mpir/mpn/x86_64w/amd64/rsh1sub_n.asm

124 lines
3.0 KiB
NASM

; AMD64 mpn_rsh1sub_n
; Copyright 2009 Jason Moxham
; 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.
;
; (rdi,rcx)=((rsi,rcx)-(rdx,rcx))/2
; return bottom bit of difference
; subtraction treated as two compliment
%include "..\yasm_mac.inc"
%define reg_save_list rbx, rsi, rdi, r12
CPU Athlon64
BITS 64
FRAME_PROC mpn_rsh1sub_n, 0, reg_save_list
movsxd rax, r9d
lea rdi, [rcx+rax*8-32]
lea rsi, [rdx+rax*8-32]
lea rdx, [r8+rax*8-32]
mov rcx, rax
mov r8, 4
sub r8, rcx
mov r12, [rsi+r8*8]
sub r12, [rdx+r8*8]
sbb rbx, rbx
mov rax, r12
and rax, 1
cmp r8, 0
jge L_skiplp
L_lp:
mov r11, [rsi+r8*8+32]
mov r10, [rsi+r8*8+24]
add rbx, 1
mov rcx, [rsi+r8*8+8]
mov r9, [rsi+r8*8+16]
sbb rcx, [rdx+r8*8+8]
sbb r9, [rdx+r8*8+16]
sbb r10, [rdx+r8*8+24]
sbb r11, [rdx+r8*8+32]
sbb rbx, rbx
bt r11, 0
rcr r10, 1
rcr r9, 1
rcr rcx, 1
rcr r12, 1
mov [rdi+r8*8], r12
mov [rdi+r8*8+8], rcx
mov [rdi+r8*8+16], r9
mov [rdi+r8*8+24], r10
mov r12, r11
add r8, 4
jnc L_lp
L_skiplp:
cmp r8, 2
ja L_case0
jz L_case1
jp L_case2
L_case3:
mov r10, [rsi+r8*8+24]
add rbx, 1
mov rcx, [rsi+r8*8+8]
mov r9, [rsi+r8*8+16]
sbb rcx, [rdx+r8*8+8]
sbb r9, [rdx+r8*8+16]
sbb r10, [rdx+r8*8+24]
rcr r10, 1
rcr r9, 1
rcr rcx, 1
rcr r12, 1
mov [rdi+r8*8], r12
mov [rdi+r8*8+8], rcx
mov [rdi+r8*8+16], r9
mov [rdi+r8*8+24], r10
jmp L_xit
xalign 16
L_case2:
add rbx, 1
mov rcx, [rsi+r8*8+8]
mov r9, [rsi+r8*8+16]
sbb rcx, [rdx+r8*8+8]
sbb r9, [rdx+r8*8+16]
rcr r9, 1
rcr rcx, 1
rcr r12, 1
mov [rdi+r8*8], r12
mov [rdi+r8*8+8], rcx
mov [rdi+r8*8+16], r9
jmp L_xit
xalign 16
L_case1:
add rbx, 1
mov rcx, [rsi+r8*8+8]
sbb rcx, [rdx+r8*8+8]
rcr rcx, 1
rcr r12, 1
mov [rdi+r8*8], r12
mov [rdi+r8*8+8], rcx
jmp L_xit
xalign 16
L_case0:
add rbx, 1
rcr r12, 1
mov [rdi+r8*8], r12
L_xit:
END_PROC reg_save_list
end