From 33372cbd4075e70b1e365a6dd6708edd0d68c3a4 Mon Sep 17 00:00:00 2001
From: David Carlier <devnexen@gmail.com>
Date: Mon, 27 Apr 2020 20:28:17 +0100
Subject: [PATCH] cpu instruction spin wait for arm32/64

---
 configure.ac | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/configure.ac b/configure.ac
index f67fc3d71f..98cb4bc8cb 100644
--- a/configure.ac
+++ b/configure.ac
@@ -416,6 +416,16 @@ case "${host_cpu}" in
 	    fi
 	fi
 	;;
+  aarch64|arm*)
+	HAVE_CPU_SPINWAIT=1
+    AC_CACHE_VAL([je_cv_yield],
+      [JE_COMPILABLE([yield instruction], [],
+                    [[__asm__ volatile("yield"); return 0;]],
+                    [je_cv_yield])])
+	if test "x${je_cv_yield}" = "xyes" ; then
+	CPU_SPINWAIT='__asm__ volatile("yield")'
+	fi
+    ;;
   *)
 	HAVE_CPU_SPINWAIT=0
 	;;