1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/graphite2/src/direct_machine.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,117 @@
1.4 +/* GRAPHITE2 LICENSING
1.5 +
1.6 + Copyright 2010, SIL International
1.7 + All rights reserved.
1.8 +
1.9 + This library is free software; you can redistribute it and/or modify
1.10 + it under the terms of the GNU Lesser General Public License as published
1.11 + by the Free Software Foundation; either version 2.1 of License, or
1.12 + (at your option) any later version.
1.13 +
1.14 + This program is distributed in the hope that it will be useful,
1.15 + but WITHOUT ANY WARRANTY; without even the implied warranty of
1.16 + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
1.17 + Lesser General Public License for more details.
1.18 +
1.19 + You should also have received a copy of the GNU Lesser General Public
1.20 + License along with this library in the file named "LICENSE".
1.21 + If not, write to the Free Software Foundation, 51 Franklin Street,
1.22 + Suite 500, Boston, MA 02110-1335, USA or visit their web page on the
1.23 + internet at http://www.fsf.org/licenses/lgpl.html.
1.24 +
1.25 +Alternatively, the contents of this file may be used under the terms of the
1.26 +Mozilla Public License (http://mozilla.org/MPL) or the GNU General Public
1.27 +License, as published by the Free Software Foundation, either version 2
1.28 +of the License or (at your option) any later version.
1.29 +*/
1.30 +// This direct threaded interpreter implmentation for machine.h
1.31 +// Author: Tim Eves
1.32 +
1.33 +// Build either this interpreter or the call_machine implementation.
1.34 +// The direct threaded interpreter is relies upon a gcc feature called
1.35 +// labels-as-values so is only portable to compilers that support the
1.36 +// extension (gcc only as far as I know) however it should build on any
1.37 +// architecture gcc supports.
1.38 +// This is twice as fast as the call threaded model and is likely faster on
1.39 +// inorder processors with short pipelines and little branch prediction such
1.40 +// as the ARM and possibly Atom chips.
1.41 +
1.42 +
1.43 +#include <cassert>
1.44 +#include <cstring>
1.45 +#include "inc/Machine.h"
1.46 +#include "inc/Segment.h"
1.47 +#include "inc/Slot.h"
1.48 +#include "inc/Rule.h"
1.49 +
1.50 +#define STARTOP(name) name: {
1.51 +#define ENDOP }; goto *((sp - sb)/Machine::STACK_MAX ? &&end : *++ip);
1.52 +#define EXIT(status) { push(status); goto end; }
1.53 +
1.54 +#define do_(name) &&name
1.55 +
1.56 +
1.57 +using namespace graphite2;
1.58 +using namespace vm;
1.59 +
1.60 +namespace {
1.61 +
1.62 +const void * direct_run(const bool get_table_mode,
1.63 + const instr * program,
1.64 + const byte * data,
1.65 + Machine::stack_t * stack,
1.66 + slotref * & __map,
1.67 + SlotMap * __smap=0)
1.68 +{
1.69 + // We need to define and return to opcode table from within this function
1.70 + // other inorder to take the addresses of the instruction bodies.
1.71 + #include "inc/opcode_table.h"
1.72 + if (get_table_mode)
1.73 + return opcode_table;
1.74 +
1.75 + // Declare virtual machine registers
1.76 + const instr * ip = program;
1.77 + const byte * dp = data;
1.78 + Machine::stack_t * sp = stack + Machine::STACK_GUARD,
1.79 + * const sb = sp;
1.80 + SlotMap & smap = *__smap;
1.81 + Segment & seg = smap.segment;
1.82 + slotref is = *__map,
1.83 + * map = __map,
1.84 + * const mapb = smap.begin()+smap.context();
1.85 + int8 flags = 0;
1.86 +
1.87 + // start the program
1.88 + goto **ip;
1.89 +
1.90 + // Pull in the opcode definitions
1.91 + #include "inc/opcodes.h"
1.92 +
1.93 + end:
1.94 + __map = map;
1.95 + *__map = is;
1.96 + return sp;
1.97 +}
1.98 +
1.99 +}
1.100 +
1.101 +const opcode_t * Machine::getOpcodeTable() throw()
1.102 +{
1.103 + slotref * dummy;
1.104 + return static_cast<const opcode_t *>(direct_run(true, 0, 0, 0, dummy, 0));
1.105 +}
1.106 +
1.107 +
1.108 +Machine::stack_t Machine::run(const instr * program,
1.109 + const byte * data,
1.110 + slotref * & is)
1.111 +{
1.112 + assert(program != 0);
1.113 +
1.114 + const stack_t *sp = static_cast<const stack_t *>(
1.115 + direct_run(false, program, data, _stack, is, &_map));
1.116 + const stack_t ret = sp == _stack+STACK_GUARD+1 ? *sp-- : 0;
1.117 + check_final_stack(sp);
1.118 + return ret;
1.119 +}
1.120 +
