buildtools/gcc/gmp/mpn/x86_64/rshift.asm
2018-03-19 15:46:45 -05:00

159 lines
3.3 KiB
NASM

dnl AMD64 mpn_rshift -- mpn right shift.
dnl Copyright 2003, 2005, 2009 Free Software Foundation, Inc.
dnl
dnl This file is part of the GNU MP Library.
dnl
dnl The GNU MP Library is free software; you can redistribute it and/or
dnl modify it under the terms of the GNU Lesser General Public License as
dnl published by the Free Software Foundation; either version 3 of the
dnl License, or (at your option) any later version.
dnl
dnl The GNU MP Library is distributed in the hope that it will be useful,
dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
dnl Lesser General Public License for more details.
dnl
dnl You should have received a copy of the GNU Lesser General Public License
dnl along with the GNU MP Library. If not, see http://www.gnu.org/licenses/.
include(`../config.m4')
C cycles/limb
C K8,K9: 2.375
C K10: 2.375
C P4: 8
C P6-15 (Core2): 2.11
C P6-28 (Atom): 5.75
C INPUT PARAMETERS
define(`rp', `%rdi')
define(`up', `%rsi')
define(`n', `%rdx')
define(`cnt', `%rcx')
ASM_START()
TEXT
ALIGN(32)
PROLOGUE(mpn_rshift)
neg R32(%rcx) C put rsh count in cl
mov (up), %rax
shl R8(%rcx), %rax C function return value
neg R32(%rcx) C put lsh count in cl
lea 1(n), R32(%r8)
lea -8(up,n,8), up
lea -8(rp,n,8), rp
neg n
and $3, R32(%r8)
je L(rlx) C jump for n = 3, 7, 11, ...
dec R32(%r8)
jne L(1)
C n = 4, 8, 12, ...
mov 8(up,n,8), %r10
shr R8(%rcx), %r10
neg R32(%rcx) C put rsh count in cl
mov 16(up,n,8), %r8
shl R8(%rcx), %r8
or %r8, %r10
mov %r10, 8(rp,n,8)
inc n
jmp L(rll)
L(1): dec R32(%r8)
je L(1x) C jump for n = 1, 5, 9, 13, ...
C n = 2, 6, 10, 16, ...
mov 8(up,n,8), %r10
shr R8(%rcx), %r10
neg R32(%rcx) C put rsh count in cl
mov 16(up,n,8), %r8
shl R8(%rcx), %r8
or %r8, %r10
mov %r10, 8(rp,n,8)
inc n
neg R32(%rcx) C put lsh count in cl
L(1x):
cmp $-1, n
je L(ast)
mov 8(up,n,8), %r10
shr R8(%rcx), %r10
mov 16(up,n,8), %r11
shr R8(%rcx), %r11
neg R32(%rcx) C put rsh count in cl
mov 16(up,n,8), %r8
mov 24(up,n,8), %r9
shl R8(%rcx), %r8
or %r8, %r10
shl R8(%rcx), %r9
or %r9, %r11
mov %r10, 8(rp,n,8)
mov %r11, 16(rp,n,8)
add $2, n
L(rll): neg R32(%rcx) C put lsh count in cl
L(rlx): mov 8(up,n,8), %r10
shr R8(%rcx), %r10
mov 16(up,n,8), %r11
shr R8(%rcx), %r11
add $4, n C 4
jb L(end) C 2
ALIGN(16)
L(top):
C finish stuff from lsh block
neg R32(%rcx) C put rsh count in cl
mov -16(up,n,8), %r8
mov -8(up,n,8), %r9
shl R8(%rcx), %r8
or %r8, %r10
shl R8(%rcx), %r9
or %r9, %r11
mov %r10, -24(rp,n,8)
mov %r11, -16(rp,n,8)
C start two new rsh
mov (up,n,8), %r8
mov 8(up,n,8), %r9
shl R8(%rcx), %r8
shl R8(%rcx), %r9
C finish stuff from rsh block
neg R32(%rcx) C put lsh count in cl
mov -8(up,n,8), %r10
mov 0(up,n,8), %r11
shr R8(%rcx), %r10
or %r10, %r8
shr R8(%rcx), %r11
or %r11, %r9
mov %r8, -8(rp,n,8)
mov %r9, 0(rp,n,8)
C start two new lsh
mov 8(up,n,8), %r10
mov 16(up,n,8), %r11
shr R8(%rcx), %r10
shr R8(%rcx), %r11
add $4, n
jae L(top) C 2
L(end):
neg R32(%rcx) C put rsh count in cl
mov -8(up), %r8
shl R8(%rcx), %r8
or %r8, %r10
mov (up), %r9
shl R8(%rcx), %r9
or %r9, %r11
mov %r10, -16(rp)
mov %r11, -8(rp)
neg R32(%rcx) C put lsh count in cl
L(ast): mov (up), %r10
shr R8(%rcx), %r10
mov %r10, (rp)
ret
EPILOGUE()