[LLVMdev] SCCP and undef branches

[Domagoj Babic]

Hi,

Here's something I don't understand... How come that UNDEF can
appear as a branch condition at all? I just can't think of any ways.

If you write something like

fun() {
  int x;
  if (x > 100) {
     ...
  } else {
     ...
  }
}

LLVM generates a boolean temporary that compares (uninitialized)
value of x with 100.

Second, if it already can appear, isn't that a bug that should be
reported by the compiler?

Domagoj
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