https://reviews.llvm.org/D113289

Please consider this small example:

loop {
  var = *ptr;
  if (var) break;
  *ptr= var + 1;
}

After this patch, it will be:
var0 = *ptr;
loop {
  var1 = phi (var0, var2);
  if (var1) break;
  var2 = var1 + 1;
  *ptr = var2;
}

https://www.cnbeta.com/articles/tech/1211623.htm


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FROM 222.129.53.*