https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114399
Bug ID: 114399
Summary: [14] RISC-V rv32i miscompile
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: patrick at rivosinc dot com
Target Milestone: ---
Testcase:
int a;
struct b {
long long c;
};
struct d {
short e;
long long f;
};
union {
struct b g;
struct d h;
} i;
int main() {
i.h.f++;
a = i.g.c >> 1;
__builtin_printf("%X\n", a);
}
Commands:
> gcc red.c -o red.out -m32 -fno-strict-aliasing -static
> ./red.out
80000000
> riscv64-unknown-linux-gnu-gcc -mabi=ilp32 -march=rv32i red.c -o red.out
> -fno-strict-aliasing -static
> /scratch/tc-testing/tc-mar-19/build-rv32-64-gcv/bin/qemu-riscv32 red.out
0
Discovered/tested with r14-9544-gc7a774edbf8 (not bisected)
Found via fuzzer.
I don't think this has any undefined behavior but the combo of union/struct has
me a bit wary.
