[444] | 1 | /* |
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| 2 | FUNCTION |
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| 3 | <<strtoufix16>>, <<strtoufix32>>, <<strtoufix64>>---string to signed fixed point |
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| 4 | |
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| 5 | INDEX |
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| 6 | strtoufix16 |
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| 7 | INDEX |
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| 8 | strtoufix32 |
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| 9 | INDEX |
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| 10 | strtoufix64 |
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| 11 | INDEX |
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| 12 | _strtoufix16_r |
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| 13 | INDEX |
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| 14 | _strtoufix32_r |
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| 15 | INDEX |
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| 16 | _strtoufix64_r |
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| 17 | |
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| 18 | SYNOPSIS |
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| 19 | #include <stdlib.h> |
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| 20 | __uint16_t strtoufix16 (const char *<[s]>, char **<[ptr]>); |
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| 21 | |
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| 22 | __uint32_t strtoufix32 (const char *<[s]>, char **<[ptr]>); |
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| 23 | |
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| 24 | __uint64_t strtoufix64 (const char *<[s]>, char **<[ptr]>); |
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| 25 | |
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| 26 | __uint16_t _strtoufix16_r (void *<[reent]>, |
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| 27 | const char *<[s]>, char **<[ptr]>); |
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| 28 | |
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| 29 | __uint32_t _strtoufix32_r (void *<[reent]>, |
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| 30 | const char *<[s]>, char **<[ptr]>); |
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| 31 | |
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| 32 | __uint64_t _strtoufix64_r (void *<[reent]>, |
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| 33 | const char *<[s]>, char **<[ptr]>); |
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| 34 | |
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| 35 | DESCRIPTION |
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| 36 | The function <<strtoufix16>> converts the string <<*<[s]>>> to |
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| 37 | a fixed-point 16-bits fraction representation. The function |
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| 38 | follows the same rules as <<strtod>>. |
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| 39 | |
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| 40 | The substring converted is the longest initial |
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| 41 | subsequence of <[s]>, beginning with the first |
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| 42 | non-whitespace character, that has the format: |
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| 43 | .[+|-]<[digits]>[.][<[digits]>][(e|E)[+|-]<[digits]>] |
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| 44 | The substring contains no characters if <[s]> is empty, consists |
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| 45 | entirely of whitespace, or if the first non-whitespace |
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| 46 | character is something other than <<+>>, <<->>, <<.>>, or a |
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| 47 | digit. If the substring is empty, no conversion is done, and |
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| 48 | the value of <[s]> is stored in <<*<[ptr]>>>. Otherwise, |
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| 49 | the substring is converted, and a pointer to the final string |
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| 50 | (which will contain at least the terminating null character of |
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| 51 | <[s]>) is stored in <<*<[ptr]>>>. If you want no |
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| 52 | assignment to <<*<[ptr]>>>, pass a null pointer as <[ptr]>. |
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| 53 | |
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| 54 | <<strtoufix32>> is identical to <<strtoufix16>> except that it |
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| 55 | converts to fixed-point 32-bit fraction representation. |
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| 56 | <<strtoufix64>> is also similar, except that it converts |
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| 57 | to fixed-point 64-bit fraction. |
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| 58 | |
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| 59 | The alternate functions <<_strtoufix16_r>>, <<_strtoufix32_r>>, |
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| 60 | and <<_strtoufix64_r>> are reentrant versions. |
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| 61 | The extra argument <[reent]> is a pointer to a reentrancy structure. |
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| 62 | |
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| 63 | RETURNS |
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| 64 | The functions return the converted substring value, if any. If |
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| 65 | no conversion can be performed, then 0 is returned. If the converted |
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| 66 | value is a NaN, 0 is returned and errno is set to <<EDOM>>. |
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| 67 | If the converted value exceeds the maximum positive unsigned fixed-point value, |
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| 68 | the output value is saturated to the maximum value and <<ERANGE>> is stored in |
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| 69 | errno. If the converted value is less than 0, then the output is saturated to 0 |
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| 70 | and <<ERANGE>> is stored in errno. Otherwise, the converted value is returned in the |
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| 71 | specified fixed-point format. |
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| 72 | |
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| 73 | PORTABILITY |
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| 74 | <<strtoufix16>>, <<strtoufix32>>, and <<strtoufix64>> are non-standard. |
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| 75 | |
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| 76 | The OS subroutines of <<strtod>> are required. |
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| 77 | */ |
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| 78 | |
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| 79 | #ifdef __SPE__ |
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| 80 | |
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| 81 | #include <_ansi.h> |
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| 82 | #include <limits.h> |
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| 83 | #include <errno.h> |
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| 84 | #include <stdlib.h> |
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| 85 | #include <reent.h> |
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| 86 | #include "vfieeefp.h" |
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| 87 | |
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| 88 | /* |
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| 89 | * Convert a string to a fixed-point 16-bit value. |
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| 90 | * |
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| 91 | * Ignores `locale' stuff. |
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| 92 | */ |
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| 93 | __uint16_t |
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| 94 | _strtoufix16_r (struct _reent *rptr, |
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| 95 | const char *nptr, |
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| 96 | char **endptr) |
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| 97 | { |
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| 98 | union double_union dbl; |
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| 99 | unsigned long tmp, tmp2, result; |
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| 100 | int exp, negexp; |
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| 101 | |
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| 102 | dbl.d = _strtod_r (rptr, nptr, endptr); |
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| 103 | |
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| 104 | /* treat NAN as domain error, +/- infinity as saturation */ |
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| 105 | if (!finite(dbl.d)) |
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| 106 | { |
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| 107 | if (isnan (dbl.d)) |
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| 108 | { |
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| 109 | rptr->_errno = EDOM; |
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| 110 | return 0; |
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| 111 | } |
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| 112 | rptr->_errno = ERANGE; |
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| 113 | if (word0(dbl) & Sign_bit) |
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| 114 | return 0; |
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| 115 | return USHRT_MAX; |
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| 116 | } |
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| 117 | |
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| 118 | /* check for normal saturation */ |
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| 119 | if (dbl.d >= 1.0) |
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| 120 | { |
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| 121 | rptr->_errno = ERANGE; |
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| 122 | return USHRT_MAX; |
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| 123 | } |
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| 124 | else if (dbl.d < 0) |
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| 125 | { |
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| 126 | rptr->_errno = ERANGE; |
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| 127 | return 0; |
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| 128 | } |
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| 129 | |
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| 130 | /* otherwise we have normal postive number in range */ |
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| 131 | |
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| 132 | /* strip off exponent */ |
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| 133 | exp = ((word0(dbl) & Exp_mask) >> Exp_shift) - Bias; |
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| 134 | negexp = -exp; |
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| 135 | if (negexp > 16) |
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| 136 | return 0; |
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| 137 | /* add in implicit normalized bit */ |
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| 138 | tmp = word0(dbl) | Exp_msk1; |
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| 139 | /* remove exponent and sign */ |
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| 140 | tmp <<= Ebits; |
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| 141 | /* perform rounding */ |
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| 142 | tmp2 = tmp + (1 << (negexp + 14)); |
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| 143 | result = tmp2 >> (negexp + 15); |
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| 144 | /* if rounding causes carry, must add carry bit in */ |
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| 145 | if (tmp2 < tmp) |
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| 146 | { |
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| 147 | if (negexp == 0) |
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| 148 | { |
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| 149 | /* we have overflow which means saturation */ |
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| 150 | rptr->_errno = ERANGE; |
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| 151 | return USHRT_MAX; |
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| 152 | } |
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| 153 | result |= (1 << (16 - negexp)); |
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| 154 | } |
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| 155 | |
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| 156 | return (__uint16_t)result; |
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| 157 | } |
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| 158 | |
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| 159 | #ifndef _REENT_ONLY |
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| 160 | |
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| 161 | __uint16_t |
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| 162 | strtoufix16 (const char *s, |
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| 163 | char **ptr) |
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| 164 | { |
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| 165 | return _strtoufix16_r (_REENT, s, ptr); |
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| 166 | } |
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| 167 | |
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| 168 | #endif |
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| 169 | |
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| 170 | #endif /* __SPE__ */ |
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