4 #include "cl_sysdep.h"
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16 const cl_I digits_to_I (const char * MSBptr, uintL len, uintD base)
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19 var uintD* erg_MSDptr;
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21 var uintD* erg_LSDptr;
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22 if ((base & (base-1)) == 0) {
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23 // Fast path for powers of two: write the digits from least
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24 // significant to most significant into the result NUDS.
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25 var int b = (base==2 ? 1 : base==4 ? 2 : base==8 ? 3 : base==16 ? 4 : /*base==32*/ 5);
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26 num_stack_alloc(1+(len*b)/intDsize,,erg_LSDptr=);
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27 erg_MSDptr = erg_LSDptr; erg_len = 0;
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28 var uintD d = 0; // resulting digit
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29 var int ch_where = 0; // position of ch inside d
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31 { var uintB ch = *(const uintB *)(MSBptr+len-1); // next character
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32 if (!(ch=='.')) // skip decimal point
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33 { // Compute value of ch ('0'-'9','A'-'Z','a'-'z'):
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35 if (ch > '9'-'0') // not a digit?
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36 { ch = ch+'0'-'A'+10;
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37 if (ch > 'Z'-'A'+10) // not an uppercase letter?
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38 { ch = ch+'A'-'a'; } // must be lowercase!
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40 d = d | (uintD)ch<<ch_where;
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41 ch_where = ch_where+b;
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42 if (ch_where >= intDsize) {
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43 // d is ready to be written into the NUDS:
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44 lsprefnext(erg_MSDptr) = d;
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45 ch_where = ch_where-intDsize;
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46 d = (uintD)ch >> b-ch_where; // carry
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52 if (d != 0) { // is there anything left over?
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53 lsprefnext(erg_MSDptr) = d;
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57 // Slow path: Add digits one by one for non-powers of two.
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58 // Platz fürs Ergebnis:
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59 // 1+ceiling(len*log(base)/(intDsize*log(2))) or some more digits
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60 var uintL need = 1+floor(len,intDsize*256); // > len/(intDsize*256) >=0
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61 switch (base) // multiply need with ceiling(256*log(base)/log(2)):
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63 //case 2: need = 256*need; break;
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64 case 3: need = 406*need; break;
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65 //case 4: need = 512*need; break;
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66 case 5: need = 595*need; break;
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67 case 6: need = 662*need; break;
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68 case 7: need = 719*need; break;
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69 //case 8: need = 768*need; break;
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70 case 9: need = 812*need; break;
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71 case 10: need = 851*need; break;
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72 case 11: need = 886*need; break;
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73 case 12: need = 918*need; break;
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74 case 13: need = 948*need; break;
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75 case 14: need = 975*need; break;
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76 case 15: need = 1001*need; break;
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77 //case 16: need = 1024*need; break;
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78 case 17: need = 1047*need; break;
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79 case 18: need = 1068*need; break;
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80 case 19: need = 1088*need; break;
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81 case 20: need = 1107*need; break;
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82 case 21: need = 1125*need; break;
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83 case 22: need = 1142*need; break;
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84 case 23: need = 1159*need; break;
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85 case 24: need = 1174*need; break;
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86 case 25: need = 1189*need; break;
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87 case 26: need = 1204*need; break;
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88 case 27: need = 1218*need; break;
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89 case 28: need = 1231*need; break;
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90 case 29: need = 1244*need; break;
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91 case 30: need = 1257*need; break;
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92 case 31: need = 1269*need; break;
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93 //case 32: need = 1280*need; break;
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94 case 33: need = 1292*need; break;
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95 case 34: need = 1303*need; break;
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96 case 35: need = 1314*need; break;
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97 case 36: need = 1324*need; break;
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100 // Now we have need >= len*log(base)/(intDsize*log(2)).
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102 // Add digits one by one:
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103 num_stack_alloc(need,,erg_LSDptr=);
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104 erg_MSDptr = erg_LSDptr; erg_len = 0;
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106 { // erg_MSDptr/erg_len/erg_LSDptr is a NUDS, erg_len < need.
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107 var uintB ch = *(const uintB *)MSBptr; MSBptr++; // next character
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108 if (!(ch=='.')) // skip decimal point
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109 { // Compute value of ('0'-'9','A'-'Z','a'-'z'):
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111 if (ch > '9'-'0') // not a digit?
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112 { ch = ch+'0'-'A'+10;
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113 if (ch > 'Z'-'A'+10) // not an uppercase letter?
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114 { ch = ch+'A'-'a'; } // must be lowercase!
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116 // multiply erg with base and add ch:
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117 {var uintD carry = mulusmall_loop_lsp(base,erg_LSDptr,erg_len,ch);
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119 // need to extend NUDS:
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120 { lsprefnext(erg_MSDptr) = carry; erg_len++; }
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125 return NUDS_to_I(erg_MSDptr,erg_len);
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