perf_reg_value
u64 perf_reg_value(struct pt_regs *regs, int idx);
val = perf_reg_value(regs, bit);
int perf_reg_value(u64 *valp, struct regs_dump *regs, int id);
ret = perf_reg_value(&start, ui->sample->user_regs,
if (perf_reg_value(&val, user_regs, perf_reg) == 0)
if (perf_reg_value(&val, user_regs, ip_perf_reg) == 0)
err = perf_reg_value(&ip, data->user_regs, perf_arch_reg_ip(e_machine));
ret = perf_reg_value(&start, perf_sample__user_regs(ui->sample),
ret = perf_reg_value(&val, perf_sample__user_regs(ui->sample), id);
ret = perf_reg_value(&val, perf_sample__user_regs(ui->sample),