From ac50fd3a71288b22160f849efb4650d814f3847e Mon Sep 17 00:00:00 2001
From: Dmitri Smirnov <dmitrism@microsoft.com>
Date: Wed, 13 Jan 2016 14:51:58 -0800
Subject: [PATCH] Align statistics   Use Yield macro to make it a little more
 portable between platforms.

---
 port/port_posix.h   | 2 ++
 port/win/port_win.h | 2 +-
 util/statistics.h   | 8 +++++++-
 3 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/port/port_posix.h b/port/port_posix.h
index efcd1aa8e..74c42f31b 100644
--- a/port/port_posix.h
+++ b/port/port_posix.h
@@ -16,6 +16,8 @@
 // in fact, we could use that one
 #define ROCKSDB_PRIszt "zu"
 
+#define __declspec(S)
+
 #define ROCKSDB_NOEXCEPT noexcept
 
 #undef PLATFORM_IS_LITTLE_ENDIAN
diff --git a/port/win/port_win.h b/port/win/port_win.h
index 9ee7d96be..d901c40bf 100644
--- a/port/win/port_win.h
+++ b/port/win/port_win.h
@@ -245,7 +245,7 @@ extern void InitOnce(OnceType* once, void (*initializer)());
 
 static inline void AsmVolatilePause() {
 #if defined(_M_IX86) || defined(_M_X64)
-  ::_mm_pause();
+  YieldProcessor();
 #endif
   // it would be nice to get "wfe" on ARM here
 }
diff --git a/util/statistics.h b/util/statistics.h
index 55914f59e..b42fb43a5 100644
--- a/util/statistics.h
+++ b/util/statistics.h
@@ -61,7 +61,13 @@ class StatisticsImpl : public Statistics {
     char padding[64 - sizeof(std::atomic_uint_fast64_t)];
   };
 
-  Ticker tickers_[INTERNAL_TICKER_ENUM_MAX] __attribute__((aligned(64)));
+  static_assert(sizeof(Ticker) == 64, "Expecting to fit into 64 bytes");
+
+  // Attributes expand to nothing depending on the platform
+  __declspec(align(64))
+  Ticker tickers_[INTERNAL_TICKER_ENUM_MAX]
+     __attribute__((aligned(64)));
+  __declspec(align(64))
   HistogramImpl histograms_[INTERNAL_HISTOGRAM_ENUM_MAX]
       __attribute__((aligned(64)));
 };