()->pos());

     if (op >= OP_ADD && op <= OP_NE) {

         if (binary->type()->isFloat())

             op = Opcode(int(op) + int(OP_ADD_F - OP_ADD));

     } else {

         assert(binary->type()->isInt32());

     }

     __ binary(op);

 }

 void

 HIRTranslator::visitConvert(HConvert *convert)

 {

     convert->in()->accept(this);

     __ unary(convert->opcode());

 }

 void

 HIRTranslator::visitToRef(HToRef *hir)

 {

     HIR *in = hir->in();

     // See if we can bind a direct reference.

     if (in->isLValue() && in->toLValue()->ref(emitter_))

         return;

     // No, we can't. So instead we create an on-stack reference.

     in->accept(this);

     __ slotref_lifo();

 }

 void

 ke::EmitHIR(Zone *zone, BytecodeEmitter &emitter, HIR *hir)

 {

     HIRTranslator translator(zone, emitter);

     translator.translate(hir);

 }