https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77599
Jeffrey A. Law <law at redhat dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
CC| |law at redhat dot com
Resolution|--- |INVALID
--- Comment #2 from Jeffrey A. Law <law at redhat dot com> ---
The problem here is you're using -mshort on *-linux-gnu which IMHO is invalid.
Linux defines int32_t as a "int". And -mshort changes the width of an int to
16 bits, at which point anything prototyped using int32_t has just changed its
ABI in a meaningful way (similarly for uint32_t, but unsigned). You can see
this in the .optimized dump file:
x (long unsigned int y)
{
unsigned int _1;
unsigned int _2;
long unsigned int _4;
;; basic block 2, loop depth 0, count 0, freq 10000, maybe hot
;; prev block 0, next block 1, flags: (NEW, REACHABLE, VISITED)
;; pred: ENTRY [100.0%] (FALLTHRU,EXECUTABLE)
_1 = (unsigned int) y_3(D);
_2 = __builtin_bswap32 (_1);
_4 = (long unsigned int) _2;
return _4;
}
Note the type of the _1 and _2. They are both unsigned ints, so 16 bits.
If you try this test on a bare metal target such as m68k-elf or without the
-mshort, you'll get the expected and desired result.
