inline bool MacroAssembler::is_load_const_at(address a) {
const int* p_inst = (int *) a;
bool b = is_lis(*p_inst++);
if (is_ori(*p_inst)) {
p_inst++;
b = b && is_rldicr(*p_inst++); // TODO: could be made more precise: `sldi'!
b = b && is_oris(*p_inst++);
b = b && is_ori(*p_inst);
} else if (is_lis(*p_inst)) {
p_inst++;
b = b && is_ori(*p_inst++);
b = b && is_ori(*p_inst);
// TODO: could enhance reliability by adding is_insrdi
} else return false;
return b;
}
bool is_immediate_pair(inst_t* instp) {
// find out if instp points to lis followed by ori/addi/load/store
inst_t i1 = instp[0];
if (!is_lis(i1)) return false;
fint reg = RT(i1);
inst_t i2 = instp[1];
return
is_ori(i2) && RA(i2) == reg && RS(i2) == reg
|| is_addi(i2) && RT(i2) == reg && RS(i2) == reg
|| is_load_store_immediate(i2) && RA(i2) == reg;
}
// Detect narrow oop constants.
inline bool MacroAssembler::is_set_narrow_oop(address a, address bound) {
const address inst2_addr = a;
const int inst2 = *(int *)a;
// The relocation points to the second instruction, the ori.
if (!is_ori(inst2)) return false;
// The ori reads and writes the same register dst.
const int dst = inv_rta_field(inst2);
if (inv_rs_field(inst2) != dst) return false;
// Now, find the preceding addis which writes to dst.
int inst1 = 0;
address inst1_addr = inst2_addr - BytesPerInstWord;
while (inst1_addr >= bound) {
inst1 = *(int *) inst1_addr;
if (is_lis(inst1) && inv_rs_field(inst1) == dst) return true;
inst1_addr -= BytesPerInstWord;
}
return false;
}
