On Sun, Nov 11, 2018 at 9:02 AM bin.cheng <bin.ch...@linux.alibaba.com> wrote: > > Hi, > This patch fixes PR84648 by adjusting exit conditions for loop-until-wrap > cases. > It only handles simple cases in which IV.base are constants because we rely on > current niter analyzer which doesn't handle parameterized bound in wrapped > case. It could be relaxed in the future. > > Bootstrap and test on x86_64 in progress.
Please use TYPE_MIN/MAX_VALUE or wi::min/max_value consistently. Either tree_int_cst_equal (iv0->base, TYPE_MIN_VALUE (type)) or wide_int_to_tree (niter_type, wi::max_value (TYPE_PRECISION (type), TYPE_SIGN (type))). Also + iv0->base = low; + iv0->step = fold_convert (niter_type, integer_one_node); build_int_cst (niter_type, 1); + iv1->base = high; + iv1->step = integer_zero_node; build_int_cst (niter_type, 0); With the code, what happens to signed IVs? I suppose we figure out things earlier by means of undefined overflow? Apart from the above nits OK for trunk. Thanks, Richard. > Thanks, > bin > 2018-11-11 Bin Cheng <bin.ch...@linux.alibaba.com> > > PR tree-optimization/84648 > * tree-ssa-loop-niter.c (adjust_cond_for_loop_until_wrap): New. > (number_of_iterations_cond): Adjust exit cond for loop-until-wrap case > by calling adjust_cond_for_loop_until_wrap. > > 2018-11-11 Bin Cheng <bin.ch...@linux.alibaba.com> > > PR tree-optimization/84648 > * gcc.dg/tree-ssa/pr84648.c: New test.
