https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92282
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2019-10-30
Component|tree-optimization |middle-end
Ever confirmed|0 |1
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
This is fold-const.c split_tree/associate_trees at work.
else if (TREE_CODE (in) == BIT_NOT_EXPR
&& code == PLUS_EXPR)
{
/* -1 - X is folded to ~X, undo that here. Do _not_ do this
when IN is constant. */
*litp = build_minus_one_cst (type);
*minus_varp = TREE_OPERAND (in, 0);
In the end we want to help optimizing ~A - 1. Might be possible to reject
the specific simplification (if no constant was eliminated or the constant
got "large") in the caller of associate_trees.
