https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95492
Bug ID: 95492
Summary: Avoid recursive inlining for -O2
Product: gcc
Version: 10.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: david.bolvansky at gmail dot com
Target Milestone: ---
Test case from PR90949:
int puts(const char*);
void free(void*);
void* malloc(unsigned long);
#define NULL 0
struct Node
{
struct Node* child;
};
void walk(struct Node* module, int cleanup)
{
if (module == NULL) {
return;
}
if (!cleanup) {
puts("No cleanup");
}
walk(module->child, cleanup);
if (cleanup) {
free(module);
}
}
int main()
{
struct Node* node = malloc(sizeof(struct Node));
node->child = NULL;
walk(node, 1);
}
https://godbolt.org/z/aqVApt
Since GCC 10, GCC inlines recursion with -O2/-O3. With -O3, new bigger code is
justified, but for -O2, it is quite questionable whether GCC should inline it
or not (or possibly, less agressive "inlining" for -O2)
