dnl x86 mpn_add_n/mpn_sub_n -- mpn addition and subtraction.
dnl Copyright 1992, 1994-1996, 1999-2002 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 P5 3.375
C P6 3.125
C K6 3.5
C K7 2.25
C P4 8.75
movl %ecx,%eax
shrl $3,%ecx C compute count for unrolled loop
negl %eax
andl $7,%eax C get index where to start loop jz L(oopgo) C necessary special case for 0
incl %ecx C adjust loop count
shll $2,%eax C adjustment for pointers...
subl %eax,%edi C ... since they are offset ...
subl %eax,%esi C ... by a constant when we ...
subl %eax,%edx C ... enter the loop
shrl $2,%eax C restore previous value
ifdef(`PIC',`
C Calculate start address in loop for PIC. Due to limitations in
C old gas, LF(M4_function_n,oop)-L(0a)-3 cannot be put into the leal call L(0a)
L(0a): leal (%eax,%eax,8),%eax
addl (%esp),%eax
addl $L(oop)-L(0a)-3,%eax
addl $4,%esp ',`
C Calculate start address in loop for non-PIC.
leal L(oop)-3(%eax,%eax,8),%eax ')
C These lines initialize carry from the 5th parameter. Should be
C possible to simplify.
pushl %ebp FRAME_pushl()
movl PARAM_CARRY,%ebp
shrl %ebp C shift bit 0 into carry
popl %ebp FRAME_popl()
movl %ecx,%eax
shrl $3,%ecx C compute count for unrolled loop
negl %eax
andl $7,%eax C get index where to start loop jz L(oop) C necessary special case for 0
incl %ecx C adjust loop count
shll $2,%eax C adjustment for pointers...
subl %eax,%edi C ... since they are offset ...
subl %eax,%esi C ... by a constant when we ...
subl %eax,%edx C ... enter the loop
shrl $2,%eax C restore previous value
ifdef(`PIC',`
C Calculate start address in loop for PIC. Due to limitations in
C some assemblers, L(oop)-L(0b)-3 cannot be put into the leal call L(0b)
L(0b): leal (%eax,%eax,8),%eax
addl (%esp),%eax
addl $L(oop)-L(0b)-3,%eax
addl $4,%esp ',`
C Calculate start address in loop for non-PIC.
leal L(oop)-3(%eax,%eax,8),%eax ') jmp *%eax C jump into loop
L(oopgo):
pushl %ebp FRAME_pushl()
movl PARAM_CARRY,%ebp
shrl %ebp C shift bit 0 into carry
popl %ebp FRAME_popl()
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