BP
AX, DX, CX, BX, SI, DI, BP, SP, // 16-bit
REGINFO( BP, "%bp", EBP),
REGINFO(EBP, "%ebp", BP),
REGSTORAGE(SI), REGSTORAGE(DI), REGSTORAGE(BP), REGSTORAGE(SP),
static struct regclass regclass_16 = { "16-bit", { AX, DX, CX, BX, SI, DI, BP }};
_Static_assert(sizeof(BP) == sizeof(int), "is bad?");