>> Which one is right?
Hi, Richard. Let me explain this situation.

Both situations are possible. It's depending on the 'ELSE' value whether it is unitialized value.

For reduction case:

for (int i = 0; i < n; i++)
  result += a[i]

The trailing elements should be well-defined, keep the original value. Otherwise, it will cause run-time issue.

For integer DIV operation:

for (int i = 0; i < n; i++)
  a[i] = a[i] / b[i];

The trailling elements are DON'T care (or undefined), I will use unitialized value in 'ELSE' value.
Then later 'expand' stage will expand it into "clobber scratch" RTL.

 Thanks.


juzhe.zhong@rivai.ai