instrlist_t*
instrlist_clone(dcontext_t *dcontext, instrlist_t *old)
{
instr_t *inst, *copy;
instrlist_t *newlist = instrlist_create(dcontext);
inst = instrlist_first(old);
while (inst != NULL) {
copy = instr_clone(dcontext, inst);
/* to copy instr targets we temporarily clobber note field */
instr_set_note(inst, (void *)copy);
instrlist_append(newlist, copy);
inst = instr_get_next(inst);
}
/* Fix up instr src if it is an instr and restore note field */
/* Note: we do not allows instruction update code cache,
* which is very dangerous.
* So we do not support instr as dst opnd and won't fix up here if any.
*/
for (inst = instrlist_first(old), copy = instrlist_first(newlist);
inst != NULL && copy != NULL;
inst = instr_get_next(inst), copy = instr_get_next(copy)) {
int i;
for (i = 0; i < inst->num_srcs; i++) {
instr_t *tgt;
opnd_t op = instr_get_src(copy, i);
if (!opnd_is_instr(op))
continue;
CLIENT_ASSERT(opnd_get_instr(op) != NULL,
"instrlist_clone: NULL instr operand");
tgt = (instr_t *) instr_get_note(opnd_get_instr(op));
CLIENT_ASSERT(tgt != NULL,
"instrlist_clone: operand instr not in instrlist");
if (opnd_is_far_instr(op)) {
instr_set_src(copy, i,
opnd_create_far_instr
(opnd_get_segment_selector(op), tgt));
} else
instr_set_src(copy, i,
opnd_create_instr(tgt));
}
}
for (inst = instrlist_first(old), copy = instrlist_first(newlist);
inst != NULL && copy != NULL;
inst = instr_get_next(inst), copy = instr_get_next(copy)) {
/* restore note field */
instr_set_note(inst, instr_get_note(copy));
}
#ifdef CLIENT_INTERFACE
newlist->fall_through_bb = old->fall_through_bb;
#endif
return newlist;
}
/* Check if current instrumentation can be merged into previous aflags
* (or on ARM, GPR) save/restore inserted by drx_restore_arith_flags.
* Returns NULL if cannot merge. Otherwise, returns the right insertion point,
* i.e., DRX_NOTE_AFLAGS_RESTORE_BEGIN label instr.
*
* This routine looks for labels inserted by drx_restore_arith_flags,
* so changes to drx_restore_arith_flags may affect this routine.
* On ARM the labels are from drx_insert_counter_update.
*/
static instr_t *
merge_prev_drx_spill(instr_t *where, bool aflags)
{
instr_t *instr;
#ifdef DEBUG
bool has_sahf = false;
#endif
if (where == NULL)
return NULL;
instr = instr_get_prev(where);
if (instr == NULL)
return NULL;
if (!instr_is_label(instr))
return NULL;
/* Check if prev instr is DRX_NOTE_AFLAGS_RESTORE_END.
* We bail even there is only a label instr in between, which
* might be a target of internal cti.
*/
if (instr_get_note(instr) != NOTE_VAL(DRX_NOTE_AFLAGS_RESTORE_END))
return NULL;
/* find DRX_NOTE_AFLAGS_RESTORE_BEGIN */
for (instr = instr_get_prev(instr);
instr != NULL;
instr = instr_get_prev(instr)) {
if (instr_is_app(instr)) {
/* we do not expect any app instr */
ASSERT(false, "drx aflags restore is corrupted");
return NULL;
}
if (instr_is_label(instr)) {
if (instr_get_note(instr) == NOTE_VAL(DRX_NOTE_AFLAGS_RESTORE_BEGIN)) {
ASSERT(!aflags || has_sahf, "missing sahf");
return instr;
}
/* we do not expect any other label instr */
ASSERT(false, "drx aflags restore is corrupted");
return NULL;
#ifdef DEBUG
} else {
if (instr_get_note(instr) == NOTE_VAL(DRX_NOTE_AFLAGS_RESTORE_SAHF))
has_sahf = true;
#endif
}
}
return NULL;
}