dnl AMD64 mpn_mod_34lsub1 -- remainder modulo 2^48-1.
dnl Copyright 2000-2002, 2004, 2005, 2007, 2010-2012 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 1.0
C AMD K10 1.12
C Intel P4 3.25
C Intel core2 1.5
C Intel corei 1.5
C Intel atom 2.5
C VIA nano 1.75
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. In particular, try to avoid
adc and
C sbb to placate Pentium4.
C * It seems possible to reach 2.67 c/l by using a cleaner 6-way unrolling,
C without the dual loop exits.
ABI_SUPPORT(DOS64)
ABI_SUPPORT(STD64)
ASM_START()
TEXT
ALIGN(32)
PROLOGUE(mpn_mod_34lsub1)
FUNC_ENTRY(2)
mov $0x0000FFFFFFFFFFFF, %r11
sub $2, %rsi
ja L(gt2)
mov (ap), %rax
nop
jb L(1)
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(1): FUNC_EXIT()
ret
ALIGN(16)
L(gt2):
xor R32(%rax), R32(%rax)
xor R32(%rcx), R32(%rcx)
xor R32(%rdx), R32(%rdx)
xor %r8, %r8
xor %r9, %r9
xor %r10, %r10
L(top):
add (ap), %rax
adc $0, %r10
add 8(ap), %rcx
adc $0, %r8
add 16(ap), %rdx
adc $0, %r9
sub $3, %rsi
jng L(
end)
add 24(ap), %rax
adc $0, %r10
add 32(ap), %rcx
adc $0, %r8
add 40(ap), %rdx
lea 48(ap), ap
adc $0, %r9
sub $3, %rsi
jg L(top)
add $-24, ap
L(
end):
add %r9, %rax
adc %r10, %rcx
adc %r8, %rdx
inc %rsi
mov $0x1, R32(%r10)
js L(combine)
mov $0x10000, R32(%r10)
adc 24(ap), %rax
dec %rsi
js L(combine)
adc 32(ap), %rcx
mov $0x100000000, %r10
L(combine):
sbb %rsi, %rsi C
carry
mov %rax, %rdi C 0mod3
shr $48, %rax C 0mod3 high
and %r10, %rsi C
carry masked
and %r11, %rdi C 0mod3 low
mov R32(%rcx), R32(%r10) C 1mod3
add %rsi, %rax C apply
carry
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()
