Move MASK_ABS macro to libavcodec/mathops.h

This macro is only used in two places, both in libavcodec, so this
is a more sensible place for it.

Two small tweaks to the macro are made:

- removing the trailing semicolon
- dropping unnecessary 'volatile' from the x86 asm

Signed-off-by: Mans Rullgard <mans@mansr.com>

libavcodec/mathops.h

@@ -138,6 +138,13 @@ if ((y) < (x)) {\
 }
 #endif
 
+#ifndef MASK_ABS
+#define MASK_ABS(mask, level) do {              \
+        mask  = level >> 31;                    \
+        level = (level ^ mask) - mask;          \
+    } while (0)
+#endif
+
 #ifndef NEG_SSR32
 #   define NEG_SSR32(a,s) ((( int32_t)(a))>>(32-(s)))
 #endif

libavcodec/mpeg12enc.c

@@ -885,7 +885,7 @@ static void mpeg1_encode_block(MpegEncContext *s,
             run = i - last_non_zero - 1;
 
             alevel= level;
-            MASK_ABS(sign, alevel)
+            MASK_ABS(sign, alevel);
             sign&=1;
 
             if (alevel <= mpeg1_max_level[0][run]){

libavcodec/x86/mathops.h

@@ -101,6 +101,12 @@ __asm__ volatile(\
 );
 #endif
 
+#define MASK_ABS(mask, level)                   \
+    __asm__ ("cltd                   \n\t"      \
+             "xorl %1, %0            \n\t"      \
+             "subl %1, %0            \n\t"      \
+             : "+a"(level), "=&d"(mask))
+
 // avoid +32 for shift optimization (gcc should do that ...)
 #define NEG_SSR32 NEG_SSR32
 static inline  int32_t NEG_SSR32( int32_t a, int8_t s){

libavutil/internal.h

@@ -96,22 +96,6 @@ struct AVDictionary {
 
 #define av_abort()      do { av_log(NULL, AV_LOG_ERROR, "Abort at %s:%d\n", __FILE__, __LINE__); abort(); } while (0)
 
-/* math */
-
-#if ARCH_X86 && HAVE_INLINE_ASM
-#define MASK_ABS(mask, level)\
-            __asm__ volatile(\
-                "cltd                   \n\t"\
-                "xorl %1, %0            \n\t"\
-                "subl %1, %0            \n\t"\
-                : "+a" (level), "=&d" (mask)\
-            );
-#else
-#define MASK_ABS(mask, level)\
-            mask  = level >> 31;\
-            level = (level ^ mask) - mask;
-#endif
-
 /* avoid usage of dangerous/inappropriate system functions */
 #undef  malloc
 #define malloc please_use_av_malloc