_R_AST
memcpy(&gr[_REG_AT], &tf->tf_regs[_R_AST], sizeof(mips_reg_t) * 31);
CTASSERT(_R_AST == _REG_AT);
for (size_t i = _R_AST; i < 32; i++) {
memcpy(&tf->tf_regs[_R_AST], &gr[_REG_AT],
{ "at", (long *)&ddb_regs.r_regs[_R_AST], DB_SETF_REGS, NULL },
gdb_regs[ 1] = regs->r_regs[_R_AST]; /* AT */
tf->tf_regs[_R_AST], tf->tf_regs[_R_V0], tf->tf_regs[_R_V1]);