Roberto COSTA writes: > Andrew Haley wrote: > > Chris Jefferson writes: > > > > > One thing which comes up regularly in various C and C++ > > > messageboards is that statements like "f() + g()" and "a(f(), g())" > > > do not declare which order f() and g() will be executed in. > > > > > > How hard would it be to fix the order of execution in gcc/g++? > > > Could someone point me to the piece of code which must change, or > > > if it is only a very small change, the actual change required? I > > > would very much like to be able to benchmark this, as I can find no > > > previous case where someone has tried fixing the order of execution > > > to see if it actually makes any measureable difference. > > > > The easiest way is during gimplification: you'd walk over the arglist > > from left to right, calling > > > > gimplify_expr (&arg, pre_p, post_p, > > is_gimple_formal_tmp_var, fb_rvalue); > > > > on each arg. > > But would it be sufficient?
I think so. > I guess you would also have to make sure that further passes (i.e. > out-of-ssa) do not revert what you have just done. If any arg had side-effects that would be a bug. Andrew.
