From ced7c17426ecae0f66b5f4d45e458a4043a9e35c Mon Sep 17 00:00:00 2001
From: Alex Lorenz <arphaman@gmail.com>
Date: Tue, 21 Jul 2020 17:21:20 -0700
Subject: [PATCH] Revert "[libcxx] use __builtin_isnan in std::isnan."

This reverts commit 767eadd782291026b9b87be871de6bcd347c7d14.
---
 libcxx/include/math.h | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/libcxx/include/math.h b/libcxx/include/math.h
index c9b4733e9c446..194df2077bb1c 100644
--- a/libcxx/include/math.h
+++ b/libcxx/include/math.h
@@ -510,11 +510,7 @@ _LIBCPP_INLINE_VISIBILITY
 bool
 __libcpp_isnan(_A1 __lcpp_x) _NOEXCEPT
 {
-#if __has_builtin(__builtin_isnan)
-    return __builtin_isnan(__lcpp_x);
-#else
     return isnan(__lcpp_x);
-#endif
 }
 
 #undef isnan