dnl AMD64 mpn_mod_34lsub1 -- remainder modulo 2^48-1.
dnl Copyright 2000-2002, 2004, 2005, 2007, 2009-2012 Free Software Foundation,
dnl 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 AMD K8,K9 0.67 0.583 is possible with zero-reg instead of $0, 4-way
C AMD K10 0.67 this seems hard to beat
C AMD bd1 1
C AMD bobcat 1.07
C Intel P4 7.35 terrible, use old code
C Intel core2 1.25 1+epsilon with huge unrolling
C Intel NHM 1.15 this seems hard to beat
C Intel SBR 0.93
C Intel atom 2.5
C VIA nano 1.25 this seems hard to beat
C INPUT PARAMETERS
define(`ap', %rdi)
define(`n', %rsi)
C mp_limb_t mpn_mod_34lsub1 (mp_srcptr up, mp_size_t n)
C TODO
C * Review feed-in and wind-down code.
ABI_SUPPORT(DOS64)
ABI_SUPPORT(STD64)
ASM_START()
TEXT
ALIGN(32)
PROLOGUE(mpn_mod_34lsub1)
FUNC_ENTRY(2)
mov $0x0000FFFFFFFFFFFF, %r11
mov (ap), %rax
cmp $2, %rsi
ja L(gt2)
jb L(one)
mov 8(ap), %rsi
mov %rax, %rdx
shr $48, %rax C src[0] low
and %r11, %rdx C src[0] high
add %rdx, %rax
mov R32(%rsi), R32(%rdx)
shr $32, %rsi C src[1] high
add %rsi, %rax
shl $16, %rdx C src[1] low
add %rdx, %rax
L(one): FUNC_EXIT()
ret
C Don't change this, the wind-down code is not able to handle greater values
define(UNROLL,3)
L(gt2): mov 8(ap), %rcx
mov 16(ap), %rdx
xor %r9, %r9
add $24, ap
sub $eval(UNROLL*3+3), %rsi
jc L(end)
ALIGN(16)
L(top):
add (ap), %rax
adc 8(ap), %rcx
adc 16(ap), %rdx
adc $0, %r9
forloop(i,1,UNROLL-1,`dnl
add eval(i*24)(ap), %rax
adc eval(i*24+8)(ap), %rcx
adc eval(i*24+16)(ap), %rdx
adc $0, %r9
')dnl
add $eval(UNROLL*24), ap
sub $eval(UNROLL*3), %rsi
jnc L(top)
L(end):
lea L(tab)(%rip), %r8
ifdef(`PIC',
` movslq 36(%r8,%rsi,4), %r10
add %r10, %r8
jmp *%r8
',`
jmp *72(%r8,%rsi,8)
')
JUMPTABSECT
ALIGN(8)
L(tab): JMPENT( L(0), L(tab))
JMPENT( L(1), L(tab))
JMPENT( L(2), L(tab))
JMPENT( L(3), L(tab))
JMPENT( L(4), L(tab))
JMPENT( L(5), L(tab))
JMPENT( L(6), L(tab))
JMPENT( L(7), L(tab))
JMPENT( L(8), L(tab))
TEXT
L(6): add (ap), %rax
adc 8(ap), %rcx
adc 16(ap), %rdx
adc $0, %r9
add $24, ap
L(3): add (ap), %rax
adc 8(ap), %rcx
adc 16(ap), %rdx
jmp L(cj1)
L(7): add (ap), %rax
adc 8(ap), %rcx
adc 16(ap), %rdx
adc $0, %r9
add $24, ap
L(4): add (ap), %rax
adc 8(ap), %rcx
adc 16(ap), %rdx
adc $0, %r9
add $24, ap
L(1): add (ap), %rax
adc $0, %rcx
jmp L(cj2)
L(8): add (ap), %rax
adc 8(ap), %rcx
adc 16(ap), %rdx
adc $0, %r9
add $24, ap
L(5): add (ap), %rax
adc 8(ap), %rcx
adc 16(ap), %rdx
adc $0, %r9
add $24, ap
L(2): add (ap), %rax
adc 8(ap), %rcx
L(cj2): adc $0, %rdx
L(cj1): adc $0, %r9
L(0): add %r9, %rax
adc $0, %rcx
adc $0, %rdx
adc $0, %rax
mov %rax, %rdi C 0mod3
shr $48, %rax C 0mod3 high
and %r11, %rdi C 0mod3 low
mov R32(%rcx), R32(%r10) C 1mod3
shr $32, %rcx C 1mod3 high
add %rdi, %rax C apply 0mod3 low
movzwl %dx, R32(%rdi) C 2mod3
shl $16, %r10 C 1mod3 low
add %rcx, %rax C apply 1mod3 high
shr $16, %rdx C 2mod3 high
add %r10, %rax C apply 1mod3 low
shl $32, %rdi C 2mod3 low
add %rdx, %rax C apply 2mod3 high
add %rdi, %rax C apply 2mod3 low
FUNC_EXIT()
ret
EPILOGUE()