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?
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
