On 09/15/2006 04:32 PM, Ross Ridge wrote:
Also, I don't think it's safe if you merge only functions in COMDAT
sections.
Consider:
#include <assert.h>
template <class T> T foo(T a) { return a; }
template <class T> T bar(T a) { return a; }
int
main() {
assert((int (*)(int)) foo<int> != (int (*)(int)) bar<int>);
}
Both foo<int> and bar<int> get put in their own COMDAT section and their
RTL and assembly are the same, but it's not safe to merge them.
Merge can be safely done like this:
If both functions A and B are not inlined functions, and they have single
entry points, and memcmp of their asm code is zero, and the code is large
enough, then the asm code of the functions B is replaced by "jmp A" instruction.
Regards,
Roman
