static inline int l1_unscale(int n, int mant, int scale_factor) { int shift, mod; int64_t val; shift = scale_factor_modshift[scale_factor]; mod = shift & 3; shift >>= 2; val = MUL64(mant + (-1 << n) + 1, scale_factor_mult[n-1][mod]); shift += n; /* NOTE: at this point, 1 <= shift >= 21 + 15 */ return (int)((val + (1LL << (shift - 1))) >> shift); }