https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101009
Bug ID: 101009
Summary: wrong code with "-O3 -fno-tree-sra"
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: suochenyao at 163 dot com
Target Milestone: ---
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OS and Platform:
CentOS Linux release 7.8.2003 (Core), x86_64 GNU/Linux
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Program:
int printf(const char *, ...);
struct a {
unsigned b;
unsigned c;
} e, *f = &e;
int d = 1;
int main() {
for (; d; d--) {
struct a g[] = {{2, 1}, {2, 1}};
*f = g[1];
}
printf("%d\n", e.c);
}
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gcc version:
$ gcc -v
Using built-in specs.
COLLECT_GCC=/data/bin/gcc-dev/bin/gcc
COLLECT_LTO_WRAPPER=/data/bin/gcc-dev/libexec/gcc/x86_64-pc-linux-gnu/12.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../configure --prefix=/data/bin/gcc-dev --disable-multilib
--enable-languages=c,c++
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 12.0.0 20210609 (experimental) (GCC)
git version: 53cb324cb4f9475d4eabcd9f5a858c5edaacc0cf
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Command Lines:
$ gcc -O3 -fno-tree-sra -Wall -Wextra -fno-strict-aliasing -fwrapv a.c -o
a1.out
$ gcc a.c -o a2.out
$ ./a1.out
0
$ ./a2.out
1
