mpir/mpn/x86_64/amd64/copyi.as

;  Copyright 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
;
;  This file is part of the GNU MP Library.
;
;  The GNU MP Library is free software; you can redistribute it and/or
;  modify it under the terms of the GNU Lesser General Public License as
;  published by the Free Software Foundation; either version 2.1 of the
;  License, or (at your option) any later version.
;
;  The GNU MP Library is distributed in the hope that it will be useful,
;  but WITHOUT ANY WARRANTY; without even the implied warranty of
;  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
;  Lesser General Public License for more details.
;
;  You should have received a copy of the GNU Lesser General Public
;  License along with the GNU MP Library; see the file COPYING.LIB.  If
;  not, write to the Free Software Foundation, Inc., 59 Temple Place -
;  Suite 330, Boston, MA 02111-1307, USA.
;
;  Provided by Brian Gladman AMD64 using the Microsoft VC++ v8 64-bit
;  compiler and the YASM assembler.

; AMD64 mpn_copyi -- incrementing copy limb vector
;
;  Calling interface:
;
; void mpn_copyi(
;     mp_ptr dst,    rdi
;     mp_srcptr src, rsi
;     mp_size_t size rdx
; )

%include '../yasm_mac.inc'

%define    UNROLL_THRESHOLD 16

%define  d_ptr  rdi
%define  s_ptr  rsi
%define  s_len  rdx
%define  s_lend edx

    BITS    64

GLOBAL_FUNC mpn_copyi
    movsxd  s_len,s_lend
    or      s_len,s_len                 ; none to move?
    jz      label1
    mov     rax,s_ptr                   ; find relative alignment of
    xor     rax,d_ptr                   ; source and destination (min
    mov     r9,s_ptr                    ; 8-byte alignment assumed)
    lea     s_ptr,[s_ptr+s_len*8]
    lea     d_ptr,[d_ptr+s_len*8]
    neg     s_len
    cmp     s_len,byte -UNROLL_THRESHOLD
    jbe     label2                      ; if many limbs to move
label0: 
    mov     rax,[s_ptr+s_len*8]         ; short move via rax
    mov     [d_ptr+s_len*8],rax
    inc     s_len
    jnz     label0                      ; avoid single byte ret that
label1: 
    rep     ret                         ; interferes with branch prediction

label2: 
    test    al,8
    jnz     label7                      ; not 16 byte aligned
    test    r9,8                        ; see if src is on 16 byte
    jz      label3                      ; boundary
    mov     rax,[s_ptr+s_len*8]         ; if not do a one limb copy
    mov     [d_ptr+s_len*8],rax
    inc     s_len
label3: 
    lea     s_len,[s_len+3]             ; now 16 byte aligned
label4: 
    prefetchnta [s_ptr+s_len*8-24+3*64] ; should this be +4*64 ??
    movdqa  xmm0,[s_ptr+s_len*8-24]     ; move 32 bytes at a time
    movntdq [d_ptr+s_len*8-24],xmm0
    movdqa  xmm0,[s_ptr+s_len*8-8]
    movntdq [d_ptr+s_len*8-8],xmm0
    add     s_len,4
    jl      label4
    sfence
    test    s_len,2
    jnz     label5
    movdqa  xmm0,[s_ptr+s_len*8-24]     ; move 16 bytes if necessary
    movdqa  [d_ptr+s_len*8-24],xmm0
    add     s_len,2
label5:  
    test    s_len,1
    jnz     label6
    movq    xmm0,[s_ptr+s_len*8-24]     ; move 8 bytes if necessary
    movq    [d_ptr+s_len*8-24],xmm0
label6: 
    ret

label7: 
    lea     s_len,[s_len+1]             ; move 8 bytes at a time
label8: 
    movq    xmm0,[s_ptr+s_len*8-8]
    movq    xmm1,[s_ptr+s_len*8]
    movq    [d_ptr+s_len*8-8],xmm0
    movq    [d_ptr+s_len*8],xmm1
    add     s_len,2
    jl      label8
    test    s_len,1
    jnz     label9
    movq    xmm0,[s_ptr-8]
    movq    [d_ptr-8],xmm0
label9: 
    ret