| xf.li | bdd93d5 | 2023-05-12 07:10:14 -0700 | [diff] [blame] | 1 | /* i80386 __mpn_rshift -- |
| 2 | Copyright (C) 1992-2016 Free Software Foundation, Inc. |
| 3 | This file is part of the GNU MP Library. |
| 4 | |
| 5 | The GNU MP Library is free software; you can redistribute it and/or modify |
| 6 | it under the terms of the GNU Lesser General Public License as published by |
| 7 | the Free Software Foundation; either version 2.1 of the License, or (at your |
| 8 | option) any later version. |
| 9 | |
| 10 | The GNU MP Library is distributed in the hope that it will be useful, but |
| 11 | WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
| 12 | or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public |
| 13 | License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU Lesser General Public License |
| 16 | along with the GNU MP Library; see the file COPYING.LIB. If not, |
| 17 | see <http://www.gnu.org/licenses/>. */ |
| 18 | |
| 19 | #include "sysdep.h" |
| 20 | #include "asm-syntax.h" |
| 21 | |
| 22 | #define PARMS 4+12 /* space for 3 saved regs */ |
| 23 | #define RES PARMS |
| 24 | #define S RES+4 |
| 25 | #define SIZE S+4 |
| 26 | #define CNT SIZE+4 |
| 27 | |
| 28 | .text |
| 29 | ENTRY (__mpn_rshift) |
| 30 | |
| 31 | pushl %edi |
| 32 | cfi_adjust_cfa_offset (4) |
| 33 | pushl %esi |
| 34 | cfi_adjust_cfa_offset (4) |
| 35 | pushl %ebx |
| 36 | cfi_adjust_cfa_offset (4) |
| 37 | |
| 38 | movl RES(%esp),%edi |
| 39 | cfi_rel_offset (edi, 8) |
| 40 | movl S(%esp),%esi |
| 41 | cfi_rel_offset (esi, 4) |
| 42 | movl SIZE(%esp),%edx |
| 43 | movl CNT(%esp),%ecx |
| 44 | leal -4(%edi,%edx,4),%edi |
| 45 | leal (%esi,%edx,4),%esi |
| 46 | negl %edx |
| 47 | |
| 48 | movl (%esi,%edx,4),%ebx /* read least significant limb */ |
| 49 | cfi_rel_offset (ebx, 0) |
| 50 | cfi_remember_state |
| 51 | xorl %eax,%eax |
| 52 | shrdl %cl,%ebx,%eax /* compute carry limb */ |
| 53 | incl %edx |
| 54 | jz L(end) |
| 55 | pushl %eax /* push carry limb onto stack */ |
| 56 | cfi_adjust_cfa_offset (4) |
| 57 | testb $1,%dl |
| 58 | jnz L(1) /* enter loop in the middle */ |
| 59 | movl %ebx,%eax |
| 60 | |
| 61 | ALIGN (3) |
| 62 | L(oop): movl (%esi,%edx,4),%ebx /* load next higher limb */ |
| 63 | shrdl %cl,%ebx,%eax /* compute result limb */ |
| 64 | movl %eax,(%edi,%edx,4) /* store it */ |
| 65 | incl %edx |
| 66 | L(1): movl (%esi,%edx,4),%eax |
| 67 | shrdl %cl,%eax,%ebx |
| 68 | movl %ebx,(%edi,%edx,4) |
| 69 | incl %edx |
| 70 | jnz L(oop) |
| 71 | |
| 72 | shrl %cl,%eax /* compute most significant limb */ |
| 73 | movl %eax,(%edi) /* store it */ |
| 74 | |
| 75 | popl %eax /* pop carry limb */ |
| 76 | cfi_adjust_cfa_offset (-4) |
| 77 | |
| 78 | popl %ebx |
| 79 | cfi_adjust_cfa_offset (-4) |
| 80 | cfi_restore (ebx) |
| 81 | popl %esi |
| 82 | cfi_adjust_cfa_offset (-4) |
| 83 | cfi_restore (esi) |
| 84 | popl %edi |
| 85 | cfi_adjust_cfa_offset (-4) |
| 86 | cfi_restore (edi) |
| 87 | |
| 88 | ret |
| 89 | |
| 90 | cfi_restore_state |
| 91 | L(end): shrl %cl,%ebx /* compute most significant limb */ |
| 92 | movl %ebx,(%edi) /* store it */ |
| 93 | |
| 94 | popl %ebx |
| 95 | cfi_adjust_cfa_offset (-4) |
| 96 | cfi_restore (ebx) |
| 97 | popl %esi |
| 98 | cfi_adjust_cfa_offset (-4) |
| 99 | cfi_restore (esi) |
| 100 | popl %edi |
| 101 | cfi_adjust_cfa_offset (-4) |
| 102 | cfi_restore (edi) |
| 103 | |
| 104 | ret |
| 105 | END (__mpn_rshift) |