https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114202
Bug ID: 114202
Summary: [14] RISC-V rv64gcv: miscompile at -O3
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 printf(const char *, ...);
signed char a, d;
_Bool b;
signed char c[324];
int e;
int main() {
c[63] = 50;
for (int f = 0; f < 9; f++) {
for (unsigned g = 0; g < 12; g++)
for (char h = 0; h < 8; h++)
e = a += c[g * 9];
b = e ? d : 0;
}
printf("%d\n", a);
}
Commands:
> /scratch/tc-testing/tc-feb-20/build-rv64gcv/bin/riscv64-unknown-linux-gnu-gcc
> -march=rv64gcv -O3 -fwrapv red.c -o red.out
> /scratch/tc-testing/tc-feb-20-llvm/build/bin/qemu-riscv64 red.out
32
> /scratch/tc-testing/tc-feb-20/build-rv64gcv/bin/riscv64-unknown-linux-gnu-gcc
> -march=rv64gcv -O2 -fwrapv red.c -o red.out
> /scratch/tc-testing/tc-feb-20-llvm/build/bin/qemu-riscv64 red.out
16
With the overflows (-fwrapv) the expected value is 16.
Tested/found using r14-9084-g61ab046a327 (not bisected)
Found via fuzzer.
