message: [XLA] Don't use Pow for simple expressions
  Using Pow to handle squaring or taking the reciprocal is overkill, Pow is not going to be as accurate as the straightforward formulation without relying on optimization in the compiler or the Pow implementation to kick in.
diff: @@ -25,11 +25,9 @@ XlaOp Sqrt(XlaOp operand) { return Pow(operand, ScalarLike(operand, 0.5)); }
  XlaOp Rsqrt(XlaOp operand) { return Pow(operand, ScalarLike(operand, -0.5)); }
  -XlaOp Square(XlaOp operand) { return Pow(operand, ScalarLike(operand, 2.0)); }
  +XlaOp Square(XlaOp operand) { return operand * operand; }
  -XlaOp Reciprocal(XlaOp operand) {
  - return Pow(operand, ScalarLike(operand, -1.0));
  -}
  +XlaOp Reciprocal(XlaOp operand) { return ScalarLike(operand, 1.0) / operand; }
  namespace {
  