diff options
| author | Diego Novillo <dnovillo@redhat.com> | 2005-10-01 14:01:10 +0000 |
|---|---|---|
| committer | Diego Novillo <dnovillo@redhat.com> | 2005-10-01 14:01:10 +0000 |
| commit | 4918f499a48a7ffd13050622abf95e4e0b3b3b0e (patch) | |
| tree | 56d54960a5f3cb32009d25c70337006d490d27a7 /gcc/tree-vrp.c | |
| parent | 7e7700ca7cbcf77ab268f469be6797c43a5cf4da (diff) | |
* tree-vrp.c (value_inside_range, range_includes_zero_p): Add
FIXME note regarding quirky semantics.
git-svn-id: https://gcc.gnu.org/svn/gcc/trunk@104860 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/tree-vrp.c')
| -rw-r--r-- | gcc/tree-vrp.c | 24 |
1 files changed, 22 insertions, 2 deletions
diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c index 0e5ea09b5d5..de7a931cb15 100644 --- a/gcc/tree-vrp.c +++ b/gcc/tree-vrp.c @@ -564,7 +564,23 @@ compare_values (tree val1, tree val2) /* Return 1 if VAL is inside value range VR (VR->MIN <= VAL <= VR->MAX), 0 if VAL is not inside VR, - -2 if we cannot tell either way. */ + -2 if we cannot tell either way. + + FIXME, the current semantics of this functions are a bit quirky + when taken in the context of VRP. In here we do not care + about VR's type. If VR is the anti-range ~[3, 5] the call + value_inside_range (4, VR) will return 1. + + This is counter-intuitive in a strict sense, but the callers + currently expect this. They are calling the function + merely to determine whether VR->MIN <= VAL <= VR->MAX. The + callers are applying the VR_RANGE/VR_ANTI_RANGE semantics + themselves. + + This also applies to value_ranges_intersect_p and + range_includes_zero_p. The semantics of VR_RANGE and + VR_ANTI_RANGE should be encoded here, but that also means + adapting the users of these functions to the new semantics. */ static inline int value_inside_range (tree val, value_range_t *vr) @@ -596,7 +612,11 @@ value_ranges_intersect_p (value_range_t *vr0, value_range_t *vr1) } -/* Return true if VR includes the value zero, false otherwise. */ +/* Return true if VR includes the value zero, false otherwise. FIXME, + currently this will return false for an anti-range like ~[-4, 3]. + This will be wrong when the semantics of value_inside_range are + modified (currently the users of this function expect these + semantics). */ static inline bool range_includes_zero_p (value_range_t *vr) |