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* [Bug c/110458] New: -Warray-bounds=2 new false positive @ 2023-06-28 15:09 sirl at gcc dot gnu.org 2023-06-28 19:21 ` [Bug tree-optimization/110458] " pinskia at gcc dot gnu.org ` (5 more replies) 0 siblings, 6 replies; 7+ messages in thread From: sirl at gcc dot gnu.org @ 2023-06-28 15:09 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110458 Bug ID: 110458 Summary: -Warray-bounds=2 new false positive Product: gcc Version: 14.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: sirl at gcc dot gnu.org Target Milestone: --- Created attachment 55412 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=55412&action=edit testcase Since somewhere between r14-1870 and r14-2097 a new -Warray-bounds=2 false positive is shown for this little testcase: typedef struct { unsigned arr1[4]; unsigned arr2[4]; } data; void f_notok(void *arrayOut) { int i; unsigned *arr2; unsigned *arr1; data *dataOut; dataOut = (data *)arrayOut; arr1 = dataOut[0].arr1; arr2 = dataOut[0].arr2; i = 0; for (; i < 4; i++) { arr1[i] = 0; arr2[i] = 0; } } When compiled with trunk@r2097 "gcc -O2 -W -Wall -Warray-bounds=2 -c bug-Warray-bounds-eq-2.c" the warning is: bug-Warray-bounds-eq-2.c: In function 'f_notok': bug-Warray-bounds-eq-2.c:16:13: warning: '__builtin_memset' offset [16, 31] from the object at 'arrayOut' is out of the bounds of referenced subobject 'arr1' with type 'unsigned int[4]' at offset 0 [-Warray-bounds=] 16 | arr1[i] = 0; | ~~~~~~~~^~~ bug-Warray-bounds-eq-2.c:2:12: note: subobject 'arr1' declared here 2 | unsigned arr1[4]; | ^~~~ gcc-13.1.1 and earlier didn't warn here. The attached full testcase also shows that slight variations in the code silence the warning. ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug tree-optimization/110458] -Warray-bounds=2 new false positive 2023-06-28 15:09 [Bug c/110458] New: -Warray-bounds=2 new false positive sirl at gcc dot gnu.org @ 2023-06-28 19:21 ` pinskia at gcc dot gnu.org 2023-06-29 10:13 ` sirl at gcc dot gnu.org ` (4 subsequent siblings) 5 siblings, 0 replies; 7+ messages in thread From: pinskia at gcc dot gnu.org @ 2023-06-28 19:21 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110458 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Component|c |tree-optimization Keywords| |diagnostic --- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> --- The problem is ldist does: arr1_8 = &MEM[(struct data *)arrayOut_7(D)].arr1; __builtin_memset (arr1_8, 0, 32); (which is kinda of correct). I think there are other bug related to this similar thing ... ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug tree-optimization/110458] -Warray-bounds=2 new false positive 2023-06-28 15:09 [Bug c/110458] New: -Warray-bounds=2 new false positive sirl at gcc dot gnu.org 2023-06-28 19:21 ` [Bug tree-optimization/110458] " pinskia at gcc dot gnu.org @ 2023-06-29 10:13 ` sirl at gcc dot gnu.org 2023-06-29 15:54 ` [Bug tree-optimization/110458] [14 Regression] " pinskia at gcc dot gnu.org ` (3 subsequent siblings) 5 siblings, 0 replies; 7+ messages in thread From: sirl at gcc dot gnu.org @ 2023-06-29 10:13 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110458 --- Comment #2 from Franz Sirl <sirl at gcc dot gnu.org> --- This has been exposed by commit r14-2013-gfb0447b1f6b7373f57cb3a3d17a46803cfd9909d "Hide IVOPTs strip_offset". ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug tree-optimization/110458] [14 Regression] -Warray-bounds=2 new false positive 2023-06-28 15:09 [Bug c/110458] New: -Warray-bounds=2 new false positive sirl at gcc dot gnu.org 2023-06-28 19:21 ` [Bug tree-optimization/110458] " pinskia at gcc dot gnu.org 2023-06-29 10:13 ` sirl at gcc dot gnu.org @ 2023-06-29 15:54 ` pinskia at gcc dot gnu.org 2023-08-09 9:21 ` sirl at gcc dot gnu.org ` (2 subsequent siblings) 5 siblings, 0 replies; 7+ messages in thread From: pinskia at gcc dot gnu.org @ 2023-06-29 15:54 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110458 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Summary|-Warray-bounds=2 new false |[14 Regression] |positive |-Warray-bounds=2 new false | |positive Target Milestone|--- |14.0 ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug tree-optimization/110458] [14 Regression] -Warray-bounds=2 new false positive 2023-06-28 15:09 [Bug c/110458] New: -Warray-bounds=2 new false positive sirl at gcc dot gnu.org ` (2 preceding siblings ...) 2023-06-29 15:54 ` [Bug tree-optimization/110458] [14 Regression] " pinskia at gcc dot gnu.org @ 2023-08-09 9:21 ` sirl at gcc dot gnu.org 2024-03-08 15:29 ` law at gcc dot gnu.org 2024-05-07 7:40 ` [Bug tree-optimization/110458] [14/15 " rguenth at gcc dot gnu.org 5 siblings, 0 replies; 7+ messages in thread From: sirl at gcc dot gnu.org @ 2023-08-09 9:21 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110458 --- Comment #3 from Franz Sirl <sirl at gcc dot gnu.org> --- Actually Comment 2 is only true for the original testcode (which was quite fragile to reproduce). The reduced testcode started to fail with the backwards jump threader rewrite in r12-2591-g2e96b5f14e4025691b57d2301d71aa6092ed44bc and a simple -Warray-bounds. This is proven by the fact that compiling the testcase with gcc@r12-2591 with an additional --param=threader-mode=legacy makes the warning go away. So this bug maybe a duplicate of the other bugs (couldn't find a metabug) related to r12-2591. ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug tree-optimization/110458] [14 Regression] -Warray-bounds=2 new false positive 2023-06-28 15:09 [Bug c/110458] New: -Warray-bounds=2 new false positive sirl at gcc dot gnu.org ` (3 preceding siblings ...) 2023-08-09 9:21 ` sirl at gcc dot gnu.org @ 2024-03-08 15:29 ` law at gcc dot gnu.org 2024-05-07 7:40 ` [Bug tree-optimization/110458] [14/15 " rguenth at gcc dot gnu.org 5 siblings, 0 replies; 7+ messages in thread From: law at gcc dot gnu.org @ 2024-03-08 15:29 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110458 Jeffrey A. Law <law at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Priority|P3 |P2 CC| |law at gcc dot gnu.org ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug tree-optimization/110458] [14/15 Regression] -Warray-bounds=2 new false positive 2023-06-28 15:09 [Bug c/110458] New: -Warray-bounds=2 new false positive sirl at gcc dot gnu.org ` (4 preceding siblings ...) 2024-03-08 15:29 ` law at gcc dot gnu.org @ 2024-05-07 7:40 ` rguenth at gcc dot gnu.org 5 siblings, 0 replies; 7+ messages in thread From: rguenth at gcc dot gnu.org @ 2024-05-07 7:40 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110458 Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Target Milestone|14.0 |14.2 --- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> --- GCC 14.1 is being released, retargeting bugs to GCC 14.2. ^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2024-05-07 7:40 UTC | newest] Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2023-06-28 15:09 [Bug c/110458] New: -Warray-bounds=2 new false positive sirl at gcc dot gnu.org 2023-06-28 19:21 ` [Bug tree-optimization/110458] " pinskia at gcc dot gnu.org 2023-06-29 10:13 ` sirl at gcc dot gnu.org 2023-06-29 15:54 ` [Bug tree-optimization/110458] [14 Regression] " pinskia at gcc dot gnu.org 2023-08-09 9:21 ` sirl at gcc dot gnu.org 2024-03-08 15:29 ` law at gcc dot gnu.org 2024-05-07 7:40 ` [Bug tree-optimization/110458] [14/15 " rguenth at gcc dot gnu.org
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