https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111738
Bug ID: 111738
Summary: incorrect code when PGO is enabled
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: iamanonymous.cs at gmail dot com
Target Milestone: ---
*******************************************************************************
OS and Platform:
$ uname -a:
Linux ubuntu 4.15.0-213-generic #224-Ubuntu SMP Mon Jun 19 13:30:12 UTC 2023
x86_64 x86_64 x86_64 GNU/Linux
*******************************************************************************
gcc version:
$ gcc -v
Using built-in specs.
COLLECT_GCC=/root/gcc_set/new_gcc/bin/gcc
COLLECT_LTO_WRAPPER=/root/gcc_set/new_gcc/libexec/gcc/x86_64-pc-linux-gnu/14.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc/configure --prefix=/root/gcc_set/new_gcc
--with-gmp=/root/build_essential --with-mpfr=/root/build_essential
--with-mpc=/root/build_essential --enable-languages=c,c++ --disable-multilib
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 14.0.0 20230719 (experimental) (GCC)
git version:85da0b40538fb0d17d89de1e7905984668e3dfef
*******************************************************************************
Program:
$ cat a.c
a = 4, b = 0, d = 0, e = 0, f = 0;
**c = &b;
*g = &a;
h() {
i();
if (f)
e = 0;
}
i() {
float j = 0;
int **k = &b;
*k = &j;
*g |= **c;
if (*g)
;
else {
long *l = d = (*l)++;
}
}
main() {
h();
printf("%d\n", a);
}
*******************************************************************************
Command Lines:
# The profile directory is used to save profile information.
$ gcc -O3 -w -fprofile-generate=profile a.c -o a.out
$ ./a.out
4
$ gcc -O3 -w -fprofile-use=profile -Wno-missing-profile -fprofile-correction
a.c
-o a.out
$ ./a.out
32764
We can found that, the output of the executable is incorrect when the profile
guided optimization is enabled.
