patch-src_external_atomic__queue_defs.h

--- src/external/atomic_queue/defs.h.orig	2020-07-23 22:01:34 UTC
+++ src/external/atomic_queue/defs.h
@@ -6,11 +6,15 @@
 
 #include <atomic>
 
+#if defined(__FreeBSD__) || defined(__DragonFly__)
+#include <machine/param.h> // for CACHE_LINE_SIZE
+#endif
+
 #if defined(__x86_64__) || defined(_M_X64) || \
     defined(__i386__) || defined(_M_IX86)
 #include <emmintrin.h>
 namespace atomic_queue {
-constexpr int CACHE_LINE_SIZE = 64;
+//constexpr int CACHE_LINE_SIZE = 64;
 static inline void spin_loop_pause() noexcept {
     _mm_pause();
 }
@@ -18,7 +22,7 @@ static inline void spin_loop_pause() noexcept {
 #elif defined(__arm__) || defined(__aarch64__)
 // TODO: These need to be verified as I do not have access to ARM platform.
 namespace atomic_queue {
-constexpr int CACHE_LINE_SIZE = 64;
+//constexpr int CACHE_LINE_SIZE = 64;
 static inline void spin_loop_pause() noexcept {
 #if (defined(__ARM_ARCH_6K__) || \
      defined(__ARM_ARCH_6Z__) || \
@@ -37,6 +41,10 @@ static inline void spin_loop_pause() noexcept {
 #endif
 }
 } // namespace atomic_queue
+#elif defined(__powerpc__)
+static inline void spin_loop_pause() noexcept {
+    asm volatile("ori 0,0,0" ::: "memory");
+}
 #else
 #error "Unknown CPU architecture."
 #endif