glibc/sysdeps/sparc/sparc64/rshift.S

/* SPARC v9 __mpn_rshift --

   Copyright (C) 1996, 1999 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., 59 Temple Place - Suite 330, Boston,
   MA 02111-1307, USA.  */

#include <sysdep.h>

/* INPUT PARAMETERS
   res_ptr	%o0
   src_ptr	%o1
   size		%o2
   cnt		%o3  */

	.register	%g2, #scratch
	.register	%g3, #scratch

ENTRY(__mpn_rshift)
	ldx	[%o1],%g2	! load first limb
	sub	%g0,%o3,%o5	! negate shift count
	add	%o2,-1,%o2
	andcc	%o2,4-1,%g4	! number of limbs in first loop
	sllx	%g2,%o5,%g1	! compute function result
	be,pn	%xcc,.L0	! if multiple of 4 limbs, skip first loop
	 mov	%g1,%g5

	sub	%o2,%g4,%o2	! adjust count for main loop

.Loop0:	ldx	[%o1+8],%g3
	add	%o0,8,%o0
	add	%o1,8,%o1
	srlx	%g2,%o3,%o4
	addcc	%g4,-1,%g4
	sllx	%g3,%o5,%g1
	mov	%g3,%g2
	or	%o4,%g1,%o4
	bne,pt	%xcc,.Loop0
	 stx	%o4,[%o0-8]

.L0:	brz,pn	%o2,.Lend
	 nop

.Loop:	ldx	[%o1+8],%g3
	add	%o0,32,%o0
	srlx	%g2,%o3,%o4
	addcc	%o2,-4,%o2
	sllx	%g3,%o5,%g1

	ldx	[%o1+16],%g2
	srlx	%g3,%o3,%g4
	or	%o4,%g1,%o4
	stx	%o4,[%o0-32]
	sllx	%g2,%o5,%g1

	ldx	[%o1+24],%g3
	srlx	%g2,%o3,%o4
	or	%g4,%g1,%g4
	stx	%g4,[%o0-24]
	sllx	%g3,%o5,%g1

	ldx	[%o1+32],%g2
	srlx	%g3,%o3,%g4
	or	%o4,%g1,%o4
	stx	%o4,[%o0-16]
	sllx	%g2,%o5,%g1

	add	%o1,32,%o1
	or	%g4,%g1,%g4
	bne,pt	%xcc,.Loop
	 stx	%g4,[%o0-8]

.Lend:	srlx	%g2,%o3,%g2
	stx	%g2,[%o0-0]

	jmpl	%o7+8,%g0
	 mov	%g5,%o0

END(__mpn_rshift)