mpir/mpn/x86_64/k8/half.asm
2011-07-13 09:48:02 +00:00

62 lines
1.4 KiB
NASM

dnl mpn_half
dnl Copyright 2011 The Code Cavern
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')
ASM_START()
PROLOGUE(mpn_half)
mov %rsi,%rax
lea -8(%rdi,%rsi,8),%rdi
shr $2,%rsi
and $3,%eax
jz t1
shrq $1,(%rdi)
lea -8(%rdi),%rdi
dec %rax
jz t1
rcrq $1,(%rdi)
lea -8(%rdi),%rdi
dec %rax
jz t1
rcrq $1,(%rdi)
lea -8(%rdi),%rdi
t1:
sbb %rdx,%rdx
cmp $0,%rsi
jz skiplp
add %rdx,%rdx
.align 16
lp:
rcrq $1,(%rdi)
nop
rcrq $1,-8(%rdi)
rcrq $1,-16(%rdi)
rcrq $1,-24(%rdi)
nop
dec %rsi
lea -32(%rdi),%rdi
jnz lp
sbb %rdx,%rdx
skiplp:
sbb %rdx,%rax
ret
EPILOGUE()