dnl ARM v6t2 mpn_divrem_1 and mpn_preinv_divrem_1.
dnl Contributed to the GNU project by Torbjörn Granlund.
dnl Copyright 2012 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 norm unorm frac
C StrongARM - - -
C XScale - - -
C Cortex-A7 ? ? ?
C Cortex-A8 ? ? ?
C Cortex-A9 13 14 13
C Cortex-A15 11.4 11.8 11.1
C TODO
C * Optimise inner-loops better, they could likely run a cycle or two faster.
C * Decrease register usage, streamline non-loop code.
define(`qp_arg', `r0')
define(`fn', `r1')
define(`up_arg', `r2')
define(`n_arg', `r3')
define(`d_arg', `0')
define(`dinv_arg',`4')
define(`cnt_arg', `8')
define(`n', `r9')
define(`qp', `r5')
define(`up', `r6')
define(`cnt', `r7')
define(`tnc', `r10')
define(`dinv', `r0')
define(`d', `r4')
ASM_START()
PROLOGUE(mpn_preinv_divrem_1)
stmfd sp!, {r4, r5, r6, r7, r8, r9, r10, r11, lr}
ldr d, [sp, #9*4+d_arg]
ldr cnt, [sp, #9*4+cnt_arg]
str r1, [sp, #9*4+d_arg] C reuse d stack slot for fn
sub n, r3, #1
add r3, r1, n
cmp d, #0
add qp, qp_arg, r3, lsl #2 C put qp at Q[] end
add up, up_arg, n, lsl #2 C put up at U[] end
ldr dinv, [sp, #9*4+dinv_arg]
blt L(nent)
b L(uent)
EPILOGUE()
PROLOGUE(mpn_divrem_1)
stmfd sp!, {r4, r5, r6, r7, r8, r9, r10, r11, lr}
sub n, r3, #1
ldr d, [sp, #9*4+d_arg] C d
str r1, [sp, #9*4+d_arg] C reuse d stack slot for fn
add r3, r1, n
cmp d, #0
add qp, qp_arg, r3, lsl #2 C put qp at Q[] end
add up, up_arg, n, lsl #2 C put up at U[] end
blt L(normalised)
L(unnorm):
clz cnt, d
mov r0, d, lsl cnt C pass d << cnt
bl mpn_invert_limb
L(uent):
mov d, d, lsl cnt C d <<= cnt
cmp n, #0
mov r1, #0 C r
blt L(frac)
ldr r11, [up, #0]
rsb tnc, cnt, #32
mov r1, r11, lsr tnc
mov r11, r11, lsl cnt
beq L(uend)
ldr r3, [up, #-4]!
orr r2, r11, r3, lsr tnc
b L(mid)
L(utop):
mls r1, d, r8, r11
mov r11, r3, lsl cnt
ldr r3, [up, #-4]!
cmp r1, r2
addhi r1, r1, d
subhi r8, r8, #1
orr r2, r11, r3, lsr tnc
cmp r1, d
bcs L(ufx)
L(uok): str r8, [qp], #-4
L(mid): add r8, r1, #1
mov r11, r2
umlal r2, r8, r1, dinv
subs n, n, #1
bne L(utop)
mls r1, d, r8, r11
mov r11, r3, lsl cnt
cmp r1, r2
addhi r1, r1, d
subhi r8, r8, #1
cmp r1, d
rsbcs r1, d, r1
addcs r8, r8, #1
str r8, [qp], #-4
L(uend):add r8, r1, #1
mov r2, r11
umlal r2, r8, r1, dinv
mls r1, d, r8, r11
cmp r1, r2
addhi r1, r1, d
subhi r8, r8, #1
cmp r1, d
rsbcs r1, d, r1
addcs r8, r8, #1
str r8, [qp], #-4
L(frac):
ldr r2, [sp, #9*4+d_arg] C fn
cmp r2, #0
beq L(fend)
L(ftop):mov r6, #0
add r3, r1, #1
umlal r6, r3, r1, dinv
mov r8, #0
mls r1, d, r3, r8
cmp r1, r6
addhi r1, r1, d
subhi r3, r3, #1
subs r2, r2, #1
str r3, [qp], #-4
bne L(ftop)
L(fend):mov r11, r1, lsr cnt
L(rtn): mov r0, r11
ldmfd sp!, {r4, r5, r6, r7, r8, r9, r10, r11, pc}
L(normalised):
mov r0, d
bl mpn_invert_limb
L(nent):
cmp n, #0
mov r11, #0 C r
blt L(nend)
ldr r11, [up, #0]
cmp r11, d
movlo r2, #0 C hi q limb
movhs r2, #1 C hi q limb
subhs r11, r11, d
str r2, [qp], #-4
cmp n, #0
beq L(nend)
L(ntop):ldr r1, [up, #-4]!
add r12, r11, #1
umlal r1, r12, r11, dinv
ldr r3, [up, #0]
mls r11, d, r12, r3
cmp r11, r1
addhi r11, r11, d
subhi r12, r12, #1
cmp d, r11
bls L(nfx)
L(nok): str r12, [qp], #-4
subs n, n, #1
bne L(ntop)
L(nend):mov r1, r11 C r
mov cnt, #0 C shift cnt
b L(frac)
L(nfx): add r12, r12, #1
rsb r11, d, r11
b L(nok)
L(ufx): rsb r1, d, r1
add r8, r8, #1
b L(uok)
EPILOGUE()