glibc/sysdeps/rs6000/lshift.s

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# IBM POWER __mpn_lshift --
# Copyright (C) 1992, 1994 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., 59 Temple Place - Suite 330, Boston,
# MA 02111-1307, USA.
# INPUT PARAMETERS
# res_ptr r3
# s_ptr r4
# size r5
# cnt r6
.toc
.extern __mpn_lshift[DS]
.extern .__mpn_lshift
.csect [PR]
.align 2
.globl __mpn_lshift
.globl .__mpn_lshift
.csect __mpn_lshift[DS]
__mpn_lshift:
.long .__mpn_lshift, TOC[tc0], 0
.csect [PR]
.__mpn_lshift:
sli 0,5,2
cax 9,3,0
cax 4,4,0
sfi 8,6,32
mtctr 5 # put limb count in CTR loop register
lu 0,-4(4) # read most significant limb
sre 3,0,8 # compute carry out limb, and init MQ register
bdz Lend2 # if just one limb, skip loop
lu 0,-4(4) # read 2:nd most significant limb
sreq 7,0,8 # compute most significant limb of result
bdz Lend # if just two limb, skip loop
Loop: lu 0,-4(4) # load next lower limb
stu 7,-4(9) # store previous result during read latency
sreq 7,0,8 # compute result limb
bdn Loop # loop back until CTR is zero
Lend: stu 7,-4(9) # store 2:nd least significant limb
Lend2: sle 7,0,6 # compute least significant limb
st 7,-4(9) # store it" \
br