dnl PowerPC-64 mpn_mod_34lsub1 -- modulo 2^48-1.
dnl Copyright 2005 Free Software Foundation, Inc.
dnl This file is part of the GNU MP Library.
dnl
dnl The GNU MP Library is free software; you can redistribute it and/or modify
dnl it under the terms of either:
dnl
dnl * the GNU Lesser General Public License as published by the Free
dnl Software Foundation; either version 3 of the License, or (at your
dnl option) any later version.
dnl
dnl or
dnl
dnl * the GNU General Public License as published by the Free Software
dnl Foundation; either version 2 of the License, or (at your option) any
dnl later version.
dnl
dnl or both in parallel, as here.
dnl
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 General Public License
dnl for more details.
dnl
dnl You should have received copies of the GNU General Public License and the
dnl GNU Lesser General Public License along with the GNU MP Library. If not,
dnl see https://www.gnu.org/licenses/.
include(`../config.m4')
C cycles/limb
C POWER3/PPC630 1.33
C POWER4/PPC970 1.5
C POWER5 1.32
C POWER6 2.35
C POWER7 1
C INPUT PARAMETERS
define(`up',`r3')
define(`n',`r4')
ASM_START()
PROLOGUE(mpn_mod_34lsub1)
li r8, 0
li r9, 0
li r10, 0
li r11, 0
cmpdi cr6, n, 3
blt cr6, L(lt3)
li r0, -0x5556 C 0xFFFFFFFFFFFFAAAA
rldimi r0, r0, 16, 32 C 0xFFFFFFFFAAAAAAAA
rldimi r0, r0, 32, 63 C 0xAAAAAAAAAAAAAAAB
mulhdu r0, r0, n
srdi r0, r0, 1 C r0 = [n / 3]
mtctr r0
ld r5, 0(up)
ld r6, 8(up)
ld r7, 16(up)
addi up, up, 24
bdz L(end)
ALIGN(16)
L(top): addc r8, r8, r5
nop
ld r5, 0(up)
adde r9, r9, r6
ld r6, 8(up)
adde r10, r10, r7
ld r7, 16(up)
addi up, up, 48
addze r11, r11
bdz L(endx)
addc r8, r8, r5
nop
ld r5, -24(up)
adde r9, r9, r6
ld r6, -16(up)
adde r10, r10, r7
ld r7, -8(up)
addze r11, r11
bdnz L(top)
addi up, up, 24
L(endx):
addi up, up, -24
L(end): addc r8, r8, r5
adde r9, r9, r6
adde r10, r10, r7
addze r11, r11
sldi r5, r0, 1
add r5, r5, r0 C r11 = n / 3 * 3
sub n, n, r5 C n = n mod 3
L(lt3): cmpdi cr6, n, 1
blt cr6, L(2)
ld r5, 0(up)
addc r8, r8, r5
li r6, 0
beq cr6, L(1)
ld r6, 8(up)
L(1): adde r9, r9, r6
addze r10, r10
addze r11, r11
L(2): rldicl r0, r8, 0, 16 C r0 = r8 mod 2^48
srdi r3, r8, 48 C r3 = r8 div 2^48
rldic r4, r9, 16, 16 C r4 = (r9 mod 2^32) << 16
srdi r5, r9, 32 C r5 = r9 div 2^32
rldic r6, r10, 32, 16 C r6 = (r10 mod 2^16) << 32
srdi r7, r10, 16 C r7 = r10 div 2^16
add r0, r0, r3
add r4, r4, r5
add r6, r6, r7
add r0, r0, r4
add r6, r6, r11
add r3, r0, r6
blr
EPILOGUE()
C |__r10__|__r9___|__r8___|
C |-----|-----|-----|-----|