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-rw-r--r--sysdeps/i386/bits/htontoh.h79
1 files changed, 79 insertions, 0 deletions
diff --git a/sysdeps/i386/bits/htontoh.h b/sysdeps/i386/bits/htontoh.h
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--- /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 */