1 files changed, 79 insertions, 0 deletions
diff --git a/sysdeps/i386/bits/htontoh.h b/sysdeps/i386/bits/htontoh.h
new file mode 100644
index 0000000000..590b509875
--- /dev/null
+++ b/sysdeps/i386/bits/htontoh.h
@@ -0,0 +1,79 @@
+/* Copyright (C) 1997 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#ifndef _NETINET_IN_H
+# error "Don't include this file directly, use <netinet/in.h>"
+#endif
+
+#if defined __GNUC__ && __GNUC__ >= 2
+/* We can use inline assembler instructions to optimize the code.  */
+
+/* To swap the bytes in a word the i486 processors and up provide the
+   `bswap' opcode.  On i386 we have to use three instructions.  */
+# if !defined __i486__ && !defined __pentium__ && !defined __pentiumpro__
+
+extern __inline u_int32_t
+__ntohl (u_int32_t netlong)
+{
+  register u_int32_t hostlong;
+
+  __asm__ ("rorw $8, %w0; rorl $16, %0; rorw $8, %w0"
+	   : "=r" (hostlong)
+	   : "0" (netlong));
+
+  return hostlong;
+}
+
+# else
+
+extern __inline u_int32_t
+__ntohl (u_int32_t netlong)
+{
+  register u_int32_t hostlong;
+
+  __asm__ ("bswap %0" : "=r" (hostlong) : "0" (netlong));
+
+  return hostlong;
+}
+
+# endif
+
+/* For a short word we have a simple solution.  */
+extern __inline u_int16_t
+__ntohs (u_int16_t netshort)
+{
+  register u_int16_t hostshort;
+
+  __asm__ ("rorw $8, %w0" : "=r" (hostshort) : "0" (netshort));
+}
+
+
+/* The other direction can be handled with the same functions.  */
+extern __inline u_int32_t
+__htonl (u_int32_t hostlong)
+{
+  return __ntohl (hostlong);
+}
+
+extern __inline u_int16_t
+__htons (u_int16_t hostshort)
+{
+  return __ntohs (hostshort);
+}
+
+#endif /* GNU CC */