fs/bcachefs/bkey.c

792 	unsigned i, byte, bit_offset, align, shl, shr;
839 	bit_offset = format->key_u64s * 64;
841 		bit_offset -= format->bits_per_field[i];
843 	byte = bit_offset / 8;
844 	bit_offset -= byte * 8;
848 	if (bit_offset == 0 && bits == 8) {
851 	} else if (bit_offset == 0 && bits == 16) {
854 	} else if (bit_offset + bits <= 32) {
855 		align = min(4 - DIV_ROUND_UP(bit_offset + bits, 8), byte & 3);
857 		bit_offset += align * 8;
859 		BUG_ON(bit_offset + bits > 32);
864 		if (bit_offset) {
866 			I3(0xc1, 0xe8, bit_offset);
869 		if (bit_offset + bits < 32) {
877 	} else if (bit_offset + bits <= 64) {
878 		align = min(8 - DIV_ROUND_UP(bit_offset + bits, 8), byte & 7);
880 		bit_offset += align * 8;
882 		BUG_ON(bit_offset + bits > 64);
887 		shl = 64 - bit_offset - bits;
888 		shr = bit_offset + shl;
900 		align = min(4 - DIV_ROUND_UP(bit_offset + bits, 8), byte & 3);
902 		bit_offset += align * 8;
904 		BUG_ON(bit_offset + bits > 96);
913 		shr = bit_offset + bits - 64;
914 		BUG_ON(shr > bit_offset);
916 		/* shr rax, bit_offset */
925 		shr = bit_offset - shr;