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* [Bug rtl-optimization/116479] New: [15 Regression] wrong code with -O -funroll-loops -finline-stringops -fmodulo-sched --param=max-iterations-computation-cost=637924876 on aarch64
@ 2024-08-25 12:09 zsojka at seznam dot cz
2024-08-25 17:43 ` [Bug rtl-optimization/116479] " pinskia at gcc dot gnu.org
2024-08-25 17:53 ` pinskia at gcc dot gnu.org
0 siblings, 2 replies; 3+ messages in thread
From: zsojka at seznam dot cz @ 2024-08-25 12:09 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116479
Bug ID: 116479
Summary: [15 Regression] wrong code with -O -funroll-loops
-finline-stringops -fmodulo-sched
--param=max-iterations-computation-cost=637924876 on
aarch64
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Keywords: wrong-code
Severity: normal
Priority: P3
Component: rtl-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: zsojka at seznam dot cz
Target Milestone: ---
Host: x86_64-pc-linux-gnu
Target: aarch64-unknown-linux-gnu
Created attachment 58996
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=58996&action=edit
reduced testcase
Output:
$ arch64-unknown-linux-gnu-gcc -O -funroll-loops -finline-stringops
-fmodulo-sched --param=max-iterations-computation-cost=637924687 testcase.c
-static
$ qemu-aarch64 -- ./a.out
qemu: uncaught target signal 11 (Segmentation fault) - core dumped
Segmentation fault
On the asm level:
...
foo:
...
mov x4, 695
mov x1, x3
.L2:
...
sub x4, x4, #8
cbnz x4, .L2
...
ret
x4 wraps over 0 (since 695%8 != 0), and the program crashes with:
x4 0xfffffffffffd7c0f -164849
$ aarch64-unknown-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest-aarch64/bin/aarch64-unknown-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-r15-3158-20240825101449-g91f549537ca-checking-yes-rtl-df-extra-aarch64/bin/../libexec/gcc/aarch64-unknown-linux-gnu/15.0.0/lto-wrapper
Target: aarch64-unknown-linux-gnu
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++
--enable-valgrind-annotations --disable-nls --enable-checking=yes,rtl,df,extra
--with-cloog --with-ppl --with-isl
--with-sysroot=/usr/aarch64-unknown-linux-gnu --build=x86_64-pc-linux-gnu
--host=x86_64-pc-linux-gnu --target=aarch64-unknown-linux-gnu
--with-ld=/usr/bin/aarch64-unknown-linux-gnu-ld
--with-as=/usr/bin/aarch64-unknown-linux-gnu-as --enable-libsanitizer
--disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-r15-3158-20240825101449-g91f549537ca-checking-yes-rtl-df-extra-aarch64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 15.0.0 20240825 (experimental) (GCC)
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug rtl-optimization/116479] [15 Regression] wrong code with -O -funroll-loops -finline-stringops -fmodulo-sched --param=max-iterations-computation-cost=637924876 on aarch64
2024-08-25 12:09 [Bug rtl-optimization/116479] New: [15 Regression] wrong code with -O -funroll-loops -finline-stringops -fmodulo-sched --param=max-iterations-computation-cost=637924876 on aarch64 zsojka at seznam dot cz
@ 2024-08-25 17:43 ` pinskia at gcc dot gnu.org
2024-08-25 17:53 ` pinskia at gcc dot gnu.org
1 sibling, 0 replies; 3+ messages in thread
From: pinskia at gcc dot gnu.org @ 2024-08-25 17:43 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116479
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|--- |15.0
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug rtl-optimization/116479] [15 Regression] wrong code with -O -funroll-loops -finline-stringops -fmodulo-sched --param=max-iterations-computation-cost=637924876 on aarch64
2024-08-25 12:09 [Bug rtl-optimization/116479] New: [15 Regression] wrong code with -O -funroll-loops -finline-stringops -fmodulo-sched --param=max-iterations-computation-cost=637924876 on aarch64 zsojka at seznam dot cz
2024-08-25 17:43 ` [Bug rtl-optimization/116479] " pinskia at gcc dot gnu.org
@ 2024-08-25 17:53 ` pinskia at gcc dot gnu.org
1 sibling, 0 replies; 3+ messages in thread
From: pinskia at gcc dot gnu.org @ 2024-08-25 17:53 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116479
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
See Also| |https://gcc.gnu.org/bugzill
| |a/show_bug.cgi?id=110791
Status|UNCONFIRMED |NEW
Ever confirmed|0 |1
Last reconfirmed| |2024-08-25
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Confirmed.
Looks like fmodulo-sched didn't do anything for the testcase in GCC 14 but does
on the trunk. So maybe a latent bug ...
^ permalink raw reply [flat|nested] 3+ messages in thread
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2024-08-25 12:09 [Bug rtl-optimization/116479] New: [15 Regression] wrong code with -O -funroll-loops -finline-stringops -fmodulo-sched --param=max-iterations-computation-cost=637924876 on aarch64 zsojka at seznam dot cz
2024-08-25 17:43 ` [Bug rtl-optimization/116479] " pinskia at gcc dot gnu.org
2024-08-25 17:53 ` pinskia at gcc dot gnu.org
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