add FASTDIV macro for ARM. Reported speed-up on MPEG-4 decoding: 1.8%

Patch by Siarhei Siamashka %siarhei P siamashka A gmail P com%
Original thread:
Date: Sep 28, 2006 2:26 AM
Subject: [Ffmpeg-devel] [PATCH] ARM implementation of FASTDIV


git-svn-id: file:///var/local/repositories/ffmpeg/trunk@6366 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

libavutil/internal.h

@@ -114,6 +114,17 @@ extern const uint32_t inverse[256];
             );\
         ret;\
     })
+#elif defined(ARCH_ARMV4L)
+#    define FASTDIV(a,b) \
+    ({\
+        int ret,dmy;\
+        asm volatile(\
+            "umull %1, %0, %2, %3"\
+            :"=&r"(ret),"=&r"(dmy)\
+            :"r"(a),"r"(inverse[b])\
+            );\
+        ret;\
+    })
 #elif defined(CONFIG_FASTDIV)
 #    define FASTDIV(a,b)   ((uint32_t)((((uint64_t)a)*inverse[b])>>32))
 #else