1 files changed, 67 insertions, 0 deletions
diff --git a/libgo/runtime/go-append.c b/libgo/runtime/go-append.c
new file mode 100644
index 000000000..91493b1b7
--- /dev/null
+++ b/libgo/runtime/go-append.c
@@ -0,0 +1,67 @@
+/* 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-type.h"
+#include "go-panic.h"
+#include "array.h"
+#include "runtime.h"
+#include "malloc.h"
+
+/* We should be OK if we don't split the stack here, since the only
+   libc functions we call are memcpy and memmove.  If we don't do
+   this, we will always split the stack, because of memcpy and
+   memmove.  */
+extern struct __go_open_array
+__go_append (struct __go_open_array, void *, size_t, size_t)
+  __attribute__ ((no_split_stack));
+
+struct __go_open_array
+__go_append (struct __go_open_array a, void *bvalues, size_t bcount,
+	     size_t element_size)
+{
+  size_t ucount;
+  int count;
+
+  if (bvalues == NULL || bcount == 0)
+    return a;
+
+  ucount = (size_t) a.__count + bcount;
+  count = (int) ucount;
+  if ((size_t) count != ucount || count <= a.__count)
+    __go_panic_msg ("append: slice overflow");
+
+  if (count > a.__capacity)
+    {
+      int m;
+      void *n;
+
+      m = a.__capacity;
+      if (m == 0)
+	m = (int) bcount;
+      else
+	{
+	  do
+	    {
+	      if (a.__count < 1024)
+		m += m;
+	      else
+		m += m / 4;
+	    }
+	  while (m < count);
+	}
+
+      n = __go_alloc (m * element_size);
+      __builtin_memcpy (n, a.__values, a.__count * element_size);
+
+      a.__values = n;
+      a.__capacity = m;
+    }
+
+  __builtin_memmove ((char *) a.__values + a.__count * element_size,
+		     bvalues, bcount * element_size);
+  a.__count = count;
+  return a;
+}