src/inc/opcodes.h

/*  GRAPHITE2 LICENSING

    Copyright 2010, SIL International
    All rights reserved.

    This library is free software; you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published
    by the Free Software Foundation; either version 2.1 of License, or
    (at your option) any later version.

    This program 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
    Lesser General Public License for more details.

    You should also have received a copy of the GNU Lesser General Public
    License along with this library in the file named "LICENSE".
    If not, write to the Free Software Foundation, 51 Franklin Street,
    Suite 500, Boston, MA 02110-1335, USA or visit their web page on the
    internet at http://www.fsf.org/licenses/lgpl.html.

Alternatively, the contents of this file may be used under the terms of the
Mozilla Public License (http://mozilla.org/MPL) or the GNU General Public
License, as published by the Free Software Foundation, either version 2
of the License or (at your option) any later version.
*/
#pragma once
// This file will be pulled into and integrated into a machine implmentation
// DO NOT build directly and under no circumstances ever #include headers in
// here or you will break the direct_machine.
//
// Implementers' notes
// ==================
// You have access to a few primitives and the full C++ code:
//    declare_params(n) Tells the interpreter how many bytes of parameter
//                      space to claim for this instruction uses and
//                      initialises the param pointer.  You *must* before the
//                      first use of param.
//    use_params(n)     Claim n extra bytes of param space beyond what was
//                      claimed using delcare_param.
//    param             A const byte pointer for the parameter space claimed by
//                      this instruction.
//    binop(op)         Implement a binary operation on the stack using the
//                      specified C++ operator.
//    NOT_IMPLEMENTED   Any instruction body containing this will exit the
//                      program with an assertion error.  Instructions that are
//                      not implemented should also be marked NILOP in the
//                      opcodes tables this will cause the code class to spot
//                      them in a live code stream and throw a runtime_error
//                      instead.
//    push(n)           Push the value n onto the stack.
//    pop()             Pop the top most value and return it.
//
//    You have access to the following named fast 'registers':
//        sp        = The pointer to the current top of stack, the last value
//                    pushed.
//        seg       = A reference to the Segment this code is running over.
//        is        = The current slot index
//        isb       = The original base slot index at the start of this rule
//        isf       = The first positioned slot
//        isl       = The last positioned slot
//        ip        = The current instruction pointer
//        endPos    = Position of advance of last cluster
//        dir       = writing system directionality of the font


// #define NOT_IMPLEMENTED     assert(false)
// #define NOT_IMPLEMENTED

#define binop(op)           const uint32 a = pop(); *sp = uint32(*sp) op a
#define sbinop(op)          const int32 a = pop(); *sp = int32(*sp) op a
#define use_params(n)       dp += n

#define declare_params(n)   const byte * param = dp; \
                            use_params(n);

#define push(n)             { *++sp = n; }
#define pop()               (*sp--)
#define slotat(x)           (map[(x)])
#define DIE                 { is=seg.last(); status = Machine::died_early; EXIT(1); }
#define POSITIONED          1

STARTOP(nop)
    do {} while (0);
ENDOP

STARTOP(push_byte)
    declare_params(1);
    push(int8(*param));
ENDOP

STARTOP(push_byte_u)
    declare_params(1);
    push(uint8(*param));
ENDOP

STARTOP(push_short)
    declare_params(2);
    const int16 r   = int16(param[0]) << 8
                    | uint8(param[1]);
    push(r);
ENDOP

STARTOP(push_short_u)
    declare_params(2);
    const uint16 r  = uint16(param[0]) << 8
                    | uint8(param[1]);
    push(r);
ENDOP

STARTOP(push_long)
    declare_params(4);
    const  int32 r  = int32(param[0]) << 24
                    | uint32(param[1]) << 16
                    | uint32(param[2]) << 8
                    | uint8(param[3]);
    push(r);
ENDOP

STARTOP(add)
    binop(+);
ENDOP

STARTOP(sub)
    binop(-);
ENDOP

STARTOP(mul)
    binop(*);
ENDOP

STARTOP(div_)
    const int32 b = pop();
    const int32 a = int32(*sp);
    if (b == 0 || (a == std::numeric_limits<int32>::min() && b == -1)) DIE;
    *sp = int32(*sp) / b;
ENDOP

STARTOP(min_)
    const int32 a = pop(), b = *sp;
    if (a < b) *sp = a;
ENDOP

STARTOP(max_)
    const int32 a = pop(), b = *sp;
    if (a > b) *sp = a;
ENDOP

STARTOP(neg)
    *sp = uint32(-int32(*sp));
ENDOP

STARTOP(trunc8)
    *sp = uint8(*sp);
ENDOP

STARTOP(trunc16)
    *sp = uint16(*sp);
ENDOP

STARTOP(cond)
    const uint32 f = pop(), t = pop(), c = pop();
    push(c ? t : f);
ENDOP

STARTOP(and_)
    binop(&&);
ENDOP

STARTOP(or_)
    binop(||);
ENDOP

STARTOP(not_)
    *sp = !*sp;
ENDOP

STARTOP(equal)
    binop(==);
ENDOP

STARTOP(not_eq_)
    binop(!=);
ENDOP

STARTOP(less)
    sbinop(<);
ENDOP

STARTOP(gtr)
    sbinop(>);
ENDOP

STARTOP(less_eq)
    sbinop(<=);
ENDOP

STARTOP(gtr_eq)
    sbinop(>=);
ENDOP

STARTOP(next)
    if (map - &smap[0] >= int(smap.size())) DIE
    if (is)
    {
        if (is == smap.highwater())
            smap.highpassed(true);
        is = is->next();
    }
    ++map;
ENDOP

//STARTOP(next_n)
//    use_params(1);
//    NOT_IMPLEMENTED;
    //declare_params(1);
    //const size_t num = uint8(*param);
//ENDOP

//STARTOP(copy_next)
//     if (is) is = is->next();
//     ++map;
// ENDOP

STARTOP(put_glyph_8bit_obs)
    declare_params(1);
    const unsigned int output_class = uint8(*param);
    is->setGlyph(&seg, seg.getClassGlyph(output_class, 0));
ENDOP

STARTOP(put_subs_8bit_obs)
    declare_params(3);
    const int           slot_ref     = int8(param[0]);
    const unsigned int  input_class  = uint8(param[1]),
                        output_class = uint8(param[2]);
    uint16 index;
    slotref slot = slotat(slot_ref);
    if (slot)
    {
        index = seg.findClassIndex(input_class, slot->gid());
        is->setGlyph(&seg, seg.getClassGlyph(output_class, index));
    }
ENDOP

STARTOP(put_copy)
    declare_params(1);
    const int  slot_ref = int8(*param);
    if (is && !is->isDeleted())
    {
        slotref ref = slotat(slot_ref);
        if (ref && ref != is)
        {
            int16 *tempUserAttrs = is->userAttrs();
            if (is->attachedTo() || is->firstChild()) DIE
            Slot *prev = is->prev();
            Slot *next = is->next();
            memcpy(tempUserAttrs, ref->userAttrs(), seg.numAttrs() * sizeof(uint16));
            memcpy(is, ref, sizeof(Slot));
            is->firstChild(NULL);
            is->nextSibling(NULL);
            is->userAttrs(tempUserAttrs);
            is->next(next);
            is->prev(prev);
            if (is->attachedTo())
                is->attachedTo()->child(is);
        }
        is->markCopied(false);
        is->markDeleted(false);
    }
ENDOP

STARTOP(insert)
    if (smap.decMax() <= 0) DIE;
    Slot *newSlot = seg.newSlot();
    if (!newSlot) DIE;
    Slot *iss = is;
    while (iss && iss->isDeleted()) iss = iss->next();
    if (!iss)
    {
        if (seg.last())
        {
            seg.last()->next(newSlot);
            newSlot->prev(seg.last());
            newSlot->before(seg.last()->before());
            seg.last(newSlot);
        }
        else
        {
            seg.first(newSlot);
            seg.last(newSlot);
        }
    }
    else if (iss->prev())
    {
        iss->prev()->next(newSlot);
        newSlot->prev(iss->prev());
        newSlot->before(iss->prev()->after());
    }
    else
    {
        newSlot->prev(NULL);
        newSlot->before(iss->before());
        seg.first(newSlot);
    }
    newSlot->next(iss);
    if (iss)
    {
        iss->prev(newSlot);
        newSlot->originate(iss->original());
        newSlot->after(iss->before());
    }
    else if (newSlot->prev())
    {
        newSlot->originate(newSlot->prev()->original());
        newSlot->after(newSlot->prev()->after());
    }
    else
    {
        newSlot->originate(seg.defaultOriginal());
    }
    if (is == smap.highwater())
        smap.highpassed(false);
    is = newSlot;
    seg.extendLength(1);
    if (map != &smap[-1])
        --map;
ENDOP

STARTOP(delete_)
    if (!is || is->isDeleted()) DIE
    is->markDeleted(true);
    if (is->prev())
        is->prev()->next(is->next());
    else
        seg.first(is->next());

    if (is->next())
        is->next()->prev(is->prev());
    else
        seg.last(is->prev());


    if (is == smap.highwater())
            smap.highwater(is->next());
    if (is->prev())
        is = is->prev();
    seg.extendLength(-1);
ENDOP

STARTOP(assoc)
    declare_params(1);
    unsigned int  num = uint8(*param);
    const int8 *  assocs = reinterpret_cast<const int8 *>(param+1);
    use_params(num);
    int max = -1;
    int min = -1;

    while (num-- > 0)
    {
        int sr = *assocs++;
        slotref ts = slotat(sr);
        if (ts && (min == -1 || ts->before() < min)) min = ts->before();
        if (ts && ts->after() > max) max = ts->after();
    }
    if (min > -1)   // implies max > -1
    {
        is->before(min);
        is->after(max);
    }
ENDOP

STARTOP(cntxt_item)
    // It turns out this is a cunningly disguised condition forward jump.
    declare_params(3);
    const int       is_arg = int8(param[0]);
    const size_t    iskip  = uint8(param[1]),
                    dskip  = uint8(param[2]);

    if (mapb + is_arg != map)
    {
        ip += iskip;
        dp += dskip;
        push(true);
    }
ENDOP

STARTOP(attr_set)
    declare_params(1);
    const attrCode      slat = attrCode(uint8(*param));
    const          int  val  = pop();
    is->setAttr(&seg, slat, 0, val, smap);
ENDOP

STARTOP(attr_add)
    declare_params(1);
    const attrCode      slat = attrCode(uint8(*param));
    const     uint32_t  val  = pop();
    if ((slat == gr_slatPosX || slat == gr_slatPosY) && (flags & POSITIONED) == 0)
    {
        seg.positionSlots(0, *smap.begin(), *(smap.end()-1), seg.currdir());
        flags |= POSITIONED;
    }
    uint32_t res = uint32_t(is->getAttr(&seg, slat, 0));
    is->setAttr(&seg, slat, 0, int32_t(val + res), smap);
ENDOP

STARTOP(attr_sub)
    declare_params(1);
    const attrCode      slat = attrCode(uint8(*param));
    const     uint32_t  val  = pop();
    if ((slat == gr_slatPosX || slat == gr_slatPosY) && (flags & POSITIONED) == 0)
    {
        seg.positionSlots(0, *smap.begin(), *(smap.end()-1), seg.currdir());
        flags |= POSITIONED;
    }
    uint32_t res = uint32_t(is->getAttr(&seg, slat, 0));
    is->setAttr(&seg, slat, 0, int32_t(res - val), smap);
ENDOP

STARTOP(attr_set_slot)
    declare_params(1);
    const attrCode  slat   = attrCode(uint8(*param));
    const int       offset = int(map - smap.begin())*int(slat == gr_slatAttTo);
    const int       val    = pop()  + offset;
    is->setAttr(&seg, slat, offset, val, smap);
ENDOP

STARTOP(iattr_set_slot)
    declare_params(2);
    const attrCode  slat = attrCode(uint8(param[0]));
    const uint8     idx  = uint8(param[1]);
    const int       val  = int(pop()  + (map - smap.begin())*int(slat == gr_slatAttTo));
    is->setAttr(&seg, slat, idx, val, smap);
ENDOP

STARTOP(push_slot_attr)
    declare_params(2);
    const attrCode      slat     = attrCode(uint8(param[0]));
    const int           slot_ref = int8(param[1]);
    if ((slat == gr_slatPosX || slat == gr_slatPosY) && (flags & POSITIONED) == 0)
    {
        seg.positionSlots(0, *smap.begin(), *(smap.end()-1), seg.currdir());
        flags |= POSITIONED;
    }
    slotref slot = slotat(slot_ref);
    if (slot)
    {
        int res = slot->getAttr(&seg, slat, 0);
        push(res);
    }
ENDOP

STARTOP(push_glyph_attr_obs)
    declare_params(2);
    const unsigned int  glyph_attr = uint8(param[0]);
    const int           slot_ref   = int8(param[1]);
    slotref slot = slotat(slot_ref);
    if (slot)
        push(int32(seg.glyphAttr(slot->gid(), glyph_attr)));
ENDOP

STARTOP(push_glyph_metric)
    declare_params(3);
    const unsigned int  glyph_attr  = uint8(param[0]);
    const int           slot_ref    = int8(param[1]);
    const signed int    attr_level  = uint8(param[2]);
    slotref slot = slotat(slot_ref);
    if (slot)
        push(seg.getGlyphMetric(slot, glyph_attr, attr_level, dir));
ENDOP

STARTOP(push_feat)
    declare_params(2);
    const unsigned int  feat        = uint8(param[0]);
    const int           slot_ref    = int8(param[1]);
    slotref slot = slotat(slot_ref);
    if (slot)
    {
        uint8 fid = seg.charinfo(slot->original())->fid();
        push(seg.getFeature(fid, feat));
    }
ENDOP

STARTOP(push_att_to_gattr_obs)
    declare_params(2);
    const unsigned int  glyph_attr  = uint8(param[0]);
    const int           slot_ref    = int8(param[1]);
    slotref slot = slotat(slot_ref);
    if (slot)
    {
        slotref att = slot->attachedTo();
        if (att) slot = att;
        push(int32(seg.glyphAttr(slot->gid(), glyph_attr)));
    }
ENDOP

STARTOP(push_att_to_glyph_metric)
    declare_params(3);
    const unsigned int  glyph_attr  = uint8(param[0]);
    const int           slot_ref    = int8(param[1]);
    const signed int    attr_level  = uint8(param[2]);
    slotref slot = slotat(slot_ref);
    if (slot)
    {
        slotref att = slot->attachedTo();
        if (att) slot = att;
        push(int32(seg.getGlyphMetric(slot, glyph_attr, attr_level, dir)));
    }
ENDOP

STARTOP(push_islot_attr)
    declare_params(3);
    const attrCode  slat     = attrCode(uint8(param[0]));
    const int           slot_ref = int8(param[1]),
                        idx      = uint8(param[2]);
    if ((slat == gr_slatPosX || slat == gr_slatPosY) && (flags & POSITIONED) == 0)
    {
        seg.positionSlots(0, *smap.begin(), *(smap.end()-1), seg.currdir());
        flags |= POSITIONED;
    }
    slotref slot = slotat(slot_ref);
    if (slot)
    {
        int res = slot->getAttr(&seg, slat, idx);
        push(res);
    }
ENDOP

#if 0
STARTOP(push_iglyph_attr) // not implemented
    NOT_IMPLEMENTED;
ENDOP
#endif

STARTOP(pop_ret)
    const uint32 ret = pop();
    EXIT(ret);
ENDOP

STARTOP(ret_zero)
    EXIT(0);
ENDOP

STARTOP(ret_true)
    EXIT(1);
ENDOP

STARTOP(iattr_set)
    declare_params(2);
    const attrCode      slat = attrCode(uint8(param[0]));
    const uint8         idx  = uint8(param[1]);
    const          int  val  = pop();
    is->setAttr(&seg, slat, idx, val, smap);
ENDOP

STARTOP(iattr_add)
    declare_params(2);
    const attrCode      slat = attrCode(uint8(param[0]));
    const uint8         idx  = uint8(param[1]);
    const     uint32_t  val  = pop();
    if ((slat == gr_slatPosX || slat == gr_slatPosY) && (flags & POSITIONED) == 0)
    {
        seg.positionSlots(0, *smap.begin(), *(smap.end()-1), seg.currdir());
        flags |= POSITIONED;
    }
    uint32_t res = uint32_t(is->getAttr(&seg, slat, idx));
    is->setAttr(&seg, slat, idx, int32_t(val + res), smap);
ENDOP

STARTOP(iattr_sub)
    declare_params(2);
    const attrCode      slat = attrCode(uint8(param[0]));
    const uint8         idx  = uint8(param[1]);
    const     uint32_t  val  = pop();
    if ((slat == gr_slatPosX || slat == gr_slatPosY) && (flags & POSITIONED) == 0)
    {
        seg.positionSlots(0, *smap.begin(), *(smap.end()-1), seg.currdir());
        flags |= POSITIONED;
    }
    uint32_t res = uint32_t(is->getAttr(&seg, slat, idx));
    is->setAttr(&seg, slat, idx, int32_t(res - val), smap);
ENDOP

STARTOP(push_proc_state)
    use_params(1);
    push(1);
ENDOP

STARTOP(push_version)
    push(0x00030000);
ENDOP

STARTOP(put_subs)
    declare_params(5);
    const int        slot_ref     = int8(param[0]);
    const unsigned int  input_class  = uint8(param[1]) << 8
                                     | uint8(param[2]);
    const unsigned int  output_class = uint8(param[3]) << 8
                                     | uint8(param[4]);
    slotref slot = slotat(slot_ref);
    if (slot)
    {
        int index = seg.findClassIndex(input_class, slot->gid());
        is->setGlyph(&seg, seg.getClassGlyph(output_class, index));
    }
ENDOP

#if 0
STARTOP(put_subs2) // not implemented
    NOT_IMPLEMENTED;
ENDOP

STARTOP(put_subs3) // not implemented
    NOT_IMPLEMENTED;
ENDOP
#endif

STARTOP(put_glyph)
    declare_params(2);
    const unsigned int output_class  = uint8(param[0]) << 8
                                     | uint8(param[1]);
    is->setGlyph(&seg, seg.getClassGlyph(output_class, 0));
ENDOP

STARTOP(push_glyph_attr)
    declare_params(3);
    const unsigned int  glyph_attr  = uint8(param[0]) << 8
                                    | uint8(param[1]);
    const int           slot_ref    = int8(param[2]);
    slotref slot = slotat(slot_ref);
    if (slot)
        push(int32(seg.glyphAttr(slot->gid(), glyph_attr)));
ENDOP

STARTOP(push_att_to_glyph_attr)
    declare_params(3);
    const unsigned int  glyph_attr  = uint8(param[0]) << 8
                                    | uint8(param[1]);
    const int           slot_ref    = int8(param[2]);
    slotref slot = slotat(slot_ref);
    if (slot)
    {
        slotref att = slot->attachedTo();
        if (att) slot = att;
        push(int32(seg.glyphAttr(slot->gid(), glyph_attr)));
    }
ENDOP

STARTOP(temp_copy)
    slotref newSlot = seg.newSlot();
    if (!newSlot || !is) DIE;
    int16 *tempUserAttrs = newSlot->userAttrs();
    memcpy(newSlot, is, sizeof(Slot));
    memcpy(tempUserAttrs, is->userAttrs(), seg.numAttrs() * sizeof(uint16));
    newSlot->userAttrs(tempUserAttrs);
    newSlot->markCopied(true);
    *map = newSlot;
ENDOP

STARTOP(band)
    binop(&);
ENDOP

STARTOP(bor)
    binop(|);
ENDOP

STARTOP(bnot)
    *sp = ~*sp;
ENDOP

STARTOP(setbits)
    declare_params(4);
    const uint16 m  = uint16(param[0]) << 8
                    | uint8(param[1]);
    const uint16 v  = uint16(param[2]) << 8
                    | uint8(param[3]);
    *sp = ((*sp) & ~m) | v;
ENDOP

STARTOP(set_feat)
    declare_params(2);
    const unsigned int  feat        = uint8(param[0]);
    const int           slot_ref    = int8(param[1]);
    slotref slot = slotat(slot_ref);
    if (slot)
    {
        uint8 fid = seg.charinfo(slot->original())->fid();
        seg.setFeature(fid, feat, pop());
    }
ENDOP