32bit 64bit - Strtol implementation different behaviour on 32 and 64 bit machine -

#include <ctype.h> #include <string.h> #include <stdio.h> #include <tgmath.h> #include <limits.h> #include <stdbool.h> #include <errno.h> #define negative -1 #define positive 1 #define octal 8 #define decimal 10 #define hexadecimal 16 #define base_min 2 #define base_max 36 long int strtol (const char * str, char ** endptr, int base) {     if(base < 0 ||  base == 1 || base > base_max)     {         errno = einval;         return 0l;     }     else     {         bool conversion = true;         int = 0, sign = positive, save;         while(isspace(*(str + i)))             i++;         if(*(str + i) == '\0')         {             conversion = false;             save = i;         }         if(*(str + i) == '-')         {             sign = negative;             i++;         }         else if(*(str + i) == '+')             i++;         if(base == 0) // find out base         {             if(*(str + i) == '0')             {                 if(toupper(*(str + + 1)) == 'x')                 {                     base = hexadecimal;                     i++;                 }                 else                     base = octal;                 i++;             }             else                 base = decimal;         }         else if(base == octal)         {             if(*(str + i) == '0')                 i++;         }         else if(base == hexadecimal)         {             if(*(str + i) == '0')                 if(*(str + + 1) == 'x' || *(str + + 1) == 'x')                     += 2;         }         int start = i, end, exp, check = i;         long int long_int, sum, multiplier;         if(conversion) // find out correct part of string corresponding number         {             if(base < decimal)             {                 while(*(str + i) >= '0' && *(str + i) < base + '0') // numbers 0 base - 1                     i++;             }             else if(base == decimal)             {                 while(*(str + i) >= '0' && *(str + i) <= '9') // numbers 0 9                     i++;             }             else             {                 while((*(str + i) >= '0' && *(str + i) <= '9') || (toupper(*(str + i)) >= 'a' && toupper(*(str + i)) < 'a' + base - 10))                         i++;// numbers 0 9 , uper , lowercase letters a + base - 11             }         }         if(i == check && conversion) //no digits @         {             conversion = false;             save = i;         }         else if(endptr != null && conversion) // assign pointer             *endptr = (char *) (str + i);         if(conversion)         {             for(end = - 1, exp = 0, long_int = 0l; end >= start; end--, exp++)             {                 multiplier = pow(base, exp);                 sum = 0l;                 if(*(str + end) >= '0' && *(str + end) <= '9')                      sum = (*(str + end) - '0') * multiplier;                 else if(*(str + end) >= 'a' && *(str + i) <= (base == base_max ? 'z' : 'f'))                      sum = (*(str + end) - 'a' + 10) * multiplier;                 else if(*(str + end) >= 'a' && *(str + i) <= (base == base_max ? 'z' : 'f'))                     sum = (*(str + end) - 'a' + 10) * multiplier;                 if(long_int <= long_min + sum)                 {                     errno = erange;                     return long_min;                 }                 if(long_int >= long_max - sum)                 {                     errno = erange;                     return long_max;                 }                 else                     long_int += sum;             }             return sign * long_int;         }         else         {             if(endptr != null)             {// if base 16 check if string given not in form 0xincorrect string in way need return xincorrect part of string                 if(base == hexadecimal && save >= 2 && toupper(*(str + save - 1)) == 'x' && *(str + save - 2) == '0')                     *endptr = (char *) str + save - 1;                 else if(base == octal && save >= 1 && *(str + save - 1) == '0')                     *endptr = (char *) str + save;// if string of base 8 , in form 0incorrect string                 else                            //then return after 0 endptr string                     *endptr = (char *) str;//in other cases no conversion done return original pointer             }             return 0l;         }     } } 

i've got problem writing implementation of strtol() function. thing compiled on 64 bit machine , output correct today checked on machine 32-bit , got wrong. 32-bit machine showed result example string "7fffffff" out of range when on 64-bits results strtol succeded same th standard function. checked errno value , 32-bit machine it's set erange shouldn't , it's not not on 64-bit. have program checks if implementation gives same output standard 1 different strings. spent few hours looking possible bug i'm out of ideas? tips?