| /* i80386 __mpn_rshift -- |
| Copyright (C) 1992, 1994, 1997 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 Library General Public License as published by |
| the Free Software Foundation; either version 2 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 Library General Public |
| License for more details. |
| |
| You should have received a copy of the GNU Library General Public License |
| along with the GNU MP Library; see the file COPYING.LIB. If not, write to |
| the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
| MA 02111-1307, USA. */ |
| |
| /* |
| INPUT PARAMETERS |
| res_ptr (sp + 4) |
| s_ptr (sp + 8) |
| size (sp + 12) |
| cnt (sp + 16) |
| */ |
| |
| #include "sysdep.h" |
| #include "asm-syntax.h" |
| |
| .text |
| ALIGN (3) |
| .globl C_SYMBOL_NAME(__mpn_rshift) |
| ASM_TYPE_DIRECTIVE(C_SYMBOL_NAME(__mpn_rshift),@function) |
| C_SYMBOL_NAME(__mpn_rshift:) |
| pushl %edi |
| pushl %esi |
| pushl %ebx |
| |
| movl 16(%esp),%edi /* res_ptr */ |
| movl 20(%esp),%esi /* s_ptr */ |
| movl 24(%esp),%edx /* size */ |
| movl 28(%esp),%ecx /* cnt */ |
| |
| leal -4(%edi,%edx,4),%edi |
| leal (%esi,%edx,4),%esi |
| negl %edx |
| |
| movl (%esi,%edx,4),%ebx /* read least significant limb */ |
| xorl %eax,%eax |
| shrdl %cl,%ebx,%eax /* compute carry limb */ |
| incl %edx |
| jz L(end) |
| pushl %eax /* push carry limb onto stack */ |
| testb $1,%edx |
| jnz L(1) /* enter loop in the middle */ |
| movl %ebx,%eax |
| |
| ALIGN (3) |
| L(oop): movl (%esi,%edx,4),%ebx /* load next higher limb */ |
| shrdl %cl,%ebx,%eax /* compute result limb */ |
| movl %eax,(%edi,%edx,4) /* store it */ |
| incl %edx |
| L(1): movl (%esi,%edx,4),%eax |
| shrdl %cl,%eax,%ebx |
| movl %ebx,(%edi,%edx,4) |
| incl %edx |
| jnz L(oop) |
| |
| shrl %cl,%eax /* compute most significant limb */ |
| movl %eax,(%edi) /* store it */ |
| |
| popl %eax /* pop carry limb */ |
| |
| popl %ebx |
| popl %esi |
| popl %edi |
| ret |
| |
| L(end): shrl %cl,%ebx /* compute most significant limb */ |
| movl %ebx,(%edi) /* store it */ |
| |
| popl %ebx |
| popl %esi |
| popl %edi |
| ret |
| |
| ASM_SIZE_DIRECTIVE(C_SYMBOL_NAME(__mpn_rshift)) |
