Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: John.Adriaan at BigPond dot com
Target Milestone: ---
For the following, please assume:
A. `sizeof(bool)` equals `1`;
B. `sizeof(unsigned)` equals `4`;
C. `-fstrict-volatile-bitfields` is ON;
D. The compiler target
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93209
--- Comment #1 from John Adriaan ---
I've also looked at the `unsigned : 0;` anonymous field. Frankly, it changes
nothing. Maybe it should?
struct S {
bool b : 1;
unsigned i : 1;
unsigned : 0;
}; // S
With
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93209
--- Comment #2 from John Adriaan ---
Wow: I just realised. The following code for my proposal is problematic:
struct S {
bool b : 1;
unsigned i : 1;
unsigned : 0;
char c : 8;
}; // S
Should `c`
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93209
--- Comment #4 from John Adriaan ---
@RichardBiener,
I used the different types to prove my point: if they're all `unsigned`, it
still happens.
And the ABI merely defines whether `-fstrict-volatile-bitfields` is the default
or not (for ARM, it
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93209
--- Comment #5 from John Adriaan ---
@RichardBiener,
By "it still happens", I meant that accesses to `s.i` still occur as described.
Changing `s.b` to be of type `unsigned` changes its accesses to match those of
`s.i` - in other words, the type
