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authorRichard Biener <rguenther@suse.de>2018-08-20 14:01:05 +0000
committerRichard Biener <rguenth@gcc.gnu.org>2018-08-20 14:01:05 +0000
commit4864297f7858617a5fe406d3651a46446b41db7a (patch)
treede3c91f061f06808d33eae5fc49ebd56fd9fc3a6 /gcc/tree-vrp.c
parenta2c5e1ae5988cef25799a569f3255ac14c8ba41a (diff)
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re PR c++/78655 (gcc doesn't exploit the fact that the result of pointer addition can not be nullptr)
2018-08-20 Richard Biener <rguenther@suse.de> PR tree-optimization/78655 * tree-vrp.c (extract_range_from_binary_expr_1): Make pointer + offset nonnull if either operand is nonnull work. * gcc.dg/tree-ssa/evrp11.c: New testcase. From-SVN: r263662
Diffstat (limited to 'gcc/tree-vrp.c')
-rw-r--r--gcc/tree-vrp.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index d553a25..2ddb0c2 100644
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -1437,6 +1437,7 @@ extract_range_from_binary_expr_1 (value_range *vr,
&& code != PLUS_EXPR
&& code != MINUS_EXPR
&& code != RSHIFT_EXPR
+ && code != POINTER_PLUS_EXPR
&& (vr0.type == VR_VARYING
|| vr1.type == VR_VARYING
|| vr0.type != vr1.type
@@ -1467,7 +1468,11 @@ extract_range_from_binary_expr_1 (value_range *vr,
{
/* For pointer types, we are really only interested in asserting
whether the expression evaluates to non-NULL. */
- if (range_is_nonnull (&vr0) || range_is_nonnull (&vr1))
+ if (range_is_nonnull (&vr0)
+ || range_is_nonnull (&vr1)
+ || (vr1.type == VR_RANGE
+ && !symbolic_range_p (&vr1)
+ && !range_includes_zero_p (vr1.min, vr1.max)))
set_value_range_to_nonnull (vr, expr_type);
else if (range_is_null (&vr0) && range_is_null (&vr1))
set_value_range_to_null (vr, expr_type);