ProjNode* mod_proj() { return proj_out(mod_proj_num); }
//------------------------------is_range_check---------------------------------
// Return 0 if not a range check. Return 1 if a range check and set index and
// offset. Return 2 if we had to negate the test. Index is NULL if the check
// is versus a constant.
int IfNode::is_range_check(Node* &range, Node* &index, jint &offset) {
Node* b = in(1);
if (b == NULL || !b->is_Bool()) return 0;
BoolNode* bn = b->as_Bool();
Node* cmp = bn->in(1);
if (cmp == NULL) return 0;
if (cmp->Opcode() != Op_CmpU) return 0;
Node* l = cmp->in(1);
Node* r = cmp->in(2);
int flip_test = 1;
if (bn->_test._test == BoolTest::le) {
l = cmp->in(2);
r = cmp->in(1);
flip_test = 2;
} else if (bn->_test._test != BoolTest::lt) {
return 0;
}
if (l->is_top()) return 0; // Top input means dead test
if (r->Opcode() != Op_LoadRange) return 0;
// We have recognized one of these forms:
// Flip 1: If (Bool[<] CmpU(l, LoadRange)) ...
// Flip 2: If (Bool[<=] CmpU(LoadRange, l)) ...
// Make sure it's a real range check by requiring an uncommon trap
// along the OOB path. Otherwise, it's possible that the user wrote
// something which optimized to look like a range check but behaves
// in some other way.
Node* iftrap = proj_out(flip_test == 2 ? true : false);
bool found_trap = false;
if (iftrap != NULL) {
Node* u = iftrap->unique_ctrl_out();
if (u != NULL) {
// It could be a merge point (Region) for uncommon trap.
if (u->is_Region()) {
Node* c = u->unique_ctrl_out();
if (c != NULL) {
iftrap = u;
u = c;
}
}
if (u->in(0) == iftrap && u->is_CallStaticJava()) {
int req = u->as_CallStaticJava()->uncommon_trap_request();
if (Deoptimization::trap_request_reason(req) ==
Deoptimization::Reason_range_check) {
found_trap = true;
}
}
}
}
if (!found_trap) return 0; // sorry, no cigar
// Look for index+offset form
Node* ind = l;
jint off = 0;
if (l->is_top()) {
return 0;
} else if (l->is_Add()) {
if ((off = l->in(1)->find_int_con(0)) != 0) {
ind = l->in(2);
} else if ((off = l->in(2)->find_int_con(0)) != 0) {
ind = l->in(1);
}
} else if ((off = l->find_int_con(-1)) >= 0) {
// constant offset with no variable index
ind = NULL;
} else {
// variable index with no constant offset (or dead negative index)
off = 0;
}
// Return all the values:
index = ind;
offset = off;
range = r;
return flip_test;
}
ProjNode* div_proj() { return proj_out(div_proj_num); }
