//Check that all basic blocks should only end with terminator IR.
void IRBB::verify()
{
UINT c = 0;
C<IR*> * ct;
for (IR * ir = BB_irlist(this).get_head(&ct);
ir != NULL; ir = BB_irlist(this).get_next(&ct)) {
ASSERT0(ir->is_single());
ASSERT0(ir->get_bb() == this);
switch (IR_code(ir)) {
case IR_ST:
case IR_STPR:
case IR_STARRAY:
case IR_IST:
case IR_PHI:
case IR_REGION:
case IR_CALL:
case IR_ICALL:
case IR_GOTO:
case IR_IGOTO:
case IR_TRUEBR:
case IR_FALSEBR:
case IR_RETURN:
case IR_SWITCH:
break;
default: ASSERT(0, ("BB does not supported this kind of IR."));
}
if (is_bb_down_boundary(ir)) {
ASSERT(ir == BB_last_ir(this), ("invalid BB down boundary."));
}
c++;
}
ASSERT0(c == getNumOfIR());
}
//Return true if 'occ' does not be modified till meeting 'use_ir'.
//e.g:
// xx = occ //def_ir
// ..
// ..
// yy = xx //use_ir
//
//'def_ir': ir stmt.
//'occ': opnd of 'def_ir'
//'use_ir': stmt in use-list of 'def_ir'.
bool IR_CP::is_available(IR const* def_ir, IR const* occ, IR * use_ir)
{
if (def_ir == use_ir) { return false; }
if (occ->is_const()) { return true; }
//Need check overlapped MDSet.
//e.g: Suppose occ is '*p + *q', p->a, q->b.
//occ can NOT reach 'def_ir' if one of p, q, a, b
//modified during the path.
IRBB * defbb = def_ir->get_bb();
IRBB * usebb = use_ir->get_bb();
if (defbb == usebb) {
//Both def_ir and use_ir are in same BB.
C<IR*> * ir_holder = NULL;
bool f = BB_irlist(defbb).find(const_cast<IR*>(def_ir), &ir_holder);
CK_USE(f);
IR * ir;
for (ir = BB_irlist(defbb).get_next(&ir_holder);
ir != NULL && ir != use_ir;
ir = BB_irlist(defbb).get_next(&ir_holder)) {
if (m_du->is_may_def(ir, occ, true)) {
return false;
}
}
if (ir == NULL) {
;//use_ir appears prior to def_ir. Do more check via live_in_expr.
} else {
ASSERT(ir == use_ir, ("def_ir should be in same bb to use_ir"));
return true;
}
}
ASSERT0(use_ir->is_stmt());
DefDBitSetCore const* availin_expr =
m_du->getAvailInExpr(BB_id(usebb), NULL);
ASSERT0(availin_expr);
if (availin_expr->is_contain(IR_id(occ))) {
IR * u;
for (u = BB_first_ir(usebb); u != use_ir && u != NULL;
u = BB_next_ir(usebb)) {
//Check if 'u' override occ's value.
if (m_du->is_may_def(u, occ, true)) {
return false;
}
}
ASSERT(u != NULL && u == use_ir,
("Not find use_ir in bb, may be it has "
"been removed by other optimization"));
return true;
}
return false;
}
void IRBB::dump(Region * ru)
{
if (g_tfile == NULL) { return; }
g_indent = 0;
fprintf(g_tfile, "\n----- BB%d ------", BB_id(this));
if (get_lab_list().get_elem_count() > 0) {
fprintf(g_tfile, "\nLABEL:");
dumpBBLabel(get_lab_list(), g_tfile);
}
//Attributes
fprintf(g_tfile, "\nATTR:");
if (BB_is_entry(this)) {
fprintf(g_tfile, "entry_bb ");
}
//if (BB_is_exit(this)) {
// fprintf(g_tfile, "exit_bb ");
//}
if (BB_is_fallthrough(this)) {
fprintf(g_tfile, "fall_through ");
}
if (BB_is_target(this)) {
fprintf(g_tfile, "branch_target ");
}
//IR list
fprintf(g_tfile, "\nSTMT NUM:%d", getNumOfIR());
g_indent += 3;
TypeMgr * dm = ru->get_type_mgr();
for (IR * ir = BB_first_ir(this);
ir != NULL; ir = BB_irlist(this).get_next()) {
ASSERT0(IR_next(ir) == NULL && IR_prev(ir) == NULL);
ASSERT0(ir->get_bb() == this);
dump_ir(ir, dm, NULL, true, true, false);
}
g_indent -= 3;
fprintf(g_tfile, "\n");
fflush(g_tfile);
}
/* Encode expression for single BB.
Scan IR statement literally, and encoding it for generating
the unique id for each individual expressions, and update
the 'GEN-SET' and 'KILL-SET' of IR-EXPR for BB as well as. */
void IR_EXPR_TAB::encode_bb(IRBB * bb)
{
C<IR*> * ct;
for (IR * ir = BB_irlist(bb).get_head(&ct);
ir != NULL; ir = BB_irlist(bb).get_next(&ct)) {
ASSERT0(ir->is_stmt());
switch (IR_code(ir)) {
case IR_ST:
{
ExpRep * ie = encode_expr(ST_rhs(ir));
if (ie != NULL) {
set_map_ir2ir_expr(ST_rhs(ir), ie);
}
}
break;
case IR_STPR:
{
ExpRep * ie = encode_expr(STPR_rhs(ir));
if (ie != NULL) {
set_map_ir2ir_expr(STPR_rhs(ir), ie);
}
}
break;
case IR_STARRAY:
{
ExpRep * ie = encode_expr(ARR_base(ir));
if (ie != NULL) {
set_map_ir2ir_expr(ARR_base(ir), ie);
}
for (IR * sub = ARR_sub_list(ir); sub != NULL; sub = IR_next(sub)) {
ExpRep * ie = encode_expr(sub);
if (ie != NULL) {
set_map_ir2ir_expr(sub, ie);
}
}
ie = encode_expr(STARR_rhs(ir));
if (ie != NULL) {
set_map_ir2ir_expr(STARR_rhs(ir), ie);
}
}
break;
case IR_IST:
{
ExpRep * ie = encode_expr(IST_rhs(ir));
if (ie != NULL) {
set_map_ir2ir_expr(IST_rhs(ir), ie);
}
ie = encode_istore_memaddr(IST_base(ir));
if (ie != NULL) {
set_map_ir2ir_expr(IST_base(ir), ie);
}
}
break;
case IR_ICALL: //indirective call
{
ExpRep * ie = encode_expr(ICALL_callee(ir));
if (ie != NULL) {
set_map_ir2ir_expr(ICALL_callee(ir), ie);
}
}
case IR_CALL:
{
IR * parm = CALL_param_list(ir);
while (parm != NULL) {
ExpRep * ie = encode_expr(parm);
if (ie != NULL) {
set_map_ir2ir_expr(parm, ie);
}
parm = IR_next(parm);
}
}
break;
case IR_GOTO:
break;
case IR_IGOTO:
{
ExpRep * ie = encode_expr(IGOTO_vexp(ir));
if (ie != NULL) {
set_map_ir2ir_expr(IGOTO_vexp(ir), ie);
}
}
break;
case IR_DO_WHILE:
case IR_WHILE_DO:
case IR_DO_LOOP: //loop with init , boundary , and step info
case IR_IF:
ASSERT(0, ("High level IR should be simplified"));
break;
case IR_LABEL:
break;
case IR_CASE:
case IR_REGION:
break;
case IR_TRUEBR:
case IR_FALSEBR:
{
ExpRep * ie = encode_expr(BR_det(ir));
if (ie != NULL) {
set_map_ir2ir_expr(BR_det(ir), ie);
}
}
break;
case IR_SWITCH:
{
ExpRep * ie = encode_expr(SWITCH_vexp(ir));
if (ie != NULL) {
set_map_ir2ir_expr(SWITCH_vexp(ir), ie);
}
}
break;
case IR_RETURN:
{
ExpRep * ie = encode_expr(RET_exp(ir));
if (ie != NULL) {
set_map_ir2ir_expr(RET_exp(ir), ie);
}
}
break;
case IR_PHI:
break;
default: ASSERT0(0);
} //end switch
} //end for IR
//dump_ir_expr_tab();
}
//'usevec': for local used.
bool IR_CP::doProp(IN IRBB * bb, Vector<IR*> & usevec)
{
bool change = false;
C<IR*> * cur_iter, * next_iter;
for (BB_irlist(bb).get_head(&cur_iter),
next_iter = cur_iter; cur_iter != NULL; cur_iter = next_iter) {
IR * def_stmt = cur_iter->val();
BB_irlist(bb).get_next(&next_iter);
if (!is_copy(def_stmt)) { continue; }
DUSet const* useset = NULL;
UINT num_of_use = 0;
SSAInfo * ssainfo = NULL;
bool ssadu = false;
if ((ssainfo = def_stmt->get_ssainfo()) != NULL &&
SSA_uses(ssainfo).get_elem_count() != 0) {
//Record use_stmt in another vector to facilitate this function
//if it is not in use-list any more after copy-propagation.
SEGIter * sc;
for (INT u = SSA_uses(ssainfo).get_first(&sc);
u >= 0; u = SSA_uses(ssainfo).get_next(u, &sc)) {
IR * use = m_ru->get_ir(u);
ASSERT0(use);
usevec.set(num_of_use, use);
num_of_use++;
}
ssadu = true;
} else if (def_stmt->get_exact_ref() == NULL &&
!def_stmt->is_void()) {
//Allowing copy propagate exact or VOID value.
continue;
} else if ((useset = def_stmt->readDUSet()) != NULL &&
useset->get_elem_count() != 0) {
//Record use_stmt in another vector to facilitate this function
//if it is not in use-list any more after copy-propagation.
DUIter di = NULL;
for (INT u = useset->get_first(&di);
u >= 0; u = useset->get_next(u, &di)) {
IR * use = m_ru->get_ir(u);
usevec.set(num_of_use, use);
num_of_use++;
}
} else {
continue;
}
IR const* prop_value = get_propagated_value(def_stmt);
for (UINT i = 0; i < num_of_use; i++) {
IR * use = usevec.get(i);
ASSERT0(use->is_exp());
IR * use_stmt = use->get_stmt();
ASSERT0(use_stmt->is_stmt());
ASSERT0(use_stmt->get_bb() != NULL);
IRBB * use_bb = use_stmt->get_bb();
if (!ssadu &&
!(bb == use_bb && bb->is_dom(def_stmt, use_stmt, true)) &&
!m_cfg->is_dom(BB_id(bb), BB_id(use_bb))) {
//'def_stmt' must dominate 'use_stmt'.
//e.g:
// if (...) {
// g = 10; //S1
// }
// ... = g; //S2
//g can not be propagted since S1 is not dominate S2.
continue;
}
if (!is_available(def_stmt, prop_value, use_stmt)) {
//The value that will be propagated can
//not be killed during 'ir' and 'use_stmt'.
//e.g:
// g = a; //S1
// if (...) {
// a = ...; //S3
// }
// ... = g; //S2
//g can not be propagted since a is killed by S3.
continue;
}
if (!ssadu && !m_du->isExactAndUniqueDef(def_stmt, use)) {
//Only single definition is allowed.
//e.g:
// g = 20; //S3
// if (...) {
// g = 10; //S1
// }
// ... = g; //S2
//g can not be propagted since there are
//more than one definitions are able to get to S2.
continue;
}
if (!canBeCandidate(prop_value)) {
continue;
}
CPCtx lchange;
IR * old_use_stmt = use_stmt;
replaceExp(use, prop_value, lchange, ssadu);
ASSERT(use_stmt && use_stmt->is_stmt(),
("ensure use_stmt still legal"));
change |= CPC_change(lchange);
if (!CPC_change(lchange)) { continue; }
//Indicate whether use_stmt is the next stmt of def_stmt.
bool is_next = false;
if (next_iter != NULL && use_stmt == next_iter->val()) {
is_next = true;
}
RefineCtx rf;
use_stmt = m_ru->refineIR(use_stmt, change, rf);
if (use_stmt == NULL && is_next) {
//use_stmt has been optimized and removed by refineIR().
next_iter = cur_iter;
BB_irlist(bb).get_next(&next_iter);
}
if (use_stmt != NULL && use_stmt != old_use_stmt) {
//use_stmt has been removed and new stmt generated.
ASSERT(old_use_stmt->is_undef(), ("the old one should be freed"));
C<IR*> * irct = NULL;
BB_irlist(use_bb).find(old_use_stmt, &irct);
ASSERT0(irct);
BB_irlist(use_bb).insert_before(use_stmt, irct);
BB_irlist(use_bb).remove(irct);
}
} //end for each USE
} //end for IR
return change;
}
