From dfbcf5bc752a08bd9df8f19c5a5b6db6a6b519a7 Mon Sep 17 00:00:00 2001
From: Jared Boone <jboone@earfeast.com>
Date: Wed, 10 Feb 2016 10:15:42 -0800
Subject: [PATCH] Extract some constexpr math utilities to utility.hpp

...my dumping ground for so many random bits.
---
 firmware/common/dsp_fft.hpp | 9 +--------
 firmware/common/utility.hpp | 8 ++++++++
 2 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/firmware/common/dsp_fft.hpp b/firmware/common/dsp_fft.hpp
index a360721a..65dd8098 100644
--- a/firmware/common/dsp_fft.hpp
+++ b/firmware/common/dsp_fft.hpp
@@ -32,6 +32,7 @@
 #include "dsp_types.hpp"
 #include "complex.hpp"
 #include "hal.h"
+#include "utility.hpp"
 
 namespace std {
 	/* https://github.com/AE9RB/fftbench/blob/master/cxlr.hpp
@@ -47,14 +48,6 @@ namespace std {
 	}
 } /* namespace std */
 
-constexpr bool power_of_two(const size_t n) {
-	return (n & (n - 1)) == 0;
-}
-
-constexpr size_t log_2(const size_t n, const size_t p = 0) {
-	return (n <= 1) ? p : log_2(n / 2, p + 1);
-}
-
 template<typename T, size_t N>
 void fft_swap(const buffer_c16_t src, std::array<T, N>& dst) {
 	static_assert(power_of_two(N), "only defined for N == power of two");
diff --git a/firmware/common/utility.hpp b/firmware/common/utility.hpp
index 2a2dc9f4..02caa1a1 100644
--- a/firmware/common/utility.hpp
+++ b/firmware/common/utility.hpp
@@ -61,6 +61,14 @@ inline constexpr T pow(const T base, unsigned const exponent) {
 	return (exponent == 0) ? 1 : (base * pow(base, exponent - 1));
 }
 
+constexpr bool power_of_two(const size_t n) {
+	return (n & (n - 1)) == 0;
+}
+
+constexpr size_t log_2(const size_t n, const size_t p = 0) {
+	return (n <= 1) ? p : log_2(n / 2, p + 1);
+}
+
 float complex16_mag_squared_to_dbv_norm(const float c16_mag_squared);
 
 inline float magnitude_squared(const std::complex<float> c) {