Disabled use of sha3-permute.asm

ChangeLog

+2012-12-30  Niels Möller  <nisse@lysator.liu.se>
+
+	* configure.ac: Disabled use of sha3-permute.asm.
+
 2012-12-20  Niels Möller  <nisse@lysator.liu.se>
 
 	From Tim Rühsen:

configure.ac

@@ -245,7 +245,7 @@ if test "x$enable_assembler" = xyes ; then
 		 md5-compress.asm memxor.asm \
 		 salsa20-crypt.asm salsa20-core-internal.asm \
 		 serpent-encrypt.asm serpent-decrypt.asm \
-		 sha1-compress.asm sha3-permute.asm machine.m4; do
+		 sha1-compress.asm machine.m4; do
 #       echo "Looking for $srcdir/$asm_path/$tmp_f"
       if test -f "$srcdir/$asm_path/$tmp_f"; then
 #        echo found

x86_64/sha3-permute.asm

@@ -17,6 +17,12 @@ C along with the nettle library; see the file COPYING.LIB.  If not, write to
 C the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 C MA 02111-1301, USA.
 
+C NOTE: This code is currently unused. It gives a modest speedup on
+C Intel processors, running at roughly two instructions per cycle, and
+C a large slowdown on AMD processors, running at only a single
+C instruction per cycle. Maybe it can be rewritten to not move data
+C back and forth between xmm registers and regular 64-bit registers.
+
 define(<CTX>, <%rdi>)		C 25 64-bit values, 200 bytes.
 define(<COUNT>, <%r8>)		C Avoid clobbering %rsi, for W64.