Re: optimization/9566: Inline function produces much worse code than manual inlining.

[Andrew Pinski <pinskia at physics dot uc dot edu>]

Actually it is because C++'s this is pointer, so it spills the struct 
the stack because of it.
This g3 is the same as g1. Sorry about the pervious message, I did not 
look at it too much.

struct A {
  char const* src;
  char* dest;
  void copy() { *++dest = *++src; }
};

void g1() {
  A a;
  for(int i = 0; i < 10; ++i)
    a.copy();
}
void g3() {
  A a;
  for(int i = 0; i < 10; ++i)
  {
    A *b = &a;
    *++b->dest = *++b->src;
  }
}

A way to fix if the pointer to a local variable is only used for 
load/store and not used for passing into a function or the pointer does 
not change, is to remove the pointer and change it to what the pointer 
points to (this might only be able to do on the ssa-branch).

(As a side, it is still bad also on the ssa-branch from `3.5-tree-ssa 
20030117`.)

Thanks,
Andrew Pinski