From 91a831e2d0a3062756b395abc8c1e33b1f80022c Mon Sep 17 00:00:00 2001
From: Cameron Gutman <aicommander@gmail.com>
Date: Sun, 3 Jan 2021 14:02:55 -0600
Subject: [PATCH] Implement SDL_MostSignificantBitIndex32 using MSVC intrinsics

---
 include/SDL_bits.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/include/SDL_bits.h b/include/SDL_bits.h
index d4c28166c..f073abeb2 100644
--- a/include/SDL_bits.h
+++ b/include/SDL_bits.h
@@ -73,6 +73,12 @@ SDL_MostSignificantBitIndex32(Uint32 x)
         return -1;
     }
     return 31 - _SDL_clz_watcom(x);
+#elif defined(_MSC_VER)
+    unsigned long index;
+    if (_BitScanReverse(&index, x)) {
+        return index;
+    }
+    return -1;
 #else
     /* Based off of Bit Twiddling Hacks by Sean Eron Anderson
      * <seander@cs.stanford.edu>, released in the public domain.