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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 2 | pj | 1 | /* Project: OSLib |
| 2 | * Description: The OS Construction Kit |
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| 3 | * Date: 1.6.2000 |
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| 4 | * Idea by: Luca Abeni & Gerardo Lamastra |
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| 5 | * |
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| 6 | * OSLib is an SO project aimed at developing a common, easy-to-use |
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| 7 | * low-level infrastructure for developing OS kernels and Embedded |
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| 8 | * Applications; it partially derives from the HARTIK project but it |
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| 9 | * currently is independently developed. |
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| 10 | * |
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| 11 | * OSLib is distributed under GPL License, and some of its code has |
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| 12 | * been derived from the Linux kernel source; also some important |
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| 13 | * ideas come from studying the DJGPP go32 extender. |
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| 14 | * |
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| 15 | * We acknowledge the Linux Community, Free Software Foundation, |
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| 16 | * D.J. Delorie and all the other developers who believe in the |
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| 17 | * freedom of software and ideas. |
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| 18 | * |
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| 19 | * For legalese, check out the included GPL license. |
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| 20 | */ |
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| 21 | |||
| 22 | #include <ll/i386/stdlib.h> |
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| 23 | #include <ll/i386/string.h> |
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| 24 | #include <ll/i386/limits.h> |
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| 25 | #include <ll/stdarg.h> |
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| 26 | #include <ll/ctype.h> |
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| 27 | #include <ll/math.h> |
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| 28 | |||
| 29 | FILE(strod); |
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| 30 | |||
| 31 | double strtod(char *s,char **scan_end) |
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| 32 | { |
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| 33 | int sign,i; |
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| 34 | double result = 0; |
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| 35 | double value; |
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| 36 | double mantissa = 0,divisor = 1; |
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| 37 | unsigned short power = 0; |
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| 38 | /* Evaluate sign */ |
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| 39 | if (*s == '-') { |
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| 40 | sign = -1; |
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| 41 | s++; |
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| 42 | } |
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| 43 | else sign = 1; |
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| 44 | /* Skip trailing zeros */ |
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| 45 | while (*s == '0') s++; |
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| 46 | /* Convert integer part */ |
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| 47 | while (*s <= '9' && *s >= '0') { |
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| 48 | value = *s++ - '0'; |
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| 49 | result *= 10.0; |
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| 50 | result += value; |
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| 51 | } |
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| 52 | /* Detect floating point & mantissa */ |
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| 53 | if (*s == '.') { |
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| 54 | s++; |
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| 55 | while (*s <= '9' && *s >= '0') { |
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| 56 | value = *s++ - '0'; |
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| 57 | mantissa *= 10.0; |
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| 58 | mantissa += value; |
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| 59 | divisor *= 10.0; |
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| 60 | } |
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| 61 | } |
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| 62 | mantissa /= divisor; |
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| 63 | /* Adjust result */ |
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| 64 | result += mantissa; |
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| 65 | /* Adjust sign */ |
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| 66 | result *= sign; |
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| 67 | /* Detect exponent */ |
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| 68 | if (*s == 'e' || *s == 'E') { |
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| 69 | s++; |
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| 70 | if (*s == '-') { |
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| 71 | sign = -1; |
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| 72 | s++; |
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| 73 | } else if (*s == '+') { |
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| 74 | sign = 1; |
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| 75 | s++; |
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| 76 | } |
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| 77 | else sign = 1; |
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| 78 | while (*s <= '9' && *s >= '0') { |
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| 79 | value = *s++ - '0'; |
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| 80 | power *= 10.0; |
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| 81 | power += value; |
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| 82 | } |
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| 83 | } |
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| 84 | /* Adjust result on exponent sign */ |
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| 85 | if (sign > 0) for (i = 0; i < power; i++) result *= 10.0; |
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| 86 | else for (i = 0; i < power; i++) result /= 10.0; |
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| 87 | if (scan_end != 0L) *scan_end = s; |
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| 88 | return(result); |
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| 89 | } |