11rcombs/libass/rasterizer: MSVC ilog2

0001-MSVC-ilog2.patch

From 3183dff76442ac06e4fb19fd2f7be99a34d18522 Mon Sep 17 00:00:00 2001
From: Oleg Oshmyan <chortos@inbox.lv>
Date: Sun, 27 Apr 2014 01:28:59 +0100
Subject: [PATCH] MSVC ilog2

---
 libass/ass_rasterizer.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/libass/ass_rasterizer.c b/libass/ass_rasterizer.c
index 7baf91f..8cdbfd0 100644
--- a/libass/ass_rasterizer.c
+++ b/libass/ass_rasterizer.c
@@ -20,12 +20,21 @@
 #include "ass_rasterizer.h"
 #include <assert.h>
 
+#ifdef _MSC_VER
+#include <intrin.h>
+#pragma intrinsic(_BitScanReverse)
+#endif
+
 
 
 static inline int ilog2(uint32_t n)  // XXX: different compilers
 {
 #ifdef __GNUC__
     return __builtin_clz(n) ^ 31;
+#elif defined(_MSC_VER)
+    int res;
+    _BitScanReverse(&res, n);
+    return res;
 #else
     int res = 0;
     for (int ord = 16; ord; ord /= 2)
-- 
1.9.1