dnl Intel Pentium 4 mpn_popcount, mpn_hamdist -- population count
and
dnl hamming distance.
dnl Copyright 2000-2002, 2007 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 popcount hamdist
C P3
model 9 (Banias) ? ?
C P3
model 13 (Dothan) 6 6
C P4
model 0 (Willamette)
C P4
model 1 (?)
C P4
model 2 (Northwood) 8 9
C P4
model 3 (Prescott) 8 9
C P4
model 4 (Nocona)
C unsigned long mpn_popcount (mp_srcptr src, mp_size_t size)
;
C unsigned long mpn_hamdist (mp_srcptr src, mp_srcptr src2, mp_size_t size)
;
C
C Loading with unaligned movq
's costs an extra 1 c/l and hence is avoided.
C Two
movd's and a punpckldq seems to be the same speed as an aligned movq,
C
and using them saves fiddling about with alignment testing on entry.
C
C
For popcount there
's 13 mmx instructions in the loop, so perhaps 6.5 c/l
C might be possible, but 8 c/l relying on out-of-order execution is already
C quite reasonable.
ifdef(`OPERATION_popcount
',,
`
ifdef(`OPERATION_hamdist
',,
`m4_error(`Need OPERATION_popcount
or OPERATION_hamdist defined
')')
')
define(HAM,
m4_assert_numargs(1)
`
ifdef(`OPERATION_hamdist
',`$1')
')
define(
POP,
m4_assert_numargs(1)
`
ifdef(`OPERATION_popcount
',`$1')
')
HAM(`
defframe(PARAM_SIZE, 12)
defframe(PARAM_SRC2, 8)
defframe(PARAM_SRC, 4)
define(M4_function,mpn_hamdist)
')
POP(`
defframe(PARAM_SIZE, 8)
defframe(PARAM_SRC, 4)
define(M4_function,mpn_popcount)
')
MULFUNC_PROLOGUE(mpn_popcount mpn_hamdist)
ifdef(`PIC
',,`
dnl non-PIC
RODATA
ALIGN(8)
L(rodata_AAAAAAAAAAAAAAAA):
.long 0xAAAAAAAA
.long 0xAAAAAAAA
L(rodata_3333333333333333):
.long 0x33333333
.long 0x33333333
L(rodata_0F0F0F0F0F0F0F0F):
.long 0x0F0F0F0F
.long 0x0F0F0F0F
')
TEXT
ALIGN(16)
PROLOGUE(M4_function)
deflit(`FRAME
',0)
movl PARAM_SIZE, %
ecx
movl PARAM_SRC, %
eax
ifdef(`PIC
',`
movl $0xAAAAAAAA, %
edx
movd %
edx, %mm7
punpckldq %mm7, %mm7
movl $0x33333333, %
edx
movd %
edx, %mm6
punpckldq %mm6, %mm6
movl $0x0F0F0F0F, %
edx
movd %
edx, %mm5
punpckldq %mm5, %mm5
HAM(` movl PARAM_SRC2, %
edx')
',`
dnl non-PIC
HAM(` movl PARAM_SRC2, %
edx')
movq L(rodata_AAAAAAAAAAAAAAAA), %mm7
movq L(rodata_3333333333333333), %mm6
movq L(rodata_0F0F0F0F0F0F0F0F), %mm5
')
pxor %mm4, %mm4 C
zero
pxor %mm0, %mm0 C total
subl $1, %
ecx
ja L(top)
L(last):
movd (%
eax,%
ecx,4), %mm1 C src high limb
HAM(`
movd (%
edx,%
ecx,4), %mm2
pxor %mm2, %mm1
')
jmp L(loaded)
L(top):
C
eax src
C ebx
C
ecx counter, size-1 to 2
or 1, inclusive
C
edx [hamdist] src2
C
C mm0 total (low
dword)
C mm1 (scratch)
C mm2 (scratch)
C mm3
C mm4 0x0000000000000000
C mm5 0x0F0F0F0F0F0F0F0F
C mm6 0x3333333333333333
C mm7 0xAAAAAAAAAAAAAAAA
movd (%
eax), %mm1
movd 4(%
eax), %mm2
punpckldq %mm2, %mm1
addl $8, %
eax
HAM(`
movd (%
edx), %mm2
movd 4(%
edx), %mm3
punpckldq %mm3, %mm2
pxor %mm2, %mm1
addl $8, %
edx
')
L(loaded):
movq %mm7, %mm2
pand %mm1, %mm2
psrlq $1, %mm2
psubd %mm2, %mm1 C bit pairs
movq %mm6, %mm2
pand %mm1, %mm2
psrlq $2, %mm1
pand %mm6, %mm1
paddd %mm2, %mm1 C nibbles
movq %mm5, %mm2
pand %mm1, %mm2
psrlq $4, %mm1
pand %mm5, %mm1
paddd %mm2, %mm1 C bytes
psadbw( %mm4, %mm1)
paddd %mm1, %mm0 C to total
subl $2, %
ecx
jg L(top)
C
ecx is 0
or -1 representing respectively 1
or 0 further limbs
jz L(last)
movd %mm0, %
eax
emms
ret
EPILOGUE()
