https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96754
Bug ID: 96754
Summary: Failure to optimize strcpy+strlen to memcpy when
strlen is done after strcpy
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: gabravier at gmail dot com
Target Milestone: ---
size_t f1(char *a, const char *b)
{
strcpy(a, b);
return strlen(b);
}
size_t f2(char *a, const char *b)
{
size_t sz = strlen(b);
memcpy(a, b, sz + 1);
return sz;
}
f1 can be optimized to f2. Using this intermediary form :
size_t f(char *a, const char *b)
{
size_t tmp = strlen(b);
strcpy(a, b);
return tmp;
}
Results in the optimization being done properly, but it would be nice if it was
doable even if the `strlen` wasn't done prior to the `strcpy`.
