mpir/mpn/x86_64/k8/k8only/rshift2.asm

125 lines
2.4 KiB
NASM

dnl mpn_rshift2
dnl Copyright 2009 Jason Moxham
dnl This file is part of the MPIR Library.
dnl The MPIR Library is free software; you can redistribute it and/or modify
dnl it under the terms of the GNU Lesser General Public License as published
dnl by the Free Software Foundation; either version 2.1 of the License, or (at
dnl your option) any later version.
dnl The MPIR 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 Lesser General Public
dnl License for more details.
dnl You should have received a copy of the GNU Lesser General Public License
dnl along with the MPIR Library; see the file COPYING.LIB. If not, write
dnl to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
dnl Boston, MA 02110-1301, USA.
include(`../config.m4')
C ret mpn_rshift2(mp_ptr,mp_ptr,mp_size_t)
C rax rdi, rsi, rdx
ASM_START()
PROLOGUE(mpn_rshift2)
mov %rdx,%rcx
lea 24(%rsi),%rsi
lea 24(%rdi),%rdi
xor %eax,%eax
xor %edx,%edx
sub $4,%rcx
jc skiplp
ALIGN(16)
lp:
mov (%rsi,%rcx,8),%r8
mov -8(%rsi,%rcx,8),%r9
mov -16(%rsi,%rcx,8),%r10
mov -24(%rsi,%rcx,8),%r11
add %rax,%rax
rcr $1,%r8
rcr $1,%r9
rcr $1,%r10
rcr $1,%r11
sbb %rax,%rax
add %rdx,%rdx
rcr $1,%r8
rcr $1,%r9
rcr $1,%r10
rcr $1,%r11
mov %r11,-24(%rdi,%rcx,8)
sbb %rdx,%rdx
mov %r8,(%rdi,%rcx,8)
sub $4,%rcx
mov %r9,24(%rdi,%rcx,8)
mov %r10,16(%rdi,%rcx,8)
jnc lp
skiplp:
cmp $-2,%rcx
ja case3
je case2
jp case1
case0:
lea (%rax,%rdx,2),%rax
neg %rax
shl $62,%rax
ret
ALIGN(16)
case3:
mov (%rsi,%rcx,8),%r8
mov -8(%rsi,%rcx,8),%r9
mov -16(%rsi,%rcx,8),%r10
add %rax,%rax
rcr $1,%r8
rcr $1,%r9
rcr $1,%r10
sbb %rax,%rax
add %rdx,%rdx
rcr $1,%r8
rcr $1,%r9
rcr $1,%r10
sbb %rdx,%rdx
mov %r8,(%rdi,%rcx,8)
mov %r9,-8(%rdi,%rcx,8)
mov %r10,-16(%rdi,%rcx,8)
lea (%rax,%rdx,2),%rax
neg %rax
shl $62,%rax
ret
ALIGN(16)
case2:
mov (%rsi,%rcx,8),%r8
mov -8(%rsi,%rcx,8),%r9
add %rax,%rax
rcr $1,%r8
rcr $1,%r9
sbb %rax,%rax
add %rdx,%rdx
rcr $1,%r8
rcr $1,%r9
sbb %rdx,%rdx
mov %r8,(%rdi,%rcx,8)
mov %r9,-8(%rdi,%rcx,8)
lea (%rax,%rdx,2),%rax
neg %rax
shl $62,%rax
ret
ALIGN(16)
case1:
mov (%rsi,%rcx,8),%r8
add %rax,%rax
rcr $1,%r8
sbb %rax,%rax
add %rdx,%rdx
rcr $1,%r8
sbb %rdx,%rdx
mov %r8,(%rdi,%rcx,8)
lea (%rax,%rdx,2),%rax
neg %rax
shl $62,%rax
ret
EPILOGUE()