https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120242
Bug ID: 120242
Summary: [15/16 regression] RISC-V: Miscompile at -O[23]
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: ewlu at rivosinc dot com
Target Milestone: ---
Testcase:
char f1(char a, char b) {
return b == 0 ? a : b;
}
int f2(int a, int b) {
return b ? a : 0;
}
struct l {
unsigned m;
int n;
};
struct l ae;
char af = -2;
unsigned ah = 4;
int aj = 8;
int *test = &aj;
int main() {
ao:
if (f2(f1(4, af++), *test) <= 0) {
for (; ae.n; ae.n++)
;
if (ah)
goto ao;
}
__builtin_printf("%d\n", af);
}
Commands:
-O3
> /scratch/ewlu/daily-upstream-build/build-gcv/bin/riscv64-unknown-linux-gnu-gcc
> -O3 red.c -o user-config.out -fsigned-char -fno-strict-aliasing -fwrapv
> QEMU_CPU=rv64,vlen=128,rvv_ta_all_1s=true,rvv_ma_all_1s=true,v=true,vext_spec=v1.0,zve32f=true,zve64f=true
> timeout --verbose -k 0.1 4
> /scratch/ewlu/daily-upstream-build/build-gcv/bin/qemu-riscv64 user-config.out
> 12
2
-O2
> /scratch/ewlu/daily-upstream-build/build-gcv/bin/riscv64-unknown-linux-gnu-gcc
> -O2 red.c -o user-config.out -fsigned-char -fno-strict-aliasing -fwrapv
> QEMU_CPU=rv64,vlen=128,rvv_ta_all_1s=true,rvv_ma_all_1s=true,v=true,vext_spec=v1.0,zve32f=true,zve64f=true
> timeout --verbose -k 0.1 4
> /scratch/ewlu/daily-upstream-build/build-gcv/bin/qemu-riscv64 user-config.out
> 12
2
-O1
> /scratch/ewlu/daily-upstream-build/build-gcv/bin/riscv64-unknown-linux-gnu-gcc
> -O1 red.c -o user-config.out -fsigned-char -fno-strict-aliasing -fwrapv
> QEMU_CPU=rv64,vlen=128,rvv_ta_all_1s=true,rvv_ma_all_1s=true,v=true,vext_spec=v1.0,zve32f=true,zve64f=true
> timeout --verbose -k 0.1 4
> /scratch/ewlu/daily-upstream-build/build-gcv/bin/qemu-riscv64 user-config.out
> 12
1
Bisected to r15-9239-g4d7a634f6d4 as the first bad commit
Found via fuzzer
