| /* x86-64 __mpn_rshift -- |
| Copyright (C) 2007-2014 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, |
| see <http://www.gnu.org/licenses/>. */ |
| |
| #include "sysdep.h" |
| #include "asm-syntax.h" |
| |
| #define rp %rdi |
| #define up %rsi |
| #define n %rdx |
| #define cnt %cl |
| |
| .text |
| ENTRY (__mpn_rshift) |
| mov %edx, %eax |
| and $3, %eax |
| jne L(nb00) |
| L(b00): /* n = 4, 8, 12, ... */ |
| mov (up), %r10 |
| mov 8(up), %r11 |
| xor %eax, %eax |
| shrd %cl, %r10, %rax |
| mov 16(up), %r8 |
| lea 8(up), up |
| lea -24(rp), rp |
| sub $4, n |
| jmp L(00) |
| |
| L(nb00):/* n = 1, 5, 9, ... */ |
| cmp $2, %eax |
| jae L(nb01) |
| L(b01): mov (up), %r9 |
| xor %eax, %eax |
| shrd %cl, %r9, %rax |
| sub $2, n |
| jb L(le1) |
| mov 8(up), %r10 |
| mov 16(up), %r11 |
| lea 16(up), up |
| lea -16(rp), rp |
| jmp L(01) |
| L(le1): shr %cl, %r9 |
| mov %r9, (rp) |
| ret |
| |
| L(nb01):/* n = 2, 6, 10, ... */ |
| jne L(b11) |
| L(b10): mov (up), %r8 |
| mov 8(up), %r9 |
| xor %eax, %eax |
| shrd %cl, %r8, %rax |
| sub $3, n |
| jb L(le2) |
| mov 16(up), %r10 |
| lea 24(up), up |
| lea -8(rp), rp |
| jmp L(10) |
| L(le2): shrd %cl, %r9, %r8 |
| mov %r8, (rp) |
| shr %cl, %r9 |
| mov %r9, 8(rp) |
| ret |
| |
| .p2align 4 |
| L(b11): /* n = 3, 7, 11, ... */ |
| mov (up), %r11 |
| mov 8(up), %r8 |
| xor %eax, %eax |
| shrd %cl, %r11, %rax |
| mov 16(up), %r9 |
| lea 32(up), up |
| sub $4, n |
| jb L(end) |
| |
| .p2align 4 |
| L(top): shrd %cl, %r8, %r11 |
| mov -8(up), %r10 |
| mov %r11, (rp) |
| L(10): shrd %cl, %r9, %r8 |
| mov (up), %r11 |
| mov %r8, 8(rp) |
| L(01): shrd %cl, %r10, %r9 |
| mov 8(up), %r8 |
| mov %r9, 16(rp) |
| L(00): shrd %cl, %r11, %r10 |
| mov 16(up), %r9 |
| mov %r10, 24(rp) |
| add $32, up |
| lea 32(rp), rp |
| sub $4, n |
| jnc L(top) |
| |
| L(end): shrd %cl, %r8, %r11 |
| mov %r11, (rp) |
| shrd %cl, %r9, %r8 |
| mov %r8, 8(rp) |
| shr %cl, %r9 |
| mov %r9, 16(rp) |
| ret |
| END (__mpn_rshift) |