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1 /**************************************************************** |
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2 * |
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3 * The author of this software is David M. Gay. |
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4 * |
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5 * Copyright (c) 1991, 2000, 2001 by Lucent Technologies. |
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6 * |
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7 * Permission to use, copy, modify, and distribute this software for any |
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8 * purpose without fee is hereby granted, provided that this entire notice |
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9 * is included in all copies of any software which is or includes a copy |
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10 * or modification of this software and in all copies of the supporting |
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11 * documentation for such software. |
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12 * |
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13 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED |
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14 * WARRANTY. IN PARTICULAR, NEITHER THE AUTHOR NOR LUCENT MAKES ANY |
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15 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY |
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16 * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE. |
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17 * |
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18 ***************************************************************/ |
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19 |
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20 /* Please send bug reports to David M. Gay (dmg at acm dot org, |
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21 * with " at " changed at "@" and " dot " changed to "."). */ |
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22 |
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23 /* On a machine with IEEE extended-precision registers, it is |
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24 * necessary to specify double-precision (53-bit) rounding precision |
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25 * before invoking strtod or dtoa. If the machine uses (the equivalent |
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26 * of) Intel 80x87 arithmetic, the call |
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27 * _control87(PC_53, MCW_PC); |
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28 * does this with many compilers. Whether this or another call is |
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29 * appropriate depends on the compiler; for this to work, it may be |
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30 * necessary to #include "float.h" or another system-dependent header |
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31 * file. |
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32 */ |
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33 |
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34 /* strtod for IEEE-, VAX-, and IBM-arithmetic machines. |
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35 * |
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36 * This strtod returns a nearest machine number to the input decimal |
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37 * string (or sets errno to ERANGE). With IEEE arithmetic, ties are |
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38 * broken by the IEEE round-even rule. Otherwise ties are broken by |
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39 * biased rounding (add half and chop). |
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40 * |
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41 * Inspired loosely by William D. Clinger's paper "How to Read Floating |
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42 * Point Numbers Accurately" [Proc. ACM SIGPLAN '90, pp. 92-101]. |
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43 * |
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44 * Modifications: |
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45 * |
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46 * 1. We only require IEEE, IBM, or VAX double-precision |
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47 * arithmetic (not IEEE double-extended). |
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48 * 2. We get by with floating-point arithmetic in a case that |
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49 * Clinger missed -- when we're computing d * 10^n |
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50 * for a small integer d and the integer n is not too |
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51 * much larger than 22 (the maximum integer k for which |
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52 * we can represent 10^k exactly), we may be able to |
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53 * compute (d*10^k) * 10^(e-k) with just one roundoff. |
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54 * 3. Rather than a bit-at-a-time adjustment of the binary |
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55 * result in the hard case, we use floating-point |
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56 * arithmetic to determine the adjustment to within |
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57 * one bit; only in really hard cases do we need to |
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58 * compute a second residual. |
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59 * 4. Because of 3., we don't need a large table of powers of 10 |
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60 * for ten-to-e (just some small tables, e.g. of 10^k |
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61 * for 0 <= k <= 22). |
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62 */ |
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63 |
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64 /* |
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65 * #define IEEE_8087 for IEEE-arithmetic machines where the least |
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66 * significant byte has the lowest address. |
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67 * #define IEEE_MC68k for IEEE-arithmetic machines where the most |
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68 * significant byte has the lowest address. |
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69 * #define Long int on machines with 32-bit ints and 64-bit longs. |
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70 * #define IBM for IBM mainframe-style floating-point arithmetic. |
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71 * #define VAX for VAX-style floating-point arithmetic (D_floating). |
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72 * #define No_leftright to omit left-right logic in fast floating-point |
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73 * computation of dtoa. |
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74 * #define Honor_FLT_ROUNDS if FLT_ROUNDS can assume the values 2 or 3 |
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75 * and strtod and dtoa should round accordingly. Unless Trust_FLT_ROUNDS |
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76 * is also #defined, fegetround() will be queried for the rounding mode. |
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77 * Note that both FLT_ROUNDS and fegetround() are specified by the C99 |
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78 * standard (and are specified to be consistent, with fesetround() |
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79 * affecting the value of FLT_ROUNDS), but that some (Linux) systems |
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80 * do not work correctly in this regard, so using fegetround() is more |
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81 * portable than using FLT_FOUNDS directly. |
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82 * #define Check_FLT_ROUNDS if FLT_ROUNDS can assume the values 2 or 3 |
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83 * and Honor_FLT_ROUNDS is not #defined. |
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84 * #define RND_PRODQUOT to use rnd_prod and rnd_quot (assembly routines |
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85 * that use extended-precision instructions to compute rounded |
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86 * products and quotients) with IBM. |
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87 * #define ROUND_BIASED for IEEE-format with biased rounding. |
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88 * #define Inaccurate_Divide for IEEE-format with correctly rounded |
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89 * products but inaccurate quotients, e.g., for Intel i860. |
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90 * #define NO_LONG_LONG on machines that do not have a "long long" |
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91 * integer type (of >= 64 bits). On such machines, you can |
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92 * #define Just_16 to store 16 bits per 32-bit Long when doing |
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93 * high-precision integer arithmetic. Whether this speeds things |
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94 * up or slows things down depends on the machine and the number |
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95 * being converted. If long long is available and the name is |
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96 * something other than "long long", #define Llong to be the name, |
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97 * and if "unsigned Llong" does not work as an unsigned version of |
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98 * Llong, #define #ULLong to be the corresponding unsigned type. |
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99 * #define KR_headers for old-style C function headers. |
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100 * #define Bad_float_h if your system lacks a float.h or if it does not |
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101 * define some or all of DBL_DIG, DBL_MAX_10_EXP, DBL_MAX_EXP, |
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102 * FLT_RADIX, FLT_ROUNDS, and DBL_MAX. |
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103 * #define MALLOC your_malloc, where your_malloc(n) acts like malloc(n) |
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104 * if memory is available and otherwise does something you deem |
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105 * appropriate. If MALLOC is undefined, malloc will be invoked |
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106 * directly -- and assumed always to succeed. Similarly, if you |
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107 * want something other than the system's free() to be called to |
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108 * recycle memory acquired from MALLOC, #define FREE to be the |
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109 * name of the alternate routine. (FREE or free is only called in |
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110 * pathological cases, e.g., in a dtoa call after a dtoa return in |
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111 * mode 3 with thousands of digits requested.) |
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112 * #define Omit_Private_Memory to omit logic (added Jan. 1998) for making |
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113 * memory allocations from a private pool of memory when possible. |
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114 * When used, the private pool is PRIVATE_MEM bytes long: 2304 bytes, |
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115 * unless #defined to be a different length. This default length |
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116 * suffices to get rid of MALLOC calls except for unusual cases, |
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117 * such as decimal-to-binary conversion of a very long string of |
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118 * digits. The longest string dtoa can return is about 751 bytes |
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119 * long. For conversions by strtod of strings of 800 digits and |
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120 * all dtoa conversions in single-threaded executions with 8-byte |
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121 * pointers, PRIVATE_MEM >= 7400 appears to suffice; with 4-byte |
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122 * pointers, PRIVATE_MEM >= 7112 appears adequate. |
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123 * #define NO_INFNAN_CHECK if you do not wish to have INFNAN_CHECK |
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124 * #defined automatically on IEEE systems. On such systems, |
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125 * when INFNAN_CHECK is #defined, strtod checks |
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126 * for Infinity and NaN (case insensitively). On some systems |
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127 * (e.g., some HP systems), it may be necessary to #define NAN_WORD0 |
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128 * appropriately -- to the most significant word of a quiet NaN. |
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129 * (On HP Series 700/800 machines, -DNAN_WORD0=0x7ff40000 works.) |
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130 * When INFNAN_CHECK is #defined and No_Hex_NaN is not #defined, |
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131 * strtod also accepts (case insensitively) strings of the form |
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132 * NaN(x), where x is a string of hexadecimal digits and spaces; |
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133 * if there is only one string of hexadecimal digits, it is taken |
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134 * for the 52 fraction bits of the resulting NaN; if there are two |
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135 * or more strings of hex digits, the first is for the high 20 bits, |
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136 * the second and subsequent for the low 32 bits, with intervening |
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137 * white space ignored; but if this results in none of the 52 |
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138 * fraction bits being on (an IEEE Infinity symbol), then NAN_WORD0 |
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139 * and NAN_WORD1 are used instead. |
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140 * #define MULTIPLE_THREADS if the system offers preemptively scheduled |
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141 * multiple threads. In this case, you must provide (or suitably |
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142 * #define) two locks, acquired by ACQUIRE_DTOA_LOCK(n) and freed |
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143 * by FREE_DTOA_LOCK(n) for n = 0 or 1. (The second lock, accessed |
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144 * in pow5mult, ensures lazy evaluation of only one copy of high |
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145 * powers of 5; omitting this lock would introduce a small |
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146 * probability of wasting memory, but would otherwise be harmless.) |
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147 * You must also invoke freedtoa(s) to free the value s returned by |
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148 * dtoa. You may do so whether or not MULTIPLE_THREADS is #defined. |
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149 * #define NO_IEEE_Scale to disable new (Feb. 1997) logic in strtod that |
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150 * avoids underflows on inputs whose result does not underflow. |
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151 * If you #define NO_IEEE_Scale on a machine that uses IEEE-format |
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152 * floating-point numbers and flushes underflows to zero rather |
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153 * than implementing gradual underflow, then you must also #define |
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154 * Sudden_Underflow. |
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155 * #define USE_LOCALE to use the current locale's decimal_point value. |
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156 * #define SET_INEXACT if IEEE arithmetic is being used and extra |
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157 * computation should be done to set the inexact flag when the |
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158 * result is inexact and avoid setting inexact when the result |
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159 * is exact. In this case, dtoa.c must be compiled in |
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160 * an environment, perhaps provided by #include "dtoa.c" in a |
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161 * suitable wrapper, that defines two functions, |
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162 * int get_inexact(void); |
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163 * void clear_inexact(void); |
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164 * such that get_inexact() returns a nonzero value if the |
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165 * inexact bit is already set, and clear_inexact() sets the |
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166 * inexact bit to 0. When SET_INEXACT is #defined, strtod |
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167 * also does extra computations to set the underflow and overflow |
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168 * flags when appropriate (i.e., when the result is tiny and |
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169 * inexact or when it is a numeric value rounded to +-infinity). |
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170 * #define NO_ERRNO if strtod should not assign errno = ERANGE when |
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171 * the result overflows to +-Infinity or underflows to 0. |
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172 * #define NO_HEX_FP to omit recognition of hexadecimal floating-point |
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173 * values by strtod. |
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174 * #define NO_STRTOD_BIGCOMP (on IEEE-arithmetic systems only for now) |
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175 * to disable logic for "fast" testing of very long input strings |
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176 * to strtod. This testing proceeds by initially truncating the |
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177 * input string, then if necessary comparing the whole string with |
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178 * a decimal expansion to decide close cases. This logic is only |
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179 * used for input more than STRTOD_DIGLIM digits long (default 40). |
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180 */ |
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181 |
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182 #define IEEE_8087 |
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183 #define NO_HEX_FP |
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184 |
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185 #ifndef Long |
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186 #if __LP64__ |
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187 #define Long int |
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188 #else |
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189 #define Long long |
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190 #endif |
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191 #endif |
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192 #ifndef ULong |
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193 typedef unsigned Long ULong; |
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194 #endif |
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195 |
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196 #ifdef DEBUG |
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197 #include "stdio.h" |
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198 #define Bug(x) {fprintf(stderr, "%s\n", x); exit(1);} |
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199 #endif |
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200 |
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201 #include "stdlib.h" |
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202 #include "string.h" |
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203 |
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204 #ifdef USE_LOCALE |
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205 #include "locale.h" |
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206 #endif |
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207 |
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208 #ifdef Honor_FLT_ROUNDS |
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209 #ifndef Trust_FLT_ROUNDS |
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210 #include <fenv.h> |
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211 #endif |
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212 #endif |
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213 |
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214 #ifdef MALLOC |
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215 #ifdef KR_headers |
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216 extern char *MALLOC(); |
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217 #else |
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218 extern void *MALLOC(size_t); |
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219 #endif |
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220 #else |
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221 #define MALLOC malloc |
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222 #endif |
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223 |
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224 #ifndef Omit_Private_Memory |
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225 #ifndef PRIVATE_MEM |
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226 #define PRIVATE_MEM 2304 |
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227 #endif |
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228 #define PRIVATE_mem ((unsigned)((PRIVATE_MEM+sizeof(double)-1)/sizeof(double))) |
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229 static double private_mem[PRIVATE_mem], *pmem_next = private_mem; |
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230 #endif |
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231 |
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232 #undef IEEE_Arith |
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233 #undef Avoid_Underflow |
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234 #ifdef IEEE_MC68k |
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235 #define IEEE_Arith |
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236 #endif |
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237 #ifdef IEEE_8087 |
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238 #define IEEE_Arith |
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239 #endif |
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240 |
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241 #ifdef IEEE_Arith |
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242 #ifndef NO_INFNAN_CHECK |
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243 #undef INFNAN_CHECK |
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244 #define INFNAN_CHECK |
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245 #endif |
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246 #else |
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247 #undef INFNAN_CHECK |
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248 #define NO_STRTOD_BIGCOMP |
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249 #endif |
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250 |
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251 #include "errno.h" |
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252 |
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253 #ifdef Bad_float_h |
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254 |
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255 #ifdef IEEE_Arith |
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256 #define DBL_DIG 15 |
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257 #define DBL_MAX_10_EXP 308 |
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258 #define DBL_MAX_EXP 1024 |
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259 #define FLT_RADIX 2 |
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260 #endif /*IEEE_Arith*/ |
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261 |
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262 #ifdef IBM |
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263 #define DBL_DIG 16 |
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264 #define DBL_MAX_10_EXP 75 |
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265 #define DBL_MAX_EXP 63 |
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266 #define FLT_RADIX 16 |
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267 #define DBL_MAX 7.2370055773322621e+75 |
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268 #endif |
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269 |
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270 #ifdef VAX |
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271 #define DBL_DIG 16 |
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272 #define DBL_MAX_10_EXP 38 |
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273 #define DBL_MAX_EXP 127 |
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274 #define FLT_RADIX 2 |
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275 #define DBL_MAX 1.7014118346046923e+38 |
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276 #endif |
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277 |
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278 #ifndef LONG_MAX |
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279 #define LONG_MAX 2147483647 |
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280 #endif |
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281 |
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282 #else /* ifndef Bad_float_h */ |
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283 #include "float.h" |
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284 #endif /* Bad_float_h */ |
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285 |
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286 #ifndef __MATH_H__ |
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287 #include "math.h" |
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288 #endif |
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289 |
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290 namespace dmg_fp { |
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291 |
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292 #ifndef CONST |
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293 #ifdef KR_headers |
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294 #define CONST /* blank */ |
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295 #else |
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296 #define CONST const |
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297 #endif |
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298 #endif |
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299 |
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300 #if defined(IEEE_8087) + defined(IEEE_MC68k) + defined(VAX) + defined(IBM) != 1 |
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301 Exactly one of IEEE_8087, IEEE_MC68k, VAX, or IBM should be defined. |
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302 #endif |
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303 |
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304 typedef union { double d; ULong L[2]; } U; |
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305 |
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306 #ifdef IEEE_8087 |
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307 #define word0(x) (x)->L[1] |
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308 #define word1(x) (x)->L[0] |
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309 #else |
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310 #define word0(x) (x)->L[0] |
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311 #define word1(x) (x)->L[1] |
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312 #endif |
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313 #define dval(x) (x)->d |
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314 |
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315 #ifndef STRTOD_DIGLIM |
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316 #define STRTOD_DIGLIM 40 |
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317 #endif |
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318 |
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319 #ifdef DIGLIM_DEBUG |
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320 extern int strtod_diglim; |
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321 #else |
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322 #define strtod_diglim STRTOD_DIGLIM |
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323 #endif |
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324 |
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325 /* The following definition of Storeinc is appropriate for MIPS processors. |
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326 * An alternative that might be better on some machines is |
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327 * #define Storeinc(a,b,c) (*a++ = b << 16 | c & 0xffff) |
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328 */ |
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329 #if defined(IEEE_8087) + defined(VAX) |
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330 #define Storeinc(a,b,c) (((unsigned short *)a)[1] = (unsigned short)b, \ |
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331 ((unsigned short *)a)[0] = (unsigned short)c, a++) |
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332 #else |
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333 #define Storeinc(a,b,c) (((unsigned short *)a)[0] = (unsigned short)b, \ |
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334 ((unsigned short *)a)[1] = (unsigned short)c, a++) |
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335 #endif |
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336 |
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337 /* #define P DBL_MANT_DIG */ |
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338 /* Ten_pmax = floor(P*log(2)/log(5)) */ |
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339 /* Bletch = (highest power of 2 < DBL_MAX_10_EXP) / 16 */ |
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340 /* Quick_max = floor((P-1)*log(FLT_RADIX)/log(10) - 1) */ |
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341 /* Int_max = floor(P*log(FLT_RADIX)/log(10) - 1) */ |
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342 |
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343 #ifdef IEEE_Arith |
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344 #define Exp_shift 20 |
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345 #define Exp_shift1 20 |
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346 #define Exp_msk1 0x100000 |
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347 #define Exp_msk11 0x100000 |
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348 #define Exp_mask 0x7ff00000 |
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349 #define P 53 |
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350 #define Nbits 53 |
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351 #define Bias 1023 |
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352 #define Emax 1023 |
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353 #define Emin (-1022) |
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354 #define Exp_1 0x3ff00000 |
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355 #define Exp_11 0x3ff00000 |
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356 #define Ebits 11 |
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357 #define Frac_mask 0xfffff |
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358 #define Frac_mask1 0xfffff |
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359 #define Ten_pmax 22 |
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360 #define Bletch 0x10 |
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361 #define Bndry_mask 0xfffff |
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362 #define Bndry_mask1 0xfffff |
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363 #define LSB 1 |
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364 #define Sign_bit 0x80000000 |
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365 #define Log2P 1 |
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366 #define Tiny0 0 |
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367 #define Tiny1 1 |
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368 #define Quick_max 14 |
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369 #define Int_max 14 |
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370 #ifndef NO_IEEE_Scale |
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371 #define Avoid_Underflow |
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372 #ifdef Flush_Denorm /* debugging option */ |
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373 #undef Sudden_Underflow |
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374 #endif |
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375 #endif |
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376 |
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377 #ifndef Flt_Rounds |
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378 #ifdef FLT_ROUNDS |
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379 #define Flt_Rounds FLT_ROUNDS |
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380 #else |
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381 #define Flt_Rounds 1 |
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382 #endif |
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383 #endif /*Flt_Rounds*/ |
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384 |
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385 #ifdef Honor_FLT_ROUNDS |
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386 #undef Check_FLT_ROUNDS |
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387 #define Check_FLT_ROUNDS |
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388 #else |
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389 #define Rounding Flt_Rounds |
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390 #endif |
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391 |
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392 #else /* ifndef IEEE_Arith */ |
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393 #undef Check_FLT_ROUNDS |
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394 #undef Honor_FLT_ROUNDS |
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395 #undef SET_INEXACT |
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396 #undef Sudden_Underflow |
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397 #define Sudden_Underflow |
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398 #ifdef IBM |
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399 #undef Flt_Rounds |
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400 #define Flt_Rounds 0 |
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401 #define Exp_shift 24 |
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402 #define Exp_shift1 24 |
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403 #define Exp_msk1 0x1000000 |
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404 #define Exp_msk11 0x1000000 |
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405 #define Exp_mask 0x7f000000 |
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406 #define P 14 |
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407 #define Nbits 56 |
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408 #define Bias 65 |
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409 #define Emax 248 |
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410 #define Emin (-260) |
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411 #define Exp_1 0x41000000 |
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412 #define Exp_11 0x41000000 |
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413 #define Ebits 8 /* exponent has 7 bits, but 8 is the right value in b2d */ |
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414 #define Frac_mask 0xffffff |
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415 #define Frac_mask1 0xffffff |
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416 #define Bletch 4 |
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417 #define Ten_pmax 22 |
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418 #define Bndry_mask 0xefffff |
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419 #define Bndry_mask1 0xffffff |
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420 #define LSB 1 |
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421 #define Sign_bit 0x80000000 |
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422 #define Log2P 4 |
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423 #define Tiny0 0x100000 |
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424 #define Tiny1 0 |
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425 #define Quick_max 14 |
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426 #define Int_max 15 |
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427 #else /* VAX */ |
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428 #undef Flt_Rounds |
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429 #define Flt_Rounds 1 |
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430 #define Exp_shift 23 |
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431 #define Exp_shift1 7 |
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432 #define Exp_msk1 0x80 |
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433 #define Exp_msk11 0x800000 |
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434 #define Exp_mask 0x7f80 |
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435 #define P 56 |
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436 #define Nbits 56 |
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437 #define Bias 129 |
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438 #define Emax 126 |
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439 #define Emin (-129) |
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440 #define Exp_1 0x40800000 |
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441 #define Exp_11 0x4080 |
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442 #define Ebits 8 |
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443 #define Frac_mask 0x7fffff |
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444 #define Frac_mask1 0xffff007f |
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445 #define Ten_pmax 24 |
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446 #define Bletch 2 |
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447 #define Bndry_mask 0xffff007f |
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448 #define Bndry_mask1 0xffff007f |
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449 #define LSB 0x10000 |
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450 #define Sign_bit 0x8000 |
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451 #define Log2P 1 |
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452 #define Tiny0 0x80 |
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453 #define Tiny1 0 |
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454 #define Quick_max 15 |
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455 #define Int_max 15 |
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456 #endif /* IBM, VAX */ |
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457 #endif /* IEEE_Arith */ |
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458 |
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459 #ifndef IEEE_Arith |
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460 #define ROUND_BIASED |
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461 #endif |
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462 |
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463 #ifdef RND_PRODQUOT |
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464 #define rounded_product(a,b) a = rnd_prod(a, b) |
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465 #define rounded_quotient(a,b) a = rnd_quot(a, b) |
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466 #ifdef KR_headers |
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467 extern double rnd_prod(), rnd_quot(); |
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468 #else |
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469 extern double rnd_prod(double, double), rnd_quot(double, double); |
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470 #endif |
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471 #else |
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472 #define rounded_product(a,b) a *= b |
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473 #define rounded_quotient(a,b) a /= b |
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474 #endif |
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475 |
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476 #define Big0 (Frac_mask1 | Exp_msk1*(DBL_MAX_EXP+Bias-1)) |
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477 #define Big1 0xffffffff |
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478 |
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479 #ifndef Pack_32 |
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480 #define Pack_32 |
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481 #endif |
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482 |
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483 typedef struct BCinfo BCinfo; |
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484 struct |
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485 BCinfo { int dp0, dp1, dplen, dsign, e0, inexact, nd, nd0, rounding, scale, uflchk; }; |
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486 |
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487 #ifdef KR_headers |
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488 #define FFFFFFFF ((((unsigned long)0xffff)<<16)|(unsigned long)0xffff) |
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489 #else |
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490 #define FFFFFFFF 0xffffffffUL |
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491 #endif |
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492 |
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493 #ifdef NO_LONG_LONG |
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494 #undef ULLong |
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495 #ifdef Just_16 |
|
496 #undef Pack_32 |
|
497 /* When Pack_32 is not defined, we store 16 bits per 32-bit Long. |
|
498 * This makes some inner loops simpler and sometimes saves work |
|
499 * during multiplications, but it often seems to make things slightly |
|
500 * slower. Hence the default is now to store 32 bits per Long. |
|
501 */ |
|
502 #endif |
|
503 #else /* long long available */ |
|
504 #ifndef Llong |
|
505 #define Llong long long |
|
506 #endif |
|
507 #ifndef ULLong |
|
508 #define ULLong unsigned Llong |
|
509 #endif |
|
510 #endif /* NO_LONG_LONG */ |
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511 |
|
512 #ifndef MULTIPLE_THREADS |
|
513 #define ACQUIRE_DTOA_LOCK(n) /*nothing*/ |
|
514 #define FREE_DTOA_LOCK(n) /*nothing*/ |
|
515 #endif |
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516 |
|
517 #define Kmax 7 |
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518 |
|
519 double strtod(const char *s00, char **se); |
|
520 char *dtoa(double d, int mode, int ndigits, |
|
521 int *decpt, int *sign, char **rve); |
|
522 |
|
523 struct |
|
524 Bigint { |
|
525 struct Bigint *next; |
|
526 int k, maxwds, sign, wds; |
|
527 ULong x[1]; |
|
528 }; |
|
529 |
|
530 typedef struct Bigint Bigint; |
|
531 |
|
532 static Bigint *freelist[Kmax+1]; |
|
533 |
|
534 static Bigint * |
|
535 Balloc |
|
536 #ifdef KR_headers |
|
537 (k) int k; |
|
538 #else |
|
539 (int k) |
|
540 #endif |
|
541 { |
|
542 int x; |
|
543 Bigint *rv; |
|
544 #ifndef Omit_Private_Memory |
|
545 unsigned int len; |
|
546 #endif |
|
547 |
|
548 ACQUIRE_DTOA_LOCK(0); |
|
549 /* The k > Kmax case does not need ACQUIRE_DTOA_LOCK(0), */ |
|
550 /* but this case seems very unlikely. */ |
|
551 if (k <= Kmax && (rv = freelist[k])) |
|
552 freelist[k] = rv->next; |
|
553 else { |
|
554 x = 1 << k; |
|
555 #ifdef Omit_Private_Memory |
|
556 rv = (Bigint *)MALLOC(sizeof(Bigint) + (x-1)*sizeof(ULong)); |
|
557 #else |
|
558 len = (sizeof(Bigint) + (x-1)*sizeof(ULong) + sizeof(double) - 1) |
|
559 /sizeof(double); |
|
560 if (k <= Kmax && pmem_next - private_mem + len <= PRIVATE_mem) { |
|
561 rv = (Bigint*)pmem_next; |
|
562 pmem_next += len; |
|
563 } |
|
564 else |
|
565 rv = (Bigint*)MALLOC(len*sizeof(double)); |
|
566 #endif |
|
567 rv->k = k; |
|
568 rv->maxwds = x; |
|
569 } |
|
570 FREE_DTOA_LOCK(0); |
|
571 rv->sign = rv->wds = 0; |
|
572 return rv; |
|
573 } |
|
574 |
|
575 static void |
|
576 Bfree |
|
577 #ifdef KR_headers |
|
578 (v) Bigint *v; |
|
579 #else |
|
580 (Bigint *v) |
|
581 #endif |
|
582 { |
|
583 if (v) { |
|
584 if (v->k > Kmax) |
|
585 #ifdef FREE |
|
586 FREE((void*)v); |
|
587 #else |
|
588 free((void*)v); |
|
589 #endif |
|
590 else { |
|
591 ACQUIRE_DTOA_LOCK(0); |
|
592 v->next = freelist[v->k]; |
|
593 freelist[v->k] = v; |
|
594 FREE_DTOA_LOCK(0); |
|
595 } |
|
596 } |
|
597 } |
|
598 |
|
599 #define Bcopy(x,y) memcpy((char *)&x->sign, (char *)&y->sign, \ |
|
600 y->wds*sizeof(Long) + 2*sizeof(int)) |
|
601 |
|
602 static Bigint * |
|
603 multadd |
|
604 #ifdef KR_headers |
|
605 (b, m, a) Bigint *b; int m, a; |
|
606 #else |
|
607 (Bigint *b, int m, int a) /* multiply by m and add a */ |
|
608 #endif |
|
609 { |
|
610 int i, wds; |
|
611 #ifdef ULLong |
|
612 ULong *x; |
|
613 ULLong carry, y; |
|
614 #else |
|
615 ULong carry, *x, y; |
|
616 #ifdef Pack_32 |
|
617 ULong xi, z; |
|
618 #endif |
|
619 #endif |
|
620 Bigint *b1; |
|
621 |
|
622 wds = b->wds; |
|
623 x = b->x; |
|
624 i = 0; |
|
625 carry = a; |
|
626 do { |
|
627 #ifdef ULLong |
|
628 y = *x * (ULLong)m + carry; |
|
629 carry = y >> 32; |
|
630 *x++ = y & FFFFFFFF; |
|
631 #else |
|
632 #ifdef Pack_32 |
|
633 xi = *x; |
|
634 y = (xi & 0xffff) * m + carry; |
|
635 z = (xi >> 16) * m + (y >> 16); |
|
636 carry = z >> 16; |
|
637 *x++ = (z << 16) + (y & 0xffff); |
|
638 #else |
|
639 y = *x * m + carry; |
|
640 carry = y >> 16; |
|
641 *x++ = y & 0xffff; |
|
642 #endif |
|
643 #endif |
|
644 } |
|
645 while(++i < wds); |
|
646 if (carry) { |
|
647 if (wds >= b->maxwds) { |
|
648 b1 = Balloc(b->k+1); |
|
649 Bcopy(b1, b); |
|
650 Bfree(b); |
|
651 b = b1; |
|
652 } |
|
653 b->x[wds++] = carry; |
|
654 b->wds = wds; |
|
655 } |
|
656 return b; |
|
657 } |
|
658 |
|
659 static Bigint * |
|
660 s2b |
|
661 #ifdef KR_headers |
|
662 (s, nd0, nd, y9, dplen) CONST char *s; int nd0, nd, dplen; ULong y9; |
|
663 #else |
|
664 (CONST char *s, int nd0, int nd, ULong y9, int dplen) |
|
665 #endif |
|
666 { |
|
667 Bigint *b; |
|
668 int i, k; |
|
669 Long x, y; |
|
670 |
|
671 x = (nd + 8) / 9; |
|
672 for(k = 0, y = 1; x > y; y <<= 1, k++) ; |
|
673 #ifdef Pack_32 |
|
674 b = Balloc(k); |
|
675 b->x[0] = y9; |
|
676 b->wds = 1; |
|
677 #else |
|
678 b = Balloc(k+1); |
|
679 b->x[0] = y9 & 0xffff; |
|
680 b->wds = (b->x[1] = y9 >> 16) ? 2 : 1; |
|
681 #endif |
|
682 |
|
683 i = 9; |
|
684 if (9 < nd0) { |
|
685 s += 9; |
|
686 do b = multadd(b, 10, *s++ - '0'); |
|
687 while(++i < nd0); |
|
688 s += dplen; |
|
689 } |
|
690 else |
|
691 s += dplen + 9; |
|
692 for(; i < nd; i++) |
|
693 b = multadd(b, 10, *s++ - '0'); |
|
694 return b; |
|
695 } |
|
696 |
|
697 static int |
|
698 hi0bits |
|
699 #ifdef KR_headers |
|
700 (x) ULong x; |
|
701 #else |
|
702 (ULong x) |
|
703 #endif |
|
704 { |
|
705 int k = 0; |
|
706 |
|
707 if (!(x & 0xffff0000)) { |
|
708 k = 16; |
|
709 x <<= 16; |
|
710 } |
|
711 if (!(x & 0xff000000)) { |
|
712 k += 8; |
|
713 x <<= 8; |
|
714 } |
|
715 if (!(x & 0xf0000000)) { |
|
716 k += 4; |
|
717 x <<= 4; |
|
718 } |
|
719 if (!(x & 0xc0000000)) { |
|
720 k += 2; |
|
721 x <<= 2; |
|
722 } |
|
723 if (!(x & 0x80000000)) { |
|
724 k++; |
|
725 if (!(x & 0x40000000)) |
|
726 return 32; |
|
727 } |
|
728 return k; |
|
729 } |
|
730 |
|
731 static int |
|
732 lo0bits |
|
733 #ifdef KR_headers |
|
734 (y) ULong *y; |
|
735 #else |
|
736 (ULong *y) |
|
737 #endif |
|
738 { |
|
739 int k; |
|
740 ULong x = *y; |
|
741 |
|
742 if (x & 7) { |
|
743 if (x & 1) |
|
744 return 0; |
|
745 if (x & 2) { |
|
746 *y = x >> 1; |
|
747 return 1; |
|
748 } |
|
749 *y = x >> 2; |
|
750 return 2; |
|
751 } |
|
752 k = 0; |
|
753 if (!(x & 0xffff)) { |
|
754 k = 16; |
|
755 x >>= 16; |
|
756 } |
|
757 if (!(x & 0xff)) { |
|
758 k += 8; |
|
759 x >>= 8; |
|
760 } |
|
761 if (!(x & 0xf)) { |
|
762 k += 4; |
|
763 x >>= 4; |
|
764 } |
|
765 if (!(x & 0x3)) { |
|
766 k += 2; |
|
767 x >>= 2; |
|
768 } |
|
769 if (!(x & 1)) { |
|
770 k++; |
|
771 x >>= 1; |
|
772 if (!x) |
|
773 return 32; |
|
774 } |
|
775 *y = x; |
|
776 return k; |
|
777 } |
|
778 |
|
779 static Bigint * |
|
780 i2b |
|
781 #ifdef KR_headers |
|
782 (i) int i; |
|
783 #else |
|
784 (int i) |
|
785 #endif |
|
786 { |
|
787 Bigint *b; |
|
788 |
|
789 b = Balloc(1); |
|
790 b->x[0] = i; |
|
791 b->wds = 1; |
|
792 return b; |
|
793 } |
|
794 |
|
795 static Bigint * |
|
796 mult |
|
797 #ifdef KR_headers |
|
798 (a, b) Bigint *a, *b; |
|
799 #else |
|
800 (Bigint *a, Bigint *b) |
|
801 #endif |
|
802 { |
|
803 Bigint *c; |
|
804 int k, wa, wb, wc; |
|
805 ULong *x, *xa, *xae, *xb, *xbe, *xc, *xc0; |
|
806 ULong y; |
|
807 #ifdef ULLong |
|
808 ULLong carry, z; |
|
809 #else |
|
810 ULong carry, z; |
|
811 #ifdef Pack_32 |
|
812 ULong z2; |
|
813 #endif |
|
814 #endif |
|
815 |
|
816 if (a->wds < b->wds) { |
|
817 c = a; |
|
818 a = b; |
|
819 b = c; |
|
820 } |
|
821 k = a->k; |
|
822 wa = a->wds; |
|
823 wb = b->wds; |
|
824 wc = wa + wb; |
|
825 if (wc > a->maxwds) |
|
826 k++; |
|
827 c = Balloc(k); |
|
828 for(x = c->x, xa = x + wc; x < xa; x++) |
|
829 *x = 0; |
|
830 xa = a->x; |
|
831 xae = xa + wa; |
|
832 xb = b->x; |
|
833 xbe = xb + wb; |
|
834 xc0 = c->x; |
|
835 #ifdef ULLong |
|
836 for(; xb < xbe; xc0++) { |
|
837 if ((y = *xb++)) { |
|
838 x = xa; |
|
839 xc = xc0; |
|
840 carry = 0; |
|
841 do { |
|
842 z = *x++ * (ULLong)y + *xc + carry; |
|
843 carry = z >> 32; |
|
844 *xc++ = z & FFFFFFFF; |
|
845 } |
|
846 while(x < xae); |
|
847 *xc = carry; |
|
848 } |
|
849 } |
|
850 #else |
|
851 #ifdef Pack_32 |
|
852 for(; xb < xbe; xb++, xc0++) { |
|
853 if (y = *xb & 0xffff) { |
|
854 x = xa; |
|
855 xc = xc0; |
|
856 carry = 0; |
|
857 do { |
|
858 z = (*x & 0xffff) * y + (*xc & 0xffff) + carry; |
|
859 carry = z >> 16; |
|
860 z2 = (*x++ >> 16) * y + (*xc >> 16) + carry; |
|
861 carry = z2 >> 16; |
|
862 Storeinc(xc, z2, z); |
|
863 } |
|
864 while(x < xae); |
|
865 *xc = carry; |
|
866 } |
|
867 if (y = *xb >> 16) { |
|
868 x = xa; |
|
869 xc = xc0; |
|
870 carry = 0; |
|
871 z2 = *xc; |
|
872 do { |
|
873 z = (*x & 0xffff) * y + (*xc >> 16) + carry; |
|
874 carry = z >> 16; |
|
875 Storeinc(xc, z, z2); |
|
876 z2 = (*x++ >> 16) * y + (*xc & 0xffff) + carry; |
|
877 carry = z2 >> 16; |
|
878 } |
|
879 while(x < xae); |
|
880 *xc = z2; |
|
881 } |
|
882 } |
|
883 #else |
|
884 for(; xb < xbe; xc0++) { |
|
885 if (y = *xb++) { |
|
886 x = xa; |
|
887 xc = xc0; |
|
888 carry = 0; |
|
889 do { |
|
890 z = *x++ * y + *xc + carry; |
|
891 carry = z >> 16; |
|
892 *xc++ = z & 0xffff; |
|
893 } |
|
894 while(x < xae); |
|
895 *xc = carry; |
|
896 } |
|
897 } |
|
898 #endif |
|
899 #endif |
|
900 for(xc0 = c->x, xc = xc0 + wc; wc > 0 && !*--xc; --wc) ; |
|
901 c->wds = wc; |
|
902 return c; |
|
903 } |
|
904 |
|
905 static Bigint *p5s; |
|
906 |
|
907 static Bigint * |
|
908 pow5mult |
|
909 #ifdef KR_headers |
|
910 (b, k) Bigint *b; int k; |
|
911 #else |
|
912 (Bigint *b, int k) |
|
913 #endif |
|
914 { |
|
915 Bigint *b1, *p5, *p51; |
|
916 int i; |
|
917 static int p05[3] = { 5, 25, 125 }; |
|
918 |
|
919 if ((i = k & 3)) |
|
920 b = multadd(b, p05[i-1], 0); |
|
921 |
|
922 if (!(k >>= 2)) |
|
923 return b; |
|
924 if (!(p5 = p5s)) { |
|
925 /* first time */ |
|
926 #ifdef MULTIPLE_THREADS |
|
927 ACQUIRE_DTOA_LOCK(1); |
|
928 if (!(p5 = p5s)) { |
|
929 p5 = p5s = i2b(625); |
|
930 p5->next = 0; |
|
931 } |
|
932 FREE_DTOA_LOCK(1); |
|
933 #else |
|
934 p5 = p5s = i2b(625); |
|
935 p5->next = 0; |
|
936 #endif |
|
937 } |
|
938 for(;;) { |
|
939 if (k & 1) { |
|
940 b1 = mult(b, p5); |
|
941 Bfree(b); |
|
942 b = b1; |
|
943 } |
|
944 if (!(k >>= 1)) |
|
945 break; |
|
946 if (!(p51 = p5->next)) { |
|
947 #ifdef MULTIPLE_THREADS |
|
948 ACQUIRE_DTOA_LOCK(1); |
|
949 if (!(p51 = p5->next)) { |
|
950 p51 = p5->next = mult(p5,p5); |
|
951 p51->next = 0; |
|
952 } |
|
953 FREE_DTOA_LOCK(1); |
|
954 #else |
|
955 p51 = p5->next = mult(p5,p5); |
|
956 p51->next = 0; |
|
957 #endif |
|
958 } |
|
959 p5 = p51; |
|
960 } |
|
961 return b; |
|
962 } |
|
963 |
|
964 static Bigint * |
|
965 lshift |
|
966 #ifdef KR_headers |
|
967 (b, k) Bigint *b; int k; |
|
968 #else |
|
969 (Bigint *b, int k) |
|
970 #endif |
|
971 { |
|
972 int i, k1, n, n1; |
|
973 Bigint *b1; |
|
974 ULong *x, *x1, *xe, z; |
|
975 |
|
976 #ifdef Pack_32 |
|
977 n = k >> 5; |
|
978 #else |
|
979 n = k >> 4; |
|
980 #endif |
|
981 k1 = b->k; |
|
982 n1 = n + b->wds + 1; |
|
983 for(i = b->maxwds; n1 > i; i <<= 1) |
|
984 k1++; |
|
985 b1 = Balloc(k1); |
|
986 x1 = b1->x; |
|
987 for(i = 0; i < n; i++) |
|
988 *x1++ = 0; |
|
989 x = b->x; |
|
990 xe = x + b->wds; |
|
991 #ifdef Pack_32 |
|
992 if (k &= 0x1f) { |
|
993 k1 = 32 - k; |
|
994 z = 0; |
|
995 do { |
|
996 *x1++ = *x << k | z; |
|
997 z = *x++ >> k1; |
|
998 } |
|
999 while(x < xe); |
|
1000 if ((*x1 = z)) |
|
1001 ++n1; |
|
1002 } |
|
1003 #else |
|
1004 if (k &= 0xf) { |
|
1005 k1 = 16 - k; |
|
1006 z = 0; |
|
1007 do { |
|
1008 *x1++ = *x << k & 0xffff | z; |
|
1009 z = *x++ >> k1; |
|
1010 } |
|
1011 while(x < xe); |
|
1012 if (*x1 = z) |
|
1013 ++n1; |
|
1014 } |
|
1015 #endif |
|
1016 else do |
|
1017 *x1++ = *x++; |
|
1018 while(x < xe); |
|
1019 b1->wds = n1 - 1; |
|
1020 Bfree(b); |
|
1021 return b1; |
|
1022 } |
|
1023 |
|
1024 static int |
|
1025 cmp |
|
1026 #ifdef KR_headers |
|
1027 (a, b) Bigint *a, *b; |
|
1028 #else |
|
1029 (Bigint *a, Bigint *b) |
|
1030 #endif |
|
1031 { |
|
1032 ULong *xa, *xa0, *xb, *xb0; |
|
1033 int i, j; |
|
1034 |
|
1035 i = a->wds; |
|
1036 j = b->wds; |
|
1037 #ifdef DEBUG |
|
1038 if (i > 1 && !a->x[i-1]) |
|
1039 Bug("cmp called with a->x[a->wds-1] == 0"); |
|
1040 if (j > 1 && !b->x[j-1]) |
|
1041 Bug("cmp called with b->x[b->wds-1] == 0"); |
|
1042 #endif |
|
1043 if (i -= j) |
|
1044 return i; |
|
1045 xa0 = a->x; |
|
1046 xa = xa0 + j; |
|
1047 xb0 = b->x; |
|
1048 xb = xb0 + j; |
|
1049 for(;;) { |
|
1050 if (*--xa != *--xb) |
|
1051 return *xa < *xb ? -1 : 1; |
|
1052 if (xa <= xa0) |
|
1053 break; |
|
1054 } |
|
1055 return 0; |
|
1056 } |
|
1057 |
|
1058 static Bigint * |
|
1059 diff |
|
1060 #ifdef KR_headers |
|
1061 (a, b) Bigint *a, *b; |
|
1062 #else |
|
1063 (Bigint *a, Bigint *b) |
|
1064 #endif |
|
1065 { |
|
1066 Bigint *c; |
|
1067 int i, wa, wb; |
|
1068 ULong *xa, *xae, *xb, *xbe, *xc; |
|
1069 #ifdef ULLong |
|
1070 ULLong borrow, y; |
|
1071 #else |
|
1072 ULong borrow, y; |
|
1073 #ifdef Pack_32 |
|
1074 ULong z; |
|
1075 #endif |
|
1076 #endif |
|
1077 |
|
1078 i = cmp(a,b); |
|
1079 if (!i) { |
|
1080 c = Balloc(0); |
|
1081 c->wds = 1; |
|
1082 c->x[0] = 0; |
|
1083 return c; |
|
1084 } |
|
1085 if (i < 0) { |
|
1086 c = a; |
|
1087 a = b; |
|
1088 b = c; |
|
1089 i = 1; |
|
1090 } |
|
1091 else |
|
1092 i = 0; |
|
1093 c = Balloc(a->k); |
|
1094 c->sign = i; |
|
1095 wa = a->wds; |
|
1096 xa = a->x; |
|
1097 xae = xa + wa; |
|
1098 wb = b->wds; |
|
1099 xb = b->x; |
|
1100 xbe = xb + wb; |
|
1101 xc = c->x; |
|
1102 borrow = 0; |
|
1103 #ifdef ULLong |
|
1104 do { |
|
1105 y = (ULLong)*xa++ - *xb++ - borrow; |
|
1106 borrow = y >> 32 & (ULong)1; |
|
1107 *xc++ = y & FFFFFFFF; |
|
1108 } |
|
1109 while(xb < xbe); |
|
1110 while(xa < xae) { |
|
1111 y = *xa++ - borrow; |
|
1112 borrow = y >> 32 & (ULong)1; |
|
1113 *xc++ = y & FFFFFFFF; |
|
1114 } |
|
1115 #else |
|
1116 #ifdef Pack_32 |
|
1117 do { |
|
1118 y = (*xa & 0xffff) - (*xb & 0xffff) - borrow; |
|
1119 borrow = (y & 0x10000) >> 16; |
|
1120 z = (*xa++ >> 16) - (*xb++ >> 16) - borrow; |
|
1121 borrow = (z & 0x10000) >> 16; |
|
1122 Storeinc(xc, z, y); |
|
1123 } |
|
1124 while(xb < xbe); |
|
1125 while(xa < xae) { |
|
1126 y = (*xa & 0xffff) - borrow; |
|
1127 borrow = (y & 0x10000) >> 16; |
|
1128 z = (*xa++ >> 16) - borrow; |
|
1129 borrow = (z & 0x10000) >> 16; |
|
1130 Storeinc(xc, z, y); |
|
1131 } |
|
1132 #else |
|
1133 do { |
|
1134 y = *xa++ - *xb++ - borrow; |
|
1135 borrow = (y & 0x10000) >> 16; |
|
1136 *xc++ = y & 0xffff; |
|
1137 } |
|
1138 while(xb < xbe); |
|
1139 while(xa < xae) { |
|
1140 y = *xa++ - borrow; |
|
1141 borrow = (y & 0x10000) >> 16; |
|
1142 *xc++ = y & 0xffff; |
|
1143 } |
|
1144 #endif |
|
1145 #endif |
|
1146 while(!*--xc) |
|
1147 wa--; |
|
1148 c->wds = wa; |
|
1149 return c; |
|
1150 } |
|
1151 |
|
1152 static double |
|
1153 ulp |
|
1154 #ifdef KR_headers |
|
1155 (x) U *x; |
|
1156 #else |
|
1157 (U *x) |
|
1158 #endif |
|
1159 { |
|
1160 Long L; |
|
1161 U u; |
|
1162 |
|
1163 L = (word0(x) & Exp_mask) - (P-1)*Exp_msk1; |
|
1164 #ifndef Avoid_Underflow |
|
1165 #ifndef Sudden_Underflow |
|
1166 if (L > 0) { |
|
1167 #endif |
|
1168 #endif |
|
1169 #ifdef IBM |
|
1170 L |= Exp_msk1 >> 4; |
|
1171 #endif |
|
1172 word0(&u) = L; |
|
1173 word1(&u) = 0; |
|
1174 #ifndef Avoid_Underflow |
|
1175 #ifndef Sudden_Underflow |
|
1176 } |
|
1177 else { |
|
1178 L = -L >> Exp_shift; |
|
1179 if (L < Exp_shift) { |
|
1180 word0(&u) = 0x80000 >> L; |
|
1181 word1(&u) = 0; |
|
1182 } |
|
1183 else { |
|
1184 word0(&u) = 0; |
|
1185 L -= Exp_shift; |
|
1186 word1(&u) = L >= 31 ? 1 : 1 << 31 - L; |
|
1187 } |
|
1188 } |
|
1189 #endif |
|
1190 #endif |
|
1191 return dval(&u); |
|
1192 } |
|
1193 |
|
1194 static double |
|
1195 b2d |
|
1196 #ifdef KR_headers |
|
1197 (a, e) Bigint *a; int *e; |
|
1198 #else |
|
1199 (Bigint *a, int *e) |
|
1200 #endif |
|
1201 { |
|
1202 ULong *xa, *xa0, w, y, z; |
|
1203 int k; |
|
1204 U d; |
|
1205 #ifdef VAX |
|
1206 ULong d0, d1; |
|
1207 #else |
|
1208 #define d0 word0(&d) |
|
1209 #define d1 word1(&d) |
|
1210 #endif |
|
1211 |
|
1212 xa0 = a->x; |
|
1213 xa = xa0 + a->wds; |
|
1214 y = *--xa; |
|
1215 #ifdef DEBUG |
|
1216 if (!y) Bug("zero y in b2d"); |
|
1217 #endif |
|
1218 k = hi0bits(y); |
|
1219 *e = 32 - k; |
|
1220 #ifdef Pack_32 |
|
1221 if (k < Ebits) { |
|
1222 d0 = Exp_1 | y >> (Ebits - k); |
|
1223 w = xa > xa0 ? *--xa : 0; |
|
1224 d1 = y << ((32-Ebits) + k) | w >> (Ebits - k); |
|
1225 goto ret_d; |
|
1226 } |
|
1227 z = xa > xa0 ? *--xa : 0; |
|
1228 if (k -= Ebits) { |
|
1229 d0 = Exp_1 | y << k | z >> (32 - k); |
|
1230 y = xa > xa0 ? *--xa : 0; |
|
1231 d1 = z << k | y >> (32 - k); |
|
1232 } |
|
1233 else { |
|
1234 d0 = Exp_1 | y; |
|
1235 d1 = z; |
|
1236 } |
|
1237 #else |
|
1238 if (k < Ebits + 16) { |
|
1239 z = xa > xa0 ? *--xa : 0; |
|
1240 d0 = Exp_1 | y << k - Ebits | z >> Ebits + 16 - k; |
|
1241 w = xa > xa0 ? *--xa : 0; |
|
1242 y = xa > xa0 ? *--xa : 0; |
|
1243 d1 = z << k + 16 - Ebits | w << k - Ebits | y >> 16 + Ebits - k; |
|
1244 goto ret_d; |
|
1245 } |
|
1246 z = xa > xa0 ? *--xa : 0; |
|
1247 w = xa > xa0 ? *--xa : 0; |
|
1248 k -= Ebits + 16; |
|
1249 d0 = Exp_1 | y << k + 16 | z << k | w >> 16 - k; |
|
1250 y = xa > xa0 ? *--xa : 0; |
|
1251 d1 = w << k + 16 | y << k; |
|
1252 #endif |
|
1253 ret_d: |
|
1254 #ifdef VAX |
|
1255 word0(&d) = d0 >> 16 | d0 << 16; |
|
1256 word1(&d) = d1 >> 16 | d1 << 16; |
|
1257 #else |
|
1258 #undef d0 |
|
1259 #undef d1 |
|
1260 #endif |
|
1261 return dval(&d); |
|
1262 } |
|
1263 |
|
1264 static Bigint * |
|
1265 d2b |
|
1266 #ifdef KR_headers |
|
1267 (d, e, bits) U *d; int *e, *bits; |
|
1268 #else |
|
1269 (U *d, int *e, int *bits) |
|
1270 #endif |
|
1271 { |
|
1272 Bigint *b; |
|
1273 int de, k; |
|
1274 ULong *x, y, z; |
|
1275 #ifndef Sudden_Underflow |
|
1276 int i; |
|
1277 #endif |
|
1278 #ifdef VAX |
|
1279 ULong d0, d1; |
|
1280 d0 = word0(d) >> 16 | word0(d) << 16; |
|
1281 d1 = word1(d) >> 16 | word1(d) << 16; |
|
1282 #else |
|
1283 #define d0 word0(d) |
|
1284 #define d1 word1(d) |
|
1285 #endif |
|
1286 |
|
1287 #ifdef Pack_32 |
|
1288 b = Balloc(1); |
|
1289 #else |
|
1290 b = Balloc(2); |
|
1291 #endif |
|
1292 x = b->x; |
|
1293 |
|
1294 z = d0 & Frac_mask; |
|
1295 d0 &= 0x7fffffff; /* clear sign bit, which we ignore */ |
|
1296 #ifdef Sudden_Underflow |
|
1297 de = (int)(d0 >> Exp_shift); |
|
1298 #ifndef IBM |
|
1299 z |= Exp_msk11; |
|
1300 #endif |
|
1301 #else |
|
1302 if ((de = (int)(d0 >> Exp_shift))) |
|
1303 z |= Exp_msk1; |
|
1304 #endif |
|
1305 #ifdef Pack_32 |
|
1306 if ((y = d1)) { |
|
1307 if ((k = lo0bits(&y))) { |
|
1308 x[0] = y | z << (32 - k); |
|
1309 z >>= k; |
|
1310 } |
|
1311 else |
|
1312 x[0] = y; |
|
1313 #ifndef Sudden_Underflow |
|
1314 i = |
|
1315 #endif |
|
1316 b->wds = (x[1] = z) ? 2 : 1; |
|
1317 } |
|
1318 else { |
|
1319 k = lo0bits(&z); |
|
1320 x[0] = z; |
|
1321 #ifndef Sudden_Underflow |
|
1322 i = |
|
1323 #endif |
|
1324 b->wds = 1; |
|
1325 k += 32; |
|
1326 } |
|
1327 #else |
|
1328 if (y = d1) { |
|
1329 if (k = lo0bits(&y)) |
|
1330 if (k >= 16) { |
|
1331 x[0] = y | z << 32 - k & 0xffff; |
|
1332 x[1] = z >> k - 16 & 0xffff; |
|
1333 x[2] = z >> k; |
|
1334 i = 2; |
|
1335 } |
|
1336 else { |
|
1337 x[0] = y & 0xffff; |
|
1338 x[1] = y >> 16 | z << 16 - k & 0xffff; |
|
1339 x[2] = z >> k & 0xffff; |
|
1340 x[3] = z >> k+16; |
|
1341 i = 3; |
|
1342 } |
|
1343 else { |
|
1344 x[0] = y & 0xffff; |
|
1345 x[1] = y >> 16; |
|
1346 x[2] = z & 0xffff; |
|
1347 x[3] = z >> 16; |
|
1348 i = 3; |
|
1349 } |
|
1350 } |
|
1351 else { |
|
1352 #ifdef DEBUG |
|
1353 if (!z) |
|
1354 Bug("Zero passed to d2b"); |
|
1355 #endif |
|
1356 k = lo0bits(&z); |
|
1357 if (k >= 16) { |
|
1358 x[0] = z; |
|
1359 i = 0; |
|
1360 } |
|
1361 else { |
|
1362 x[0] = z & 0xffff; |
|
1363 x[1] = z >> 16; |
|
1364 i = 1; |
|
1365 } |
|
1366 k += 32; |
|
1367 } |
|
1368 while(!x[i]) |
|
1369 --i; |
|
1370 b->wds = i + 1; |
|
1371 #endif |
|
1372 #ifndef Sudden_Underflow |
|
1373 if (de) { |
|
1374 #endif |
|
1375 #ifdef IBM |
|
1376 *e = (de - Bias - (P-1) << 2) + k; |
|
1377 *bits = 4*P + 8 - k - hi0bits(word0(d) & Frac_mask); |
|
1378 #else |
|
1379 *e = de - Bias - (P-1) + k; |
|
1380 *bits = P - k; |
|
1381 #endif |
|
1382 #ifndef Sudden_Underflow |
|
1383 } |
|
1384 else { |
|
1385 *e = de - Bias - (P-1) + 1 + k; |
|
1386 #ifdef Pack_32 |
|
1387 *bits = 32*i - hi0bits(x[i-1]); |
|
1388 #else |
|
1389 *bits = (i+2)*16 - hi0bits(x[i]); |
|
1390 #endif |
|
1391 } |
|
1392 #endif |
|
1393 return b; |
|
1394 } |
|
1395 #undef d0 |
|
1396 #undef d1 |
|
1397 |
|
1398 static double |
|
1399 ratio |
|
1400 #ifdef KR_headers |
|
1401 (a, b) Bigint *a, *b; |
|
1402 #else |
|
1403 (Bigint *a, Bigint *b) |
|
1404 #endif |
|
1405 { |
|
1406 U da, db; |
|
1407 int k, ka, kb; |
|
1408 |
|
1409 dval(&da) = b2d(a, &ka); |
|
1410 dval(&db) = b2d(b, &kb); |
|
1411 #ifdef Pack_32 |
|
1412 k = ka - kb + 32*(a->wds - b->wds); |
|
1413 #else |
|
1414 k = ka - kb + 16*(a->wds - b->wds); |
|
1415 #endif |
|
1416 #ifdef IBM |
|
1417 if (k > 0) { |
|
1418 word0(&da) += (k >> 2)*Exp_msk1; |
|
1419 if (k &= 3) |
|
1420 dval(&da) *= 1 << k; |
|
1421 } |
|
1422 else { |
|
1423 k = -k; |
|
1424 word0(&db) += (k >> 2)*Exp_msk1; |
|
1425 if (k &= 3) |
|
1426 dval(&db) *= 1 << k; |
|
1427 } |
|
1428 #else |
|
1429 if (k > 0) |
|
1430 word0(&da) += k*Exp_msk1; |
|
1431 else { |
|
1432 k = -k; |
|
1433 word0(&db) += k*Exp_msk1; |
|
1434 } |
|
1435 #endif |
|
1436 return dval(&da) / dval(&db); |
|
1437 } |
|
1438 |
|
1439 static CONST double |
|
1440 tens[] = { |
|
1441 1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9, |
|
1442 1e10, 1e11, 1e12, 1e13, 1e14, 1e15, 1e16, 1e17, 1e18, 1e19, |
|
1443 1e20, 1e21, 1e22 |
|
1444 #ifdef VAX |
|
1445 , 1e23, 1e24 |
|
1446 #endif |
|
1447 }; |
|
1448 |
|
1449 static CONST double |
|
1450 #ifdef IEEE_Arith |
|
1451 bigtens[] = { 1e16, 1e32, 1e64, 1e128, 1e256 }; |
|
1452 static CONST double tinytens[] = { 1e-16, 1e-32, 1e-64, 1e-128, |
|
1453 #ifdef Avoid_Underflow |
|
1454 9007199254740992.*9007199254740992.e-256 |
|
1455 /* = 2^106 * 1e-256 */ |
|
1456 #else |
|
1457 1e-256 |
|
1458 #endif |
|
1459 }; |
|
1460 /* The factor of 2^53 in tinytens[4] helps us avoid setting the underflow */ |
|
1461 /* flag unnecessarily. It leads to a song and dance at the end of strtod. */ |
|
1462 #define Scale_Bit 0x10 |
|
1463 #define n_bigtens 5 |
|
1464 #else |
|
1465 #ifdef IBM |
|
1466 bigtens[] = { 1e16, 1e32, 1e64 }; |
|
1467 static CONST double tinytens[] = { 1e-16, 1e-32, 1e-64 }; |
|
1468 #define n_bigtens 3 |
|
1469 #else |
|
1470 bigtens[] = { 1e16, 1e32 }; |
|
1471 static CONST double tinytens[] = { 1e-16, 1e-32 }; |
|
1472 #define n_bigtens 2 |
|
1473 #endif |
|
1474 #endif |
|
1475 |
|
1476 #undef Need_Hexdig |
|
1477 #ifdef INFNAN_CHECK |
|
1478 #ifndef No_Hex_NaN |
|
1479 #define Need_Hexdig |
|
1480 #endif |
|
1481 #endif |
|
1482 |
|
1483 #ifndef Need_Hexdig |
|
1484 #ifndef NO_HEX_FP |
|
1485 #define Need_Hexdig |
|
1486 #endif |
|
1487 #endif |
|
1488 |
|
1489 #ifdef Need_Hexdig /*{*/ |
|
1490 static unsigned char hexdig[256]; |
|
1491 |
|
1492 static void |
|
1493 #ifdef KR_headers |
|
1494 htinit(h, s, inc) unsigned char *h; unsigned char *s; int inc; |
|
1495 #else |
|
1496 htinit(unsigned char *h, unsigned char *s, int inc) |
|
1497 #endif |
|
1498 { |
|
1499 int i, j; |
|
1500 for(i = 0; (j = s[i]) !=0; i++) |
|
1501 h[j] = i + inc; |
|
1502 } |
|
1503 |
|
1504 static void |
|
1505 #ifdef KR_headers |
|
1506 hexdig_init() |
|
1507 #else |
|
1508 hexdig_init(void) |
|
1509 #endif |
|
1510 { |
|
1511 #define USC (unsigned char *) |
|
1512 htinit(hexdig, USC "0123456789", 0x10); |
|
1513 htinit(hexdig, USC "abcdef", 0x10 + 10); |
|
1514 htinit(hexdig, USC "ABCDEF", 0x10 + 10); |
|
1515 } |
|
1516 #endif /* } Need_Hexdig */ |
|
1517 |
|
1518 #ifdef INFNAN_CHECK |
|
1519 |
|
1520 #ifndef NAN_WORD0 |
|
1521 #define NAN_WORD0 0x7ff80000 |
|
1522 #endif |
|
1523 |
|
1524 #ifndef NAN_WORD1 |
|
1525 #define NAN_WORD1 0 |
|
1526 #endif |
|
1527 |
|
1528 static int |
|
1529 match |
|
1530 #ifdef KR_headers |
|
1531 (sp, t) char **sp, *t; |
|
1532 #else |
|
1533 (CONST char **sp, CONST char *t) |
|
1534 #endif |
|
1535 { |
|
1536 int c, d; |
|
1537 CONST char *s = *sp; |
|
1538 |
|
1539 while((d = *t++)) { |
|
1540 if ((c = *++s) >= 'A' && c <= 'Z') |
|
1541 c += 'a' - 'A'; |
|
1542 if (c != d) |
|
1543 return 0; |
|
1544 } |
|
1545 *sp = s + 1; |
|
1546 return 1; |
|
1547 } |
|
1548 |
|
1549 #ifndef No_Hex_NaN |
|
1550 static void |
|
1551 hexnan |
|
1552 #ifdef KR_headers |
|
1553 (rvp, sp) U *rvp; CONST char **sp; |
|
1554 #else |
|
1555 (U *rvp, CONST char **sp) |
|
1556 #endif |
|
1557 { |
|
1558 ULong c, x[2]; |
|
1559 CONST char *s; |
|
1560 int c1, havedig, udx0, xshift; |
|
1561 |
|
1562 if (!hexdig['0']) |
|
1563 hexdig_init(); |
|
1564 x[0] = x[1] = 0; |
|
1565 havedig = xshift = 0; |
|
1566 udx0 = 1; |
|
1567 s = *sp; |
|
1568 /* allow optional initial 0x or 0X */ |
|
1569 while((c = *(CONST unsigned char*)(s+1)) && c <= ' ') |
|
1570 ++s; |
|
1571 if (s[1] == '0' && (s[2] == 'x' || s[2] == 'X')) |
|
1572 s += 2; |
|
1573 while((c = *(CONST unsigned char*)++s)) { |
|
1574 if ((c1 = hexdig[c])) |
|
1575 c = c1 & 0xf; |
|
1576 else if (c <= ' ') { |
|
1577 if (udx0 && havedig) { |
|
1578 udx0 = 0; |
|
1579 xshift = 1; |
|
1580 } |
|
1581 continue; |
|
1582 } |
|
1583 #ifdef GDTOA_NON_PEDANTIC_NANCHECK |
|
1584 else if (/*(*/ c == ')' && havedig) { |
|
1585 *sp = s + 1; |
|
1586 break; |
|
1587 } |
|
1588 else |
|
1589 return; /* invalid form: don't change *sp */ |
|
1590 #else |
|
1591 else { |
|
1592 do { |
|
1593 if (/*(*/ c == ')') { |
|
1594 *sp = s + 1; |
|
1595 break; |
|
1596 } |
|
1597 } while((c = *++s)); |
|
1598 break; |
|
1599 } |
|
1600 #endif |
|
1601 havedig = 1; |
|
1602 if (xshift) { |
|
1603 xshift = 0; |
|
1604 x[0] = x[1]; |
|
1605 x[1] = 0; |
|
1606 } |
|
1607 if (udx0) |
|
1608 x[0] = (x[0] << 4) | (x[1] >> 28); |
|
1609 x[1] = (x[1] << 4) | c; |
|
1610 } |
|
1611 if ((x[0] &= 0xfffff) || x[1]) { |
|
1612 word0(rvp) = Exp_mask | x[0]; |
|
1613 word1(rvp) = x[1]; |
|
1614 } |
|
1615 } |
|
1616 #endif /*No_Hex_NaN*/ |
|
1617 #endif /* INFNAN_CHECK */ |
|
1618 |
|
1619 #ifdef Pack_32 |
|
1620 #define ULbits 32 |
|
1621 #define kshift 5 |
|
1622 #define kmask 31 |
|
1623 #else |
|
1624 #define ULbits 16 |
|
1625 #define kshift 4 |
|
1626 #define kmask 15 |
|
1627 #endif |
|
1628 #ifndef NO_HEX_FP /*{*/ |
|
1629 |
|
1630 static void |
|
1631 #ifdef KR_headers |
|
1632 rshift(b, k) Bigint *b; int k; |
|
1633 #else |
|
1634 rshift(Bigint *b, int k) |
|
1635 #endif |
|
1636 { |
|
1637 ULong *x, *x1, *xe, y; |
|
1638 int n; |
|
1639 |
|
1640 x = x1 = b->x; |
|
1641 n = k >> kshift; |
|
1642 if (n < b->wds) { |
|
1643 xe = x + b->wds; |
|
1644 x += n; |
|
1645 if (k &= kmask) { |
|
1646 n = 32 - k; |
|
1647 y = *x++ >> k; |
|
1648 while(x < xe) { |
|
1649 *x1++ = (y | (*x << n)) & 0xffffffff; |
|
1650 y = *x++ >> k; |
|
1651 } |
|
1652 if ((*x1 = y) !=0) |
|
1653 x1++; |
|
1654 } |
|
1655 else |
|
1656 while(x < xe) |
|
1657 *x1++ = *x++; |
|
1658 } |
|
1659 if ((b->wds = x1 - b->x) == 0) |
|
1660 b->x[0] = 0; |
|
1661 } |
|
1662 |
|
1663 static ULong |
|
1664 #ifdef KR_headers |
|
1665 any_on(b, k) Bigint *b; int k; |
|
1666 #else |
|
1667 any_on(Bigint *b, int k) |
|
1668 #endif |
|
1669 { |
|
1670 int n, nwds; |
|
1671 ULong *x, *x0, x1, x2; |
|
1672 |
|
1673 x = b->x; |
|
1674 nwds = b->wds; |
|
1675 n = k >> kshift; |
|
1676 if (n > nwds) |
|
1677 n = nwds; |
|
1678 else if (n < nwds && (k &= kmask)) { |
|
1679 x1 = x2 = x[n]; |
|
1680 x1 >>= k; |
|
1681 x1 <<= k; |
|
1682 if (x1 != x2) |
|
1683 return 1; |
|
1684 } |
|
1685 x0 = x; |
|
1686 x += n; |
|
1687 while(x > x0) |
|
1688 if (*--x) |
|
1689 return 1; |
|
1690 return 0; |
|
1691 } |
|
1692 |
|
1693 enum { /* rounding values: same as FLT_ROUNDS */ |
|
1694 Round_zero = 0, |
|
1695 Round_near = 1, |
|
1696 Round_up = 2, |
|
1697 Round_down = 3 |
|
1698 }; |
|
1699 |
|
1700 static Bigint * |
|
1701 #ifdef KR_headers |
|
1702 increment(b) Bigint *b; |
|
1703 #else |
|
1704 increment(Bigint *b) |
|
1705 #endif |
|
1706 { |
|
1707 ULong *x, *xe; |
|
1708 Bigint *b1; |
|
1709 |
|
1710 x = b->x; |
|
1711 xe = x + b->wds; |
|
1712 do { |
|
1713 if (*x < (ULong)0xffffffffL) { |
|
1714 ++*x; |
|
1715 return b; |
|
1716 } |
|
1717 *x++ = 0; |
|
1718 } while(x < xe); |
|
1719 { |
|
1720 if (b->wds >= b->maxwds) { |
|
1721 b1 = Balloc(b->k+1); |
|
1722 Bcopy(b1,b); |
|
1723 Bfree(b); |
|
1724 b = b1; |
|
1725 } |
|
1726 b->x[b->wds++] = 1; |
|
1727 } |
|
1728 return b; |
|
1729 } |
|
1730 |
|
1731 void |
|
1732 #ifdef KR_headers |
|
1733 gethex(sp, rvp, rounding, sign) |
|
1734 CONST char **sp; U *rvp; int rounding, sign; |
|
1735 #else |
|
1736 gethex( CONST char **sp, U *rvp, int rounding, int sign) |
|
1737 #endif |
|
1738 { |
|
1739 Bigint *b; |
|
1740 CONST unsigned char *decpt, *s0, *s, *s1; |
|
1741 Long e, e1; |
|
1742 ULong L, lostbits, *x; |
|
1743 int big, denorm, esign, havedig, k, n, nbits, up, zret; |
|
1744 #ifdef IBM |
|
1745 int j; |
|
1746 #endif |
|
1747 enum { |
|
1748 #ifdef IEEE_Arith /*{{*/ |
|
1749 emax = 0x7fe - Bias - P + 1, |
|
1750 emin = Emin - P + 1 |
|
1751 #else /*}{*/ |
|
1752 emin = Emin - P, |
|
1753 #ifdef VAX |
|
1754 emax = 0x7ff - Bias - P + 1 |
|
1755 #endif |
|
1756 #ifdef IBM |
|
1757 emax = 0x7f - Bias - P |
|
1758 #endif |
|
1759 #endif /*}}*/ |
|
1760 }; |
|
1761 #ifdef USE_LOCALE |
|
1762 int i; |
|
1763 #ifdef NO_LOCALE_CACHE |
|
1764 const unsigned char *decimalpoint = (unsigned char*) |
|
1765 localeconv()->decimal_point; |
|
1766 #else |
|
1767 const unsigned char *decimalpoint; |
|
1768 static unsigned char *decimalpoint_cache; |
|
1769 if (!(s0 = decimalpoint_cache)) { |
|
1770 s0 = (unsigned char*)localeconv()->decimal_point; |
|
1771 if ((decimalpoint_cache = (unsigned char*) |
|
1772 MALLOC(strlen((CONST char*)s0) + 1))) { |
|
1773 strcpy((char*)decimalpoint_cache, (CONST char*)s0); |
|
1774 s0 = decimalpoint_cache; |
|
1775 } |
|
1776 } |
|
1777 decimalpoint = s0; |
|
1778 #endif |
|
1779 #endif |
|
1780 |
|
1781 if (!hexdig['0']) |
|
1782 hexdig_init(); |
|
1783 havedig = 0; |
|
1784 s0 = *(CONST unsigned char **)sp + 2; |
|
1785 while(s0[havedig] == '0') |
|
1786 havedig++; |
|
1787 s0 += havedig; |
|
1788 s = s0; |
|
1789 decpt = 0; |
|
1790 zret = 0; |
|
1791 e = 0; |
|
1792 if (hexdig[*s]) |
|
1793 havedig++; |
|
1794 else { |
|
1795 zret = 1; |
|
1796 #ifdef USE_LOCALE |
|
1797 for(i = 0; decimalpoint[i]; ++i) { |
|
1798 if (s[i] != decimalpoint[i]) |
|
1799 goto pcheck; |
|
1800 } |
|
1801 decpt = s += i; |
|
1802 #else |
|
1803 if (*s != '.') |
|
1804 goto pcheck; |
|
1805 decpt = ++s; |
|
1806 #endif |
|
1807 if (!hexdig[*s]) |
|
1808 goto pcheck; |
|
1809 while(*s == '0') |
|
1810 s++; |
|
1811 if (hexdig[*s]) |
|
1812 zret = 0; |
|
1813 havedig = 1; |
|
1814 s0 = s; |
|
1815 } |
|
1816 while(hexdig[*s]) |
|
1817 s++; |
|
1818 #ifdef USE_LOCALE |
|
1819 if (*s == *decimalpoint && !decpt) { |
|
1820 for(i = 1; decimalpoint[i]; ++i) { |
|
1821 if (s[i] != decimalpoint[i]) |
|
1822 goto pcheck; |
|
1823 } |
|
1824 decpt = s += i; |
|
1825 #else |
|
1826 if (*s == '.' && !decpt) { |
|
1827 decpt = ++s; |
|
1828 #endif |
|
1829 while(hexdig[*s]) |
|
1830 s++; |
|
1831 }/*}*/ |
|
1832 if (decpt) |
|
1833 e = -(((Long)(s-decpt)) << 2); |
|
1834 pcheck: |
|
1835 s1 = s; |
|
1836 big = esign = 0; |
|
1837 switch(*s) { |
|
1838 case 'p': |
|
1839 case 'P': |
|
1840 switch(*++s) { |
|
1841 case '-': |
|
1842 esign = 1; |
|
1843 /* no break */ |
|
1844 case '+': |
|
1845 s++; |
|
1846 } |
|
1847 if ((n = hexdig[*s]) == 0 || n > 0x19) { |
|
1848 s = s1; |
|
1849 break; |
|
1850 } |
|
1851 e1 = n - 0x10; |
|
1852 while((n = hexdig[*++s]) !=0 && n <= 0x19) { |
|
1853 if (e1 & 0xf8000000) |
|
1854 big = 1; |
|
1855 e1 = 10*e1 + n - 0x10; |
|
1856 } |
|
1857 if (esign) |
|
1858 e1 = -e1; |
|
1859 e += e1; |
|
1860 } |
|
1861 *sp = (char*)s; |
|
1862 if (!havedig) |
|
1863 *sp = (char*)s0 - 1; |
|
1864 if (zret) |
|
1865 goto retz1; |
|
1866 if (big) { |
|
1867 if (esign) { |
|
1868 #ifdef IEEE_Arith |
|
1869 switch(rounding) { |
|
1870 case Round_up: |
|
1871 if (sign) |
|
1872 break; |
|
1873 goto ret_tiny; |
|
1874 case Round_down: |
|
1875 if (!sign) |
|
1876 break; |
|
1877 goto ret_tiny; |
|
1878 } |
|
1879 #endif |
|
1880 goto retz; |
|
1881 #ifdef IEEE_Arith |
|
1882 ret_tiny: |
|
1883 #ifndef NO_ERRNO |
|
1884 errno = ERANGE; |
|
1885 #endif |
|
1886 word0(rvp) = 0; |
|
1887 word1(rvp) = 1; |
|
1888 return; |
|
1889 #endif /* IEEE_Arith */ |
|
1890 } |
|
1891 switch(rounding) { |
|
1892 case Round_near: |
|
1893 goto ovfl1; |
|
1894 case Round_up: |
|
1895 if (!sign) |
|
1896 goto ovfl1; |
|
1897 goto ret_big; |
|
1898 case Round_down: |
|
1899 if (sign) |
|
1900 goto ovfl1; |
|
1901 goto ret_big; |
|
1902 } |
|
1903 ret_big: |
|
1904 word0(rvp) = Big0; |
|
1905 word1(rvp) = Big1; |
|
1906 return; |
|
1907 } |
|
1908 n = s1 - s0 - 1; |
|
1909 for(k = 0; n > (1 << (kshift-2)) - 1; n >>= 1) |
|
1910 k++; |
|
1911 b = Balloc(k); |
|
1912 x = b->x; |
|
1913 n = 0; |
|
1914 L = 0; |
|
1915 #ifdef USE_LOCALE |
|
1916 for(i = 0; decimalpoint[i+1]; ++i); |
|
1917 #endif |
|
1918 while(s1 > s0) { |
|
1919 #ifdef USE_LOCALE |
|
1920 if (*--s1 == decimalpoint[i]) { |
|
1921 s1 -= i; |
|
1922 continue; |
|
1923 } |
|
1924 #else |
|
1925 if (*--s1 == '.') |
|
1926 continue; |
|
1927 #endif |
|
1928 if (n == ULbits) { |
|
1929 *x++ = L; |
|
1930 L = 0; |
|
1931 n = 0; |
|
1932 } |
|
1933 L |= (hexdig[*s1] & 0x0f) << n; |
|
1934 n += 4; |
|
1935 } |
|
1936 *x++ = L; |
|
1937 b->wds = n = x - b->x; |
|
1938 n = ULbits*n - hi0bits(L); |
|
1939 nbits = Nbits; |
|
1940 lostbits = 0; |
|
1941 x = b->x; |
|
1942 if (n > nbits) { |
|
1943 n -= nbits; |
|
1944 if (any_on(b,n)) { |
|
1945 lostbits = 1; |
|
1946 k = n - 1; |
|
1947 if (x[k>>kshift] & 1 << (k & kmask)) { |
|
1948 lostbits = 2; |
|
1949 if (k > 0 && any_on(b,k)) |
|
1950 lostbits = 3; |
|
1951 } |
|
1952 } |
|
1953 rshift(b, n); |
|
1954 e += n; |
|
1955 } |
|
1956 else if (n < nbits) { |
|
1957 n = nbits - n; |
|
1958 b = lshift(b, n); |
|
1959 e -= n; |
|
1960 x = b->x; |
|
1961 } |
|
1962 if (e > Emax) { |
|
1963 ovfl: |
|
1964 Bfree(b); |
|
1965 ovfl1: |
|
1966 #ifndef NO_ERRNO |
|
1967 errno = ERANGE; |
|
1968 #endif |
|
1969 word0(rvp) = Exp_mask; |
|
1970 word1(rvp) = 0; |
|
1971 return; |
|
1972 } |
|
1973 denorm = 0; |
|
1974 if (e < emin) { |
|
1975 denorm = 1; |
|
1976 n = emin - e; |
|
1977 if (n >= nbits) { |
|
1978 #ifdef IEEE_Arith /*{*/ |
|
1979 switch (rounding) { |
|
1980 case Round_near: |
|
1981 if (n == nbits && (n < 2 || any_on(b,n-1))) |
|
1982 goto ret_tiny; |
|
1983 break; |
|
1984 case Round_up: |
|
1985 if (!sign) |
|
1986 goto ret_tiny; |
|
1987 break; |
|
1988 case Round_down: |
|
1989 if (sign) |
|
1990 goto ret_tiny; |
|
1991 } |
|
1992 #endif /* } IEEE_Arith */ |
|
1993 Bfree(b); |
|
1994 retz: |
|
1995 #ifndef NO_ERRNO |
|
1996 errno = ERANGE; |
|
1997 #endif |
|
1998 retz1: |
|
1999 rvp->d = 0.; |
|
2000 return; |
|
2001 } |
|
2002 k = n - 1; |
|
2003 if (lostbits) |
|
2004 lostbits = 1; |
|
2005 else if (k > 0) |
|
2006 lostbits = any_on(b,k); |
|
2007 if (x[k>>kshift] & 1 << (k & kmask)) |
|
2008 lostbits |= 2; |
|
2009 nbits -= n; |
|
2010 rshift(b,n); |
|
2011 e = emin; |
|
2012 } |
|
2013 if (lostbits) { |
|
2014 up = 0; |
|
2015 switch(rounding) { |
|
2016 case Round_zero: |
|
2017 break; |
|
2018 case Round_near: |
|
2019 if (lostbits & 2 |
|
2020 && (lostbits & 1) | (x[0] & 1)) |
|
2021 up = 1; |
|
2022 break; |
|
2023 case Round_up: |
|
2024 up = 1 - sign; |
|
2025 break; |
|
2026 case Round_down: |
|
2027 up = sign; |
|
2028 } |
|
2029 if (up) { |
|
2030 k = b->wds; |
|
2031 b = increment(b); |
|
2032 x = b->x; |
|
2033 if (denorm) { |
|
2034 #if 0 |
|
2035 if (nbits == Nbits - 1 |
|
2036 && x[nbits >> kshift] & 1 << (nbits & kmask)) |
|
2037 denorm = 0; /* not currently used */ |
|
2038 #endif |
|
2039 } |
|
2040 else if (b->wds > k |
|
2041 || ((n = nbits & kmask) !=0 |
|
2042 && hi0bits(x[k-1]) < 32-n)) { |
|
2043 rshift(b,1); |
|
2044 if (++e > Emax) |
|
2045 goto ovfl; |
|
2046 } |
|
2047 } |
|
2048 } |
|
2049 #ifdef IEEE_Arith |
|
2050 if (denorm) |
|
2051 word0(rvp) = b->wds > 1 ? b->x[1] & ~0x100000 : 0; |
|
2052 else |
|
2053 word0(rvp) = (b->x[1] & ~0x100000) | ((e + 0x3ff + 52) << 20); |
|
2054 word1(rvp) = b->x[0]; |
|
2055 #endif |
|
2056 #ifdef IBM |
|
2057 if ((j = e & 3)) { |
|
2058 k = b->x[0] & ((1 << j) - 1); |
|
2059 rshift(b,j); |
|
2060 if (k) { |
|
2061 switch(rounding) { |
|
2062 case Round_up: |
|
2063 if (!sign) |
|
2064 increment(b); |
|
2065 break; |
|
2066 case Round_down: |
|
2067 if (sign) |
|
2068 increment(b); |
|
2069 break; |
|
2070 case Round_near: |
|
2071 j = 1 << (j-1); |
|
2072 if (k & j && ((k & (j-1)) | lostbits)) |
|
2073 increment(b); |
|
2074 } |
|
2075 } |
|
2076 } |
|
2077 e >>= 2; |
|
2078 word0(rvp) = b->x[1] | ((e + 65 + 13) << 24); |
|
2079 word1(rvp) = b->x[0]; |
|
2080 #endif |
|
2081 #ifdef VAX |
|
2082 /* The next two lines ignore swap of low- and high-order 2 bytes. */ |
|
2083 /* word0(rvp) = (b->x[1] & ~0x800000) | ((e + 129 + 55) << 23); */ |
|
2084 /* word1(rvp) = b->x[0]; */ |
|
2085 word0(rvp) = ((b->x[1] & ~0x800000) >> 16) | ((e + 129 + 55) << 7) | (b->x[1] << 16); |
|
2086 word1(rvp) = (b->x[0] >> 16) | (b->x[0] << 16); |
|
2087 #endif |
|
2088 Bfree(b); |
|
2089 } |
|
2090 #endif /*}!NO_HEX_FP*/ |
|
2091 |
|
2092 static int |
|
2093 #ifdef KR_headers |
|
2094 dshift(b, p2) Bigint *b; int p2; |
|
2095 #else |
|
2096 dshift(Bigint *b, int p2) |
|
2097 #endif |
|
2098 { |
|
2099 int rv = hi0bits(b->x[b->wds-1]) - 4; |
|
2100 if (p2 > 0) |
|
2101 rv -= p2; |
|
2102 return rv & kmask; |
|
2103 } |
|
2104 |
|
2105 static int |
|
2106 quorem |
|
2107 #ifdef KR_headers |
|
2108 (b, S) Bigint *b, *S; |
|
2109 #else |
|
2110 (Bigint *b, Bigint *S) |
|
2111 #endif |
|
2112 { |
|
2113 int n; |
|
2114 ULong *bx, *bxe, q, *sx, *sxe; |
|
2115 #ifdef ULLong |
|
2116 ULLong borrow, carry, y, ys; |
|
2117 #else |
|
2118 ULong borrow, carry, y, ys; |
|
2119 #ifdef Pack_32 |
|
2120 ULong si, z, zs; |
|
2121 #endif |
|
2122 #endif |
|
2123 |
|
2124 n = S->wds; |
|
2125 #ifdef DEBUG |
|
2126 /*debug*/ if (b->wds > n) |
|
2127 /*debug*/ Bug("oversize b in quorem"); |
|
2128 #endif |
|
2129 if (b->wds < n) |
|
2130 return 0; |
|
2131 sx = S->x; |
|
2132 sxe = sx + --n; |
|
2133 bx = b->x; |
|
2134 bxe = bx + n; |
|
2135 q = *bxe / (*sxe + 1); /* ensure q <= true quotient */ |
|
2136 #ifdef DEBUG |
|
2137 /*debug*/ if (q > 9) |
|
2138 /*debug*/ Bug("oversized quotient in quorem"); |
|
2139 #endif |
|
2140 if (q) { |
|
2141 borrow = 0; |
|
2142 carry = 0; |
|
2143 do { |
|
2144 #ifdef ULLong |
|
2145 ys = *sx++ * (ULLong)q + carry; |
|
2146 carry = ys >> 32; |
|
2147 y = *bx - (ys & FFFFFFFF) - borrow; |
|
2148 borrow = y >> 32 & (ULong)1; |
|
2149 *bx++ = y & FFFFFFFF; |
|
2150 #else |
|
2151 #ifdef Pack_32 |
|
2152 si = *sx++; |
|
2153 ys = (si & 0xffff) * q + carry; |
|
2154 zs = (si >> 16) * q + (ys >> 16); |
|
2155 carry = zs >> 16; |
|
2156 y = (*bx & 0xffff) - (ys & 0xffff) - borrow; |
|
2157 borrow = (y & 0x10000) >> 16; |
|
2158 z = (*bx >> 16) - (zs & 0xffff) - borrow; |
|
2159 borrow = (z & 0x10000) >> 16; |
|
2160 Storeinc(bx, z, y); |
|
2161 #else |
|
2162 ys = *sx++ * q + carry; |
|
2163 carry = ys >> 16; |
|
2164 y = *bx - (ys & 0xffff) - borrow; |
|
2165 borrow = (y & 0x10000) >> 16; |
|
2166 *bx++ = y & 0xffff; |
|
2167 #endif |
|
2168 #endif |
|
2169 } |
|
2170 while(sx <= sxe); |
|
2171 if (!*bxe) { |
|
2172 bx = b->x; |
|
2173 while(--bxe > bx && !*bxe) |
|
2174 --n; |
|
2175 b->wds = n; |
|
2176 } |
|
2177 } |
|
2178 if (cmp(b, S) >= 0) { |
|
2179 q++; |
|
2180 borrow = 0; |
|
2181 carry = 0; |
|
2182 bx = b->x; |
|
2183 sx = S->x; |
|
2184 do { |
|
2185 #ifdef ULLong |
|
2186 ys = *sx++ + carry; |
|
2187 carry = ys >> 32; |
|
2188 y = *bx - (ys & FFFFFFFF) - borrow; |
|
2189 borrow = y >> 32 & (ULong)1; |
|
2190 *bx++ = y & FFFFFFFF; |
|
2191 #else |
|
2192 #ifdef Pack_32 |
|
2193 si = *sx++; |
|
2194 ys = (si & 0xffff) + carry; |
|
2195 zs = (si >> 16) + (ys >> 16); |
|
2196 carry = zs >> 16; |
|
2197 y = (*bx & 0xffff) - (ys & 0xffff) - borrow; |
|
2198 borrow = (y & 0x10000) >> 16; |
|
2199 z = (*bx >> 16) - (zs & 0xffff) - borrow; |
|
2200 borrow = (z & 0x10000) >> 16; |
|
2201 Storeinc(bx, z, y); |
|
2202 #else |
|
2203 ys = *sx++ + carry; |
|
2204 carry = ys >> 16; |
|
2205 y = *bx - (ys & 0xffff) - borrow; |
|
2206 borrow = (y & 0x10000) >> 16; |
|
2207 *bx++ = y & 0xffff; |
|
2208 #endif |
|
2209 #endif |
|
2210 } |
|
2211 while(sx <= sxe); |
|
2212 bx = b->x; |
|
2213 bxe = bx + n; |
|
2214 if (!*bxe) { |
|
2215 while(--bxe > bx && !*bxe) |
|
2216 --n; |
|
2217 b->wds = n; |
|
2218 } |
|
2219 } |
|
2220 return q; |
|
2221 } |
|
2222 |
|
2223 #ifndef NO_STRTOD_BIGCOMP |
|
2224 |
|
2225 static void |
|
2226 bigcomp |
|
2227 #ifdef KR_headers |
|
2228 (rv, s0, bc) |
|
2229 U *rv; CONST char *s0; BCinfo *bc; |
|
2230 #else |
|
2231 (U *rv, CONST char *s0, BCinfo *bc) |
|
2232 #endif |
|
2233 { |
|
2234 Bigint *b, *d; |
|
2235 int b2, bbits, d2, dd, dig, dsign, i, j, nd, nd0, p2, p5, speccase; |
|
2236 |
|
2237 dsign = bc->dsign; |
|
2238 nd = bc->nd; |
|
2239 nd0 = bc->nd0; |
|
2240 p5 = nd + bc->e0 - 1; |
|
2241 dd = speccase = 0; |
|
2242 #ifndef Sudden_Underflow |
|
2243 if (rv->d == 0.) { /* special case: value near underflow-to-zero */ |
|
2244 /* threshold was rounded to zero */ |
|
2245 b = i2b(1); |
|
2246 p2 = Emin - P + 1; |
|
2247 bbits = 1; |
|
2248 #ifdef Avoid_Underflow |
|
2249 word0(rv) = (P+2) << Exp_shift; |
|
2250 #else |
|
2251 word1(rv) = 1; |
|
2252 #endif |
|
2253 i = 0; |
|
2254 #ifdef Honor_FLT_ROUNDS |
|
2255 if (bc->rounding == 1) |
|
2256 #endif |
|
2257 { |
|
2258 speccase = 1; |
|
2259 --p2; |
|
2260 dsign = 0; |
|
2261 goto have_i; |
|
2262 } |
|
2263 } |
|
2264 else |
|
2265 #endif |
|
2266 b = d2b(rv, &p2, &bbits); |
|
2267 #ifdef Avoid_Underflow |
|
2268 p2 -= bc->scale; |
|
2269 #endif |
|
2270 /* floor(log2(rv)) == bbits - 1 + p2 */ |
|
2271 /* Check for denormal case. */ |
|
2272 i = P - bbits; |
|
2273 if (i > (j = P - Emin - 1 + p2)) { |
|
2274 #ifdef Sudden_Underflow |
|
2275 Bfree(b); |
|
2276 b = i2b(1); |
|
2277 p2 = Emin; |
|
2278 i = P - 1; |
|
2279 #ifdef Avoid_Underflow |
|
2280 word0(rv) = (1 + bc->scale) << Exp_shift; |
|
2281 #else |
|
2282 word0(rv) = Exp_msk1; |
|
2283 #endif |
|
2284 word1(rv) = 0; |
|
2285 #else |
|
2286 i = j; |
|
2287 #endif |
|
2288 } |
|
2289 #ifdef Honor_FLT_ROUNDS |
|
2290 if (bc->rounding != 1) { |
|
2291 if (i > 0) |
|
2292 b = lshift(b, i); |
|
2293 if (dsign) |
|
2294 b = increment(b); |
|
2295 } |
|
2296 else |
|
2297 #endif |
|
2298 { |
|
2299 b = lshift(b, ++i); |
|
2300 b->x[0] |= 1; |
|
2301 } |
|
2302 #ifndef Sudden_Underflow |
|
2303 have_i: |
|
2304 #endif |
|
2305 p2 -= p5 + i; |
|
2306 d = i2b(1); |
|
2307 /* Arrange for convenient computation of quotients: |
|
2308 * shift left if necessary so divisor has 4 leading 0 bits. |
|
2309 */ |
|
2310 if (p5 > 0) |
|
2311 d = pow5mult(d, p5); |
|
2312 else if (p5 < 0) |
|
2313 b = pow5mult(b, -p5); |
|
2314 if (p2 > 0) { |
|
2315 b2 = p2; |
|
2316 d2 = 0; |
|
2317 } |
|
2318 else { |
|
2319 b2 = 0; |
|
2320 d2 = -p2; |
|
2321 } |
|
2322 i = dshift(d, d2); |
|
2323 if ((b2 += i) > 0) |
|
2324 b = lshift(b, b2); |
|
2325 if ((d2 += i) > 0) |
|
2326 d = lshift(d, d2); |
|
2327 |
|
2328 /* Now b/d = exactly half-way between the two floating-point values */ |
|
2329 /* on either side of the input string. Compute first digit of b/d. */ |
|
2330 |
|
2331 if (!(dig = quorem(b,d))) { |
|
2332 b = multadd(b, 10, 0); /* very unlikely */ |
|
2333 dig = quorem(b,d); |
|
2334 } |
|
2335 |
|
2336 /* Compare b/d with s0 */ |
|
2337 |
|
2338 for(i = 0; i < nd0; ) { |
|
2339 if ((dd = s0[i++] - '0' - dig)) |
|
2340 goto ret; |
|
2341 if (!b->x[0] && b->wds == 1) { |
|
2342 if (i < nd) |
|
2343 dd = 1; |
|
2344 goto ret; |
|
2345 } |
|
2346 b = multadd(b, 10, 0); |
|
2347 dig = quorem(b,d); |
|
2348 } |
|
2349 for(j = bc->dp1; i++ < nd;) { |
|
2350 if ((dd = s0[j++] - '0' - dig)) |
|
2351 goto ret; |
|
2352 if (!b->x[0] && b->wds == 1) { |
|
2353 if (i < nd) |
|
2354 dd = 1; |
|
2355 goto ret; |
|
2356 } |
|
2357 b = multadd(b, 10, 0); |
|
2358 dig = quorem(b,d); |
|
2359 } |
|
2360 if (b->x[0] || b->wds > 1) |
|
2361 dd = -1; |
|
2362 ret: |
|
2363 Bfree(b); |
|
2364 Bfree(d); |
|
2365 #ifdef Honor_FLT_ROUNDS |
|
2366 if (bc->rounding != 1) { |
|
2367 if (dd < 0) { |
|
2368 if (bc->rounding == 0) { |
|
2369 if (!dsign) |
|
2370 goto retlow1; |
|
2371 } |
|
2372 else if (dsign) |
|
2373 goto rethi1; |
|
2374 } |
|
2375 else if (dd > 0) { |
|
2376 if (bc->rounding == 0) { |
|
2377 if (dsign) |
|
2378 goto rethi1; |
|
2379 goto ret1; |
|
2380 } |
|
2381 if (!dsign) |
|
2382 goto rethi1; |
|
2383 dval(rv) += 2.*ulp(rv); |
|
2384 } |
|
2385 else { |
|
2386 bc->inexact = 0; |
|
2387 if (dsign) |
|
2388 goto rethi1; |
|
2389 } |
|
2390 } |
|
2391 else |
|
2392 #endif |
|
2393 if (speccase) { |
|
2394 if (dd <= 0) |
|
2395 rv->d = 0.; |
|
2396 } |
|
2397 else if (dd < 0) { |
|
2398 if (!dsign) /* does not happen for round-near */ |
|
2399 retlow1: |
|
2400 dval(rv) -= ulp(rv); |
|
2401 } |
|
2402 else if (dd > 0) { |
|
2403 if (dsign) { |
|
2404 rethi1: |
|
2405 dval(rv) += ulp(rv); |
|
2406 } |
|
2407 } |
|
2408 else { |
|
2409 /* Exact half-way case: apply round-even rule. */ |
|
2410 if (word1(rv) & 1) { |
|
2411 if (dsign) |
|
2412 goto rethi1; |
|
2413 goto retlow1; |
|
2414 } |
|
2415 } |
|
2416 |
|
2417 #ifdef Honor_FLT_ROUNDS |
|
2418 ret1: |
|
2419 #endif |
|
2420 return; |
|
2421 } |
|
2422 #endif /* NO_STRTOD_BIGCOMP */ |
|
2423 |
|
2424 double |
|
2425 strtod |
|
2426 #ifdef KR_headers |
|
2427 (s00, se) CONST char *s00; char **se; |
|
2428 #else |
|
2429 (CONST char *s00, char **se) |
|
2430 #endif |
|
2431 { |
|
2432 int bb2, bb5, bbe, bd2, bd5, bbbits, bs2, c, e, e1; |
|
2433 int esign, i, j, k, nd, nd0, nf, nz, nz0, sign; |
|
2434 CONST char *s, *s0, *s1; |
|
2435 double aadj, aadj1; |
|
2436 Long L; |
|
2437 U aadj2, adj, rv, rv0; |
|
2438 ULong y, z; |
|
2439 BCinfo bc; |
|
2440 Bigint *bb, *bb1, *bd, *bd0, *bs, *delta; |
|
2441 #ifdef SET_INEXACT |
|
2442 int oldinexact; |
|
2443 #endif |
|
2444 #ifdef Honor_FLT_ROUNDS /*{*/ |
|
2445 #ifdef Trust_FLT_ROUNDS /*{{ only define this if FLT_ROUNDS really works! */ |
|
2446 bc.rounding = Flt_Rounds; |
|
2447 #else /*}{*/ |
|
2448 bc.rounding = 1; |
|
2449 switch(fegetround()) { |
|
2450 case FE_TOWARDZERO: bc.rounding = 0; break; |
|
2451 case FE_UPWARD: bc.rounding = 2; break; |
|
2452 case FE_DOWNWARD: bc.rounding = 3; |
|
2453 } |
|
2454 #endif /*}}*/ |
|
2455 #endif /*}*/ |
|
2456 #ifdef USE_LOCALE |
|
2457 CONST char *s2; |
|
2458 #endif |
|
2459 |
|
2460 sign = nz0 = nz = bc.dplen = bc.uflchk = 0; |
|
2461 dval(&rv) = 0.; |
|
2462 for(s = s00;;s++) switch(*s) { |
|
2463 case '-': |
|
2464 sign = 1; |
|
2465 /* no break */ |
|
2466 case '+': |
|
2467 if (*++s) |
|
2468 goto break2; |
|
2469 /* no break */ |
|
2470 case 0: |
|
2471 goto ret0; |
|
2472 case '\t': |
|
2473 case '\n': |
|
2474 case '\v': |
|
2475 case '\f': |
|
2476 case '\r': |
|
2477 case ' ': |
|
2478 continue; |
|
2479 default: |
|
2480 goto break2; |
|
2481 } |
|
2482 break2: |
|
2483 if (*s == '0') { |
|
2484 #ifndef NO_HEX_FP /*{*/ |
|
2485 switch(s[1]) { |
|
2486 case 'x': |
|
2487 case 'X': |
|
2488 #ifdef Honor_FLT_ROUNDS |
|
2489 gethex(&s, &rv, bc.rounding, sign); |
|
2490 #else |
|
2491 gethex(&s, &rv, 1, sign); |
|
2492 #endif |
|
2493 goto ret; |
|
2494 } |
|
2495 #endif /*}*/ |
|
2496 nz0 = 1; |
|
2497 while(*++s == '0') ; |
|
2498 if (!*s) |
|
2499 goto ret; |
|
2500 } |
|
2501 s0 = s; |
|
2502 y = z = 0; |
|
2503 for(nd = nf = 0; (c = *s) >= '0' && c <= '9'; nd++, s++) |
|
2504 if (nd < 9) |
|
2505 y = 10*y + c - '0'; |
|
2506 else if (nd < 16) |
|
2507 z = 10*z + c - '0'; |
|
2508 nd0 = nd; |
|
2509 bc.dp0 = bc.dp1 = s - s0; |
|
2510 #ifdef USE_LOCALE |
|
2511 s1 = localeconv()->decimal_point; |
|
2512 if (c == *s1) { |
|
2513 c = '.'; |
|
2514 if (*++s1) { |
|
2515 s2 = s; |
|
2516 for(;;) { |
|
2517 if (*++s2 != *s1) { |
|
2518 c = 0; |
|
2519 break; |
|
2520 } |
|
2521 if (!*++s1) { |
|
2522 s = s2; |
|
2523 break; |
|
2524 } |
|
2525 } |
|
2526 } |
|
2527 } |
|
2528 #endif |
|
2529 if (c == '.') { |
|
2530 c = *++s; |
|
2531 bc.dp1 = s - s0; |
|
2532 bc.dplen = bc.dp1 - bc.dp0; |
|
2533 if (!nd) { |
|
2534 for(; c == '0'; c = *++s) |
|
2535 nz++; |
|
2536 if (c > '0' && c <= '9') { |
|
2537 s0 = s; |
|
2538 nf += nz; |
|
2539 nz = 0; |
|
2540 goto have_dig; |
|
2541 } |
|
2542 goto dig_done; |
|
2543 } |
|
2544 for(; c >= '0' && c <= '9'; c = *++s) { |
|
2545 have_dig: |
|
2546 nz++; |
|
2547 if (c -= '0') { |
|
2548 nf += nz; |
|
2549 for(i = 1; i < nz; i++) |
|
2550 if (nd++ < 9) |
|
2551 y *= 10; |
|
2552 else if (nd <= DBL_DIG + 1) |
|
2553 z *= 10; |
|
2554 if (nd++ < 9) |
|
2555 y = 10*y + c; |
|
2556 else if (nd <= DBL_DIG + 1) |
|
2557 z = 10*z + c; |
|
2558 nz = 0; |
|
2559 } |
|
2560 } |
|
2561 } |
|
2562 dig_done: |
|
2563 e = 0; |
|
2564 if (c == 'e' || c == 'E') { |
|
2565 if (!nd && !nz && !nz0) { |
|
2566 goto ret0; |
|
2567 } |
|
2568 s00 = s; |
|
2569 esign = 0; |
|
2570 switch(c = *++s) { |
|
2571 case '-': |
|
2572 esign = 1; |
|
2573 case '+': |
|
2574 c = *++s; |
|
2575 } |
|
2576 if (c >= '0' && c <= '9') { |
|
2577 while(c == '0') |
|
2578 c = *++s; |
|
2579 if (c > '0' && c <= '9') { |
|
2580 L = c - '0'; |
|
2581 s1 = s; |
|
2582 while((c = *++s) >= '0' && c <= '9') |
|
2583 L = 10*L + c - '0'; |
|
2584 if (s - s1 > 8 || L > 19999) |
|
2585 /* Avoid confusion from exponents |
|
2586 * so large that e might overflow. |
|
2587 */ |
|
2588 e = 19999; /* safe for 16 bit ints */ |
|
2589 else |
|
2590 e = (int)L; |
|
2591 if (esign) |
|
2592 e = -e; |
|
2593 } |
|
2594 else |
|
2595 e = 0; |
|
2596 } |
|
2597 else |
|
2598 s = s00; |
|
2599 } |
|
2600 if (!nd) { |
|
2601 if (!nz && !nz0) { |
|
2602 #ifdef INFNAN_CHECK |
|
2603 /* Check for Nan and Infinity */ |
|
2604 if (!bc.dplen) |
|
2605 switch(c) { |
|
2606 case 'i': |
|
2607 case 'I': |
|
2608 if (match(&s,"nf")) { |
|
2609 --s; |
|
2610 if (!match(&s,"inity")) |
|
2611 ++s; |
|
2612 word0(&rv) = 0x7ff00000; |
|
2613 word1(&rv) = 0; |
|
2614 goto ret; |
|
2615 } |
|
2616 break; |
|
2617 case 'n': |
|
2618 case 'N': |
|
2619 if (match(&s, "an")) { |
|
2620 word0(&rv) = NAN_WORD0; |
|
2621 word1(&rv) = NAN_WORD1; |
|
2622 #ifndef No_Hex_NaN |
|
2623 if (*s == '(') /*)*/ |
|
2624 hexnan(&rv, &s); |
|
2625 #endif |
|
2626 goto ret; |
|
2627 } |
|
2628 } |
|
2629 #endif /* INFNAN_CHECK */ |
|
2630 ret0: |
|
2631 s = s00; |
|
2632 sign = 0; |
|
2633 } |
|
2634 goto ret; |
|
2635 } |
|
2636 bc.e0 = e1 = e -= nf; |
|
2637 |
|
2638 /* Now we have nd0 digits, starting at s0, followed by a |
|
2639 * decimal point, followed by nd-nd0 digits. The number we're |
|
2640 * after is the integer represented by those digits times |
|
2641 * 10**e */ |
|
2642 |
|
2643 if (!nd0) |
|
2644 nd0 = nd; |
|
2645 k = nd < DBL_DIG + 1 ? nd : DBL_DIG + 1; |
|
2646 dval(&rv) = y; |
|
2647 if (k > 9) { |
|
2648 #ifdef SET_INEXACT |
|
2649 if (k > DBL_DIG) |
|
2650 oldinexact = get_inexact(); |
|
2651 #endif |
|
2652 dval(&rv) = tens[k - 9] * dval(&rv) + z; |
|
2653 } |
|
2654 bd0 = 0; |
|
2655 if (nd <= DBL_DIG |
|
2656 #ifndef RND_PRODQUOT |
|
2657 #ifndef Honor_FLT_ROUNDS |
|
2658 && Flt_Rounds == 1 |
|
2659 #endif |
|
2660 #endif |
|
2661 ) { |
|
2662 if (!e) |
|
2663 goto ret; |
|
2664 if (e > 0) { |
|
2665 if (e <= Ten_pmax) { |
|
2666 #ifdef VAX |
|
2667 goto vax_ovfl_check; |
|
2668 #else |
|
2669 #ifdef Honor_FLT_ROUNDS |
|
2670 /* round correctly FLT_ROUNDS = 2 or 3 */ |
|
2671 if (sign) { |
|
2672 rv.d = -rv.d; |
|
2673 sign = 0; |
|
2674 } |
|
2675 #endif |
|
2676 /* rv = */ rounded_product(dval(&rv), tens[e]); |
|
2677 goto ret; |
|
2678 #endif |
|
2679 } |
|
2680 i = DBL_DIG - nd; |
|
2681 if (e <= Ten_pmax + i) { |
|
2682 /* A fancier test would sometimes let us do |
|
2683 * this for larger i values. |
|
2684 */ |
|
2685 #ifdef Honor_FLT_ROUNDS |
|
2686 /* round correctly FLT_ROUNDS = 2 or 3 */ |
|
2687 if (sign) { |
|
2688 rv.d = -rv.d; |
|
2689 sign = 0; |
|
2690 } |
|
2691 #endif |
|
2692 e -= i; |
|
2693 dval(&rv) *= tens[i]; |
|
2694 #ifdef VAX |
|
2695 /* VAX exponent range is so narrow we must |
|
2696 * worry about overflow here... |
|
2697 */ |
|
2698 vax_ovfl_check: |
|
2699 word0(&rv) -= P*Exp_msk1; |
|
2700 /* rv = */ rounded_product(dval(&rv), tens[e]); |
|
2701 if ((word0(&rv) & Exp_mask) |
|
2702 > Exp_msk1*(DBL_MAX_EXP+Bias-1-P)) |
|
2703 goto ovfl; |
|
2704 word0(&rv) += P*Exp_msk1; |
|
2705 #else |
|
2706 /* rv = */ rounded_product(dval(&rv), tens[e]); |
|
2707 #endif |
|
2708 goto ret; |
|
2709 } |
|
2710 } |
|
2711 #ifndef Inaccurate_Divide |
|
2712 else if (e >= -Ten_pmax) { |
|
2713 #ifdef Honor_FLT_ROUNDS |
|
2714 /* round correctly FLT_ROUNDS = 2 or 3 */ |
|
2715 if (sign) { |
|
2716 rv.d = -rv.d; |
|
2717 sign = 0; |
|
2718 } |
|
2719 #endif |
|
2720 /* rv = */ rounded_quotient(dval(&rv), tens[-e]); |
|
2721 goto ret; |
|
2722 } |
|
2723 #endif |
|
2724 } |
|
2725 e1 += nd - k; |
|
2726 |
|
2727 #ifdef IEEE_Arith |
|
2728 #ifdef SET_INEXACT |
|
2729 bc.inexact = 1; |
|
2730 if (k <= DBL_DIG) |
|
2731 oldinexact = get_inexact(); |
|
2732 #endif |
|
2733 #ifdef Avoid_Underflow |
|
2734 bc.scale = 0; |
|
2735 #endif |
|
2736 #ifdef Honor_FLT_ROUNDS |
|
2737 if (bc.rounding >= 2) { |
|
2738 if (sign) |
|
2739 bc.rounding = bc.rounding == 2 ? 0 : 2; |
|
2740 else |
|
2741 if (bc.rounding != 2) |
|
2742 bc.rounding = 0; |
|
2743 } |
|
2744 #endif |
|
2745 #endif /*IEEE_Arith*/ |
|
2746 |
|
2747 /* Get starting approximation = rv * 10**e1 */ |
|
2748 |
|
2749 if (e1 > 0) { |
|
2750 if ((i = e1 & 15)) |
|
2751 dval(&rv) *= tens[i]; |
|
2752 if (e1 &= ~15) { |
|
2753 if (e1 > DBL_MAX_10_EXP) { |
|
2754 ovfl: |
|
2755 #ifndef NO_ERRNO |
|
2756 errno = ERANGE; |
|
2757 #endif |
|
2758 /* Can't trust HUGE_VAL */ |
|
2759 #ifdef IEEE_Arith |
|
2760 #ifdef Honor_FLT_ROUNDS |
|
2761 switch(bc.rounding) { |
|
2762 case 0: /* toward 0 */ |
|
2763 case 3: /* toward -infinity */ |
|
2764 word0(&rv) = Big0; |
|
2765 word1(&rv) = Big1; |
|
2766 break; |
|
2767 default: |
|
2768 word0(&rv) = Exp_mask; |
|
2769 word1(&rv) = 0; |
|
2770 } |
|
2771 #else /*Honor_FLT_ROUNDS*/ |
|
2772 word0(&rv) = Exp_mask; |
|
2773 word1(&rv) = 0; |
|
2774 #endif /*Honor_FLT_ROUNDS*/ |
|
2775 #ifdef SET_INEXACT |
|
2776 /* set overflow bit */ |
|
2777 dval(&rv0) = 1e300; |
|
2778 dval(&rv0) *= dval(&rv0); |
|
2779 #endif |
|
2780 #else /*IEEE_Arith*/ |
|
2781 word0(&rv) = Big0; |
|
2782 word1(&rv) = Big1; |
|
2783 #endif /*IEEE_Arith*/ |
|
2784 goto ret; |
|
2785 } |
|
2786 e1 >>= 4; |
|
2787 for(j = 0; e1 > 1; j++, e1 >>= 1) |
|
2788 if (e1 & 1) |
|
2789 dval(&rv) *= bigtens[j]; |
|
2790 /* The last multiplication could overflow. */ |
|
2791 word0(&rv) -= P*Exp_msk1; |
|
2792 dval(&rv) *= bigtens[j]; |
|
2793 if ((z = word0(&rv) & Exp_mask) |
|
2794 > Exp_msk1*(DBL_MAX_EXP+Bias-P)) |
|
2795 goto ovfl; |
|
2796 if (z > Exp_msk1*(DBL_MAX_EXP+Bias-1-P)) { |
|
2797 /* set to largest number */ |
|
2798 /* (Can't trust DBL_MAX) */ |
|
2799 word0(&rv) = Big0; |
|
2800 word1(&rv) = Big1; |
|
2801 } |
|
2802 else |
|
2803 word0(&rv) += P*Exp_msk1; |
|
2804 } |
|
2805 } |
|
2806 else if (e1 < 0) { |
|
2807 e1 = -e1; |
|
2808 if ((i = e1 & 15)) |
|
2809 dval(&rv) /= tens[i]; |
|
2810 if (e1 >>= 4) { |
|
2811 if (e1 >= 1 << n_bigtens) |
|
2812 goto undfl; |
|
2813 #ifdef Avoid_Underflow |
|
2814 if (e1 & Scale_Bit) |
|
2815 bc.scale = 2*P; |
|
2816 for(j = 0; e1 > 0; j++, e1 >>= 1) |
|
2817 if (e1 & 1) |
|
2818 dval(&rv) *= tinytens[j]; |
|
2819 if (bc.scale && (j = 2*P + 1 - ((word0(&rv) & Exp_mask) |
|
2820 >> Exp_shift)) > 0) { |
|
2821 /* scaled rv is denormal; clear j low bits */ |
|
2822 if (j >= 32) { |
|
2823 word1(&rv) = 0; |
|
2824 if (j >= 53) |
|
2825 word0(&rv) = (P+2)*Exp_msk1; |
|
2826 else |
|
2827 word0(&rv) &= 0xffffffff << (j-32); |
|
2828 } |
|
2829 else |
|
2830 word1(&rv) &= 0xffffffff << j; |
|
2831 } |
|
2832 #else |
|
2833 for(j = 0; e1 > 1; j++, e1 >>= 1) |
|
2834 if (e1 & 1) |
|
2835 dval(&rv) *= tinytens[j]; |
|
2836 /* The last multiplication could underflow. */ |
|
2837 dval(&rv0) = dval(&rv); |
|
2838 dval(&rv) *= tinytens[j]; |
|
2839 if (!dval(&rv)) { |
|
2840 dval(&rv) = 2.*dval(&rv0); |
|
2841 dval(&rv) *= tinytens[j]; |
|
2842 #endif |
|
2843 if (!dval(&rv)) { |
|
2844 undfl: |
|
2845 dval(&rv) = 0.; |
|
2846 #ifndef NO_ERRNO |
|
2847 errno = ERANGE; |
|
2848 #endif |
|
2849 goto ret; |
|
2850 } |
|
2851 #ifndef Avoid_Underflow |
|
2852 word0(&rv) = Tiny0; |
|
2853 word1(&rv) = Tiny1; |
|
2854 /* The refinement below will clean |
|
2855 * this approximation up. |
|
2856 */ |
|
2857 } |
|
2858 #endif |
|
2859 } |
|
2860 } |
|
2861 |
|
2862 /* Now the hard part -- adjusting rv to the correct value.*/ |
|
2863 |
|
2864 /* Put digits into bd: true value = bd * 10^e */ |
|
2865 |
|
2866 bc.nd = nd; |
|
2867 #ifndef NO_STRTOD_BIGCOMP |
|
2868 bc.nd0 = nd0; /* Only needed if nd > strtod_diglim, but done here */ |
|
2869 /* to silence an erroneous warning about bc.nd0 */ |
|
2870 /* possibly not being initialized. */ |
|
2871 if (nd > strtod_diglim) { |
|
2872 /* ASSERT(strtod_diglim >= 18); 18 == one more than the */ |
|
2873 /* minimum number of decimal digits to distinguish double values */ |
|
2874 /* in IEEE arithmetic. */ |
|
2875 i = j = 18; |
|
2876 if (i > nd0) |
|
2877 j += bc.dplen; |
|
2878 for(;;) { |
|
2879 if (--j <= bc.dp1 && j >= bc.dp0) |
|
2880 j = bc.dp0 - 1; |
|
2881 if (s0[j] != '0') |
|
2882 break; |
|
2883 --i; |
|
2884 } |
|
2885 e += nd - i; |
|
2886 nd = i; |
|
2887 if (nd0 > nd) |
|
2888 nd0 = nd; |
|
2889 if (nd < 9) { /* must recompute y */ |
|
2890 y = 0; |
|
2891 for(i = 0; i < nd0; ++i) |
|
2892 y = 10*y + s0[i] - '0'; |
|
2893 for(j = bc.dp1; i < nd; ++i) |
|
2894 y = 10*y + s0[j++] - '0'; |
|
2895 } |
|
2896 } |
|
2897 #endif |
|
2898 bd0 = s2b(s0, nd0, nd, y, bc.dplen); |
|
2899 |
|
2900 for(;;) { |
|
2901 bd = Balloc(bd0->k); |
|
2902 Bcopy(bd, bd0); |
|
2903 bb = d2b(&rv, &bbe, &bbbits); /* rv = bb * 2^bbe */ |
|
2904 bs = i2b(1); |
|
2905 |
|
2906 if (e >= 0) { |
|
2907 bb2 = bb5 = 0; |
|
2908 bd2 = bd5 = e; |
|
2909 } |
|
2910 else { |
|
2911 bb2 = bb5 = -e; |
|
2912 bd2 = bd5 = 0; |
|
2913 } |
|
2914 if (bbe >= 0) |
|
2915 bb2 += bbe; |
|
2916 else |
|
2917 bd2 -= bbe; |
|
2918 bs2 = bb2; |
|
2919 #ifdef Honor_FLT_ROUNDS |
|
2920 if (bc.rounding != 1) |
|
2921 bs2++; |
|
2922 #endif |
|
2923 #ifdef Avoid_Underflow |
|
2924 j = bbe - bc.scale; |
|
2925 i = j + bbbits - 1; /* logb(rv) */ |
|
2926 if (i < Emin) /* denormal */ |
|
2927 j += P - Emin; |
|
2928 else |
|
2929 j = P + 1 - bbbits; |
|
2930 #else /*Avoid_Underflow*/ |
|
2931 #ifdef Sudden_Underflow |
|
2932 #ifdef IBM |
|
2933 j = 1 + 4*P - 3 - bbbits + ((bbe + bbbits - 1) & 3); |
|
2934 #else |
|
2935 j = P + 1 - bbbits; |
|
2936 #endif |
|
2937 #else /*Sudden_Underflow*/ |
|
2938 j = bbe; |
|
2939 i = j + bbbits - 1; /* logb(rv) */ |
|
2940 if (i < Emin) /* denormal */ |
|
2941 j += P - Emin; |
|
2942 else |
|
2943 j = P + 1 - bbbits; |
|
2944 #endif /*Sudden_Underflow*/ |
|
2945 #endif /*Avoid_Underflow*/ |
|
2946 bb2 += j; |
|
2947 bd2 += j; |
|
2948 #ifdef Avoid_Underflow |
|
2949 bd2 += bc.scale; |
|
2950 #endif |
|
2951 i = bb2 < bd2 ? bb2 : bd2; |
|
2952 if (i > bs2) |
|
2953 i = bs2; |
|
2954 if (i > 0) { |
|
2955 bb2 -= i; |
|
2956 bd2 -= i; |
|
2957 bs2 -= i; |
|
2958 } |
|
2959 if (bb5 > 0) { |
|
2960 bs = pow5mult(bs, bb5); |
|
2961 bb1 = mult(bs, bb); |
|
2962 Bfree(bb); |
|
2963 bb = bb1; |
|
2964 } |
|
2965 if (bb2 > 0) |
|
2966 bb = lshift(bb, bb2); |
|
2967 if (bd5 > 0) |
|
2968 bd = pow5mult(bd, bd5); |
|
2969 if (bd2 > 0) |
|
2970 bd = lshift(bd, bd2); |
|
2971 if (bs2 > 0) |
|
2972 bs = lshift(bs, bs2); |
|
2973 delta = diff(bb, bd); |
|
2974 bc.dsign = delta->sign; |
|
2975 delta->sign = 0; |
|
2976 i = cmp(delta, bs); |
|
2977 #ifndef NO_STRTOD_BIGCOMP |
|
2978 if (bc.nd > nd && i <= 0) { |
|
2979 if (bc.dsign) |
|
2980 break; /* Must use bigcomp(). */ |
|
2981 #ifdef Honor_FLT_ROUNDS |
|
2982 if (bc.rounding != 1) { |
|
2983 if (i < 0) |
|
2984 break; |
|
2985 } |
|
2986 else |
|
2987 #endif |
|
2988 { |
|
2989 bc.nd = nd; |
|
2990 i = -1; /* Discarded digits make delta smaller. */ |
|
2991 } |
|
2992 } |
|
2993 #endif |
|
2994 #ifdef Honor_FLT_ROUNDS |
|
2995 if (bc.rounding != 1) { |
|
2996 if (i < 0) { |
|
2997 /* Error is less than an ulp */ |
|
2998 if (!delta->x[0] && delta->wds <= 1) { |
|
2999 /* exact */ |
|
3000 #ifdef SET_INEXACT |
|
3001 bc.inexact = 0; |
|
3002 #endif |
|
3003 break; |
|
3004 } |
|
3005 if (bc.rounding) { |
|
3006 if (bc.dsign) { |
|
3007 adj.d = 1.; |
|
3008 goto apply_adj; |
|
3009 } |
|
3010 } |
|
3011 else if (!bc.dsign) { |
|
3012 adj.d = -1.; |
|
3013 if (!word1(&rv) |
|
3014 && !(word0(&rv) & Frac_mask)) { |
|
3015 y = word0(&rv) & Exp_mask; |
|
3016 #ifdef Avoid_Underflow |
|
3017 if (!bc.scale || y > 2*P*Exp_msk1) |
|
3018 #else |
|
3019 if (y) |
|
3020 #endif |
|
3021 { |
|
3022 delta = lshift(delta,Log2P); |
|
3023 if (cmp(delta, bs) <= 0) |
|
3024 adj.d = -0.5; |
|
3025 } |
|
3026 } |
|
3027 apply_adj: |
|
3028 #ifdef Avoid_Underflow |
|
3029 if (bc.scale && (y = word0(&rv) & Exp_mask) |
|
3030 <= 2*P*Exp_msk1) |
|
3031 word0(&adj) += (2*P+1)*Exp_msk1 - y; |
|
3032 #else |
|
3033 #ifdef Sudden_Underflow |
|
3034 if ((word0(&rv) & Exp_mask) <= |
|
3035 P*Exp_msk1) { |
|
3036 word0(&rv) += P*Exp_msk1; |
|
3037 dval(&rv) += adj.d*ulp(dval(&rv)); |
|
3038 word0(&rv) -= P*Exp_msk1; |
|
3039 } |
|
3040 else |
|
3041 #endif /*Sudden_Underflow*/ |
|
3042 #endif /*Avoid_Underflow*/ |
|
3043 dval(&rv) += adj.d*ulp(&rv); |
|
3044 } |
|
3045 break; |
|
3046 } |
|
3047 adj.d = ratio(delta, bs); |
|
3048 if (adj.d < 1.) |
|
3049 adj.d = 1.; |
|
3050 if (adj.d <= 0x7ffffffe) { |
|
3051 /* adj = rounding ? ceil(adj) : floor(adj); */ |
|
3052 y = adj.d; |
|
3053 if (y != adj.d) { |
|
3054 if (!((bc.rounding>>1) ^ bc.dsign)) |
|
3055 y++; |
|
3056 adj.d = y; |
|
3057 } |
|
3058 } |
|
3059 #ifdef Avoid_Underflow |
|
3060 if (bc.scale && (y = word0(&rv) & Exp_mask) <= 2*P*Exp_msk1) |
|
3061 word0(&adj) += (2*P+1)*Exp_msk1 - y; |
|
3062 #else |
|
3063 #ifdef Sudden_Underflow |
|
3064 if ((word0(&rv) & Exp_mask) <= P*Exp_msk1) { |
|
3065 word0(&rv) += P*Exp_msk1; |
|
3066 adj.d *= ulp(dval(&rv)); |
|
3067 if (bc.dsign) |
|
3068 dval(&rv) += adj.d; |
|
3069 else |
|
3070 dval(&rv) -= adj.d; |
|
3071 word0(&rv) -= P*Exp_msk1; |
|
3072 goto cont; |
|
3073 } |
|
3074 #endif /*Sudden_Underflow*/ |
|
3075 #endif /*Avoid_Underflow*/ |
|
3076 adj.d *= ulp(&rv); |
|
3077 if (bc.dsign) { |
|
3078 if (word0(&rv) == Big0 && word1(&rv) == Big1) |
|
3079 goto ovfl; |
|
3080 dval(&rv) += adj.d; |
|
3081 } |
|
3082 else |
|
3083 dval(&rv) -= adj.d; |
|
3084 goto cont; |
|
3085 } |
|
3086 #endif /*Honor_FLT_ROUNDS*/ |
|
3087 |
|
3088 if (i < 0) { |
|
3089 /* Error is less than half an ulp -- check for |
|
3090 * special case of mantissa a power of two. |
|
3091 */ |
|
3092 if (bc.dsign || word1(&rv) || word0(&rv) & Bndry_mask |
|
3093 #ifdef IEEE_Arith |
|
3094 #ifdef Avoid_Underflow |
|
3095 || (word0(&rv) & Exp_mask) <= (2*P+1)*Exp_msk1 |
|
3096 #else |
|
3097 || (word0(&rv) & Exp_mask) <= Exp_msk1 |
|
3098 #endif |
|
3099 #endif |
|
3100 ) { |
|
3101 #ifdef SET_INEXACT |
|
3102 if (!delta->x[0] && delta->wds <= 1) |
|
3103 bc.inexact = 0; |
|
3104 #endif |
|
3105 break; |
|
3106 } |
|
3107 if (!delta->x[0] && delta->wds <= 1) { |
|
3108 /* exact result */ |
|
3109 #ifdef SET_INEXACT |
|
3110 bc.inexact = 0; |
|
3111 #endif |
|
3112 break; |
|
3113 } |
|
3114 delta = lshift(delta,Log2P); |
|
3115 if (cmp(delta, bs) > 0) |
|
3116 goto drop_down; |
|
3117 break; |
|
3118 } |
|
3119 if (i == 0) { |
|
3120 /* exactly half-way between */ |
|
3121 if (bc.dsign) { |
|
3122 if ((word0(&rv) & Bndry_mask1) == Bndry_mask1 |
|
3123 && word1(&rv) == ( |
|
3124 #ifdef Avoid_Underflow |
|
3125 (bc.scale && (y = word0(&rv) & Exp_mask) <= 2*P*Exp_msk1) |
|
3126 ? (0xffffffff & (0xffffffff << (2*P+1-(y>>Exp_shift)))) : |
|
3127 #endif |
|
3128 0xffffffff)) { |
|
3129 /*boundary case -- increment exponent*/ |
|
3130 word0(&rv) = (word0(&rv) & Exp_mask) |
|
3131 + Exp_msk1 |
|
3132 #ifdef IBM |
|
3133 | Exp_msk1 >> 4 |
|
3134 #endif |
|
3135 ; |
|
3136 word1(&rv) = 0; |
|
3137 #ifdef Avoid_Underflow |
|
3138 bc.dsign = 0; |
|
3139 #endif |
|
3140 break; |
|
3141 } |
|
3142 } |
|
3143 else if (!(word0(&rv) & Bndry_mask) && !word1(&rv)) { |
|
3144 drop_down: |
|
3145 /* boundary case -- decrement exponent */ |
|
3146 #ifdef Sudden_Underflow /*{{*/ |
|
3147 L = word0(&rv) & Exp_mask; |
|
3148 #ifdef IBM |
|
3149 if (L < Exp_msk1) |
|
3150 #else |
|
3151 #ifdef Avoid_Underflow |
|
3152 if (L <= (bc.scale ? (2*P+1)*Exp_msk1 : Exp_msk1)) |
|
3153 #else |
|
3154 if (L <= Exp_msk1) |
|
3155 #endif /*Avoid_Underflow*/ |
|
3156 #endif /*IBM*/ |
|
3157 { |
|
3158 if (bc.nd >nd) { |
|
3159 bc.uflchk = 1; |
|
3160 break; |
|
3161 } |
|
3162 goto undfl; |
|
3163 } |
|
3164 L -= Exp_msk1; |
|
3165 #else /*Sudden_Underflow}{*/ |
|
3166 #ifdef Avoid_Underflow |
|
3167 if (bc.scale) { |
|
3168 L = word0(&rv) & Exp_mask; |
|
3169 if (L <= (2*P+1)*Exp_msk1) { |
|
3170 if (L > (P+2)*Exp_msk1) |
|
3171 /* round even ==> */ |
|
3172 /* accept rv */ |
|
3173 break; |
|
3174 /* rv = smallest denormal */ |
|
3175 if (bc.nd >nd) { |
|
3176 bc.uflchk = 1; |
|
3177 break; |
|
3178 } |
|
3179 goto undfl; |
|
3180 } |
|
3181 } |
|
3182 #endif /*Avoid_Underflow*/ |
|
3183 L = (word0(&rv) & Exp_mask) - Exp_msk1; |
|
3184 #endif /*Sudden_Underflow}}*/ |
|
3185 word0(&rv) = L | Bndry_mask1; |
|
3186 word1(&rv) = 0xffffffff; |
|
3187 #ifdef IBM |
|
3188 goto cont; |
|
3189 #else |
|
3190 break; |
|
3191 #endif |
|
3192 } |
|
3193 #ifndef ROUND_BIASED |
|
3194 if (!(word1(&rv) & LSB)) |
|
3195 break; |
|
3196 #endif |
|
3197 if (bc.dsign) |
|
3198 dval(&rv) += ulp(&rv); |
|
3199 #ifndef ROUND_BIASED |
|
3200 else { |
|
3201 dval(&rv) -= ulp(&rv); |
|
3202 #ifndef Sudden_Underflow |
|
3203 if (!dval(&rv)) { |
|
3204 if (bc.nd >nd) { |
|
3205 bc.uflchk = 1; |
|
3206 break; |
|
3207 } |
|
3208 goto undfl; |
|
3209 } |
|
3210 #endif |
|
3211 } |
|
3212 #ifdef Avoid_Underflow |
|
3213 bc.dsign = 1 - bc.dsign; |
|
3214 #endif |
|
3215 #endif |
|
3216 break; |
|
3217 } |
|
3218 if ((aadj = ratio(delta, bs)) <= 2.) { |
|
3219 if (bc.dsign) |
|
3220 aadj = aadj1 = 1.; |
|
3221 else if (word1(&rv) || word0(&rv) & Bndry_mask) { |
|
3222 #ifndef Sudden_Underflow |
|
3223 if (word1(&rv) == Tiny1 && !word0(&rv)) { |
|
3224 if (bc.nd >nd) { |
|
3225 bc.uflchk = 1; |
|
3226 break; |
|
3227 } |
|
3228 goto undfl; |
|
3229 } |
|
3230 #endif |
|
3231 aadj = 1.; |
|
3232 aadj1 = -1.; |
|
3233 } |
|
3234 else { |
|
3235 /* special case -- power of FLT_RADIX to be */ |
|
3236 /* rounded down... */ |
|
3237 |
|
3238 if (aadj < 2./FLT_RADIX) |
|
3239 aadj = 1./FLT_RADIX; |
|
3240 else |
|
3241 aadj *= 0.5; |
|
3242 aadj1 = -aadj; |
|
3243 } |
|
3244 } |
|
3245 else { |
|
3246 aadj *= 0.5; |
|
3247 aadj1 = bc.dsign ? aadj : -aadj; |
|
3248 #ifdef Check_FLT_ROUNDS |
|
3249 switch(bc.rounding) { |
|
3250 case 2: /* towards +infinity */ |
|
3251 aadj1 -= 0.5; |
|
3252 break; |
|
3253 case 0: /* towards 0 */ |
|
3254 case 3: /* towards -infinity */ |
|
3255 aadj1 += 0.5; |
|
3256 } |
|
3257 #else |
|
3258 if (Flt_Rounds == 0) |
|
3259 aadj1 += 0.5; |
|
3260 #endif /*Check_FLT_ROUNDS*/ |
|
3261 } |
|
3262 y = word0(&rv) & Exp_mask; |
|
3263 |
|
3264 /* Check for overflow */ |
|
3265 |
|
3266 if (y == Exp_msk1*(DBL_MAX_EXP+Bias-1)) { |
|
3267 dval(&rv0) = dval(&rv); |
|
3268 word0(&rv) -= P*Exp_msk1; |
|
3269 adj.d = aadj1 * ulp(&rv); |
|
3270 dval(&rv) += adj.d; |
|
3271 if ((word0(&rv) & Exp_mask) >= |
|
3272 Exp_msk1*(DBL_MAX_EXP+Bias-P)) { |
|
3273 if (word0(&rv0) == Big0 && word1(&rv0) == Big1) |
|
3274 goto ovfl; |
|
3275 word0(&rv) = Big0; |
|
3276 word1(&rv) = Big1; |
|
3277 goto cont; |
|
3278 } |
|
3279 else |
|
3280 word0(&rv) += P*Exp_msk1; |
|
3281 } |
|
3282 else { |
|
3283 #ifdef Avoid_Underflow |
|
3284 if (bc.scale && y <= 2*P*Exp_msk1) { |
|
3285 if (aadj <= 0x7fffffff) { |
|
3286 if ((z = aadj) <= 0) |
|
3287 z = 1; |
|
3288 aadj = z; |
|
3289 aadj1 = bc.dsign ? aadj : -aadj; |
|
3290 } |
|
3291 dval(&aadj2) = aadj1; |
|
3292 word0(&aadj2) += (2*P+1)*Exp_msk1 - y; |
|
3293 aadj1 = dval(&aadj2); |
|
3294 } |
|
3295 adj.d = aadj1 * ulp(&rv); |
|
3296 dval(&rv) += adj.d; |
|
3297 #else |
|
3298 #ifdef Sudden_Underflow |
|
3299 if ((word0(&rv) & Exp_mask) <= P*Exp_msk1) { |
|
3300 dval(&rv0) = dval(&rv); |
|
3301 word0(&rv) += P*Exp_msk1; |
|
3302 adj.d = aadj1 * ulp(&rv); |
|
3303 dval(&rv) += adj.d; |
|
3304 #ifdef IBM |
|
3305 if ((word0(&rv) & Exp_mask) < P*Exp_msk1) |
|
3306 #else |
|
3307 if ((word0(&rv) & Exp_mask) <= P*Exp_msk1) |
|
3308 #endif |
|
3309 { |
|
3310 if (word0(&rv0) == Tiny0 |
|
3311 && word1(&rv0) == Tiny1) { |
|
3312 if (bc.nd >nd) { |
|
3313 bc.uflchk = 1; |
|
3314 break; |
|
3315 } |
|
3316 goto undfl; |
|
3317 } |
|
3318 word0(&rv) = Tiny0; |
|
3319 word1(&rv) = Tiny1; |
|
3320 goto cont; |
|
3321 } |
|
3322 else |
|
3323 word0(&rv) -= P*Exp_msk1; |
|
3324 } |
|
3325 else { |
|
3326 adj.d = aadj1 * ulp(&rv); |
|
3327 dval(&rv) += adj.d; |
|
3328 } |
|
3329 #else /*Sudden_Underflow*/ |
|
3330 /* Compute adj so that the IEEE rounding rules will |
|
3331 * correctly round rv + adj in some half-way cases. |
|
3332 * If rv * ulp(rv) is denormalized (i.e., |
|
3333 * y <= (P-1)*Exp_msk1), we must adjust aadj to avoid |
|
3334 * trouble from bits lost to denormalization; |
|
3335 * example: 1.2e-307 . |
|
3336 */ |
|
3337 if (y <= (P-1)*Exp_msk1 && aadj > 1.) { |
|
3338 aadj1 = (double)(int)(aadj + 0.5); |
|
3339 if (!bc.dsign) |
|
3340 aadj1 = -aadj1; |
|
3341 } |
|
3342 adj.d = aadj1 * ulp(&rv); |
|
3343 dval(&rv) += adj.d; |
|
3344 #endif /*Sudden_Underflow*/ |
|
3345 #endif /*Avoid_Underflow*/ |
|
3346 } |
|
3347 z = word0(&rv) & Exp_mask; |
|
3348 #ifndef SET_INEXACT |
|
3349 if (bc.nd == nd) { |
|
3350 #ifdef Avoid_Underflow |
|
3351 if (!bc.scale) |
|
3352 #endif |
|
3353 if (y == z) { |
|
3354 /* Can we stop now? */ |
|
3355 L = (Long)aadj; |
|
3356 aadj -= L; |
|
3357 /* The tolerances below are conservative. */ |
|
3358 if (bc.dsign || word1(&rv) || word0(&rv) & Bndry_mask) { |
|
3359 if (aadj < .4999999 || aadj > .5000001) |
|
3360 break; |
|
3361 } |
|
3362 else if (aadj < .4999999/FLT_RADIX) |
|
3363 break; |
|
3364 } |
|
3365 } |
|
3366 #endif |
|
3367 cont: |
|
3368 Bfree(bb); |
|
3369 Bfree(bd); |
|
3370 Bfree(bs); |
|
3371 Bfree(delta); |
|
3372 } |
|
3373 Bfree(bb); |
|
3374 Bfree(bd); |
|
3375 Bfree(bs); |
|
3376 Bfree(bd0); |
|
3377 Bfree(delta); |
|
3378 #ifndef NO_STRTOD_BIGCOMP |
|
3379 if (bc.nd > nd) |
|
3380 bigcomp(&rv, s0, &bc); |
|
3381 #endif |
|
3382 #ifdef SET_INEXACT |
|
3383 if (bc.inexact) { |
|
3384 if (!oldinexact) { |
|
3385 word0(&rv0) = Exp_1 + (70 << Exp_shift); |
|
3386 word1(&rv0) = 0; |
|
3387 dval(&rv0) += 1.; |
|
3388 } |
|
3389 } |
|
3390 else if (!oldinexact) |
|
3391 clear_inexact(); |
|
3392 #endif |
|
3393 #ifdef Avoid_Underflow |
|
3394 if (bc.scale) { |
|
3395 word0(&rv0) = Exp_1 - 2*P*Exp_msk1; |
|
3396 word1(&rv0) = 0; |
|
3397 dval(&rv) *= dval(&rv0); |
|
3398 #ifndef NO_ERRNO |
|
3399 /* try to avoid the bug of testing an 8087 register value */ |
|
3400 #ifdef IEEE_Arith |
|
3401 if (!(word0(&rv) & Exp_mask)) |
|
3402 #else |
|
3403 if (word0(&rv) == 0 && word1(&rv) == 0) |
|
3404 #endif |
|
3405 errno = ERANGE; |
|
3406 #endif |
|
3407 } |
|
3408 #endif /* Avoid_Underflow */ |
|
3409 #ifdef SET_INEXACT |
|
3410 if (bc.inexact && !(word0(&rv) & Exp_mask)) { |
|
3411 /* set underflow bit */ |
|
3412 dval(&rv0) = 1e-300; |
|
3413 dval(&rv0) *= dval(&rv0); |
|
3414 } |
|
3415 #endif |
|
3416 ret: |
|
3417 if (se) |
|
3418 *se = (char *)s; |
|
3419 return sign ? -dval(&rv) : dval(&rv); |
|
3420 } |
|
3421 |
|
3422 #ifndef MULTIPLE_THREADS |
|
3423 static char *dtoa_result; |
|
3424 #endif |
|
3425 |
|
3426 static char * |
|
3427 #ifdef KR_headers |
|
3428 rv_alloc(i) int i; |
|
3429 #else |
|
3430 rv_alloc(int i) |
|
3431 #endif |
|
3432 { |
|
3433 int j, k, *r; |
|
3434 |
|
3435 j = sizeof(ULong); |
|
3436 for(k = 0; |
|
3437 sizeof(Bigint) - sizeof(ULong) - sizeof(int) + j <= (size_t)i; |
|
3438 j <<= 1) |
|
3439 k++; |
|
3440 r = (int*)Balloc(k); |
|
3441 *r = k; |
|
3442 return |
|
3443 #ifndef MULTIPLE_THREADS |
|
3444 dtoa_result = |
|
3445 #endif |
|
3446 (char *)(r+1); |
|
3447 } |
|
3448 |
|
3449 static char * |
|
3450 #ifdef KR_headers |
|
3451 nrv_alloc(s, rve, n) char *s, **rve; int n; |
|
3452 #else |
|
3453 nrv_alloc(CONST char *s, char **rve, int n) |
|
3454 #endif |
|
3455 { |
|
3456 char *rv, *t; |
|
3457 |
|
3458 t = rv = rv_alloc(n); |
|
3459 while((*t = *s++)) t++; |
|
3460 if (rve) |
|
3461 *rve = t; |
|
3462 return rv; |
|
3463 } |
|
3464 |
|
3465 /* freedtoa(s) must be used to free values s returned by dtoa |
|
3466 * when MULTIPLE_THREADS is #defined. It should be used in all cases, |
|
3467 * but for consistency with earlier versions of dtoa, it is optional |
|
3468 * when MULTIPLE_THREADS is not defined. |
|
3469 */ |
|
3470 |
|
3471 void |
|
3472 #ifdef KR_headers |
|
3473 freedtoa(s) char *s; |
|
3474 #else |
|
3475 freedtoa(char *s) |
|
3476 #endif |
|
3477 { |
|
3478 Bigint *b = (Bigint *)((int *)s - 1); |
|
3479 b->maxwds = 1 << (b->k = *(int*)b); |
|
3480 Bfree(b); |
|
3481 #ifndef MULTIPLE_THREADS |
|
3482 if (s == dtoa_result) |
|
3483 dtoa_result = 0; |
|
3484 #endif |
|
3485 } |
|
3486 |
|
3487 /* dtoa for IEEE arithmetic (dmg): convert double to ASCII string. |
|
3488 * |
|
3489 * Inspired by "How to Print Floating-Point Numbers Accurately" by |
|
3490 * Guy L. Steele, Jr. and Jon L. White [Proc. ACM SIGPLAN '90, pp. 112-126]. |
|
3491 * |
|
3492 * Modifications: |
|
3493 * 1. Rather than iterating, we use a simple numeric overestimate |
|
3494 * to determine k = floor(log10(d)). We scale relevant |
|
3495 * quantities using O(log2(k)) rather than O(k) multiplications. |
|
3496 * 2. For some modes > 2 (corresponding to ecvt and fcvt), we don't |
|
3497 * try to generate digits strictly left to right. Instead, we |
|
3498 * compute with fewer bits and propagate the carry if necessary |
|
3499 * when rounding the final digit up. This is often faster. |
|
3500 * 3. Under the assumption that input will be rounded nearest, |
|
3501 * mode 0 renders 1e23 as 1e23 rather than 9.999999999999999e22. |
|
3502 * That is, we allow equality in stopping tests when the |
|
3503 * round-nearest rule will give the same floating-point value |
|
3504 * as would satisfaction of the stopping test with strict |
|
3505 * inequality. |
|
3506 * 4. We remove common factors of powers of 2 from relevant |
|
3507 * quantities. |
|
3508 * 5. When converting floating-point integers less than 1e16, |
|
3509 * we use floating-point arithmetic rather than resorting |
|
3510 * to multiple-precision integers. |
|
3511 * 6. When asked to produce fewer than 15 digits, we first try |
|
3512 * to get by with floating-point arithmetic; we resort to |
|
3513 * multiple-precision integer arithmetic only if we cannot |
|
3514 * guarantee that the floating-point calculation has given |
|
3515 * the correctly rounded result. For k requested digits and |
|
3516 * "uniformly" distributed input, the probability is |
|
3517 * something like 10^(k-15) that we must resort to the Long |
|
3518 * calculation. |
|
3519 */ |
|
3520 |
|
3521 char * |
|
3522 dtoa |
|
3523 #ifdef KR_headers |
|
3524 (dd, mode, ndigits, decpt, sign, rve) |
|
3525 double dd; int mode, ndigits, *decpt, *sign; char **rve; |
|
3526 #else |
|
3527 (double dd, int mode, int ndigits, int *decpt, int *sign, char **rve) |
|
3528 #endif |
|
3529 { |
|
3530 /* Arguments ndigits, decpt, sign are similar to those |
|
3531 of ecvt and fcvt; trailing zeros are suppressed from |
|
3532 the returned string. If not null, *rve is set to point |
|
3533 to the end of the return value. If d is +-Infinity or NaN, |
|
3534 then *decpt is set to 9999. |
|
3535 |
|
3536 mode: |
|
3537 0 ==> shortest string that yields d when read in |
|
3538 and rounded to nearest. |
|
3539 1 ==> like 0, but with Steele & White stopping rule; |
|
3540 e.g. with IEEE P754 arithmetic , mode 0 gives |
|
3541 1e23 whereas mode 1 gives 9.999999999999999e22. |
|
3542 2 ==> max(1,ndigits) significant digits. This gives a |
|
3543 return value similar to that of ecvt, except |
|
3544 that trailing zeros are suppressed. |
|
3545 3 ==> through ndigits past the decimal point. This |
|
3546 gives a return value similar to that from fcvt, |
|
3547 except that trailing zeros are suppressed, and |
|
3548 ndigits can be negative. |
|
3549 4,5 ==> similar to 2 and 3, respectively, but (in |
|
3550 round-nearest mode) with the tests of mode 0 to |
|
3551 possibly return a shorter string that rounds to d. |
|
3552 With IEEE arithmetic and compilation with |
|
3553 -DHonor_FLT_ROUNDS, modes 4 and 5 behave the same |
|
3554 as modes 2 and 3 when FLT_ROUNDS != 1. |
|
3555 6-9 ==> Debugging modes similar to mode - 4: don't try |
|
3556 fast floating-point estimate (if applicable). |
|
3557 |
|
3558 Values of mode other than 0-9 are treated as mode 0. |
|
3559 |
|
3560 Sufficient space is allocated to the return value |
|
3561 to hold the suppressed trailing zeros. |
|
3562 */ |
|
3563 |
|
3564 int bbits, b2, b5, be, dig, i, ieps, ilim, ilim0, ilim1, |
|
3565 j, j1, k, k0, k_check, leftright, m2, m5, s2, s5, |
|
3566 spec_case, try_quick; |
|
3567 Long L; |
|
3568 #ifndef Sudden_Underflow |
|
3569 int denorm; |
|
3570 ULong x; |
|
3571 #endif |
|
3572 Bigint *b, *b1, *delta, *mlo = NULL, *mhi, *S; |
|
3573 U d2, eps, u; |
|
3574 double ds; |
|
3575 char *s, *s0; |
|
3576 #ifdef SET_INEXACT |
|
3577 int inexact, oldinexact; |
|
3578 #endif |
|
3579 #ifdef Honor_FLT_ROUNDS /*{*/ |
|
3580 int Rounding; |
|
3581 #ifdef Trust_FLT_ROUNDS /*{{ only define this if FLT_ROUNDS really works! */ |
|
3582 Rounding = Flt_Rounds; |
|
3583 #else /*}{*/ |
|
3584 Rounding = 1; |
|
3585 switch(fegetround()) { |
|
3586 case FE_TOWARDZERO: Rounding = 0; break; |
|
3587 case FE_UPWARD: Rounding = 2; break; |
|
3588 case FE_DOWNWARD: Rounding = 3; |
|
3589 } |
|
3590 #endif /*}}*/ |
|
3591 #endif /*}*/ |
|
3592 |
|
3593 #ifndef MULTIPLE_THREADS |
|
3594 if (dtoa_result) { |
|
3595 freedtoa(dtoa_result); |
|
3596 dtoa_result = 0; |
|
3597 } |
|
3598 #endif |
|
3599 |
|
3600 u.d = dd; |
|
3601 if (word0(&u) & Sign_bit) { |
|
3602 /* set sign for everything, including 0's and NaNs */ |
|
3603 *sign = 1; |
|
3604 word0(&u) &= ~Sign_bit; /* clear sign bit */ |
|
3605 } |
|
3606 else |
|
3607 *sign = 0; |
|
3608 |
|
3609 #if defined(IEEE_Arith) + defined(VAX) |
|
3610 #ifdef IEEE_Arith |
|
3611 if ((word0(&u) & Exp_mask) == Exp_mask) |
|
3612 #else |
|
3613 if (word0(&u) == 0x8000) |
|
3614 #endif |
|
3615 { |
|
3616 /* Infinity or NaN */ |
|
3617 *decpt = 9999; |
|
3618 #ifdef IEEE_Arith |
|
3619 if (!word1(&u) && !(word0(&u) & 0xfffff)) |
|
3620 return nrv_alloc("Infinity", rve, 8); |
|
3621 #endif |
|
3622 return nrv_alloc("NaN", rve, 3); |
|
3623 } |
|
3624 #endif |
|
3625 #ifdef IBM |
|
3626 dval(&u) += 0; /* normalize */ |
|
3627 #endif |
|
3628 if (!dval(&u)) { |
|
3629 *decpt = 1; |
|
3630 return nrv_alloc("0", rve, 1); |
|
3631 } |
|
3632 |
|
3633 #ifdef SET_INEXACT |
|
3634 try_quick = oldinexact = get_inexact(); |
|
3635 inexact = 1; |
|
3636 #endif |
|
3637 #ifdef Honor_FLT_ROUNDS |
|
3638 if (Rounding >= 2) { |
|
3639 if (*sign) |
|
3640 Rounding = Rounding == 2 ? 0 : 2; |
|
3641 else |
|
3642 if (Rounding != 2) |
|
3643 Rounding = 0; |
|
3644 } |
|
3645 #endif |
|
3646 |
|
3647 b = d2b(&u, &be, &bbits); |
|
3648 #ifdef Sudden_Underflow |
|
3649 i = (int)(word0(&u) >> Exp_shift1 & (Exp_mask>>Exp_shift1)); |
|
3650 #else |
|
3651 if ((i = (int)(word0(&u) >> Exp_shift1 & (Exp_mask>>Exp_shift1)))) { |
|
3652 #endif |
|
3653 dval(&d2) = dval(&u); |
|
3654 word0(&d2) &= Frac_mask1; |
|
3655 word0(&d2) |= Exp_11; |
|
3656 #ifdef IBM |
|
3657 if (j = 11 - hi0bits(word0(&d2) & Frac_mask)) |
|
3658 dval(&d2) /= 1 << j; |
|
3659 #endif |
|
3660 |
|
3661 /* log(x) ~=~ log(1.5) + (x-1.5)/1.5 |
|
3662 * log10(x) = log(x) / log(10) |
|
3663 * ~=~ log(1.5)/log(10) + (x-1.5)/(1.5*log(10)) |
|
3664 * log10(d) = (i-Bias)*log(2)/log(10) + log10(d2) |
|
3665 * |
|
3666 * This suggests computing an approximation k to log10(d) by |
|
3667 * |
|
3668 * k = (i - Bias)*0.301029995663981 |
|
3669 * + ( (d2-1.5)*0.289529654602168 + 0.176091259055681 ); |
|
3670 * |
|
3671 * We want k to be too large rather than too small. |
|
3672 * The error in the first-order Taylor series approximation |
|
3673 * is in our favor, so we just round up the constant enough |
|
3674 * to compensate for any error in the multiplication of |
|
3675 * (i - Bias) by 0.301029995663981; since |i - Bias| <= 1077, |
|
3676 * and 1077 * 0.30103 * 2^-52 ~=~ 7.2e-14, |
|
3677 * adding 1e-13 to the constant term more than suffices. |
|
3678 * Hence we adjust the constant term to 0.1760912590558. |
|
3679 * (We could get a more accurate k by invoking log10, |
|
3680 * but this is probably not worthwhile.) |
|
3681 */ |
|
3682 |
|
3683 i -= Bias; |
|
3684 #ifdef IBM |
|
3685 i <<= 2; |
|
3686 i += j; |
|
3687 #endif |
|
3688 #ifndef Sudden_Underflow |
|
3689 denorm = 0; |
|
3690 } |
|
3691 else { |
|
3692 /* d is denormalized */ |
|
3693 |
|
3694 i = bbits + be + (Bias + (P-1) - 1); |
|
3695 x = i > 32 ? word0(&u) << (64 - i) | word1(&u) >> (i - 32) |
|
3696 : word1(&u) << (32 - i); |
|
3697 dval(&d2) = x; |
|
3698 word0(&d2) -= 31*Exp_msk1; /* adjust exponent */ |
|
3699 i -= (Bias + (P-1) - 1) + 1; |
|
3700 denorm = 1; |
|
3701 } |
|
3702 #endif |
|
3703 ds = (dval(&d2)-1.5)*0.289529654602168 + 0.1760912590558 + i*0.301029995663981; |
|
3704 k = (int)ds; |
|
3705 if (ds < 0. && ds != k) |
|
3706 k--; /* want k = floor(ds) */ |
|
3707 k_check = 1; |
|
3708 if (k >= 0 && k <= Ten_pmax) { |
|
3709 if (dval(&u) < tens[k]) |
|
3710 k--; |
|
3711 k_check = 0; |
|
3712 } |
|
3713 j = bbits - i - 1; |
|
3714 if (j >= 0) { |
|
3715 b2 = 0; |
|
3716 s2 = j; |
|
3717 } |
|
3718 else { |
|
3719 b2 = -j; |
|
3720 s2 = 0; |
|
3721 } |
|
3722 if (k >= 0) { |
|
3723 b5 = 0; |
|
3724 s5 = k; |
|
3725 s2 += k; |
|
3726 } |
|
3727 else { |
|
3728 b2 -= k; |
|
3729 b5 = -k; |
|
3730 s5 = 0; |
|
3731 } |
|
3732 if (mode < 0 || mode > 9) |
|
3733 mode = 0; |
|
3734 |
|
3735 #ifndef SET_INEXACT |
|
3736 #ifdef Check_FLT_ROUNDS |
|
3737 try_quick = Rounding == 1; |
|
3738 #else |
|
3739 try_quick = 1; |
|
3740 #endif |
|
3741 #endif /*SET_INEXACT*/ |
|
3742 |
|
3743 if (mode > 5) { |
|
3744 mode -= 4; |
|
3745 try_quick = 0; |
|
3746 } |
|
3747 leftright = 1; |
|
3748 ilim = ilim1 = -1; /* Values for cases 0 and 1; done here to */ |
|
3749 /* silence erroneous "gcc -Wall" warning. */ |
|
3750 switch(mode) { |
|
3751 case 0: |
|
3752 case 1: |
|
3753 i = 18; |
|
3754 ndigits = 0; |
|
3755 break; |
|
3756 case 2: |
|
3757 leftright = 0; |
|
3758 /* no break */ |
|
3759 case 4: |
|
3760 if (ndigits <= 0) |
|
3761 ndigits = 1; |
|
3762 ilim = ilim1 = i = ndigits; |
|
3763 break; |
|
3764 case 3: |
|
3765 leftright = 0; |
|
3766 /* no break */ |
|
3767 case 5: |
|
3768 i = ndigits + k + 1; |
|
3769 ilim = i; |
|
3770 ilim1 = i - 1; |
|
3771 if (i <= 0) |
|
3772 i = 1; |
|
3773 } |
|
3774 s = s0 = rv_alloc(i); |
|
3775 |
|
3776 #ifdef Honor_FLT_ROUNDS |
|
3777 if (mode > 1 && Rounding != 1) |
|
3778 leftright = 0; |
|
3779 #endif |
|
3780 |
|
3781 if (ilim >= 0 && ilim <= Quick_max && try_quick) { |
|
3782 |
|
3783 /* Try to get by with floating-point arithmetic. */ |
|
3784 |
|
3785 i = 0; |
|
3786 dval(&d2) = dval(&u); |
|
3787 k0 = k; |
|
3788 ilim0 = ilim; |
|
3789 ieps = 2; /* conservative */ |
|
3790 if (k > 0) { |
|
3791 ds = tens[k&0xf]; |
|
3792 j = k >> 4; |
|
3793 if (j & Bletch) { |
|
3794 /* prevent overflows */ |
|
3795 j &= Bletch - 1; |
|
3796 dval(&u) /= bigtens[n_bigtens-1]; |
|
3797 ieps++; |
|
3798 } |
|
3799 for(; j; j >>= 1, i++) |
|
3800 if (j & 1) { |
|
3801 ieps++; |
|
3802 ds *= bigtens[i]; |
|
3803 } |
|
3804 dval(&u) /= ds; |
|
3805 } |
|
3806 else if ((j1 = -k)) { |
|
3807 dval(&u) *= tens[j1 & 0xf]; |
|
3808 for(j = j1 >> 4; j; j >>= 1, i++) |
|
3809 if (j & 1) { |
|
3810 ieps++; |
|
3811 dval(&u) *= bigtens[i]; |
|
3812 } |
|
3813 } |
|
3814 if (k_check && dval(&u) < 1. && ilim > 0) { |
|
3815 if (ilim1 <= 0) |
|
3816 goto fast_failed; |
|
3817 ilim = ilim1; |
|
3818 k--; |
|
3819 dval(&u) *= 10.; |
|
3820 ieps++; |
|
3821 } |
|
3822 dval(&eps) = ieps*dval(&u) + 7.; |
|
3823 word0(&eps) -= (P-1)*Exp_msk1; |
|
3824 if (ilim == 0) { |
|
3825 S = mhi = 0; |
|
3826 dval(&u) -= 5.; |
|
3827 if (dval(&u) > dval(&eps)) |
|
3828 goto one_digit; |
|
3829 if (dval(&u) < -dval(&eps)) |
|
3830 goto no_digits; |
|
3831 goto fast_failed; |
|
3832 } |
|
3833 #ifndef No_leftright |
|
3834 if (leftright) { |
|
3835 /* Use Steele & White method of only |
|
3836 * generating digits needed. |
|
3837 */ |
|
3838 dval(&eps) = 0.5/tens[ilim-1] - dval(&eps); |
|
3839 for(i = 0;;) { |
|
3840 L = dval(&u); |
|
3841 dval(&u) -= L; |
|
3842 *s++ = '0' + (int)L; |
|
3843 if (dval(&u) < dval(&eps)) |
|
3844 goto ret1; |
|
3845 if (1. - dval(&u) < dval(&eps)) |
|
3846 goto bump_up; |
|
3847 if (++i >= ilim) |
|
3848 break; |
|
3849 dval(&eps) *= 10.; |
|
3850 dval(&u) *= 10.; |
|
3851 } |
|
3852 } |
|
3853 else { |
|
3854 #endif |
|
3855 /* Generate ilim digits, then fix them up. */ |
|
3856 dval(&eps) *= tens[ilim-1]; |
|
3857 for(i = 1;; i++, dval(&u) *= 10.) { |
|
3858 L = (Long)(dval(&u)); |
|
3859 if (!(dval(&u) -= L)) |
|
3860 ilim = i; |
|
3861 *s++ = '0' + (int)L; |
|
3862 if (i == ilim) { |
|
3863 if (dval(&u) > 0.5 + dval(&eps)) |
|
3864 goto bump_up; |
|
3865 else if (dval(&u) < 0.5 - dval(&eps)) { |
|
3866 while(*--s == '0') {} |
|
3867 s++; |
|
3868 goto ret1; |
|
3869 } |
|
3870 break; |
|
3871 } |
|
3872 } |
|
3873 #ifndef No_leftright |
|
3874 } |
|
3875 #endif |
|
3876 fast_failed: |
|
3877 s = s0; |
|
3878 dval(&u) = dval(&d2); |
|
3879 k = k0; |
|
3880 ilim = ilim0; |
|
3881 } |
|
3882 |
|
3883 /* Do we have a "small" integer? */ |
|
3884 |
|
3885 if (be >= 0 && k <= Int_max) { |
|
3886 /* Yes. */ |
|
3887 ds = tens[k]; |
|
3888 if (ndigits < 0 && ilim <= 0) { |
|
3889 S = mhi = 0; |
|
3890 if (ilim < 0 || dval(&u) <= 5*ds) |
|
3891 goto no_digits; |
|
3892 goto one_digit; |
|
3893 } |
|
3894 for(i = 1; i <= k + 1; i++, dval(&u) *= 10.) { |
|
3895 L = (Long)(dval(&u) / ds); |
|
3896 dval(&u) -= L*ds; |
|
3897 #ifdef Check_FLT_ROUNDS |
|
3898 /* If FLT_ROUNDS == 2, L will usually be high by 1 */ |
|
3899 if (dval(&u) < 0) { |
|
3900 L--; |
|
3901 dval(&u) += ds; |
|
3902 } |
|
3903 #endif |
|
3904 *s++ = '0' + (int)L; |
|
3905 if (!dval(&u)) { |
|
3906 #ifdef SET_INEXACT |
|
3907 inexact = 0; |
|
3908 #endif |
|
3909 break; |
|
3910 } |
|
3911 if (i == ilim) { |
|
3912 #ifdef Honor_FLT_ROUNDS |
|
3913 if (mode > 1) |
|
3914 switch(Rounding) { |
|
3915 case 0: goto ret1; |
|
3916 case 2: goto bump_up; |
|
3917 } |
|
3918 #endif |
|
3919 dval(&u) += dval(&u); |
|
3920 if (dval(&u) > ds || (dval(&u) == ds && L & 1)) { |
|
3921 bump_up: |
|
3922 while(*--s == '9') |
|
3923 if (s == s0) { |
|
3924 k++; |
|
3925 *s = '0'; |
|
3926 break; |
|
3927 } |
|
3928 ++*s++; |
|
3929 } |
|
3930 break; |
|
3931 } |
|
3932 } |
|
3933 goto ret1; |
|
3934 } |
|
3935 |
|
3936 m2 = b2; |
|
3937 m5 = b5; |
|
3938 mhi = mlo = 0; |
|
3939 if (leftright) { |
|
3940 i = |
|
3941 #ifndef Sudden_Underflow |
|
3942 denorm ? be + (Bias + (P-1) - 1 + 1) : |
|
3943 #endif |
|
3944 #ifdef IBM |
|
3945 1 + 4*P - 3 - bbits + ((bbits + be - 1) & 3); |
|
3946 #else |
|
3947 1 + P - bbits; |
|
3948 #endif |
|
3949 b2 += i; |
|
3950 s2 += i; |
|
3951 mhi = i2b(1); |
|
3952 } |
|
3953 if (m2 > 0 && s2 > 0) { |
|
3954 i = m2 < s2 ? m2 : s2; |
|
3955 b2 -= i; |
|
3956 m2 -= i; |
|
3957 s2 -= i; |
|
3958 } |
|
3959 if (b5 > 0) { |
|
3960 if (leftright) { |
|
3961 if (m5 > 0) { |
|
3962 mhi = pow5mult(mhi, m5); |
|
3963 b1 = mult(mhi, b); |
|
3964 Bfree(b); |
|
3965 b = b1; |
|
3966 } |
|
3967 if ((j = b5 - m5)) |
|
3968 b = pow5mult(b, j); |
|
3969 } |
|
3970 else |
|
3971 b = pow5mult(b, b5); |
|
3972 } |
|
3973 S = i2b(1); |
|
3974 if (s5 > 0) |
|
3975 S = pow5mult(S, s5); |
|
3976 |
|
3977 /* Check for special case that d is a normalized power of 2. */ |
|
3978 |
|
3979 spec_case = 0; |
|
3980 if ((mode < 2 || leftright) |
|
3981 #ifdef Honor_FLT_ROUNDS |
|
3982 && Rounding == 1 |
|
3983 #endif |
|
3984 ) { |
|
3985 if (!word1(&u) && !(word0(&u) & Bndry_mask) |
|
3986 #ifndef Sudden_Underflow |
|
3987 && word0(&u) & (Exp_mask & ~Exp_msk1) |
|
3988 #endif |
|
3989 ) { |
|
3990 /* The special case */ |
|
3991 b2 += Log2P; |
|
3992 s2 += Log2P; |
|
3993 spec_case = 1; |
|
3994 } |
|
3995 } |
|
3996 |
|
3997 /* Arrange for convenient computation of quotients: |
|
3998 * shift left if necessary so divisor has 4 leading 0 bits. |
|
3999 * |
|
4000 * Perhaps we should just compute leading 28 bits of S once |
|
4001 * and for all and pass them and a shift to quorem, so it |
|
4002 * can do shifts and ors to compute the numerator for q. |
|
4003 */ |
|
4004 #ifdef Pack_32 |
|
4005 if ((i = ((s5 ? 32 - hi0bits(S->x[S->wds-1]) : 1) + s2) & 0x1f)) |
|
4006 i = 32 - i; |
|
4007 #define iInc 28 |
|
4008 #else |
|
4009 if (i = ((s5 ? 32 - hi0bits(S->x[S->wds-1]) : 1) + s2) & 0xf) |
|
4010 i = 16 - i; |
|
4011 #define iInc 12 |
|
4012 #endif |
|
4013 i = dshift(S, s2); |
|
4014 b2 += i; |
|
4015 m2 += i; |
|
4016 s2 += i; |
|
4017 if (b2 > 0) |
|
4018 b = lshift(b, b2); |
|
4019 if (s2 > 0) |
|
4020 S = lshift(S, s2); |
|
4021 if (k_check) { |
|
4022 if (cmp(b,S) < 0) { |
|
4023 k--; |
|
4024 b = multadd(b, 10, 0); /* we botched the k estimate */ |
|
4025 if (leftright) |
|
4026 mhi = multadd(mhi, 10, 0); |
|
4027 ilim = ilim1; |
|
4028 } |
|
4029 } |
|
4030 if (ilim <= 0 && (mode == 3 || mode == 5)) { |
|
4031 if (ilim < 0 || cmp(b,S = multadd(S,5,0)) <= 0) { |
|
4032 /* no digits, fcvt style */ |
|
4033 no_digits: |
|
4034 k = -1 - ndigits; |
|
4035 goto ret; |
|
4036 } |
|
4037 one_digit: |
|
4038 *s++ = '1'; |
|
4039 k++; |
|
4040 goto ret; |
|
4041 } |
|
4042 if (leftright) { |
|
4043 if (m2 > 0) |
|
4044 mhi = lshift(mhi, m2); |
|
4045 |
|
4046 /* Compute mlo -- check for special case |
|
4047 * that d is a normalized power of 2. |
|
4048 */ |
|
4049 |
|
4050 mlo = mhi; |
|
4051 if (spec_case) { |
|
4052 mhi = Balloc(mhi->k); |
|
4053 Bcopy(mhi, mlo); |
|
4054 mhi = lshift(mhi, Log2P); |
|
4055 } |
|
4056 |
|
4057 for(i = 1;;i++) { |
|
4058 dig = quorem(b,S) + '0'; |
|
4059 /* Do we yet have the shortest decimal string |
|
4060 * that will round to d? |
|
4061 */ |
|
4062 j = cmp(b, mlo); |
|
4063 delta = diff(S, mhi); |
|
4064 j1 = delta->sign ? 1 : cmp(b, delta); |
|
4065 Bfree(delta); |
|
4066 #ifndef ROUND_BIASED |
|
4067 if (j1 == 0 && mode != 1 && !(word1(&u) & 1) |
|
4068 #ifdef Honor_FLT_ROUNDS |
|
4069 && Rounding >= 1 |
|
4070 #endif |
|
4071 ) { |
|
4072 if (dig == '9') |
|
4073 goto round_9_up; |
|
4074 if (j > 0) |
|
4075 dig++; |
|
4076 #ifdef SET_INEXACT |
|
4077 else if (!b->x[0] && b->wds <= 1) |
|
4078 inexact = 0; |
|
4079 #endif |
|
4080 *s++ = dig; |
|
4081 goto ret; |
|
4082 } |
|
4083 #endif |
|
4084 if (j < 0 || (j == 0 && mode != 1 |
|
4085 #ifndef ROUND_BIASED |
|
4086 && !(word1(&u) & 1) |
|
4087 #endif |
|
4088 )) { |
|
4089 if (!b->x[0] && b->wds <= 1) { |
|
4090 #ifdef SET_INEXACT |
|
4091 inexact = 0; |
|
4092 #endif |
|
4093 goto accept_dig; |
|
4094 } |
|
4095 #ifdef Honor_FLT_ROUNDS |
|
4096 if (mode > 1) |
|
4097 switch(Rounding) { |
|
4098 case 0: goto accept_dig; |
|
4099 case 2: goto keep_dig; |
|
4100 } |
|
4101 #endif /*Honor_FLT_ROUNDS*/ |
|
4102 if (j1 > 0) { |
|
4103 b = lshift(b, 1); |
|
4104 j1 = cmp(b, S); |
|
4105 if ((j1 > 0 || (j1 == 0 && dig & 1)) |
|
4106 && dig++ == '9') |
|
4107 goto round_9_up; |
|
4108 } |
|
4109 accept_dig: |
|
4110 *s++ = dig; |
|
4111 goto ret; |
|
4112 } |
|
4113 if (j1 > 0) { |
|
4114 #ifdef Honor_FLT_ROUNDS |
|
4115 if (!Rounding) |
|
4116 goto accept_dig; |
|
4117 #endif |
|
4118 if (dig == '9') { /* possible if i == 1 */ |
|
4119 round_9_up: |
|
4120 *s++ = '9'; |
|
4121 goto roundoff; |
|
4122 } |
|
4123 *s++ = dig + 1; |
|
4124 goto ret; |
|
4125 } |
|
4126 #ifdef Honor_FLT_ROUNDS |
|
4127 keep_dig: |
|
4128 #endif |
|
4129 *s++ = dig; |
|
4130 if (i == ilim) |
|
4131 break; |
|
4132 b = multadd(b, 10, 0); |
|
4133 if (mlo == mhi) |
|
4134 mlo = mhi = multadd(mhi, 10, 0); |
|
4135 else { |
|
4136 mlo = multadd(mlo, 10, 0); |
|
4137 mhi = multadd(mhi, 10, 0); |
|
4138 } |
|
4139 } |
|
4140 } |
|
4141 else |
|
4142 for(i = 1;; i++) { |
|
4143 *s++ = dig = quorem(b,S) + '0'; |
|
4144 if (!b->x[0] && b->wds <= 1) { |
|
4145 #ifdef SET_INEXACT |
|
4146 inexact = 0; |
|
4147 #endif |
|
4148 goto ret; |
|
4149 } |
|
4150 if (i >= ilim) |
|
4151 break; |
|
4152 b = multadd(b, 10, 0); |
|
4153 } |
|
4154 |
|
4155 /* Round off last digit */ |
|
4156 |
|
4157 #ifdef Honor_FLT_ROUNDS |
|
4158 switch(Rounding) { |
|
4159 case 0: goto trimzeros; |
|
4160 case 2: goto roundoff; |
|
4161 } |
|
4162 #endif |
|
4163 b = lshift(b, 1); |
|
4164 j = cmp(b, S); |
|
4165 if (j > 0 || (j == 0 && dig & 1)) { |
|
4166 roundoff: |
|
4167 while(*--s == '9') |
|
4168 if (s == s0) { |
|
4169 k++; |
|
4170 *s++ = '1'; |
|
4171 goto ret; |
|
4172 } |
|
4173 ++*s++; |
|
4174 } |
|
4175 else { |
|
4176 #ifdef Honor_FLT_ROUNDS |
|
4177 trimzeros: |
|
4178 #endif |
|
4179 while(*--s == '0') {} |
|
4180 s++; |
|
4181 } |
|
4182 ret: |
|
4183 Bfree(S); |
|
4184 if (mhi) { |
|
4185 if (mlo && mlo != mhi) |
|
4186 Bfree(mlo); |
|
4187 Bfree(mhi); |
|
4188 } |
|
4189 ret1: |
|
4190 #ifdef SET_INEXACT |
|
4191 if (inexact) { |
|
4192 if (!oldinexact) { |
|
4193 word0(&u) = Exp_1 + (70 << Exp_shift); |
|
4194 word1(&u) = 0; |
|
4195 dval(&u) += 1.; |
|
4196 } |
|
4197 } |
|
4198 else if (!oldinexact) |
|
4199 clear_inexact(); |
|
4200 #endif |
|
4201 Bfree(b); |
|
4202 *s = 0; |
|
4203 *decpt = k + 1; |
|
4204 if (rve) |
|
4205 *rve = s; |
|
4206 return s0; |
|
4207 } |
|
4208 |
|
4209 } // namespace dmg_fp |