pow_ref            11 test/performance/fast_pow.cpp extern "C" __declspec(dllexport) float pow_ref(float x, float y) {
pow_ref            20 test/performance/fast_pow.cpp HalideExtern_2(float, pow_ref, float, float);
pow_ref            29 test/performance/fast_pow.cpp     f(x, y) = sum(pow_ref((x+1)/512.0f, (y+1+s)/512.0f));