On Thu, Nov 17, 2016 at 05:39:57PM -0800, Marek Polacek wrote:
> > Yes, there will be 119 SAVE_EXPRs, and when you -fdump-tree-original it,
> > it will be just insanely huge, but each SAVE_EXPR appears exactly twice
> > in its containing SAVE_EXPR and the second time cp_genericize_r sees
> > the SAVE_EXPR, it will do the
> > 1138 /* Other than invisiref parms, don't walk the same tree
> > twice. */
> > 1139 if (p_set->contains (stmt))
> > 1140 {
> > 1141 *walk_subtrees = 0;
> > 1142 return NULL_TREE;
> > 1143 }
> > early exit.
>
> Clearly I misread things here. I blame the cold I've caught!
>
> In any case, I'm sorry for wasting your time and I'll just close the PR.
I bet it is a compile-time hog with -fsanitize=undefined
-fdump-tree-original. So, if anything, we'd need some hack in the SAVE_EXPR
generic printing code, say track the depth of SAVE_EXPRs being printed
concurrently and if we go above a certain level of them (say 10), change
into a different mode where we print the content of SAVE_EXPR just the
first time we encounter it + e.g. the SAVE_EXPR address and then when
encountering the same SAVE_EXPR again, just print the address. When
the SAVE_EXPR nesting level shrinks below 10, clear the pointer set
of SAVE_EXPRs and resume normal behavior.
-fsanitize=undefined -fdump-tree-gimple is fast.
Jakub
