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-rw-r--r--sysdeps/i386/i586/sub_n.S136
1 files changed, 136 insertions, 0 deletions
diff --git a/sysdeps/i386/i586/sub_n.S b/sysdeps/i386/i586/sub_n.S
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+/* Pentium __mpn_sub_n -- Subtract two limb vectors of the same length > 0
+   and store difference in a third limb vector.
+
+Copyright (C) 1992, 1994, 1995 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 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 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 Library General Public
+License for more details.
+
+You should have received a copy of the GNU Library General Public License
+along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
+the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+/*
+   INPUT PARAMETERS
+   res_ptr	(sp + 4)
+   s1_ptr	(sp + 8)
+   s2_ptr	(sp + 12)
+   size		(sp + 16)
+*/
+
+#define r1	%eax
+#define r2	%edx
+#define src1	%esi
+#define src2	%ebp
+#define dst	%edi
+#define x	%ebx
+
+#include "sysdep.h"
+#include "asm-syntax.h"
+
+.text
+	ALIGN (3)
+	.globl C_SYMBOL_NAME(__mpn_sub_n)
+C_SYMBOL_NAME(__mpn_sub_n:)
+	pushl	%edi
+	pushl	%esi
+	pushl	%ebx
+	pushl	%ebp
+
+	movl	20(%esp),dst		/* res_ptr */
+	movl	24(%esp),src1		/* s1_ptr */
+	movl	28(%esp),src2		/* s2_ptr */
+	movl	32(%esp),%ecx		/* size */
+
+	movl	(src2),x
+
+	decl	%ecx
+	movl	%ecx,r2
+	shrl	$3,%ecx
+	andl	$7,r2
+	testl	%ecx,%ecx		/* zero carry flag */
+	jz	Lend
+	pushl	r2
+
+	ALIGN (3)
+Loop:	movl	28(dst),%eax		/* fetch destination cache line */
+	leal	32(dst),dst
+
+L1:	movl	(src1),r1
+	movl	4(src1),r2
+	sbbl	x,r1
+	movl	4(src2),x
+	sbbl	x,r2
+	movl	8(src2),x
+	movl	r1,-32(dst)
+	movl	r2,-28(dst)
+
+L2:	movl	8(src1),r1
+	movl	12(src1),r2
+	sbbl	x,r1
+	movl	12(src2),x
+	sbbl	x,r2
+	movl	16(src2),x
+	movl	r1,-24(dst)
+	movl	r2,-20(dst)
+
+L3:	movl	16(src1),r1
+	movl	20(src1),r2
+	sbbl	x,r1
+	movl	20(src2),x
+	sbbl	x,r2
+	movl	24(src2),x
+	movl	r1,-16(dst)
+	movl	r2,-12(dst)
+
+L4:	movl	24(src1),r1
+	movl	28(src1),r2
+	sbbl	x,r1
+	movl	28(src2),x
+	sbbl	x,r2
+	movl	32(src2),x
+	movl	r1,-8(dst)
+	movl	r2,-4(dst)
+
+	leal	32(src1),src1
+	leal	32(src2),src2
+	decl	%ecx
+	jnz	Loop
+
+	popl	r2
+Lend:
+	decl	r2			/* test r2 w/o clobbering carry */
+	js	Lend2
+	incl	r2
+Loop2:
+	leal	4(dst),dst
+	movl	(src1),r1
+	sbbl	x,r1
+	movl	4(src2),x
+	movl	r1,-4(dst)
+	leal	4(src1),src1
+	leal	4(src2),src2
+	decl	r2
+	jnz	Loop2
+Lend2:
+	movl	(src1),r1
+	sbbl	x,r1
+	movl	r1,(dst)
+
+	sbbl	%eax,%eax
+	negl	%eax
+
+	popl	%ebp
+	popl	%ebx
+	popl	%esi
+	popl	%edi
+	ret