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2021-10-31 21:20:46 +02:00

148 lines
3.7 KiB
C++

/*
* Interactive disassembler (IDA).
* Version 3.05
* Copyright (c) 1990-95 by Ilfak Guilfanov.
* ALL RIGHTS RESERVED.
* FIDO: 2:5020/209
* E-mail: ig@estar.msk.su
*
*/
#include "i860.hpp"
//------------------------------------------------------------------------
static void set_immd_bit(const insn_t &insn)
{
set_immd(insn.ea);
if ( is_defarg(get_flags(insn.ea), 1) )
return;
switch ( insn.itype )
{
case I860_and:
case I860_andh:
case I860_andnot:
case I860_andnoth:
case I860_xor:
case I860_xorh:
op_num(insn.ea, 1);
break;
}
}
//----------------------------------------------------------------------
bool i860_t::handle_operand(const insn_t &insn, const op_t &x, bool isload) const
{
dref_t xreftype;
uchar outf;
switch ( x.type )
{
case o_phrase: // 2 registers
case o_reg:
break;
case o_imm:
if ( !isload )
goto badTouch;
xreftype = dr_O;
outf = OOF_SIGNED;
goto makeImm;
case o_displ:
xreftype = isload ? dr_R : dr_W;
outf = OOF_SIGNED|OOF_ADDR;
makeImm:
set_immd_bit(insn);
if ( op_adds_xrefs(get_flags(insn.ea), x.n) )
insn.add_off_drefs(x, xreftype, outf);
break;
case o_mem:
insn.create_op_data(x.addr, x);
insn.add_dref(x.addr, x.offb, isload ? dr_R : dr_W);
break;
case o_near:
{
int iscall = has_insn_feature(insn.itype,CF_CALL);
insn.add_cref(x.addr, x.offb, iscall ? fl_CN : fl_JN);
if ( iscall && !func_does_return(x.addr) )
return false;
}
break;
default:
badTouch:
warning("%a: %s,%d: bad optype %d", insn.ea, insn.get_canon_mnem(ph), x.n, x.type);
break;
}
return true;
}
//----------------------------------------------------------------------
static bool isDual(uint32 code)
{
return int(code>>26) == 0x12 && (code & Dbit) != 0;
}
//----------------------------------------------------------------------
static int isDelayedStop(uint32 code)
{
// br bri
int opcode = int(code >> 26);
switch ( opcode )
{
case 0x10: // bri
case 0x1A: // br
return 1;
}
return 0;
}
//----------------------------------------------------------------------
static bool canFlow(const insn_t &insn)
{
if ( !is_flow(get_flags(insn.ea)) )
return 1; // no previous instructions
ea_t ea = insn.ea - 4;
flags_t F = get_flags(ea);
if ( is_flow(F) && is_code(F) )
{
if ( isDelayedStop(get_dword(ea)) ) // now or later
{
ea -= 4;
if ( !is_code(get_flags(ea)) || !isDual(get_dword(ea)) )
return 0;
return 1;
}
if ( is_flow(F) )
{
ea -= 4;
return !is_code(get_flags(ea)) || !isDelayedStop(get_dword(ea));
}
}
return 1;
}
//----------------------------------------------------------------------
int i860_t::i860_emu(const insn_t &insn) const
{
bool flow = true;
uint32 Feature = insn.get_canon_feature(ph);
if ( Feature & CF_USE1 && !handle_operand(insn, insn.Op1, true) )
flow = false;
if ( Feature & CF_USE2 && !handle_operand(insn, insn.Op2, true) )
flow = false;
if ( Feature & CF_USE3 && !handle_operand(insn, insn.Op3, true) )
flow = false;
if ( Feature & CF_JUMP )
remember_problem(PR_JUMP, insn.ea);
if ( Feature & CF_CHG1 && !handle_operand(insn, insn.Op1, false) )
flow = false;
if ( Feature & CF_CHG2 && !handle_operand(insn, insn.Op2, false) )
flow = false;
if ( Feature & CF_CHG3 && !handle_operand(insn, insn.Op3, false) )
flow = false;
if ( flow && canFlow(insn) )
add_cref(insn.ea, insn.ea + insn.size, fl_F);
return 1;
}