-// digits_to_I().
-
-// General includes.
-#include "cl_sysdep.h"
-
-// Specification.
-#include "cl_I.h"
-
-
-// Implementation.
-
-#include "cl_DS.h"
-
-namespace cln {
-
-const cl_I digits_to_I (const char * MSBptr, uintL len, uintD base)
-{
- CL_ALLOCA_STACK;
- var uintD* erg_MSDptr;
- var uintC erg_len;
- var uintD* erg_LSDptr;
- // Platz fürs Ergebnis:
- // 1+ceiling(len*log(base)/(intDsize*log(2))) oder etwas mehr Digits
- var uintL need = 1+floor(len,intDsize*256); // > len/(intDsize*256) >=0
- switch (base) // need mit ceiling(256*log(base)/log(2)) multiplizieren:
- { case 2: need = 256*need; break;
- case 3: need = 406*need; break;
- case 4: need = 512*need; break;
- case 5: need = 595*need; break;
- case 6: need = 662*need; break;
- case 7: need = 719*need; break;
- case 8: need = 768*need; break;
- case 9: need = 812*need; break;
- case 10: need = 851*need; break;
- case 11: need = 886*need; break;
- case 12: need = 918*need; break;
- case 13: need = 948*need; break;
- case 14: need = 975*need; break;
- case 15: need = 1001*need; break;
- case 16: need = 1024*need; break;
- case 17: need = 1047*need; break;
- case 18: need = 1068*need; break;
- case 19: need = 1088*need; break;
- case 20: need = 1107*need; break;
- case 21: need = 1125*need; break;
- case 22: need = 1142*need; break;
- case 23: need = 1159*need; break;
- case 24: need = 1174*need; break;
- case 25: need = 1189*need; break;
- case 26: need = 1204*need; break;
- case 27: need = 1218*need; break;
- case 28: need = 1231*need; break;
- case 29: need = 1244*need; break;
- case 30: need = 1257*need; break;
- case 31: need = 1269*need; break;
- case 32: need = 1280*need; break;
- case 33: need = 1292*need; break;
- case 34: need = 1303*need; break;
- case 35: need = 1314*need; break;
- case 36: need = 1324*need; break;
- default: NOTREACHED
- }
- // Nun gilt need >= len*log(base)/(intDsize*log(2)).
- need += 1;
- num_stack_alloc(need,,erg_LSDptr=);
- erg_MSDptr = erg_LSDptr; erg_len = 0;
- // Ziffern einzeln draufaddieren:
- while (len > 0)
- { // erg_MSDptr/erg_len/erg_LSDptr ist eine NUDS, erg_len < need.
- var uintB ch = *(const uintB *)MSBptr; MSBptr++; // nächstes Character
- if (!(ch=='.')) // Punkt überlesen
- { // Wert von ch ('0'-'9','A'-'Z','a'-'z') bilden:
- ch = ch - '0';
- if (ch > '9'-'0') // keine Ziffer?
- { ch = ch+'0'-'A'+10;
- if (ch > 'Z'-'A'+10) // kein Großbuchstabe?
- { ch = ch+'A'-'a'; } // dann ein Kleinbuchstabe
- }
- // multipliziere erg mit base und addiere ch:
- {var uintD carry = mulusmall_loop_lsp(base,erg_LSDptr,erg_len,ch);
- if (!(carry==0))
- // muß NUDS vergrößern:
- { lsprefnext(erg_MSDptr) = carry; erg_len++; }
- }}
- len--;
- }
- return NUDS_to_I(erg_MSDptr,erg_len);
-}
-
-} // namespace cln
+// digits_to_I().\r
+\r
+// General includes.\r
+#include "cl_sysdep.h"\r
+\r
+// Specification.\r
+#include "cl_I.h"\r
+\r
+\r
+// Implementation.\r
+\r
+#include "cl_DS.h"\r
+\r
+namespace cln {\r
+\r
+const cl_I digits_to_I (const char * MSBptr, uintL len, uintD base)\r
+{\r
+ CL_ALLOCA_STACK;\r
+ var uintD* erg_MSDptr;\r
+ var uintC erg_len;\r
+ var uintD* erg_LSDptr;\r
+ if ((base & (base-1)) == 0) {\r
+ // Fast path for powers of two: write the digits from least\r
+ // significant to most significant into the result NUDS.\r
+ var int b = (base==2 ? 1 : base==4 ? 2 : base==8 ? 3 : base==16 ? 4 : /*base==32*/ 5);\r
+ num_stack_alloc(1+(len*b-1)/intDsize,,erg_LSDptr=);\r
+ erg_MSDptr = erg_LSDptr; erg_len = 0;\r
+ var uintD d = 0; // resulting digit\r
+ var int ch_where = 0; // position of ch inside d\r
+ while (len > 0)\r
+ { var uintB ch = *(const uintB *)(MSBptr+len-1); // next character\r
+ if (!(ch=='.')) // skip decimal point\r
+ { // Compute value of ch ('0'-'9','A'-'Z','a'-'z'):\r
+ ch = ch - '0';\r
+ if (ch > '9'-'0') // not a digit?\r
+ { ch = ch+'0'-'A'+10;\r
+ if (ch > 'Z'-'A'+10) // not an uppercase letter?\r
+ { ch = ch+'A'-'a'; } // must be lowercase!\r
+ }\r
+ d = d | (uintD)ch<<ch_where;\r
+ ch_where = ch_where+b;\r
+ if (ch_where >= intDsize) {\r
+ // d is ready to be written into the NUDS:\r
+ lsprefnext(erg_MSDptr) = d;\r
+ ch_where = ch_where-intDsize;\r
+ d = (uintD)ch >> b-ch_where; // carry\r
+ erg_len++;\r
+ }\r
+ }\r
+ len--;\r
+ }\r
+ if (d != 0) { // is there anything left over?\r
+ lsprefnext(erg_MSDptr) = d;\r
+ ++erg_len;\r
+ }\r
+ } else {\r
+ // Slow path: Add digits one by one for non-powers of two.\r
+ // Platz fürs Ergebnis:\r
+ // 1+ceiling(len*log(base)/(intDsize*log(2))) or some more digits\r
+ var uintL need = 1+floor(len,intDsize*256); // > len/(intDsize*256) >=0\r
+ switch (base) // multiply need with ceiling(256*log(base)/log(2)):\r
+ {\r
+ //case 2: need = 256*need; break;\r
+ case 3: need = 406*need; break;\r
+ //case 4: need = 512*need; break;\r
+ case 5: need = 595*need; break;\r
+ case 6: need = 662*need; break;\r
+ case 7: need = 719*need; break;\r
+ //case 8: need = 768*need; break;\r
+ case 9: need = 812*need; break;\r
+ case 10: need = 851*need; break;\r
+ case 11: need = 886*need; break;\r
+ case 12: need = 918*need; break;\r
+ case 13: need = 948*need; break;\r
+ case 14: need = 975*need; break;\r
+ case 15: need = 1001*need; break;\r
+ //case 16: need = 1024*need; break;\r
+ case 17: need = 1047*need; break;\r
+ case 18: need = 1068*need; break;\r
+ case 19: need = 1088*need; break;\r
+ case 20: need = 1107*need; break;\r
+ case 21: need = 1125*need; break;\r
+ case 22: need = 1142*need; break;\r
+ case 23: need = 1159*need; break;\r
+ case 24: need = 1174*need; break;\r
+ case 25: need = 1189*need; break;\r
+ case 26: need = 1204*need; break;\r
+ case 27: need = 1218*need; break;\r
+ case 28: need = 1231*need; break;\r
+ case 29: need = 1244*need; break;\r
+ case 30: need = 1257*need; break;\r
+ case 31: need = 1269*need; break;\r
+ //case 32: need = 1280*need; break;\r
+ case 33: need = 1292*need; break;\r
+ case 34: need = 1303*need; break;\r
+ case 35: need = 1314*need; break;\r
+ case 36: need = 1324*need; break;\r
+ default: NOTREACHED\r
+ }\r
+ // Now we have need >= len*log(base)/(intDsize*log(2)).\r
+ need += 1;\r
+ // Add digits one by one:\r
+ num_stack_alloc(need,,erg_LSDptr=);\r
+ erg_MSDptr = erg_LSDptr; erg_len = 0;\r
+ while (len > 0)\r
+ { // erg_MSDptr/erg_len/erg_LSDptr is a NUDS, erg_len < need.\r
+ var uintB ch = *(const uintB *)MSBptr; MSBptr++; // next character\r
+ if (!(ch=='.')) // skip decimal point\r
+ { // Compute value of ('0'-'9','A'-'Z','a'-'z'):\r
+ ch = ch - '0';\r
+ if (ch > '9'-'0') // not a digit?\r
+ { ch = ch+'0'-'A'+10;\r
+ if (ch > 'Z'-'A'+10) // not an uppercase letter?\r
+ { ch = ch+'A'-'a'; } // must be lowercase!\r
+ }\r
+ // multiply erg with base and add ch:\r
+ {var uintD carry = mulusmall_loop_lsp(base,erg_LSDptr,erg_len,ch);\r
+ if (!(carry==0))\r
+ // need to extend NUDS:\r
+ { lsprefnext(erg_MSDptr) = carry; erg_len++; }\r
+ }}\r
+ len--;\r
+ }\r
+ }\r
+ return NUDS_to_I(erg_MSDptr,erg_len);\r
+}\r
+\r
+} // namespace cln\r
git://www.ginac.de / cln.git / commitdiff