https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68360
Thomas Koenig <tkoenig at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Last reconfirmed|2015-11-16 00:00:00 |2023-7-16
CC| |tkoenig at gcc dot gnu.org
--- Comment #7 from Thomas Koenig <tkoenig at gcc dot gnu.org> ---
Just stumbled across this.
A maybe simpler testcase:
typedef struct
{
unsigned long x: 42;
unsigned b: 1;
unsigned long y: 42;
} myfield;
typedef struct
{
unsigned long x: 7;
unsigned b: 1;
unsigned long y: 42;
} yourfield;
void foo(myfield *x)
{
x->b = 1;
}
void bar (yourfield *x)
{
x->b = 1;
}
gets, on RISC-V,
foo:
ld a5,0(a0)
li a4,1
slli a4,a4,42
or a5,a5,a4
sd a5,0(a0)
ret
bar:
ld a5,0(a0)
ori a5,a5,128
sd a5,0(a0)
ret
Using an indexed load byte/store byte would be an advantage for foo, at least.
