On Tue, 23 Nov 2021 09:36:22 +0100 Geert Uytterhoeven wrote:
Also, you're using __ffs(), which doesn't work for 64-bit on 32-bit architectures (afaict), so that seems a bit awkward.
Maybe we can make {u32,...}_get_bits() be doing compile-time only checks if it is indeed a constant? The __field_overflow() usage is already only done if __builtin_constant_p(v), so I guess we can do the same with __bad_mask()?
Either that or add decomposition macros. Are compilers still really bad at passing small structs by value?
Sorry, I don't get what you mean by adding decomposition macros. Can you please elaborate?
#define DECOMPOSE(_mask) \ (struct bf){ .mask = _mask, .shf = __bf_shf(_mask), }
Then drivers can save or pass around the mask and shift params broken apart as a small struct.