Implement a proper configure test for AltiVec vector declaration syntax.

Originally committed as revision 13555 to svn://svn.ffmpeg.org/ffmpeg/trunk

configure

@@ -714,6 +714,7 @@ HAVE_LIST="
     $ARCH_EXT_LIST
     $THREADS_LIST
     altivec_h
+    altivec_vector_braces
     arpa_inet_h
     bswap
     byteswap_h
@@ -1542,6 +1543,13 @@ int main(void) {
     v1 = vec_add(v2,v3);
     return 0;
 }
+EOF
+
+    # check if our compiler supports braces for vector declarations
+    check_cc <<EOF && enable altivec_vector_braces
+$inc_altivec_h
+#define AVV(x...) {x}
+int main (void) { (vector int) AVV(1); return 0; }
 EOF
 fi
 

libavutil/internal.h

@@ -50,11 +50,10 @@
 #endif
 #endif
 
-/* Use Apple-specific AltiVec syntax for vector declarations when necessary. */
-#ifdef __APPLE_CC__
-#define AVV(x...) (x)
-#else
+#ifdef HAVE_ALTIVEC_VECTOR_BRACES
 #define AVV(x...) {x}
+#else
+#define AVV(x...) (x)
 #endif
 
 #ifndef M_PI