ARM: check for VFP register arguments

Originally committed as revision 19474 to svn://svn.ffmpeg.org/ffmpeg/trunk

configure

@@ -958,6 +958,7 @@ HAVE_LIST="
     termios_h
     threads
     truncf
+    vfp_args
     VirtualAlloc
     winsock2_h
     xform_asm
@@ -2042,6 +2043,11 @@ fi
 
 # check for assembler specific support
 
+enabled arm && check_ld <<EOF && enable vfp_args
+__asm__ (".eabi_attribute 28, 1");
+int main(void) { return 0; }
+EOF
+
 enabled mips && check_asm loongson '"dmult.g $1, $2, $3"'
 
 enabled ppc && check_asm dcbzl '"dcbzl 0, 1"'

libavcodec/arm/asm.S

@@ -45,3 +45,12 @@
         ldr             \rd, =\val
 #endif
         .endm
+
+#if HAVE_VFP_ARGS
+        .eabi_attribute 28, 1
+#   define VFP
+#   define NOVFP @
+#else
+#   define VFP   @
+#   define NOVFP
+#endif