[Bug target/114200] New: [14] RISC-V fixed-length vector miscompile at -O3

[patrick at rivosinc dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114200

            Bug ID: 114200
           Summary: [14] RISC-V fixed-length vector 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 *, ...);
short a, e = 1;
_Bool b, d;
short c[300];
int main() {
  for (int f = 0; f < 19; f++) {
    for (int g = 0; g < 14; g++)
      for (int h = 0; h < 10; h++)
        a += c[g] + e;
    b += d;
  }
  printf("%d\n", a);
}

Commands:
> /scratch/tc-testing/tc-feb-20/build-rv64gcv/bin/riscv64-unknown-linux-gnu-gcc 
> -march=rv64gcv -O3 --param=riscv-autovec-preference=fixed-vlmax red.c -o 
> red.out
> /scratch/tc-testing/tc-feb-20-llvm/build/bin/qemu-riscv64 red.out
2318
> /scratch/tc-testing/tc-feb-20/build-rv64gcv/bin/riscv64-unknown-linux-gnu-gcc 
> -march=rv64gcv -O2 --param=riscv-autovec-preference=fixed-vlmax red.c -o 
> red.out
> /scratch/tc-testing/tc-feb-20-llvm/build/bin/qemu-riscv64 red.out
2660

Tested/found using r14-9084-g61ab046a327 (not bisected)

Found using fuzzer