On Thu, 3 Nov 2016, Prathamesh Kulkarni wrote: > Hi Richard, > The attached patch tries to fix PR35691, by adding the following two > transforms to match.pd: > (x == 0 && y == 0) -> (x | typeof(x)(y)) == 0. > (x != 0 || y != 0) -> (x | typeof(x)(y)) != 0. > > For GENERIC, the "and" operator is truth_andif_expr, and it seems for GIMPLE, > it gets transformed to bit_and_expr > so to match for both GENERIC and GIMPLE, I had to guard the for-stmt: > > #if GENERIC > (for op (truth_andif truth_orif) > #elif GIMPLE > (for op (bit_and bit_ior) > #endif > > Is that OK ?
As you are not removing the fold-const.c variant I'd say you should simply not look for truth_* and only handle GIMPLE. Note that we have tree-ssa-ifcombine.c which should handle the variant with control-flow (but I guess it does not and your patch wouldn't help it either). The transform would also work for vectors (element_precision for the test but also a value-matching zero which should ensure the same number of elements). Richard.
