https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88784
--- Comment #13 from rguenther at suse dot de <rguenther at suse dot de> --- On Fri, 24 May 2019, glisse at gcc dot gnu.org wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88784 > > --- Comment #12 from Marc Glisse <glisse at gcc dot gnu.org> --- > (In reply to Qi Feng from comment #11) > > I tried 2 patterns for the following test > > > > /* 1. x > y && x != 0 --> x > y */ > > /* 2. y < x && x != 0 --> y < x */ > > /* 3. x != 0 && x > y --> x > y */ > > /* 4. x != 0 && y < x --> y < x */ > > > > _Bool f1 (unsigned x, unsigned y) > > { > > return x > y && x != 0; > > } > > > > _Bool f2 (unsigned x, unsigned y) > > { > > return y < x && x != 0; > > } > > > > _Bool f3 (unsigned x, unsigned y) > > { > > return x != 0 && x > y; > > } > > > > _Bool f4 (unsigned x, unsigned y) > > { > > return x != 0 && y < x; > > } > > > > The first one is > > > > (for and (truth_and bit_and) > > (simplify > > (and:c (gt:c@2 @0 @1) (ne @0 integer_zerop)) > > (if (INTEGRAL_TYPE_P (TREE_TYPE(@0)) && TYPE_UNSIGNED (TREE_TYPE(@0)) > > && INTEGRAL_TYPE_P (TREE_TYPE(@1)) && TYPE_UNSIGNED > > (TREE_TYPE(@1))) > > @2))) > > > > The transformations did not happen as I checked the dump files of > > -fdump-tree-{original,optimized}. > > It isn't supposed to be done in original anyway. It does work in optimized > (even forwprop1) for me. Did you forget to pass -O? Did you look at some old > dump file? > > (I think you could use ANY_INTEGRAL_TYPE_P, this seems valid for vectors) I would have expected fold to first change the TRUTH_ANDIF to a TRUTH_AND and then your pattern match. But maybe I misremember that we have such transformation for cases where the 2nd operand doesn't have side-effects. While genmatch inserts checks for and rejects operands with side-effects I still wouldn't use truth_andif here. As Marc says, expecting the transform in .original is probably premature. OTOH whether it is applicable on GIMPLE in the end might depend on LOGICAL_OP_NON_SHORT_CIRCUIT and BRANCH_COST.
