public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
* [Bug tree-optimization/107372] New: Loop distribution create memcpy between structs with different storage order
@ 2022-10-24 7:48 krebbel at gcc dot gnu.org
2022-10-24 7:49 ` [Bug tree-optimization/107372] " krebbel at gcc dot gnu.org
` (3 more replies)
0 siblings, 4 replies; 5+ messages in thread
From: krebbel at gcc dot gnu.org @ 2022-10-24 7:48 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107372
Bug ID: 107372
Summary: Loop distribution create memcpy between structs with
different storage order
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: krebbel at gcc dot gnu.org
Target Milestone: ---
For t.c with "gcc -O3 t.c":
struct L
{
unsigned int val[256];
} __attribute__((scalar_storage_order ("little-endian")));
struct B
{
unsigned int val[256];
} __attribute__((scalar_storage_order ("big-endian")));
void
foo (struct L *restrict l, struct B *restrict b)
{
int i;
for (i = 0; i < 256; i++)
l->val[i] = b->val[i];
}
The loop distribution pass currently generates a memcpy although it recognizes
correctly that both sides of the assignment have different storage order:
Analyzing # of iterations of loop 1
exit condition [255, + , 4294967295] != 0
bounds on difference of bases: -255 ... -255
result:
# of iterations 255, bounded by 255
Creating dr for *b_5(D).val[i_11]
analyze_innermost: t.c:16:23: missed: failed: reverse storage order.
...
void foo (struct L * restrict l, struct B * restrict b)
{
int i;
<bb 2> [local count: 10737416]:
__builtin_memcpy (l_6(D), b_5(D), 1024);
return;
}
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug tree-optimization/107372] Loop distribution create memcpy between structs with different storage order
2022-10-24 7:48 [Bug tree-optimization/107372] New: Loop distribution create memcpy between structs with different storage order krebbel at gcc dot gnu.org
@ 2022-10-24 7:49 ` krebbel at gcc dot gnu.org
2022-10-24 13:23 ` [Bug tree-optimization/107372] Loop distribution creates " rguenth at gcc dot gnu.org
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: krebbel at gcc dot gnu.org @ 2022-10-24 7:49 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107372
--- Comment #1 from Andreas Krebbel <krebbel at gcc dot gnu.org> ---
Created attachment 53764
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=53764&action=edit
Experimental Fix
Looks like the error while analyzing the data ref is not propagated to the
upper layers to actually prevent the optimization. This patch fixes this for
me.
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug tree-optimization/107372] Loop distribution creates memcpy between structs with different storage order
2022-10-24 7:48 [Bug tree-optimization/107372] New: Loop distribution create memcpy between structs with different storage order krebbel at gcc dot gnu.org
2022-10-24 7:49 ` [Bug tree-optimization/107372] " krebbel at gcc dot gnu.org
@ 2022-10-24 13:23 ` rguenth at gcc dot gnu.org
2024-03-10 0:44 ` pinskia at gcc dot gnu.org
2024-03-10 0:45 ` pinskia at gcc dot gnu.org
3 siblings, 0 replies; 5+ messages in thread
From: rguenth at gcc dot gnu.org @ 2022-10-24 13:23 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107372
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Andreas Krebbel from comment #1)
> Created attachment 53764 [details]
> Experimental Fix
>
> Looks like the error while analyzing the data ref is not propagated to the
> upper layers to actually prevent the optimization. This patch fixes this for
> me.
But that's on purpose I think. create_data_ref does never "fail", the caller
has to check for proper analysis of the DR though. For loop distribution
we should FAIL looking at DR_STEP? Ah, for example compute_access_range
performs its own analysis so it needs to check for the storage order itself
I think or the callers need to match up storage order of source and
destination.
Your patch leaks memory.
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug tree-optimization/107372] Loop distribution creates memcpy between structs with different storage order
2022-10-24 7:48 [Bug tree-optimization/107372] New: Loop distribution create memcpy between structs with different storage order krebbel at gcc dot gnu.org
2022-10-24 7:49 ` [Bug tree-optimization/107372] " krebbel at gcc dot gnu.org
2022-10-24 13:23 ` [Bug tree-optimization/107372] Loop distribution creates " rguenth at gcc dot gnu.org
@ 2024-03-10 0:44 ` pinskia at gcc dot gnu.org
2024-03-10 0:45 ` pinskia at gcc dot gnu.org
3 siblings, 0 replies; 5+ messages in thread
From: pinskia at gcc dot gnu.org @ 2024-03-10 0:44 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107372
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Resolution|--- |FIXED
Status|UNCONFIRMED |RESOLVED
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Fixed correctly by r13-4244-g55cb8c5c9abfe8 .
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug tree-optimization/107372] Loop distribution creates memcpy between structs with different storage order
2022-10-24 7:48 [Bug tree-optimization/107372] New: Loop distribution create memcpy between structs with different storage order krebbel at gcc dot gnu.org
` (2 preceding siblings ...)
2024-03-10 0:44 ` pinskia at gcc dot gnu.org
@ 2024-03-10 0:45 ` pinskia at gcc dot gnu.org
3 siblings, 0 replies; 5+ messages in thread
From: pinskia at gcc dot gnu.org @ 2024-03-10 0:45 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107372
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|--- |11.4
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2024-03-10 0:45 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-10-24 7:48 [Bug tree-optimization/107372] New: Loop distribution create memcpy between structs with different storage order krebbel at gcc dot gnu.org
2022-10-24 7:49 ` [Bug tree-optimization/107372] " krebbel at gcc dot gnu.org
2022-10-24 13:23 ` [Bug tree-optimization/107372] Loop distribution creates " rguenth at gcc dot gnu.org
2024-03-10 0:44 ` pinskia at gcc dot gnu.org
2024-03-10 0:45 ` pinskia at gcc dot gnu.org
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).