inline void update_eflag_setnrs(instr_t *instr, t_glob_reg_state *glob_reg_state){
uint flags = instr_get_eflags(instr);
uint read_masks[MY_NUM_EFLAGS] = {
EFLAGS_READ_CF,
EFLAGS_READ_PF,
EFLAGS_READ_AF,
EFLAGS_READ_ZF,
EFLAGS_READ_SF,
EFLAGS_READ_TF,
EFLAGS_READ_IF,
EFLAGS_READ_DF,
EFLAGS_READ_OF,
EFLAGS_READ_NT,
EFLAGS_READ_RF
};
uint write_masks[MY_NUM_EFLAGS] = {
EFLAGS_WRITE_CF,
EFLAGS_WRITE_PF,
EFLAGS_WRITE_AF,
EFLAGS_WRITE_ZF,
EFLAGS_WRITE_SF,
EFLAGS_WRITE_TF,
EFLAGS_WRITE_IF,
EFLAGS_WRITE_DF,
EFLAGS_WRITE_OF,
EFLAGS_WRITE_NT,
EFLAGS_WRITE_RF
};
int i;
for(i = 0; i < MY_NUM_EFLAGS; i++){
if(TESTALL(read_masks[i], flags)){
//determine set number for rule 1: RaW (WRITTEN TO + 1)
glob_reg_state->raw_setnr = MAX(glob_reg_state->raw_setnr,
glob_reg_state->my_writtento[MY_EFLAGS_OFFSET+i]+1);
}
if(TESTALL(write_masks[i], flags)){
//determine set number for rule 2: WaR (READ FROM + 1)
glob_reg_state->war_setnr = MAX(glob_reg_state->war_setnr,
glob_reg_state->my_readfrom[MY_EFLAGS_OFFSET+i]+1);
//determine set number for rule 3: WaW (WRITTEN TO + 1)
glob_reg_state->waw_setnr = MAX(glob_reg_state->waw_setnr,
glob_reg_state->my_writtento[MY_EFLAGS_OFFSET+i]+1);
}
}
}
/* replaces inc with add 1, dec with sub 1
* returns true if successful, false if not
*/
static bool
replace_inc_with_add(void *drcontext, instr_t *instr, instrlist_t *trace)
{
instr_t *in;
uint eflags;
int opcode = instr_get_opcode(instr);
bool ok_to_replace = false;
DR_ASSERT(opcode == OP_inc || opcode == OP_dec);
#ifdef VERBOSE
dr_print_instr(drcontext, STDOUT, instr, "in replace_inc_with_add:\n\t");
#endif
/* add/sub writes CF, inc/dec does not, make sure that's ok */
for (in = instr; in != NULL; in = instr_get_next(in)) {
eflags = instr_get_eflags(in);
if ((eflags & EFLAGS_READ_CF) != 0) {
#ifdef VERBOSE
dr_print_instr(drcontext, STDOUT, in,
"\treads CF => cannot replace inc with add: ");
#endif
return false;
}
if (instr_is_exit_cti(in)) {
/* to be more sophisticated, examine instructions at
* target of exit cti (if it is a direct branch).
* for this example, we give up if we hit a branch.
*/
return false;
}
/* if writes but doesn't read, ok */
if ((eflags & EFLAGS_WRITE_CF) != 0) {
ok_to_replace = true;
break;
}
}
if (!ok_to_replace) {
#ifdef VERBOSE
dr_printf("\tno write to CF => cannot replace inc with add\n");
#endif
return false;
}
if (opcode == OP_inc) {
#ifdef VERBOSE
dr_printf("\treplacing inc with add\n");
#endif
in = INSTR_CREATE_add(drcontext, instr_get_dst(instr, 0),
OPND_CREATE_INT8(1));
} else {
#ifdef VERBOSE
dr_printf("\treplacing dec with sub\n");
#endif
in = INSTR_CREATE_sub(drcontext, instr_get_dst(instr, 0),
OPND_CREATE_INT8(1));
}
if (instr_get_prefix_flag(instr, PREFIX_LOCK))
instr_set_prefix_flag(in, PREFIX_LOCK);
instr_set_translation(in, instr_get_app_pc(instr));
instrlist_replace(trace, instr, in);
instr_destroy(drcontext, instr);
return true;
}
