diff options
Diffstat (limited to 'gcc/tree-vrp.c')
| -rw-r--r-- | gcc/tree-vrp.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c index de3eb2c..379914c 100644 --- a/gcc/tree-vrp.c +++ b/gcc/tree-vrp.c @@ -819,8 +819,19 @@ update_value_range (const_tree var, value_range_t *new_vr) || !vrp_bitmap_equal_p (old_vr->equiv, new_vr->equiv); if (is_new) - set_value_range (old_vr, new_vr->type, new_vr->min, new_vr->max, - new_vr->equiv); + { + /* Do not allow transitions up the lattice. The following + is slightly more awkward than just new_vr->type < old_vr->type + because VR_RANGE and VR_ANTI_RANGE need to be considered + the same. We may not have is_new when transitioning to + UNDEFINED or from VARYING. */ + if (new_vr->type == VR_UNDEFINED + || old_vr->type == VR_VARYING) + set_value_range_to_varying (old_vr); + else + set_value_range (old_vr, new_vr->type, new_vr->min, new_vr->max, + new_vr->equiv); + } BITMAP_FREE (new_vr->equiv); |