On 8/4/20 8:58 AM, Richard Biener wrote:
On Tue, Aug 4, 2020 at 8:40 AM Aldy Hernandez via Gcc-patches <gcc-patches@gcc.gnu.org> wrote:gcc/ChangeLog: * vr-values.c (test_for_singularity): Use irange API. (simplify_using_ranges::simplify_cond_using_ranges_1): Do not special case VR_RANGE. --- gcc/vr-values.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/gcc/vr-values.c b/gcc/vr-values.c index 90ba8fca246..e78b25596b0 100644 --- a/gcc/vr-values.c +++ b/gcc/vr-values.c @@ -3480,10 +3480,13 @@ test_for_singularity (enum tree_code cond_code, tree op0, value range information we have for op0. */ if (min && max) { - if (compare_values (vr->min (), min) == 1) - min = vr->min (); - if (compare_values (vr->max (), max) == -1) - max = vr->max (); + tree type = TREE_TYPE (op0); + tree tmin = wide_int_to_tree (type, vr->lower_bound ()); + tree tmax = wide_int_to_tree (type, vr->upper_bound ());I guess with symbolic ranges this just doesn't work anymore (or rather will give a pessimistinc upper/lower bound)?
Yes, though we do slightly better than VARYING. The symbolic normalizing code will rewrite [SYM, 5] as [-INF, 5], etc.
When I implemented this originally in the ranger branch, I pessimistically downgraded all symbolics to [MIN,MAX] to see if there was any difference in the generated code. There wasn't.
I think most of vr-values.c does no better without symbolics, with the exception of compare_value* and the corresponding code that handles comparisons and equivalences.
Aldy
