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This file is an update to the "robert_2.c" file located here: https://github.com/regehr/str2long_contest This is a contest for parsing integers with no integer overflows. The performance tests use mostly invalid input, which skews the performance results. My "robert_2.c" code is half as fast as the fastest "yang_2.c" code. That's because Yang in…
#include "str2long.h"
long str2long_robert_3(const char *str)
{
long result = 0;
int i;
if (str[0] == '-') {
if (str[1] == '\0')
error = 1;
for (i=1; str[i]=='0'; i++)
;
for (; str[i]; i++) {
int c = str[i];
if (c < '0' || '9' < c) {
error = 1;
return 0;
} else if (result < LONG_MIN/10) {
error = 1;
return 0;
} else if (result * 10 < (LONG_MIN + (c - '0'))) {
error = 1;
return 0;
} else
result = result * 10 - (c - '0');
}
} else {
if (str[0] == '\0')
error = 1;
for (i=0; str[i]=='0'; i++)
;
for (; str[i]; i++) {
int c = str[i];
if (c < '0' || '9' < c) {
error = 1;
return 0;
} else if (result > LONG_MAX/10) {
error = 1;
return 0;
} else if (result * 10 > (LONG_MAX - (c - '0'))) {
error = 1;
return 0;
} else
result = result * 10 + (c - '0');
}
}
return result;
}
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