From 378fe693a1ef51500db21b11ff05a8018c5f0e55 Mon Sep 17 00:00:00 2001
From: dominic <510002+dmah42@users.noreply.github.com>
Date: Wed, 24 Jul 2024 14:25:32 +0100
Subject: [PATCH] Use log2 now that NDK requires at least API 21 which includes
 it. (#1822)

Fixes #1820
---
 src/complexity.cc | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/src/complexity.cc b/src/complexity.cc
index eee31226..63acd504 100644
--- a/src/complexity.cc
+++ b/src/complexity.cc
@@ -27,7 +27,6 @@ namespace benchmark {
 
 // Internal function to calculate the different scalability forms
 BigOFunc* FittingCurve(BigO complexity) {
-  static const double kLog2E = 1.44269504088896340736;
   switch (complexity) {
     case oN:
       return [](IterationCount n) -> double { return static_cast<double>(n); };
@@ -36,15 +35,12 @@ BigOFunc* FittingCurve(BigO complexity) {
     case oNCubed:
       return [](IterationCount n) -> double { return std::pow(n, 3); };
     case oLogN:
-      /* Note: can't use log2 because Android's GNU STL lacks it */
-      return [](IterationCount n) {
-        return kLog2E * std::log(static_cast<double>(n));
+      return [](IterationCount n) -> double {
+        return std::log2(static_cast<double>(n));
       };
     case oNLogN:
-      /* Note: can't use log2 because Android's GNU STL lacks it */
-      return [](IterationCount n) {
-        return kLog2E * static_cast<double>(n) *
-               std::log(static_cast<double>(n));
+      return [](IterationCount n) -> double {
+        return static_cast<double>(n) * std::log2(static_cast<double>(n));
       };
     case o1:
     default: