mpir/mpn/powerpc64/rshift.asm
2008-04-17 21:03:07 +00:00

110 lines
2.3 KiB
NASM

dnl PowerPC-64 mpn_rshift -- rp[] = up[] >> cnt
dnl Copyright 2003, 2005 Free Software Foundation, Inc.
dnl This file is part of the GNU MP Library.
dnl The GNU MP Library is free software; you can redistribute it and/or modify
dnl it under the terms of the GNU Lesser General Public License as published
dnl by the Free Software Foundation; either version 2.1 of the License, or (at
dnl your option) any later version.
dnl The GNU MP Library is distributed in the hope that it will be useful, but
dnl WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
dnl or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
dnl License for more details.
dnl You should have received a copy of the GNU Lesser General Public License
dnl along with the GNU MP Library; see the file COPYING.LIB. If not, write
dnl to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
dnl Boston, MA 02110-1301, USA.
include(`../config.m4')
C cycles/limb
C POWER3/PPC630: 1.5
C POWER4/PPC970: 3.0
C INPUT PARAMETERS
define(`rp',`r3')
define(`up',`r4')
define(`n',`r5')
define(`cnt',`r6')
define(`tnc',`r5')
define(`v0',`r0')
define(`v1',`r7')
define(`u0',`r8')
define(`u1',`r9')
define(`h0',`r10')
define(`h1',`r11')
ASM_START()
PROLOGUE(mpn_rshift)
ifdef(`HAVE_ABI_mode32',
` rldicl n, n, 0, 32') C zero extend n
mtctr n C copy n to count register
addi rp, rp, -16
subfic tnc, cnt, 64 C reverse shift count
ld u0, 0(up)
srd h0, u0, cnt
sld r12, u0, tnc C return value
bdz L(1) C jump for n = 1
ld u1, 8(up)
bdz L(2) C jump for n = 2
ldu u0, 16(up)
bdz L(end) C jump for n = 3
L(oop): sld v1, u1, tnc
srd h1, u1, cnt
ld u1, 8(up)
or h0, v1, h0
stdu h0, 16(rp)
bdz L(exit)
sld v0, u0, tnc
srd h0, u0, cnt
ldu u0, 16(up)
or h1, v0, h1
std h1, 8(rp)
bdnz L(oop)
L(end): sld v1, u1, tnc
srd h1, u1, cnt
or h0, v1, h0
stdu h0, 16(rp)
sld v0, u0, tnc
srd h0, u0, cnt
or h1, v0, h1
std h1, 8(rp)
L(1): std h0, 16(rp)
ifdef(`HAVE_ABI_mode32',
` srdi r3, r12, 32
mr r4, r12
',` mr r3, r12
')
blr
L(exit): sld v0, u0, tnc
srd h0, u0, cnt
or h1, v0, h1
std h1, 8(rp)
L(2): sld v1, u1, tnc
srd h1, u1, cnt
or h0, v1, h0
stdu h0, 16(rp)
std h1, 8(rp)
ifdef(`HAVE_ABI_mode32',
` srdi r3, r12, 32
mr r4, r12
',` mr r3, r12
')
blr
EPILOGUE()