VN * IR_GVN::comp_sc_by_anon_domdef(IR const* exp, IR const* domdef,
bool & change)
{
IS_TRUE0((IR_type(exp) == IR_LD || IR_type(exp) == IR_PR) &&
m_du->is_may_def(domdef, exp, false));
SCVNE2VN * vnexp_map = m_def2sctab.get(domdef);
UINT dtsz = exp->get_dt_size(m_dm);
MD const* md = exp->get_exact_ref();
IS_TRUE0(md);
VNE_SC vexp(MD_id(md), exp->get_ofst(), dtsz);
/*
NOTE:
foo();
v1; //s1
goo();
v1; //s2
vn of s1 should not same with s2.
*/
if (vnexp_map == NULL) {
vnexp_map = new SCVNE2VN(m_pool, 16); //bsize to be evaluate.
m_def2sctab.set(domdef, vnexp_map);
}
VN * vn = vnexp_map->get(&vexp);
if (vn == NULL) {
vn = new_vn();
VN_type(vn) = VN_VAR;
vnexp_map->setv((OBJTY)&vexp, vn);
}
m_ir2vn.set(IR_id(exp), vn);
change = true;
return vn;
}
//Try to generate a MD to represent dedicated string md.
//In case, e.g: android/external/tagsoup/src/org/ccil/cowan/tagsoup/HTMLSchema.java
//There is a function allocates 3000+ string variable.
//Each string has been taken address.
//That will inflate may_point_to_set too much.
//In this situation, AA can be conservatively regard all string variables
//as same unbounded MD.
MD const* RegionMgr::genDedicateStrMD()
{
if (!m_is_regard_str_as_same_md) {
return NULL;
}
//Regard all string variables as same unbound MD.
if (m_str_md == NULL) {
SYM * s = addToSymbolTab("DedicatedVarBeRegardedAsString");
VAR * sv = get_var_mgr()->registerStringVar("DedicatedStringVar", s, 1);
VAR_allocable(sv) = false;
VAR_is_addr_taken(sv) = true;
MD md;
MD_base(&md) = sv;
MD_ty(&md) = MD_UNBOUND;
ASSERT0(MD_base(&md)->is_string());
MD const* e = m_md_sys->registerMD(md);
ASSERT0(MD_id(e) > 0);
m_str_md = e;
}
return m_str_md;
}