;  AMD64 mpn_divexact_byff
;
;  Copyright 2008 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 version 2.1 of the License, or (at
;  your option) any later version.
;  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.
;
;  Calling interface:
;
; mp_limb_t mpn_divexact_byff(
;     mp_ptr dst,       rcx
;     mp_srcptr src,    rdx
;     mp_size_t size,    r8
; )
;
;  This is an SEH leaf function (no unwind support needed)

   bits 64
   section .text

   global __gmpn_divexact_byff

%ifdef DLL
   export   __gmpn_divexact_byff
%endif

__gmpn_divexact_byff:
    mov     r8d, r8d

	xor     eax, eax
	mov     r9, r8
	and     r9, 3
	shr     r8, 2
	cmp     r8, 0
	jnz     .2      ; carry flag is clear here
	sbb     rax, [rdx]
	mov     [rcx], rax
	dec     r9
	jz      .1
	sbb     rax, [rdx+8]
	mov     [rcx+8], rax
	dec     r9
	jz      .1
	sbb     rax, [rdx+16]
	mov     [rcx+16], rax
	dec     r9
.1: sbb     rax, 0
	ret

	alignb  16, nop
.2:	sbb     rax, [rdx]
	mov     [rcx], rax
	sbb     rax, [rdx+8]
	mov     [rcx+8], rax
	sbb     rax, [rdx+16]
	mov     [rcx+16], rax
	sbb     rax, [rdx+24]
	mov     [rcx+24], rax
	lea     rdx, [rdx+32]
	dec     r8
	lea     rcx, [rcx+32]
	jnz     .2
	inc     r9
	dec     r9
	jz      .3
	sbb     rax, [rdx]
	mov     [rcx], rax
	dec     r9
	jz      .3
	sbb     rax, [rdx+8]
	mov     [rcx+8], rax
	dec     r9
	jz      .3
	sbb     rax, [rdx+16]
	mov     [rcx+16], rax
	dec     r9
.3:	sbb     rax, 0
	ret

    end