https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122042
Bug ID: 122042
Summary: wrong code at -Ofast only with attribute `cold`
assigned
Product: gcc
Version: 13.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: bouncy12578 at gmail dot com
Target Milestone: ---
$ gcc-13 -v
Using built-in specs.
COLLECT_GCC=gcc-13
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-linux-gnu/13/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none:amdgcn-amdhsa
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu
13.1.0-8ubuntu1~22.04' --with-bugurl=file:///usr/share/doc/gcc-13/README.Bugs
--enable-languages=c,ada,c++,go,d,fortran,objc,obj-c++,m2,rust --prefix=/usr
--with-gcc-major-version-only --program-suffix=-13
--program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id
--libexecdir=/usr/libexec --without-included-gettext --enable-threads=posix
--libdir=/usr/lib --enable-nls --enable-bootstrap --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes
--with-default-libstdcxx-abi=new --enable-gnu-unique-object
--disable-vtable-verify --enable-plugin --enable-default-pie --with-system-zlib
--enable-libphobos-checking=release --with-target-system-zlib=auto
--enable-objc-gc=auto --enable-multiarch --disable-werror --enable-cet
--with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32
--enable-multilib --with-tune=generic
--enable-offload-targets=nvptx-none=/build/gcc-13-IvzKaI/gcc-13-13.1.0/debian/tmp-nvptx/usr,amdgcn-amdhsa=/build/gcc-13-IvzKaI/gcc-13-13.1.0/debian/tmp-gcn/usr
--enable-offload-defaulted --without-cuda-driver --enable-checking=release
--build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
--with-build-config=bootstrap-lto-lean --enable-link-serialization=2
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 13.1.0 (Ubuntu 13.1.0-8ubuntu1~22.04)
$ cat a.c
#include "stdlib.h"
__attribute__((cold)) void f(char *arr) {
char *path = malloc(1);
for (int i = 0; i < 1; i++)
path[i] = arr[i];
while (arr[0] == '.') {
char *p = ("0");
*p = 0;
}
free(path);
}
int main() {
char b[1] = {94};
f(b);
}
$ gcc-13 a.c -Ofast -o a.out && ./a.out
Segmentation fault (core dumped)
This bug only occurs in version 13.4 and earlier, and only with -Ofast.
