/* Shift a limb left, low level routine.
   Copyright (C) 1996, 1997 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C 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 C 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 C 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>

/* mp_limb_t mpn_lshift (mp_ptr wp, mp_srcptr up, mp_size_t usize,
  			 unsigned int cnt)  */

EALIGN(__mpn_lshift,3,0)
	mtctr	%r5		# copy size into CTR
	cmplwi	%cr0,%r5,16	# is size < 16
	slwi	%r0,%r5,2
	add	%r7,%r3,%r0	# make r7 point at end of res
	add	%r4,%r4,%r0	# make r4 point at end of s1
	lwzu	%r11,-4(%r4)	# load first s1 limb
	subfic	%r8,%r6,32
	srw	%r3,%r11,%r8	# compute function return value
	bge	%cr0,L(big)	# branch if size >= 16

	bdz	L(end1)

0:	lwzu	%r10,-4(%r4)
	slw	%r9,%r11,%r6
	srw	%r12,%r10,%r8
	or	%r9,%r9,%r12
	stwu	%r9,-4(%r7)
	bdz	L(end2)
	lwzu	%r11,-4(%r4)
	slw	%r9,%r10,%r6
	srw	%r12,%r11,%r8
	or	%r9,%r9,%r12
	stwu	%r9,-4(%r7)
	bdnz	0b

L(end1):slw	%r0,%r11,%r6
	stw	%r0,-4(%r7)
	blr


/* Guaranteed not to succeed.  */
L(boom): tweq    %r0,%r0

/* We imitate a case statement, by using (yuk!) fixed-length code chunks,
   of size 4*12 bytes.  We have to do this (or something) to make this PIC.  */
L(big):	mflr    %r9
	bltl-   %cr0,L(boom)	# Never taken, only used to set LR.
	slwi    %r10,%r6,4
	mflr    %r12
	add     %r10,%r12,%r10
	slwi	%r8,%r6,5
	add     %r10,%r8,%r10
	mtctr   %r10
	addi	%r5,%r5,-1
	mtlr    %r9
	bctr

L(end2):slw	%r0,%r10,%r6
	stw	%r0,-4(%r7)
	blr

#define DO_LSHIFT(n) \
	mtctr	%r5;							\
0:	lwzu	%r10,-4(%r4);						\
	slwi	%r9,%r11,n;						\
	inslwi	%r9,%r10,n,32-n;					\
	stwu	%r9,-4(%r7);						\
	bdz-	L(end2);						\
	lwzu	%r11,-4(%r4);						\
	slwi	%r9,%r10,n;						\
	inslwi	%r9,%r11,n,32-n;					\
	stwu	%r9,-4(%r7);						\
	bdnz	0b;							\
	b	L(end1)

	DO_LSHIFT(1)
	DO_LSHIFT(2)
	DO_LSHIFT(3)
	DO_LSHIFT(4)
	DO_LSHIFT(5)
	DO_LSHIFT(6)
	DO_LSHIFT(7)
	DO_LSHIFT(8)
	DO_LSHIFT(9)
	DO_LSHIFT(10)
	DO_LSHIFT(11)
	DO_LSHIFT(12)
	DO_LSHIFT(13)
	DO_LSHIFT(14)
	DO_LSHIFT(15)
	DO_LSHIFT(16)
	DO_LSHIFT(17)
	DO_LSHIFT(18)
	DO_LSHIFT(19)
	DO_LSHIFT(20)
	DO_LSHIFT(21)
	DO_LSHIFT(22)
	DO_LSHIFT(23)
	DO_LSHIFT(24)
	DO_LSHIFT(25)
	DO_LSHIFT(26)
	DO_LSHIFT(27)
	DO_LSHIFT(28)
	DO_LSHIFT(29)
	DO_LSHIFT(30)
	DO_LSHIFT(31)

END(__mpn_lshift)