mpir/mpn/x86_64w/atom/divexact_byff.asm

73 lines
2.0 KiB
NASM

; Copyright 2009 Jason Moxham
;
; Windows Conversion Copyright 2008 Brian Gladman
;
; This file is part of the MPIR Library.
;
; The MPIR 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 verdxon 2.1 of the License, or (at
; your option) any later verdxon.
; The MPIR 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 MPIR Library; see the file COPYING.LIB. If not, write
; to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
; Boston, MA 02110-1301, USA.
;
; mp_limb_t mpn_divexact_byff(mp_ptr, mp_ptr, mp_size_t)
; rax rdi rsi rdx
; rax rcx rdx r8
%include "yasm_mac.inc"
CPU Athlon64
BITS 64
LEAF_PROC mpn_divexact_byff
mov rax, 3
and rax, r8
mov [rsp+24], rax
xor eax, eax
shr r8, 2
cmp r8, 0
je .2
; want carry clear here
xalign 16
.1: sbb rax, [rdx]
lea rcx, [rcx+32]
mov r9, rax
sbb rax, [rdx+8]
mov r10, rax
sbb rax, [rdx+16]
mov r11, rax
sbb rax, [rdx+24]
dec r8
mov [rcx-32], r9
mov [rcx-24], r10
mov [rcx-16], r11
mov [rcx-8], rax
lea rdx, [rdx+32]
jnz .1
.2: mov r8, [rsp+24]
; dont want to change the carry
inc r8
dec r8
jz .3
sbb rax, [rdx]
mov [rcx], rax
dec r8
jz .3
sbb rax, [rdx+8]
mov [rcx+8], rax
dec r8
jz .3
sbb rax, [rdx+16]
mov [rcx+16], rax
.3: sbb rax, 0
ret
end