https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119292
Bug ID: 119292
Summary: code deduplication in case of throw (improvement)
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: federico at kircheis dot it
Target Milestone: ---
Consider following snippet
~~~~
struct myclass{
myclass(int i);
};
#ifdef THROWIT
[[noreturn]] __attribute__((noinline)) void throwit(int i){
throw myclass(i);
}
#define THROW(p) throwit(p);
#else
#define THROW(p) throw myclass(p);
#endif
void foo(){
THROW(41);
}
void bar(int j){
THROW(j);
}
~~~~
https://godbolt.org/z/ja1azahe4
When writing "throw" directly, "a lot" of code is generated in the body of bar
and foo which is identical, which in turn generate a bigger binary.
When wrapping the throw in a non-inline function, this duplication does not
happen, and since throwing is not cheap (__cxa_allocate_exception allocates),
the cost of having a non-inline function should be small.
Does GCC have any option (or chance) for avoiding to wrap all "throw" in
functions to reduce the size of the binary?
