[mm_akmal]

Privet!
Pomogite pojalusto kto znaet algoritm etogo funksii ili mojet perepisat na paskale v assemblera!
Mne nada tochno izuchat samiy prostoy funksi pos(substr,str).
Zarane SPASSIBO za pomoch!
Pos из модуля SysUtils
kod takoy:

Код:

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procedure       _Pos{ substr : ShortString; s : ShortString ) : Integer}; asm {     ->EAX     Pointer to substr               } {       EDX     Pointer to string               } {     <-EAX     Position of substr in s or 0    }           PUSH    EBX         PUSH    ESI         PUSH    EDI           MOV     ESI,EAX { Point ESI to substr           }         MOV     EDI,EDX { Point EDI to s                }           XOR     ECX,ECX { ECX = Length(s)               }         MOV     CL,[EDI]         INC     EDI             { Point EDI to first char of s  }           PUSH    EDI             { remember s position to calculate index        }           XOR     EDX,EDX { EDX = Length(substr)          }         MOV     DL,[ESI]         INC     ESI             { Point ESI to first char of substr     }           DEC     EDX             { EDX = Length(substr) - 1              }         JS      @@fail  { < 0 ? return 0                        }         MOV     AL,[ESI]        { AL = first char of substr             }         INC     ESI             { Point ESI to 2'nd char of substr      }           SUB     ECX,EDX { #positions in s to look at    }                         { = Length(s) - Length(substr) + 1      }         JLE     @@fail @@loop:         REPNE   SCASB         JNE     @@fail         MOV     EBX,ECX { save outer loop counter               }         PUSH    ESI             { save outer loop substr pointer        }         PUSH    EDI             { save outer loop s pointer             }           MOV     ECX,EDX         REPE    CMPSB         POP     EDI             { restore outer loop s pointer  }         POP     ESI             { restore outer loop substr pointer     }         JE      @@found         MOV     ECX,EBX { restore outer loop counter    }         JMP     @@loop   @@fail:         POP     EDX             { get rid of saved s pointer    }         XOR     EAX,EAX         JMP     @@exit   @@found:         POP     EDX             { restore pointer to first char of s    }         MOV     EAX,EDI { EDI points of char after match        }         SUB     EAX,EDX { the difference is the correct index   } @@exit:         POP     EDI         POP     ESI         POP     EBX end;

Админ: Пользуемся тегами для оформления кода!