//Check and replace 'exp' with 'cand_expr' if they are
//equal, and update SSA info. If 'cand_expr' is NOT leaf,
//that will create redundant computation, and
//depends on later Redundancy Elimination to reverse back.
//
//'cand_expr': substitute cand_expr for exp.
// e.g: exp is pr1 of S2, cand_expr is 10.
// pr1 = 10 //S1
// g = pr1 //S2
// =>
// pr1 = 10
// g = 10
//
//NOTE: Do NOT handle stmt.
void IR_CP::replaceExpViaSSADu(IR * exp, IR const* cand_expr,
IN OUT CPCtx & ctx)
{
ASSERT0(exp && exp->is_exp() && cand_expr && cand_expr->is_exp());
ASSERT0(exp->get_exact_ref());
if (!checkTypeConsistency(exp, cand_expr)) {
return;
}
IR * parent = IR_parent(exp);
if (parent->is_ild()) {
CPC_need_recomp_aa(ctx) = true;
} else if (parent->is_ist() && exp == IST_base(parent)) {
if (!cand_expr->is_ld() &&
!cand_expr->is_pr() &&
!cand_expr->is_lda()) {
return;
}
CPC_need_recomp_aa(ctx) = true;
}
IR * newir = m_ru->dupIRTree(cand_expr);
if (cand_expr->is_read_pr() && PR_ssainfo(cand_expr) != NULL) {
PR_ssainfo(newir) = PR_ssainfo(cand_expr);
SSA_uses(PR_ssainfo(newir)).append(newir);
} else {
m_du->copyIRTreeDU(newir, cand_expr, true);
}
//cand_expr may be IR tree. And there might be PR or LD on the tree.
newir->copyRefForTree(cand_expr, m_ru);
//Add SSA use for new exp.
SSAInfo * cand_ssainfo = NULL;
if ((cand_ssainfo = cand_expr->get_ssainfo()) != NULL) {
SSA_uses(cand_ssainfo).append(newir);
}
//Remove old exp SSA use.
SSAInfo * exp_ssainfo = exp->get_ssainfo();
ASSERT0(exp_ssainfo);
ASSERT0(SSA_uses(exp_ssainfo).find(exp));
SSA_uses(exp_ssainfo).remove(exp);
CPC_change(ctx) = true;
ASSERT0(exp->get_stmt());
bool doit = parent->replaceKid(exp, newir, false);
ASSERT0(doit);
UNUSED(doit);
m_ru->freeIRTree(exp);
}
//Check and replace 'ir' with 'cand_expr' if they are
//equal, and update DU info. If 'cand_expr' is NOT leaf,
//that will create redundant computation, and
//depends on later Redundancy Elimination to reverse back.
//exp: expression which will be replaced.
//
//cand_expr: substitute cand_expr for exp.
// e.g: cand_expr is *p, cand_expr_md is MD3
// *p(MD3) = 10 //p point to MD3
// ...
// g = *q(MD3) //q point to MD3
//
//exp_use_ssadu: true if exp used SSA du info.
//
//NOTE: Do NOT handle stmt.
void IR_CP::replaceExp(IR * exp, IR const* cand_expr,
IN OUT CPCtx & ctx, bool exp_use_ssadu)
{
ASSERT0(exp && exp->is_exp() && cand_expr);
ASSERT0(exp->get_exact_ref());
if (!checkTypeConsistency(exp, cand_expr)) {
return;
}
IR * parent = IR_parent(exp);
if (parent->is_ild()) {
CPC_need_recomp_aa(ctx) = true;
} else if (parent->is_ist() && exp == IST_base(parent)) {
if (!cand_expr->is_ld() && !cand_expr->is_pr() && !cand_expr->is_lda()) {
return;
}
CPC_need_recomp_aa(ctx) = true;
}
IR * newir = m_ru->dupIRTree(cand_expr);
m_du->copyIRTreeDU(newir, cand_expr, true);
ASSERT0(cand_expr->get_stmt());
if (exp_use_ssadu) {
//Remove exp SSA use.
ASSERT0(exp->get_ssainfo());
ASSERT0(exp->get_ssainfo()->get_uses().find(exp));
exp->removeSSAUse();
} else {
m_du->removeUseOutFromDefset(exp);
}
CPC_change(ctx) = true;
ASSERT0(exp->get_stmt());
bool doit = parent->replaceKid(exp, newir, false);
ASSERT0(doit);
UNUSED(doit);
m_ru->freeIRTree(exp);
}