'bitfield' : member is bit field
Inline assembly code tries to access a bit-field member. Inline assembly cannot access bit-field members, so the last packing boundary before the bit-field member is used.
To avoid this warning, cast the bit field to an appropriate type before making the reference in inline assembly code. The following sample generates C4401:
typedef struct bitfield { signed bit : 1; } mybitfield; void main() { mybitfield bf; bf.bit = 0; __asm { mov bf.bit,0; // C4401 } /* use the following __asm block to resolve the warning int i = (int)bf.bit; __asm { mov i,0; } */ }