On Mon, Dec 4, 2017 at 6:55 AM, Jeff Law <l...@redhat.com> wrote: > > As I brought my patches for pr78496 up to the tip of the trunk I noticed > a couple testsuite regressions with -fsanitize=unreachable tests. > > The problem is VRP and EVRP analysis/optimization could exploit > __builtin_unreachable to narrow the range of an object, then use that > narrowed range to eliminate the __builtin_unreachable. That seems > fundamentally wrong if we're compiling with -fsanitize=unreachable. > > So this patch changes both to not exploit __builtin_unreachable when > -fsanitize=unreachable. > > Bootstrapped and regression tested with all three patches in this kit. > > OK for the trunk?
Jakub already fixed this in sligthly different ways. Richard. > Jeff > > * gimple-ssa-evrp-analyze.c > (evrp_range_analyzer::record_ranges_from_incoming_edge): Do not > exploit __builtin_unreachable for -fsanitize=unreachable. > * tree-vrp.c (remove_range_assertions): Similarly. > > > diff --git a/gcc/gimple-ssa-evrp-analyze.c b/gcc/gimple-ssa-evrp-analyze.c > index fb3d329..3cdf271 100644 > --- a/gcc/gimple-ssa-evrp-analyze.c > +++ b/gcc/gimple-ssa-evrp-analyze.c > @@ -193,7 +193,8 @@ evrp_range_analyzer::record_ranges_from_incoming_edge > (basic_block bb) > > /* If pred_e is really a fallthru we can record value ranges > in SSA names as well. */ > - bool is_fallthru = assert_unreachable_fallthru_edge_p (pred_e); > + bool is_fallthru = (assert_unreachable_fallthru_edge_p (pred_e) > + && (flag_sanitize & SANITIZE_UNREACHABLE) == 0); > > /* Push updated ranges only after finding all of them to avoid > ordering issues that can lead to worse ranges. */ > diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c > index a86b382..d0435a0 100644 > --- a/gcc/tree-vrp.c > +++ b/gcc/tree-vrp.c > @@ -5181,7 +5181,8 @@ remove_range_assertions (void) > is_unreachable = 0; > if (single_pred_p (bb) > && assert_unreachable_fallthru_edge_p > - (single_pred_edge (bb))) > + (single_pred_edge (bb)) > + && (flag_sanitize & SANITIZE_UNREACHABLE) == 0) > is_unreachable = 1; > } > /* Handle >
