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| Rev | Author | Line No. | Line |
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| 31 | halyavin | 1 | ; string2dword - a useless string to double word conversion routine |
| 2 | ; |
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| 3 | ; Copyright (c) 2003 Thomas Mathys |
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| 4 | ; killer@vantage.ch |
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| 5 | ; |
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| 6 | ; This program is free software; you can redistribute it and/or modify |
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| 7 | ; it under the terms of the GNU General Public License as published by |
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| 8 | ; the Free Software Foundation; either version 2 of the License, or |
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| 9 | ; (at your option) any later version. |
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| 10 | ; |
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| 11 | ; This program is distributed in the hope that it will be useful, |
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| 12 | ; but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 13 | ; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 14 | ; GNU General Public License for more details. |
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| 15 | ; |
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| 16 | ; You should have received a copy of the GNU General Public License |
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| 17 | ; along with this program; if not, write to the Free Software |
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| 18 | ; Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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| 19 | ; |
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| 20 | |||
| 21 | |||
| 22 | ;******************************************************************** |
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| 23 | ; converts an asciiz string into an unsigned doubleword. |
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| 24 | ; (base 10 is assumed) |
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| 25 | ; |
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| 26 | ; - first, leading whitespaces are skipped |
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| 27 | ; - then the function converts the string, until it |
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| 28 | ; finds the terminating zero, another character it |
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| 29 | ; cannot convert or the number becomes too large. |
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| 30 | ; |
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| 31 | ; input : esi = pointer to string |
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| 32 | ; output : eax = unsigned doubleword |
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| 33 | ; the function tries to convert as |
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| 34 | ; many digits as possible, before it |
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| 35 | ; stops. if the value of the dword |
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| 36 | ; becomes too large, 0xffffffff is |
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| 37 | ; returned. |
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| 38 | ; destroys : nothing |
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| 39 | ;******************************************************************** |
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| 40 | string2dword: |
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| 41 | push ebx |
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| 42 | push ecx |
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| 43 | push edx |
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| 44 | push esi |
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| 45 | pushfd |
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| 46 | |||
| 47 | xor ebx,ebx ; ebx : dword |
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| 48 | |||
| 49 | ; skip leading whitespaces |
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| 50 | .skipspaces: |
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| 51 | lodsb |
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| 52 | cmp al,32 ; space |
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| 53 | je .skipspaces |
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| 54 | cmp al,12 ; ff |
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| 55 | je .skipspaces |
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| 56 | cmp al,10 ; lf |
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| 57 | je .skipspaces |
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| 58 | cmp al,13 ; cr |
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| 59 | je .skipspaces |
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| 60 | cmp al,9 ; ht |
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| 61 | je .skipspaces |
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| 62 | cmp al,11 ; vt |
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| 63 | je .skipspaces |
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| 64 | |||
| 65 | ; convert string |
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| 66 | dec esi ; esi -> 1st non-whitespace |
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| 67 | .convert: |
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| 68 | xor eax,eax ; get character |
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| 69 | lodsb |
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| 70 | sub al,'0' ; convert to digit |
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| 71 | cmp al,9 ; is digit in range [0,9] ? |
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| 72 | ja .done ; nope -> stop conversion |
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| 73 | mov ecx,eax ; save new digit |
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| 74 | mov eax,10 ; dword = dword * 10 |
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| 75 | mul ebx |
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| 76 | jc .overflow |
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| 77 | add eax,ecx ; + new digit |
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| 78 | jc .overflow |
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| 79 | mov ebx,eax |
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| 80 | jmp .convert |
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| 81 | |||
| 82 | .overflow: |
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| 83 | mov ebx,0xffffffff |
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| 84 | .done: |
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| 85 | mov eax,ebx |
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| 86 | popfd |
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| 87 | pop esi |
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| 88 | pop edx |
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| 89 | pop ecx |
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| 90 | pop ebx |
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| 91 | ret |
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| 92 |