PERF_REG_MIPS_R1
case PERF_REG_MIPS_R1 ... PERF_REG_MIPS_R25:
v = regs->regs[idx - PERF_REG_MIPS_R1 + 1];
return regnum - UNW_MIPS_R1 + PERF_REG_MIPS_R1;
case PERF_REG_MIPS_R1: