From: Kefu Chai <tchaikov@gmail.com>
Date: Tue, 23 Nov 2021 16:40:54 +0000 (+0800)
Subject: cmake: test for 16-byte atomic support on mips also
X-Git-Tag: v17.1.0~328^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=709a77f22010f03aee4a4c0ab930588944cb4a58;p=ceph.git

cmake: test for 16-byte atomic support on mips also

it's reported that a mips64el build host is able to pass the test of
CheckCxxAtomic without linking against libatomic, while librbd.so
fails to link due to failures like

/usr/bin/ld: ../../../lib/librbd.so.1.16.0: undefined reference to `__atomic_store_16'
/usr/bin/ld: ../../../lib/librbd.so.1.16.0: undefined reference to `__atomic_load_16'
/usr/bin/ld: ../../../lib/librbd.so.1.16.0: undefined reference to `__atomic_compare_exchange_16'

so we have to check the existence of __atomic_load_16 instruction on
mips architecture.

Signed-off-by: Kefu Chai <tchaikov@gmail.com>
---

diff --git a/cmake/modules/CheckCxxAtomic.cmake b/cmake/modules/CheckCxxAtomic.cmake
index f2d89cf3e0b..da2be5206d6 100644
--- a/cmake/modules/CheckCxxAtomic.cmake
+++ b/cmake/modules/CheckCxxAtomic.cmake
@@ -11,7 +11,7 @@ function(check_cxx_atomics var)
 #include <atomic>
 #include <cstdint>
 
-#if __s390x__
+#if defined(__s390x__) || defined(__mips__)
 // Boost needs 16-byte atomics for tagged pointers.
 // These are implemented via inline instructions on the platform
 // if 16-byte alignment can be proven, and are delegated to libatomic