PR tree-optimization/82004
	* gimple-match-head.c (optimize_pow_to_exp): New function.
	* match.pd (pow(C,x) -> exp(log(C)*x)): Wrap with #if GIMPLE.
	Don't fold to exp if optimize_pow_to_exp is false.

	* gcc.dg/pr82004.c: New test.

From-SVN: r258930