On Mon, 1 Dec 2014, Marc Glisse wrote: > On Mon, 1 Dec 2014, Richard Biener wrote: > > > The following fixes PR64126. > > > > Bootstrapped and tested on x86_64-unknown-linux-gnu, applied. > > > > Richard. > > > > 2014-12-01 Richard Biener <rguent...@suse.de> > > > > PR middle-end/64126 > > * match.pd: Allow conversions in ~A + 1 -> -A, add -A - 1 -> ~A > > and -1 - A -> ~A. > > * fold-const.c (fold_binary_loc): Remove transforms here. > > > > Index: gcc/match.pd > > =================================================================== > > --- gcc/match.pd (revision 218144) > > +++ gcc/match.pd (working copy) > > @@ -484,8 +522,22 @@ (define_operator_list inverted_tcc_compa > > > > /* ~A + 1 -> -A */ > > (simplify > > - (plus (bit_not @0) integer_each_onep) > > - (negate @0)) > > + (plus (convert? (bit_not @0)) integer_each_onep) > > + (if (tree_nop_conversion_p (type, TREE_TYPE (@0))) > > + (negate (convert @0)))) > > + > > + /* -A - 1 -> ~A */ > > + (simplify > > + (minus (convert? (negate @0)) integer_each_onep) > > + (if (!TYPE_OVERFLOW_TRAPS (type) > > I don't understand why TYPE_OVERFLOW_TRAPS is tested for this one but not the > others.
No idea - I just copied from fold-const.c. The whole -ftrapv and now -fsanitize=overflow stuff is just very inconsistently checked. > > + && tree_nop_conversion_p (type, TREE_TYPE (@0))) > > + (bit_not (convert @0)))) > > + > > + /* -1 - A -> ~A */ > > + (simplify > > + (minus integer_all_onesp @0) > > + (if (TREE_CODE (type) != COMPLEX_TYPE) > > + (bit_not @0))) > > It should also be true for COMPLEX_TYPE where integer_all_onesp tests for > -1-i. Yeah, I have no idea why it was disabled for complex. Maybe expansion doesn't deal with ~complex properly (on some targets?). Not sure. Didn't bother to investigate as ... > (I know you are just copying from fold-const) ... I was just copying from fold-const.c ;) Richard.
