idf
int32_t idf;
GET_FLOAT_WORD(idf,df);
SET_FLOAT_WORD(df,idf&0xfffff000);
testf(idf(nextafterf(FLT_MAX, INFINITY)), INFINITY, ex_over);
testf(idf(nextafterf(INFINITY, 0.0)), FLT_MAX, 0);
testf(idf(nexttowardf(FLT_MAX, FLT_MAX * 2.0)), INFINITY, ex_over);
testf(idf(nexttowardf(INFINITY, FLT_MAX * 2.0)), FLT_MAX, 0);
static float idf(float);
u8 tvco, tpcp, tpd, tlpf, idf;
ch7xxx_readb(dvo, CH7xxx_IDF, &idf);
idf |= CH7xxx_IDF_IBS;
idf &= ~(CH7xxx_IDF_HSP | CH7xxx_IDF_VSP);
idf |= CH7xxx_IDF_HSP;
idf |= CH7xxx_IDF_VSP;
ch7xxx_writeb(dvo, CH7xxx_IDF, idf);