dnl AMD K7 mpn_add_n/mpn_sub_n -- mpn add or subtract.
dnl
dnl K7: 1.64 cycles/limb (at 16 limb/loop).
dnl Copyright (C) 1999, 2000 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., 59 Temple Place -
dnl Suite 330, Boston, MA 02111-1307, USA.
include(`../config.m4')
dnl K7: UNROLL_COUNT cycles/limb
dnl 8 1.9
dnl 16 1.64
dnl 32 1.7
dnl 64 2.0
dnl Maximum possible with the current code is 64.
deflit(UNROLL_COUNT, 16)
ifdef(`OPERATION_add_n', `
define(M4_inst, adcl)
define(M4_function_n, mpn_add_n)
define(M4_function_nc, mpn_add_nc)
define(M4_description, add)
',`ifdef(`OPERATION_sub_n', `
define(M4_inst, sbbl)
define(M4_function_n, mpn_sub_n)
define(M4_function_nc, mpn_sub_nc)
define(M4_description, subtract)
',`m4_error(`Need OPERATION_add_n or OPERATION_sub_n
')')')
MULFUNC_PROLOGUE(mpn_add_n mpn_add_nc mpn_sub_n mpn_sub_nc)
C mp_limb_t M4_function_n (mp_ptr dst, mp_srcptr src1, mp_srcptr src2,
C mp_size_t size);
C mp_limb_t M4_function_nc (mp_ptr dst, mp_srcptr src1, mp_srcptr src2,
C mp_size_t size, mp_limb_t carry);
C
C Calculate src1,size M4_description src2,size, and store the result in
C dst,size. The return value is the carry bit from the top of the result (1
C or 0).
C
C The _nc version accepts 1 or 0 for an initial carry into the low limb of
C the calculation. Note values other than 1 or 0 here will lead to garbage
C results.
C
C This code runs at 1.64 cycles/limb, which is probably the best possible
C with plain integer operations. Each limb is 2 loads and 1 store, and in
C one cycle the K7 can do two loads, or a load and a store, leading to 1.5
C c/l.
dnl Must have UNROLL_THRESHOLD >= 2, since the unrolled loop can't handle 1.
ifdef(`PIC',`
deflit(UNROLL_THRESHOLD, 8)
',`
deflit(UNROLL_THRESHOLD, 8)
')
defframe(PARAM_CARRY,20)
defframe(PARAM_SIZE, 16)
defframe(PARAM_SRC2, 12)
defframe(PARAM_SRC1, 8)
defframe(PARAM_DST, 4)
defframe(SAVE_EBP, -4)
defframe(SAVE_ESI, -8)
defframe(SAVE_EBX, -12)
defframe(SAVE_EDI, -16)
deflit(STACK_SPACE, 16)
.text
ALIGN(32)
deflit(`FRAME',0)
PROLOGUE(M4_function_nc)
movl PARAM_CARRY, %eax
jmp LF(M4_function_n,start)
EPILOGUE()
PROLOGUE(M4_function_n)
xorl %eax, %eax C carry
L(start):
movl PARAM_SIZE, %ecx
subl $STACK_SPACE, %esp
deflit(`FRAME',STACK_SPACE)
movl %edi, SAVE_EDI
movl %ebx, SAVE_EBX
cmpl $UNROLL_THRESHOLD, %ecx
movl PARAM_SRC2, %edx
movl PARAM_SRC1, %ebx
jae L(unroll)
movl PARAM_DST, %edi
leal (%ebx,%ecx,4), %ebx
leal (%edx,%ecx,4), %edx
leal (%edi,%ecx,4), %edi
negl %ecx
shrl %eax
C This loop in in a single 16 byte code block already, so no
C alignment necessary.
L(simple):
C eax scratch
C ebx src1
C ecx counter
C edx src2
C esi
C edi dst
C ebp
movl (%ebx,%ecx,4), %eax
M4_inst (%edx,%ecx,4), %eax
movl %eax, (%edi,%ecx,4)
incl %ecx
jnz L(simple)
movl $0, %eax
movl SAVE_EDI, %edi
movl SAVE_EBX, %ebx
setc %al
addl $STACK_SPACE, %esp
ret
C -----------------------------------------------------------------------------
C This is at 0x55, close enough to aligned.
L(unroll):
deflit(`FRAME',STACK_SPACE)
movl %ebp, SAVE_EBP
andl $-2, %ecx C size low bit masked out
andl $1, PARAM_SIZE C size low bit kept
movl %ecx, %edi
decl %ecx
movl PARAM_DST, %ebp
shrl $UNROLL_LOG2, %ecx
negl %edi
movl %esi, SAVE_ESI
andl $UNROLL_MASK, %edi
ifdef(`PIC',`
call L(pic_calc)
L(here):
',`
leal L(entry) (%edi,%edi,8), %esi C 9 bytes per
')
negl %edi
shrl %eax
leal ifelse(UNROLL_BYTES,256,128) (%ebx,%edi,4), %ebx
leal ifelse(UNROLL_BYTES,256,128) (%edx,%edi,4), %edx
leal ifelse(UNROLL_BYTES,256,128) (%ebp,%edi,4), %edi
jmp *%esi
ifdef(`PIC',`
L(pic_calc):
C See README.family about old gas bugs
leal (%edi,%edi,8), %esi
addl $L(entry)-L(here), %esi
addl (%esp), %esi
ret
')
C -----------------------------------------------------------------------------
ALIGN(32)
L(top):
C eax zero
C ebx src1
C ecx counter
C edx src2
C esi scratch (was computed jump)
C edi dst
C ebp scratch
leal UNROLL_BYTES(%edx), %edx
L(entry):
deflit(CHUNK_COUNT, 2)
forloop(i, 0, UNROLL_COUNT/CHUNK_COUNT-1, `
deflit(`disp0', eval(i*CHUNK_COUNT*4 ifelse(UNROLL_BYTES,256,-128)))
deflit(`disp1', eval(disp0 + 4))
Zdisp( movl, disp0,(%ebx), %esi)
movl disp1(%ebx), %ebp
Zdisp( M4_inst,disp0,(%edx), %esi)
Zdisp( movl, %esi, disp0,(%edi))
M4_inst disp1(%edx), %ebp
movl %ebp, disp1(%edi)
')
decl %ecx
leal UNROLL_BYTES(%ebx), %ebx
leal UNROLL_BYTES(%edi), %edi
jns L(top)
mov PARAM_SIZE, %esi
movl SAVE_EBP, %ebp
movl $0, %eax
decl %esi
js L(even)
movl (%ebx), %ecx
M4_inst UNROLL_BYTES(%edx), %ecx
movl %ecx, (%edi)
L(even):
movl SAVE_EDI, %edi
movl SAVE_EBX, %ebx
setc %al
movl SAVE_ESI, %esi
addl $STACK_SPACE, %esp
ret
EPILOGUE()