/*
* cond_doit: whether do (mov or jmp) it?
* args
* PACK_CC: the current condition codes
* cond: conditions (C_YES, C_LE, C_L, C_E, C_NE, C_GE, C_G)
*
* return
* TRUE: do it
* FALSE: not do it
*/
bool_t cond_doit(cc_t cc, cond_t cond)
{
bool_t doit = FALSE;
switch(cond){
case C_YES:
doit = TRUE;
break;
case C_LE:
doit = ((GET_SF(cc) ^ GET_OF(cc)) | GET_ZF(cc));
break;
case C_L:
doit = (GET_SF(cc) ^ GET_OF(cc));
break;
case C_E:
doit = (GET_ZF(cc));
break;
case C_NE:
doit = (!GET_ZF(cc));
break;
case C_GE:
doit = !(GET_SF(cc) ^ GET_OF(cc));
break;
case C_G:
doit = !(GET_SF(cc) ^ GET_OF(cc)) & !GET_ZF(cc);
break;
}
return doit;
}
/* Branch logic */
bool_t take_branch(cc_t cc, jump_t bcond) {
bool_t zf = GET_ZF(cc);
bool_t sf = GET_SF(cc);
bool_t of = GET_OF(cc);
bool_t jump = FALSE;
switch(bcond) {
case J_YES:
jump = TRUE;
break;
case J_LE:
jump = (sf^of)|zf;
break;
case J_L:
jump = sf^of;
break;
case J_E:
jump = zf;
break;
case J_NE:
jump = zf^1;
break;
case J_GE:
jump = sf^of^1;
break;
case J_G:
jump = (sf^of^1)&(zf^1);
break;
default:
jump = FALSE;
break;
}
return jump;
}
/* Branch logic */
bool_t cond_holds(cc_t cc, cond_t bcond) {
bool_t zf = GET_ZF(cc);
bool_t sf = GET_SF(cc);
bool_t of = GET_OF(cc);
bool_t jump = FALSE;
switch(bcond) {
case C_YES:
jump = TRUE;
break;
case C_LE:
jump = (sf^of)|zf;
break;
case C_L:
jump = sf^of;
break;
case C_E:
jump = zf;
break;
case C_NE:
jump = zf^1;
break;
case C_GE:
jump = sf^of^1;
break;
case C_G:
jump = (sf^of^1)&(zf^1);
break;
default:
jump = FALSE;
break;
}
return jump;
}
GLOBAL VOID
CMPXCHG32
IFN2(
IU32 *, pop1, /* pntr to dst/lsrc operand */
IU32, op2 /* rsrc operand */
)
{
/*
First do comparision and generate flags.
*/
CMP((IU32)GET_EAX(), *pop1, 32);
/*
Then swap data as required.
*/
if ( GET_ZF() ) /* ie iff EAX == op1 */
{
*pop1 = op2;
}
else
{
SET_EAX(*pop1);
}
}
/* Provide mechanism for simulator to update condition code display */
void show_cc(cc_t cc)
{
int code;
sprintf(tcl_msg, "setCC %d %d %d",
GET_ZF(cc), GET_SF(cc), GET_OF(cc));
code = Tcl_Eval(sim_interp, tcl_msg);
if (code != TCL_OK) {
fprintf(stderr, "Failed to display condition codes\n");
fprintf(stderr, "Error Message was '%s'\n", sim_interp->result);
}
}
GLOBAL VOID
LOOPNE16
IFN1(
IU32, rel_offset
)
{
SET_CX(GET_CX() - 1);
if ( GET_CX() != 0 && !GET_ZF() )
update_relative_ip(rel_offset);
}
GLOBAL VOID
LOOPE32
IFN1(
IU32, rel_offset
)
{
SET_ECX(GET_ECX() - 1);
if ( GET_ECX() != 0 && GET_ZF() )
update_relative_ip(rel_offset);
}
/*
* cond_doit: whether do (mov or jmp) it?
* args
* PACK_CC: the current condition codes
* cond: conditions (C_YES, C_LE, C_L, C_E, C_NE, C_GE, C_G)
*
* return
* TRUE: do it
* FALSE: not do it
*/
bool_t cond_doit(cc_t cc, cond_t cond)
{
bool_t doit;
bool_t ZF = GET_ZF(cc),
SF = GET_SF(cc),
OF = GET_OF(cc);
switch (cond) {
case C_YES: return TRUE;
case C_LE: return (SF^OF)|ZF;
case C_L: return SF^OF;
case C_E: return ZF;
case C_NE: return !ZF;
case C_GE: return !(SF^OF);
case C_G: return !(SF^OF)&!ZF;
default: return FALSE;
}
}
/*
* cond_doit: whether do (mov or jmp) it?
* args
* PACK_CC: the current condition codes
* cond: conditions (C_YES, C_LE, C_L, C_E, C_NE, C_GE, C_G)
*
* return
* TRUE: do it
* FALSE: not do it
*/
bool_t cond_doit(cc_t cc, cond_t cond)
{
bool_t doit = FALSE;
bool_t zero = GET_ZF(cc);
bool_t sign = GET_SF(cc);
bool_t ovf = GET_OF(cc);
switch (cond)
{
case C_YES:
doit = TRUE;
break;
case C_LE:
if (((sign^ovf)|zero)&0x1)
doit = TRUE;
break;
case C_L:
if ((sign^ovf)&0x1)
doit = TRUE;
break;
case C_E:
if ((zero)&0x1)
doit = TRUE;
break;
case C_NE:
if ((!zero)&0x1)
doit = TRUE;
break;
case C_GE:
if ((~(sign^ovf))&0x1)
doit = TRUE;
break;
case C_G:
if (((~(sign^ovf))&(~zero))&0x1)
doit = TRUE;
break;
default:
break;
}
return doit;
}