dnl AMD64 mpn_addlsh1_n -- rp[] = up[] + (vp[] << 1)
dnl AMD64 mpn_rsblsh1_n -- rp[] = (vp[] << 1) - up[]
dnl Copyright 2003, 2005-2009, 2011, 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 cycles/limb
C AMD K8,K9 2
C AMD K10 2
C AMD bd1 ?
C AMD bobcat ?
C Intel P4 13
C Intel core2 3.45
C Intel NHM ?
C Intel SBR ?
C Intel atom ?
C VIA nano ?
C Sometimes speed degenerates, supposedly related to that some operand
C alignments cause cache conflicts.
C The speed is limited by decoding/issue bandwidth. There are 22 instructions
C in the loop, which corresponds to ceil(22/3)/4 = 1.83 c/l.
C INPUT PARAMETERS
define(`rp',`%rdi')
define(`up',`%rsi')
define(`vp',`%rdx')
define(`n', `%rcx')
ifdef(`OPERATION_addlsh1_n', `
define(ADDSUB, add)
define(ADCSBB, adc)
define(func, mpn_addlsh1_n)')
ifdef(`OPERATION_rsblsh1_n', `
define(ADDSUB, sub)
define(ADCSBB, sbb)
define(func, mpn_rsblsh1_n)')
MULFUNC_PROLOGUE(mpn_addlsh1_n mpn_rsblsh1_n)
ABI_SUPPORT(DOS64)
ABI_SUPPORT(STD64)
ASM_START()
TEXT
ALIGN(16)
PROLOGUE(func)
FUNC_ENTRY(4)
push %rbp
mov (vp), %r8
mov R32(n), R32(%rax)
lea (rp,n,8), rp
lea (up,n,8), up
lea (vp,n,8), vp
neg n
xor R32(%rbp), R32(%rbp)
and $3, R32(%rax)
je L(b00)
cmp $2, R32(%rax)
jc L(b01)
je L(b10)
L(b11): add %r8, %r8
mov 8(vp,n,8), %r9
adc %r9, %r9
mov 16(vp,n,8), %r10
adc %r10, %r10
sbb R32(%rax), R32(%rax) C save scy
ADDSUB (up,n,8), %r8
ADCSBB 8(up,n,8), %r9
mov %r8, (rp,n,8)
mov %r9, 8(rp,n,8)
ADCSBB 16(up,n,8), %r10
mov %r10, 16(rp,n,8)
sbb R32(%rbp), R32(%rbp) C save acy
add $3, n
jmp L(ent)
L(b10): add %r8, %r8
mov 8(vp,n,8), %r9
adc %r9, %r9
sbb R32(%rax), R32(%rax) C save scy
ADDSUB (up,n,8), %r8
ADCSBB 8(up,n,8), %r9
mov %r8, (rp,n,8)
mov %r9, 8(rp,n,8)
sbb R32(%rbp), R32(%rbp) C save acy
add $2, n
jmp L(ent)
L(b01): add %r8, %r8
sbb R32(%rax), R32(%rax) C save scy
ADDSUB (up,n,8), %r8
mov %r8, (rp,n,8)
sbb R32(%rbp), R32(%rbp) C save acy
inc n
L(ent): jns L(end)
ALIGN(16)
L(top): add R32(%rax), R32(%rax) C restore scy
mov (vp,n,8), %r8
L(b00): adc %r8, %r8
mov 8(vp,n,8), %r9
adc %r9, %r9
mov 16(vp,n,8), %r10
adc %r10, %r10
mov 24(vp,n,8), %r11
adc %r11, %r11
sbb R32(%rax), R32(%rax) C save scy
add R32(%rbp), R32(%rbp) C restore acy
ADCSBB (up,n,8), %r8
nop C Hammer speedup!
ADCSBB 8(up,n,8), %r9
mov %r8, (rp,n,8)
mov %r9, 8(rp,n,8)
ADCSBB 16(up,n,8), %r10
ADCSBB 24(up,n,8), %r11
mov %r10, 16(rp,n,8)
mov %r11, 24(rp,n,8)
sbb R32(%rbp), R32(%rbp) C save acy
add $4, n
js L(top)
L(end):
ifdef(`OPERATION_addlsh1_n',`
add R32(%rbp), R32(%rax)
neg R32(%rax)')
ifdef(`OPERATION_rsblsh1_n',`
sub R32(%rax), R32(%rbp)
movslq R32(%rbp), %rax')
pop %rbp
FUNC_EXIT()
ret
EPILOGUE()