[Bug target/116544] New: [15] RISC-V: Miscompile at -O3

[patrick at rivosinc dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116544

            Bug ID: 116544
           Summary: [15] RISC-V: Miscompile at -O3
           Product: gcc
           Version: 15.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: patrick at rivosinc dot com
  Target Milestone: ---

Testcase:
long long a;
signed char b[60];
signed char c;
long long d[60];
int e[30];
long long *f = d;
void g(long long *j, long k) { *j = k; }
int main() {
  d[5] = 0x100000000;
  for (int h = 2; h < 7; h += 3)
    for (int i = 0; i < (c || b[h]) + 10; i += 11)
      e[2] = f[h];
  g(&a, e[2]);
  __builtin_printf("%llx\n", a);
}

Commands:
> /scratch/tc-testing/tc-compiler-fuzz-trunk/build-gcv/bin/riscv64-unknown-linux-gnu-gcc
>  -O3 red.c -o user-config.out -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,zve32x=true,zve64d=true,zve64f=true,zve64x=true
>  timeout --verbose -k 0.1 4 
> /scratch/tc-testing/tc-compiler-fuzz-trunk/build-gcv/bin/qemu-riscv64 
> user-config.out
100000000

> /scratch/tc-testing/tc-compiler-fuzz-trunk/build-gcv/bin/riscv64-unknown-linux-gnu-gcc
>  -O2 red.c -o user-config.out -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,zve32x=true,zve64d=true,zve64f=true,zve64x=true
>  timeout --verbose -k 0.1 4 
> /scratch/tc-testing/tc-compiler-fuzz-trunk/build-gcv/bin/qemu-riscv64 
> user-config.out
0