Import various libgcc functions from syslinux.

Experimentation reveals that gcc ignores -mrtd for the implicit
arithmetic functions (e.g. __udivdi3), but not for the implicit
memcpy() and memset() functions.  Mark the implicit arithmetic
functions with __attribute__((cdecl)) to compensate for this.

(Note: we cannot mark with with __cdecl, because we define __cdecl to
incorporate regparm(0) as well.)

1 files changed, 18 insertions, 0 deletions

diff --git a/src/libgcc/memcpy.c b/src/libgcc/memcpy.c
new file mode 100644
index 000000000..e98b78384
--- /dev/null
+++ b/src/libgcc/memcpy.c
@@ -0,0 +1,18 @@
+/** @file
+ *
+ * gcc sometimes likes to insert implicit calls to memcpy().
+ * Unfortunately, there doesn't seem to be any way to prevent it from
+ * doing this, or to force it to use the optimised memcpy() as seen by
+ * C code; it insists on inserting a symbol reference to "memcpy".  We
+ * therefore include wrapper functions just to keep gcc happy.
+ *
+ */
+
+#include <string.h>
+
+void * gcc_implicit_memcpy ( void *dest, const void *src,
+			     size_t len ) asm ( "memcpy" );
+
+void * gcc_implicit_memcpy ( void *dest, const void *src, size_t len ) {
+	return memcpy ( dest, src, len );
+}