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diff --git a/gmp/mpn/x86/pentium4/sse2/sub_n.asm b/gmp/mpn/x86/pentium4/sse2/sub_n.asm
new file mode 100644
index 00000000..02d5f014
--- /dev/null
+++ b/gmp/mpn/x86/pentium4/sse2/sub_n.asm
@@ -0,0 +1,115 @@
+dnl  Intel Pentium-4 mpn_sub_n -- mpn subtraction.
+
+dnl  Copyright 2001, 2002 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 3 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 License
+dnl  along with the GNU MP Library.  If not, see http://www.gnu.org/licenses/.
+
+include(`../config.m4')
+
+
+C P4 Willamette, Northwood: 4.0 cycles/limb if dst!=src1 and dst!=src2
+C			    6.0 cycles/limb if dst==src1 or dst==src2
+C P4 Prescott:		    >= 5 cycles/limb
+
+
+C mp_limb_t mpn_sub_n (mp_ptr dst, mp_srcptr src1, mp_srcptr src2,
+C                      mp_size_t size);
+C mp_limb_t mpn_sub_nc (mp_ptr dst, mp_srcptr src1, mp_srcptr src2,
+C                       mp_size_t size, mp_limb_t carry);
+C
+C The main loop code is 2x unrolled so that the carry bit can alternate
+C between mm0 and mm1.
+
+defframe(PARAM_CARRY,20)
+defframe(PARAM_SIZE, 16)
+defframe(PARAM_SRC2, 12)
+defframe(PARAM_SRC1, 8)
+defframe(PARAM_DST,  4)
+
+dnl  re-use parameter space
+define(SAVE_EBX,`PARAM_SRC1')
+
+	TEXT
+	ALIGN(8)
+
+PROLOGUE(mpn_sub_nc)
+deflit(`FRAME',0)
+
+	movd	PARAM_CARRY, %mm0
+	jmp	L(start_nc)
+
+EPILOGUE()
+
+	ALIGN(8)
+PROLOGUE(mpn_sub_n)
+deflit(`FRAME',0)
+	pxor	%mm0, %mm0
+L(start_nc):
+	movl	PARAM_SRC1, %eax
+	movl	%ebx, SAVE_EBX
+	movl	PARAM_SRC2, %ebx
+	movl	PARAM_DST, %edx
+	movl	PARAM_SIZE, %ecx
+
+	leal	(%eax,%ecx,4), %eax	C src1 end
+	leal	(%ebx,%ecx,4), %ebx	C src2 end
+	leal	(%edx,%ecx,4), %edx	C dst end
+	negl	%ecx			C -size
+
+L(top):
+	C eax	src1 end
+	C ebx	src2 end
+	C ecx	counter, limbs, negative
+	C edx	dst end
+	C mm0	carry bit
+
+	movd	(%eax,%ecx,4), %mm1
+	movd	(%ebx,%ecx,4), %mm2
+	psubq	%mm2, %mm1
+
+	psubq	%mm0, %mm1
+	movd	%mm1, (%edx,%ecx,4)
+
+	psrlq	$63, %mm1
+
+	addl	$1, %ecx
+	jz	L(done_mm1)
+
+	movd	(%eax,%ecx,4), %mm0
+	movd	(%ebx,%ecx,4), %mm2
+	psubq	%mm2, %mm0
+
+	psubq	%mm1, %mm0
+	movd	%mm0, (%edx,%ecx,4)
+
+	psrlq	$63, %mm0
+
+	addl	$1, %ecx
+	jnz	L(top)
+
+
+	movd	%mm0, %eax
+	movl	SAVE_EBX, %ebx
+	emms
+	ret
+
+L(done_mm1):
+	movd	%mm1, %eax
+	movl	SAVE_EBX, %ebx
+	emms
+	ret
+
+EPILOGUE()