269 lines
5.0 KiB
NASM
269 lines
5.0 KiB
NASM
dnl Intel P6 mpn_modexact_1_odd -- exact division style remainder.
|
|
|
|
dnl Copyright 2001, 2002 Free Software Foundation, Inc.
|
|
dnl
|
|
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
|
|
dnl modify it under the terms of the GNU Lesser General Public License as
|
|
dnl published by the Free Software Foundation; either version 2.1 of the
|
|
dnl License, or (at your option) any later version.
|
|
dnl
|
|
dnl The GNU MP Library is distributed in the hope that it will be useful,
|
|
dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
dnl Lesser General Public License for more details.
|
|
dnl
|
|
dnl You should have received a copy of the GNU Lesser General Public
|
|
dnl License along with the GNU MP Library; see the file COPYING.LIB. If
|
|
dnl not, write to the Free Software Foundation, Inc., 51 Franklin Street,
|
|
dnl Fifth Floor, Boston, MA 02110-1301, USA.
|
|
|
|
include(`../config.m4')
|
|
|
|
|
|
C odd even divisor
|
|
C P6: 10.0 12.0 cycles/limb
|
|
|
|
|
|
C void mpn_divexact_1 (mp_ptr dst, mp_srcptr src, mp_size_t size,
|
|
C mp_limb_t divisor);
|
|
C
|
|
C The odd case is basically the same as mpn_modexact_1_odd, just with an
|
|
C extra store, and it runs at the same 10 cycles which is the dependent
|
|
C chain.
|
|
C
|
|
C The shifts for the even case aren't on the dependent chain so in principle
|
|
C it could run the same too, but nothing running at 10 has been found.
|
|
C Perhaps there's too many uops (an extra 4 over the odd case).
|
|
|
|
defframe(PARAM_DIVISOR,16)
|
|
defframe(PARAM_SIZE, 12)
|
|
defframe(PARAM_SRC, 8)
|
|
defframe(PARAM_DST, 4)
|
|
|
|
defframe(SAVE_EBX, -4)
|
|
defframe(SAVE_ESI, -8)
|
|
defframe(SAVE_EDI, -12)
|
|
defframe(SAVE_EBP, -16)
|
|
defframe(VAR_INVERSE, -20)
|
|
deflit(STACK_SPACE, 20)
|
|
|
|
TEXT
|
|
|
|
ALIGN(16)
|
|
PROLOGUE(mpn_divexact_1)
|
|
deflit(`FRAME',0)
|
|
|
|
movl PARAM_DIVISOR, %eax
|
|
subl $STACK_SPACE, %esp FRAME_subl_esp(STACK_SPACE)
|
|
|
|
movl %esi, SAVE_ESI
|
|
movl PARAM_SRC, %esi
|
|
|
|
movl %ebx, SAVE_EBX
|
|
movl PARAM_SIZE, %ebx
|
|
|
|
bsfl %eax, %ecx C trailing twos
|
|
|
|
movl %ebp, SAVE_EBP
|
|
|
|
shrl %cl, %eax C d without twos
|
|
|
|
movl %eax, %edx
|
|
shrl %eax C d/2 without twos
|
|
|
|
movl %edx, PARAM_DIVISOR
|
|
andl $127, %eax
|
|
|
|
ifdef(`PIC',`
|
|
call L(movl_eip_ebp)
|
|
addl $_GLOBAL_OFFSET_TABLE_, %ebp
|
|
movl modlimb_invert_table@GOT(%ebp), %ebp
|
|
movzbl (%eax,%ebp), %ebp C inv 8 bits
|
|
|
|
',`
|
|
dnl non-PIC
|
|
movzbl modlimb_invert_table(%eax), %ebp C inv 8 bits
|
|
')
|
|
|
|
leal (%ebp,%ebp), %eax C 2*inv
|
|
|
|
imull %ebp, %ebp C inv*inv
|
|
|
|
movl %edi, SAVE_EDI
|
|
movl PARAM_DST, %edi
|
|
|
|
leal (%esi,%ebx,4), %esi C src end
|
|
|
|
imull PARAM_DIVISOR, %ebp C inv*inv*d
|
|
|
|
subl %ebp, %eax C inv = 2*inv - inv*inv*d
|
|
leal (%eax,%eax), %ebp C 2*inv
|
|
|
|
imull %eax, %eax C inv*inv
|
|
|
|
leal (%edi,%ebx,4), %edi C dst end
|
|
negl %ebx C -size
|
|
|
|
movl %edi, PARAM_DST
|
|
|
|
imull PARAM_DIVISOR, %eax C inv*inv*d
|
|
|
|
subl %eax, %ebp C inv = 2*inv - inv*inv*d
|
|
|
|
ASSERT(e,` C d*inv == 1 mod 2^BITS_PER_MP_LIMB
|
|
movl PARAM_DIVISOR, %eax
|
|
imull %ebp, %eax
|
|
cmpl $1, %eax')
|
|
|
|
movl %ebp, VAR_INVERSE
|
|
movl (%esi,%ebx,4), %eax C src[0]
|
|
|
|
orl %ecx, %ecx
|
|
jnz L(even)
|
|
|
|
C ecx initial carry is zero
|
|
jmp L(odd_entry)
|
|
|
|
|
|
C The dependent chain here is
|
|
C
|
|
C subl %edx, %eax 1
|
|
C imull %ebp, %eax 4
|
|
C mull PARAM_DIVISOR 5
|
|
C ----
|
|
C total 10
|
|
C
|
|
C and this is the measured speed. No special scheduling is necessary, out
|
|
C of order execution hides the load latency.
|
|
|
|
L(odd_top):
|
|
C eax scratch (src limb)
|
|
C ebx counter, limbs, negative
|
|
C ecx carry bit
|
|
C edx carry limb, high of last product
|
|
C esi &src[size]
|
|
C edi &dst[size]
|
|
C ebp
|
|
|
|
mull PARAM_DIVISOR
|
|
|
|
movl (%esi,%ebx,4), %eax
|
|
subl %ecx, %eax
|
|
|
|
sbbl %ecx, %ecx
|
|
subl %edx, %eax
|
|
|
|
sbbl $0, %ecx
|
|
|
|
L(odd_entry):
|
|
imull VAR_INVERSE, %eax
|
|
|
|
movl %eax, (%edi,%ebx,4)
|
|
negl %ecx
|
|
|
|
incl %ebx
|
|
jnz L(odd_top)
|
|
|
|
|
|
movl SAVE_ESI, %esi
|
|
|
|
movl SAVE_EDI, %edi
|
|
|
|
movl SAVE_EBP, %ebp
|
|
|
|
movl SAVE_EBX, %ebx
|
|
addl $STACK_SPACE, %esp
|
|
|
|
ret
|
|
|
|
|
|
L(even):
|
|
C eax src[0]
|
|
C ebx counter, limbs, negative
|
|
C ecx shift
|
|
C edx
|
|
C esi
|
|
C edi
|
|
C ebp
|
|
|
|
xorl %ebp, %ebp C initial carry bit
|
|
xorl %edx, %edx C initial carry limb (for size==1)
|
|
|
|
incl %ebx
|
|
jz L(even_one)
|
|
|
|
movl (%esi,%ebx,4), %edi C src[1]
|
|
|
|
shrdl( %cl, %edi, %eax)
|
|
|
|
jmp L(even_entry)
|
|
|
|
|
|
L(even_top):
|
|
C eax scratch
|
|
C ebx counter, limbs, negative
|
|
C ecx shift
|
|
C edx scratch
|
|
C esi &src[size]
|
|
C edi &dst[size] and scratch
|
|
C ebp carry bit
|
|
|
|
movl (%esi,%ebx,4), %edi
|
|
|
|
mull PARAM_DIVISOR
|
|
|
|
movl -4(%esi,%ebx,4), %eax
|
|
shrdl( %cl, %edi, %eax)
|
|
|
|
subl %ebp, %eax
|
|
|
|
sbbl %ebp, %ebp
|
|
subl %edx, %eax
|
|
|
|
sbbl $0, %ebp
|
|
|
|
L(even_entry):
|
|
imull VAR_INVERSE, %eax
|
|
|
|
movl PARAM_DST, %edi
|
|
negl %ebp
|
|
|
|
movl %eax, -4(%edi,%ebx,4)
|
|
incl %ebx
|
|
jnz L(even_top)
|
|
|
|
|
|
|
|
mull PARAM_DIVISOR
|
|
|
|
movl -4(%esi), %eax
|
|
|
|
L(even_one):
|
|
shrl %cl, %eax
|
|
movl SAVE_ESI, %esi
|
|
|
|
subl %ebp, %eax
|
|
movl SAVE_EBP, %ebp
|
|
|
|
subl %edx, %eax
|
|
movl SAVE_EBX, %ebx
|
|
|
|
imull VAR_INVERSE, %eax
|
|
|
|
movl %eax, -4(%edi)
|
|
movl SAVE_EDI, %edi
|
|
addl $STACK_SPACE, %esp
|
|
|
|
ret
|
|
|
|
|
|
ifdef(`PIC',`
|
|
L(movl_eip_ebp):
|
|
movl (%esp), %ebp
|
|
ret_internal
|
|
')
|
|
|
|
EPILOGUE()
|