dnl X86-32
and X86-64 mpn_popcount using SSE2.
dnl Copyright 2006, 2007, 2011, 2015, 2020 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 32-bit popcount hamdist
C cycles/limb cycles/limb
C P5 -
C P6
model 0-8,10-12 -
C P6
model 9 (Banias) ?
C P6
model 13 (Dothan) 4
C P4
model 0 (Willamette) ?
C P4
model 1 (?) ?
C P4
model 2 (Northwood) 3.9
C P4
model 3 (Prescott) ?
C P4
model 4 (Nocona) ?
C AMD K6 -
C AMD K7 -
C AMD K8 ?
C 64-bit popcount hamdist
C cycles/limb cycles/limb
C P4
model 4 (Nocona): 8
C AMD K8,K9 7.5
C AMD K10 3.5
C Intel core2 3.68
C Intel corei 3.15
C Intel atom 10.8
C VIA nano 6.5
C TODO
C * Make an mpn_hamdist based on
this. Alignment could either be handled by
C using movdqu
for one operand
and movdqa
for the other,
or by painfully
C shifting as we go. Unfortunately, there seem to be no usable shift
C instruction, except
for one that takes an immediate count.
C * It would probably be possible to cut a few cycles/limb using software
C pipelining.
C * There are 35 decode slots unused by the SSE2 instructions. Loop control
C needs just 2
or 3 slots, leaving around 32 slots.
This allows a parallel
C integer based popcount. Such a combined loop would handle 6 limbs in
C about 30 cycles on K8.
C * We could save a
byte or two by using 32-bit operations on areg.
C * Check
if using movdqa to a temp of
and then register-based pand is faster.
ifelse(GMP_LIMB_BITS,`32
',
` define(`up
', `%edx')
define(`n
', `%ecx')
define(`areg
',`%eax')
define(`breg
',`%ebx')
define(`
zero',`%xmm4')
define(`LIMB32
',` $1')
define(`LIMB64
',`dnl')
',`
define(`up
', `%rdi')
define(`n
', `%rsi')
define(`areg
',`%rax')
define(`breg
',`%rdx')
define(`
zero',`%xmm8')
define(`LIMB32
',`dnl')
define(`LIMB64
',` $1')
')
define(`mm01010101
',`%xmm6')
define(`mm00110011
',`%xmm7')
define(`mm00001111
',`%xmm2')
define(`GMP_LIMB_BYTES
', eval(GMP_LIMB_BITS/8))
define(`LIMBS_PER_XMM
', eval(16/GMP_LIMB_BYTES))
define(`LIMBS_PER_2XMM
', eval(32/GMP_LIMB_BYTES))
undefine(`psadbw
') C override inherited m4 version
C
This file is shared between 32-bit
and 64-bit builds. Only the former has
C LEAL. Default LEAL as an
alias of
LEA.
ifdef(`LEAL
',,`define(`LEAL', `
LEA($1,$2)
')')
ASM_START()
C Make cnsts global to work around Apple relocation bug.
ifdef(`DARWIN
',`
define(`cnsts
', MPN(popccnsts))
GLOBL cnsts
')
TEXT
ALIGN(32)
PROLOGUE(mpn_popcount)
LIMB32(`
mov 4(%
esp), up
')
LIMB32(`
mov 8(%
esp), n
')
LIMB32(`
push %ebx
')
pxor %xmm3, %xmm3 C
zero grand total count
LIMB64(`pxor
zero,
zero ')
LEAL( cnsts, breg)
movdqa -48(breg), mm01010101
movdqa -32(breg), mm00110011
movdqa -16(breg), mm00001111
mov up, areg
and $-16, up C round `up
' down to 128-bit boundary
and $12, areg C 32:areg = 0, 4, 8, 12
C 64:areg = 0, 8
movdqa (up), %xmm0
pand 64(breg,areg,4), %xmm0
shr $m4_log2(GMP_LIMB_BYTES), %
eax
add areg, n C compensate n
for rounded down `up
'
pxor %xmm4, %xmm4
sub $LIMBS_PER_XMM, n
jbe L(sum)
sub $LIMBS_PER_XMM, n
ja L(ent)
jmp L(lsum)
ALIGN(16)
L(top): movdqa (up), %xmm0
L(ent): movdqa 16(up), %xmm4
movdqa %xmm0, %xmm1
movdqa %xmm4, %xmm5
psrld $1, %xmm0
psrld $1, %xmm4
pand mm01010101, %xmm0
pand mm01010101, %xmm4
psubd %xmm0, %xmm1
psubd %xmm4, %xmm5
movdqa %xmm1, %xmm0
movdqa %xmm5, %xmm4
psrlq $2, %xmm1
psrlq $2, %xmm5
pand mm00110011, %xmm0
pand mm00110011, %xmm4
pand mm00110011, %xmm1
pand mm00110011, %xmm5
paddq %xmm0, %xmm1
paddq %xmm4, %xmm5
LIMB32(`pxor
zero,
zero ')
add $32, up
sub $LIMBS_PER_2XMM, n
paddq %xmm5, %xmm1
movdqa %xmm1, %xmm0
psrlq $4, %xmm1
pand mm00001111, %xmm0
pand mm00001111, %xmm1
paddq %xmm0, %xmm1
psadbw
zero, %xmm1
paddq %xmm1, %xmm3 C
add to grand total
jnc L(top)
L(
end):
add $LIMBS_PER_2XMM, n
jz L(rt)
movdqa (up), %xmm0
pxor %xmm4, %xmm4
sub $LIMBS_PER_XMM, n
jbe L(sum)
L(lsum):
movdqa %xmm0, %xmm4
movdqa 16(up), %xmm0
L(sum):
shl $m4_log2(GMP_LIMB_BYTES), n
and $12, n
pand (breg,n,4), %xmm0
movdqa %xmm0, %xmm1
movdqa %xmm4, %xmm5
psrld $1, %xmm0
psrld $1, %xmm4
pand mm01010101, %xmm0
pand mm01010101, %xmm4
psubd %xmm0, %xmm1
psubd %xmm4, %xmm5
movdqa %xmm1, %xmm0
movdqa %xmm5, %xmm4
psrlq $2, %xmm1
psrlq $2, %xmm5
pand mm00110011, %xmm0
pand mm00110011, %xmm4
pand mm00110011, %xmm1
pand mm00110011, %xmm5
paddq %xmm0, %xmm1
paddq %xmm4, %xmm5
LIMB32(`pxor
zero,
zero ')
paddq %xmm5, %xmm1
movdqa %xmm1, %xmm0
psrlq $4, %xmm1
pand mm00001111, %xmm0
pand mm00001111, %xmm1
paddq %xmm0, %xmm1
psadbw
zero, %xmm1
paddq %xmm1, %xmm3 C
add to grand total
C
Add the two 64-bit halves of the grand total counter
L(rt): movdqa %xmm3, %xmm0
psrldq $8, %xmm3
paddq %xmm3, %xmm0
movd %xmm0, areg C movq avoided due to gas bug
LIMB32(`
pop %ebx
')
ret
EPILOGUE()
DEF_OBJECT(dummy,16)
C Three magic constants used
for masking out bits
.
byte 0x55,0x55,0x55,0x55,0x55,0x55,0x55,0x55
.
byte 0x55,0x55,0x55,0x55,0x55,0x55,0x55,0x55
.
byte 0x33,0x33,0x33,0x33,0x33,0x33,0x33,0x33
.
byte 0x33,0x33,0x33,0x33,0x33,0x33,0x33,0x33
.
byte 0x0f,0x0f,0x0f,0x0f,0x0f,0x0f,0x0f,0x0f
.
byte 0x0f,0x0f,0x0f,0x0f,0x0f,0x0f,0x0f,0x0f
cnsts:
C Masks
for high
end of number
.
byte 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff
.
byte 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff
.
byte 0xff,0xff,0xff,0xff,0x00,0x00,0x00,0x00
.
byte 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00
.
byte 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff
.
byte 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00
.
byte 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff
.
byte 0xff,0xff,0xff,0xff,0x00,0x00,0x00,0x00
C Masks
for low
end of number
.
byte 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff
.
byte 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff
.
byte 0x00,0x00,0x00,0x00,0xff,0xff,0xff,0xff
.
byte 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff
.
byte 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00
.
byte 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff
.
byte 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00
.
byte 0x00,0x00,0x00,0x00,0xff,0xff,0xff,0xff
END_OBJECT(dummy)
ASM_END()
