dis.c File Reference

#include <stdio.h>
#include <stdlib.h>
#include "dcpu16.h"

Go to the source code of this file.

Classes
struct	op_code
struct	op_basic
struct	op_nbasic
union	op

Functions
static int	needWord (ut8 type)
static int	valPrint (char *out, size_t size_out, ut8 type, ut16 value)
static int	instrPrint (char *out, size_t size_out, const op *o)
static int	instrGet (ut16 in, op *o, ut16 a, ut16 b)
static int	instrGetCycles (const op *o)
int	dcpu16_disasm (char *out, size_t size_out, const ut16 *inp, int len, int *cost)

Variables
static const int	opCycle []
static const int	opCycleB [] = { 0, 2 }
static const char *	opName []
static const char *	opNameB [] = { "reserved", "jsr" }
static const char *	regs []

Function Documentation

dcpu16_disasm()

int dcpu16_disasm	(	char *	out,
		size_t	size_out,
		const ut16 *	inp,
		int	len,
		int *	cost
	)

Definition at line 130 of file dis.c.

                                                                                   {
    op o = { { 0 } };
    int delta = instrGet(inp[0], &o, inp[1], inp[2]);
    if (cost)
        *cost = instrGetCycles(&o) + ((o.b.opcode >= 0xc) ? 1 : 0);
    instrPrint(out, size_out, &o);
    // ind = (o.b.opcode >= 0xC);
    return delta << 1;
}

References op::b, delta, instrGet(), instrGetCycles(), instrPrint(), op_basic::opcode, and out.

Referenced by disassemble().

instrGet()

static int instrGet ( ut16  in, op *  o, ut16  a, ut16  b  )

static

Definition at line 94 of file dis.c.

                                                    {
    int ret = 1;
    o->code.opcode = in & 0xF;
    if (!(o->code.opcode = in & 0xF)) {
        /* Non basic op code */
        o->n.opcode = (in >> 4) & 0x3F;
        o->n.a_type = (in >> 10) & 0x3F;
 
        if (needWord(o->n.a_type)) {
            o->n.a = a;
            ret++;
        }
    } else {
        o->b.a_type = (in >> 4) & 0x3F;
        o->b.b_type = (in >> 10) & 0x3F;
        if (needWord(o->b.a_type)) {
            o->b.a = a;
            ret++;
            if (needWord(o->b.b_type)) {
                o->b.b = b;
                ret++;
            }
        } else if (needWord(o->b.b_type)) {
            o->b.b = a;
            ret++;
        }
    }
    return ret;
}

References op_basic::a, op_nbasic::a, a, op_basic::a_type, op_nbasic::a_type, op_basic::b, op::b, b, op_basic::b_type, op::code, in, op::n, needWord(), op_code::opcode, and op_nbasic::opcode.

Referenced by dcpu16_disasm().

instrGetCycles()

static int instrGetCycles ( const op *  o )

static

Definition at line 124 of file dis.c.

                                       {
    if (o->code.opcode == 0)
        return opCycleB[o->n.opcode] + needWord(o->n.a_type);
    return opCycle[o->b.opcode] + needWord(o->b.a_type) + needWord(o->b.b_type);
}

References op_basic::a_type, op_nbasic::a_type, op::b, op_basic::b_type, op::code, op::n, needWord(), op_code::opcode, op_basic::opcode, op_nbasic::opcode, opCycle, and opCycleB.

Referenced by dcpu16_disasm().

instrPrint()

static int instrPrint ( char *  out, size_t  size_out, const op *  o  )

static

Definition at line 77 of file dis.c.

                                                               {
    char arg[32], arg2[32];
    if (o->code.opcode == 0) {
        valPrint(arg, sizeof(arg), o->n.a_type, o->n.a);
        if (o->n.opcode > 1) {
            strncpy(out, "invalid", size_out);
            out[size_out - 1] = 0;
            return strlen(out);
        }
        return snprintf(out, size_out, "%s %s",
            opNameB[o->n.opcode], arg);
    }
    valPrint(arg, sizeof(arg), o->b.a_type, o->b.a);
    valPrint(arg2, sizeof(arg2), o->b.b_type, o->b.b);
    return snprintf(out, size_out, "%s %s, %s", opName[o->b.opcode], arg, arg2);
}

References op_basic::a, op_nbasic::a, op_basic::a_type, op_nbasic::a_type, op_basic::b, op::b, op_basic::b_type, op::code, op::n, op_code::opcode, op_basic::opcode, op_nbasic::opcode, opName, opNameB, out, snprintf, and valPrint().

Referenced by dcpu16_disasm().

needWord()

static int needWord ( ut8  type )

inlinestatic

Definition at line 57 of file dis.c.

                                     {
    return ((type <= 0x17) && (type > 0x0f)) || (type == 0x1e) || (type == 0x1f);
}

References type.

Referenced by instrGet(), and instrGetCycles().

valPrint()

static int valPrint ( char *  out, size_t  size_out, ut8  type, ut16  value  )

static

Definition at line 61 of file dis.c.

                                                                      {
    if (type <= 0x07)
        return snprintf(out, size_out, "%s", regs[type]);
    if (type <= 0x0f)
        return snprintf(out, size_out, "[%s]", regs[type - 0x08]);
    if (type <= 0x17)
        return snprintf(out, size_out, "[%s + %#hx]", regs[type - 0x10], value);
    if (type <= 0x1d)
        return snprintf(out, size_out, "%s", regs[type - 0x18 + 0x08]);
    if (type == 0x1e)
        return snprintf(out, size_out, "[%#hx]", value);
    if (type == 0x1f)
        return snprintf(out, size_out, "%#hx", value);
    return snprintf(out, size_out, "%#hx", (short)(type - 0x20));
}

References out, regs, snprintf, type, and value.

Referenced by instrPrint().

Variable Documentation

opCycle

const int opCycle[]

static

Initial value:

= {
    0, 1, 2, 2, 2, 3, 3, 2, 2, 1, 1, 1, 2, 2, 2, 2
}

Definition at line 38 of file dis.c.

Referenced by instrGetCycles().

opCycleB

const int opCycleB[] = { 0, 2 }

static

Definition at line 41 of file dis.c.

Referenced by instrGetCycles().

opName

const char* opName[]

static

Initial value:

= {
    "", "set",
    "add", "sub", "mul", "div", "mod",
    "shl", "shr", "and", "bor", "xor",
    "ife", "ifn", "ifg", "ifb"
}

Definition at line 43 of file dis.c.

Referenced by instrPrint().

opNameB

const char* opNameB[] = { "reserved", "jsr" }

static

Definition at line 50 of file dis.c.

Referenced by instrPrint().

regs

const char* regs[]

static

Initial value:

= {
    "a", "b", "c", "x", "y", "z", "i", "j",
    "pop", "peek", "push", "sp", "pc", "o"
}

Definition at line 52 of file dis.c.

Referenced by valPrint().