dnl ARM mpn_addmul_3.
dnl Contributed to the GNU project by Torbjörn Granlund.
dnl Copyright 2013 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 StrongARM: -
C XScale -
C ARM11 4.33
C Cortex-A5 3.28
C Cortex-A7 3.25
C Cortex-A8 3.17
C Cortex-A9 2.125
C Cortex-A15 2
C Cortex-A17 2.11
C Cortex-A53 4.18
C TODO
C * Use a fast path for n <= KARATSUBA_MUL_THRESHOLD using a jump table,
C avoiding the current multiply.
C * Start the first multiply or multiplies early.
define(`rp',`r0')
define(`up',`r1')
define(`n', `r2')
define(`vp',`r3')
define(`v0',`r4') define(`v1',`r5') define(`v2',`r6')
define(`u0',`r3') define(`u1',`r14')
define(`w0',`r7') define(`w1',`r8') define(`w2',`r9')
define(`cy0',`r10') define(`cy1',`r11') define(`cy2',`r12')
ASM_START()
PROLOGUE(mpn_addmul_3)
push { r4-r11, r14 }
ldr w0, =0xaaaaaaab C 3^{-1} mod 2^32
ldm vp, { v0,v1,v2 }
mov cy0, #0
mov cy1, #0
mov cy2, #0
C Tricky n mod 6
mul w0, w0, n C n * 3^{-1} mod 2^32
and w0, w0, #0xc0000001 C pseudo-CRT mod 3,2
sub n, n, #3
ifdef(`PIC',`
add pc, pc, w0, ror $28
nop
b L(b0)
b L(b2)
b L(b4)
.word 0xe7f000f0 C udf
b L(b3)
b L(b5)
b L(b1)
',`
ldr pc, [pc, w0, ror $28]
nop
.word L(b0), L(b2), L(b4), 0, L(b3), L(b5), L(b1)
')
L(b5): add up, up, #-8
ldr w1, [rp, #0]
ldr w2, [rp, #4]
ldr u1, [up, #8]
b L(lo5)
L(b4): add rp, rp, #-4
add up, up, #-12
ldr w2, [rp, #4]
ldr w0, [rp, #8]
ldr u0, [up, #12]
b L(lo4)
L(b3): add rp, rp, #-8
add up, up, #-16
ldr w0, [rp, #8]
ldr w1, [rp, #12]
ldr u1, [up, #16]
b L(lo3)
L(b1): add rp, rp, #8
ldr w2, [rp, #-8]
ldr w0, [rp, #-4]
ldr u1, [up, #0]
b L(lo1)
L(b0): add rp, rp, #4
add up, up, #-4
ldr w0, [rp, #-4]
ldr w1, [rp, #0]
ldr u0, [up, #4]
b L(lo0)
L(b2): add rp, rp, #12
add up, up, #4
ldr w1, [rp, #-12]
ldr w2, [rp, #-8]
ldr u0, [up, #-4]
ALIGN(16)
L(top): ldr w0, [rp, #-4]
umaal w1, cy0, u0, v0
ldr u1, [up, #0]
umaal w2, cy1, u0, v1
str w1, [rp, #-12]
umaal w0, cy2, u0, v2
L(lo1): ldr w1, [rp, #0]
umaal w2, cy0, u1, v0
ldr u0, [up, #4]
umaal w0, cy1, u1, v1
str w2, [rp, #-8]
umaal w1, cy2, u1, v2
L(lo0): ldr w2, [rp, #4]
umaal w0, cy0, u0, v0
ldr u1, [up, #8]
umaal w1, cy1, u0, v1
str w0, [rp, #-4]
umaal w2, cy2, u0, v2
L(lo5): ldr w0, [rp, #8]
umaal w1, cy0, u1, v0
ldr u0, [up, #12]
umaal w2, cy1, u1, v1
str w1, [rp, #0]
umaal w0, cy2, u1, v2
L(lo4): ldr w1, [rp, #12]
umaal w2, cy0, u0, v0
ldr u1, [up, #16]
umaal w0, cy1, u0, v1
str w2, [rp, #4]
umaal w1, cy2, u0, v2
L(lo3): ldr w2, [rp, #16]
umaal w0, cy0, u1, v0
ldr u0, [up, #20]
umaal w1, cy1, u1, v1
str w0, [rp, #8]
umaal w2, cy2, u1, v2
L(lo2): subs n, n, #6
add up, up, #24
add rp, rp, #24
bge L(top)
L(end): umaal w1, cy0, u0, v0
ldr u1, [up, #0]
umaal w2, cy1, u0, v1
str w1, [rp, #-12]
mov w0, #0
umaal w0, cy2, u0, v2
umaal w2, cy0, u1, v0
umaal w0, cy1, u1, v1
str w2, [rp, #-8]
umaal cy1, cy2, u1, v2
adds w0, w0, cy0
str w0, [rp, #-4]
adcs w1, cy1, #0
str w1, [rp, #0]
adc r0, cy2, #0
pop { r4-r11, pc }
EPILOGUE()