diff --git a/configure.in b/configure.in
index 7b8fa9fc..58dac4c7 100644
--- a/configure.in
+++ b/configure.in
@@ -3098,6 +3098,18 @@ case $sqr_basecase_source in
     cat >tune/sqr_basecase.c <<EOF
 /* not sure that an empty file can compile, so put in a dummy */
 int sqr_basecase_dummy;
+EOF
+    ;;
+  *.s)
+    sqr_max=[`sed -n 's/^def...(SQR_KARATSUBA_THRESHOLD_MAX, *\([0-9]*\))/\1/p' $sqr_basecase_source`]
+    if test -n "$sqr_max"; then
+      TUNE_SQR_OBJ=sqr_asm.o
+      AC_DEFINE_UNQUOTED(TUNE_SQR_KARATSUBA_MAX,$sqr_max,
+      [Maximum size the tune program can test for SQR_KARATSUBA_THRESHOLD])
+    fi
+    cat >tune/sqr_basecase.c <<EOF
+/* not sure that an empty file can compile, so put in a dummy */
+int sqr_basecase_dummy;
 EOF
     ;;
   *.c)
diff --git a/tune/x86_64.asm b/tune/x86_64.asm
deleted file mode 100644
index 9dd23d73..00000000
--- a/tune/x86_64.asm
+++ /dev/null
@@ -1,46 +0,0 @@
-dnl  x86 pentium time stamp counter access routine.
-
-dnl  Copyright 1999, 2000, 2003, 2004, 2005 Free Software Foundation, Inc.
-dnl
-dnl  This file is part of the GNU MP Library.
-dnl
-dnl  The GNU MP Library is free software; you can redistribute it and/or
-dnl  modify it under the terms of the GNU Lesser General Public License as
-dnl  published by the Free Software Foundation; either version 2.1 of the
-dnl  License, or (at your option) any later version.
-dnl
-dnl  The GNU MP Library is distributed in the hope that it will be useful,
-dnl  but WITHOUT ANY WARRANTY; without even the implied warranty of
-dnl  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-dnl  Lesser General Public License for more details.
-dnl
-dnl  You should have received a copy of the GNU Lesser General Public
-dnl  License along with the GNU MP Library; see the file COPYING.LIB.  If
-dnl  not, write to the Free Software Foundation, Inc., 51 Franklin Street,
-dnl  Fifth Floor, Boston, MA 02110-1301, USA.
-
-
-include(`../config.m4')
-
-
-C void speed_cyclecounter (unsigned p[2]);
-C
-C Get the pentium rdtsc cycle counter, storing the least significant word in
-C p[0] and the most significant in p[1].
-C
-C cpuid is used to serialize execution.  On big measurements this won't be
-C significant but it may help make small single measurements more accurate.
-
-PROLOGUE(speed_cyclecounter)
-
-	C rdi	p
-
-	movq	%rbx, %r10
-	xorl	%eax, %eax
-	cpuid
-	rdtsc
-	movl	%eax, (%rdi)
-	movl	%edx, 4(%rdi)
-	movq	%r10, %rbx
-	ret
-EPILOGUE()
diff --git a/tune/x86_64.s b/tune/x86_64.s
new file mode 100644
index 00000000..93b3a3eb
--- /dev/null
+++ b/tune/x86_64.s
@@ -0,0 +1,48 @@
+;  x86 pentium time stamp counter access routine.
+;
+;  Copyright 1999, 2000, 2003, 2004, 2005 Free Software Foundation, Inc.
+;
+;  This file is part of the GNU MP Library.
+;
+;  The GNU MP Library is free software; you can redistribute it and/or
+;  modify it under the terms of the GNU Lesser General Public License as
+;  published by the Free Software Foundation; either version 2.1 of the
+;  License, or (at your option) any later version.
+;
+;  The GNU MP 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
+;  Lesser General Public License for more details.
+;
+;  You should have received a copy of the GNU Lesser General Public
+;  License along with the GNU MP Library; see the file COPYING.LIB.  If
+;  not, write to the Free Software Foundation, Inc., 51 Franklin Street,
+;  Fifth Floor, Boston, MA 02110-1301, USA.
+
+
+; void speed_cyclecounter (unsigned p[2]);
+;
+; Get the pentium rdtsc cycle counter, storing the least significant word in
+; p[0] and the most significant in p[1].
+;
+; cpuid is used to serialize execution.  On big measurements this won't be
+; significant but it may help make small single measurements more accurate.
+
+    bits 64
+    section .text
+
+    global speed_cyclecounter:function
+
+speed_cyclecounter:
+	; rdi	p
+
+	mov     r10, rbx
+	xor     eax, eax
+	cpuid
+	rdtsc
+	mov	    [rdi], eax 
+	mov     [rdi+4], edx
+	mov     rbx, r10
+	ret
+
+    end