https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112346
Bug ID: 112346
Summary: Wrong code produced with -O2
Product: gcc
Version: 13.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: fchelnokov at gmail dot com
Target Milestone: ---
This program
#include <ctype.h>
char *SkipAName(char *s) {
if (('A' <= *s && *s <= 'Z') || ('a' <= *s && *s <= 'z') ) {
while (isalnum(*s)) {
s++;
}
}
return s;
}
int TestName(char *name) {
while (*name)
name++;
return 0;
}
int StrICmp(char *s1, char *s2) {
while (*s1 && *s1 == *s2) {
s1++;
s2++;
}
return *s1 - *s2;
}
int DoTable(char *s) {
char *name, c;
name = s;
s = SkipAName(s);
c = *s;
*s = 0;
TestName(name);
*s = c;
if (*s == '(')
return 3;
if (*s != ',')
return 2;
*s = 0;
return StrICmp(name, "sparse");
}
int main() {
char buf[] = "sparse,C(1)";
return DoTable(buf);
}
shall return 0, but in GCC 13 with -O2 it returns 44. Online demo:
https://gcc.godbolt.org/z/c6W33T1zK
Related discussion: https://stackoverflow.com/q/77407156/7325599
