1 files changed, 62 insertions, 0 deletions
diff --git a/libgo/runtime/go-append.c b/libgo/runtime/go-append.c
new file mode 100644
index 0000000..aa8f4a1
--- /dev/null
+++ b/libgo/runtime/go-append.c
@@ -0,0 +1,62 @@
+/* go-append.c -- the go builtin append function.
+
+   Copyright 2010 The Go Authors. All rights reserved.
+   Use of this source code is governed by a BSD-style
+   license that can be found in the LICENSE file.  */
+
+#include "go-assert.h"
+#include "go-type.h"
+#include "array.h"
+#include "runtime.h"
+#include "malloc.h"
+
+struct __go_open_array
+__go_append (const struct __go_slice_type *type,
+	     struct __go_open_array a, struct __go_open_array b)
+{
+  size_t element_size;
+  unsigned int ucount;
+  int count;
+
+  if (b.__values == NULL || b.__count == 0)
+    return a;
+
+  __go_assert (type->__common.__code == GO_SLICE);
+  element_size = type->__element_type->__size;
+
+  ucount = (unsigned int) a.__count + (unsigned int) b.__count;
+  count = (int) ucount;
+  __go_assert (ucount == (unsigned int) count && count >= a.__count);
+  if (count > a.__capacity)
+    {
+      int m;
+      struct __go_open_array n;
+
+      m = a.__capacity;
+      if (m == 0)
+	m = b.__count;
+      else
+	{
+	  do
+	    {
+	      if (a.__count < 1024)
+		m += m;
+	      else
+		m += m / 4;
+	    }
+	  while (m < count);
+	}
+
+      n.__values = __go_alloc (m * element_size);
+      n.__count = a.__count;
+      n.__capacity = m;
+      __builtin_memcpy (n.__values, a.__values, n.__count * element_size);
+
+      a = n;
+    }
+
+  __builtin_memmove ((char *) a.__values + a.__count * element_size,
+		     b.__values, b.__count * element_size);
+  a.__count = count;
+  return a;
+}