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* [Bug target/107403] New: uint64_t bitfield operation is mishandled
@ 2022-10-25 23:55 hjl.tools at gmail dot com
2022-10-26 0:00 ` [Bug target/107403] " pinskia at gcc dot gnu.org
` (3 more replies)
0 siblings, 4 replies; 5+ messages in thread
From: hjl.tools at gmail dot com @ 2022-10-25 23:55 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107403
Bug ID: 107403
Summary: uint64_t bitfield operation is mishandled
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: hjl.tools at gmail dot com
Target Milestone: ---
Target: x84
[hjl@gnu-cfl-1 tmp]$ cat foo.c
#include <stdint.h>
#include <stdio.h>
#define VAL (1ULL << 48)
struct foo
{
uint64_t x : 8;
uint64_t y : 56;
};
__attribute__ ((noinline))
uint64_t
func (struct foo i)
{
return i.y << 8ULL;
}
int
main ()
{
struct foo i;
i.x = 0;
i.y = VAL;
uint64_t x = func (i);
printf ("0x%llx\n", x);
printf ("0x%llx\n", VAL);
if (x != (VAL << 8ULL))
__builtin_abort ();
}
[hjl@gnu-cfl-1 tmp]$ gcc foo.c
[hjl@gnu-cfl-1 tmp]$ ./a.out
0x0
0x1000000000000
Aborted (core dumped)
[hjl@gnu-cfl-1 tmp]$
^ permalink raw reply [flat|nested] 5+ messages in thread* [Bug target/107403] uint64_t bitfield operation is mishandled 2022-10-25 23:55 [Bug target/107403] New: uint64_t bitfield operation is mishandled hjl.tools at gmail dot com @ 2022-10-26 0:00 ` pinskia at gcc dot gnu.org 2022-10-26 0:00 ` pinskia at gcc dot gnu.org ` (2 subsequent siblings) 3 siblings, 0 replies; 5+ messages in thread From: pinskia at gcc dot gnu.org @ 2022-10-26 0:00 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107403 --- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> --- No this is correct. i.y << 8ULL Is all done in 56bit type as the type is greater than the size of int. Note c allows this behavior while c++ does not. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug target/107403] uint64_t bitfield operation is mishandled 2022-10-25 23:55 [Bug target/107403] New: uint64_t bitfield operation is mishandled hjl.tools at gmail dot com 2022-10-26 0:00 ` [Bug target/107403] " pinskia at gcc dot gnu.org @ 2022-10-26 0:00 ` pinskia at gcc dot gnu.org 2022-10-26 0:05 ` pinskia at gcc dot gnu.org 2022-10-26 0:06 ` pinskia at gcc dot gnu.org 3 siblings, 0 replies; 5+ messages in thread From: pinskia at gcc dot gnu.org @ 2022-10-26 0:00 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107403 --- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Note gcc and clang have different implementation defined behavior here too. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug target/107403] uint64_t bitfield operation is mishandled 2022-10-25 23:55 [Bug target/107403] New: uint64_t bitfield operation is mishandled hjl.tools at gmail dot com 2022-10-26 0:00 ` [Bug target/107403] " pinskia at gcc dot gnu.org 2022-10-26 0:00 ` pinskia at gcc dot gnu.org @ 2022-10-26 0:05 ` pinskia at gcc dot gnu.org 2022-10-26 0:06 ` pinskia at gcc dot gnu.org 3 siblings, 0 replies; 5+ messages in thread From: pinskia at gcc dot gnu.org @ 2022-10-26 0:05 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107403 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- See Also| |https://gcc.gnu.org/bugzill | |a/show_bug.cgi?id=92684 Status|UNCONFIRMED |RESOLVED Resolution|--- |DUPLICATE --- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Dup of bug 94631. *** This bug has been marked as a duplicate of bug 94631 *** ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug target/107403] uint64_t bitfield operation is mishandled 2022-10-25 23:55 [Bug target/107403] New: uint64_t bitfield operation is mishandled hjl.tools at gmail dot com ` (2 preceding siblings ...) 2022-10-26 0:05 ` pinskia at gcc dot gnu.org @ 2022-10-26 0:06 ` pinskia at gcc dot gnu.org 3 siblings, 0 replies; 5+ messages in thread From: pinskia at gcc dot gnu.org @ 2022-10-26 0:06 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107403 --- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> --- See https://gcc.gnu.org/legacy-ml/gcc/2017-10/msg00192.html ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2022-10-26 0:06 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2022-10-25 23:55 [Bug target/107403] New: uint64_t bitfield operation is mishandled hjl.tools at gmail dot com 2022-10-26 0:00 ` [Bug target/107403] " pinskia at gcc dot gnu.org 2022-10-26 0:00 ` pinskia at gcc dot gnu.org 2022-10-26 0:05 ` pinskia at gcc dot gnu.org 2022-10-26 0:06 ` pinskia at gcc dot gnu.org
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