Hi!
Since Richard's build_int_cst changes to make it effectively
build_int_cst_type when extract_range_from_assert wants to subtract
or add 1 to min or max of a signed 1-bit precision type,
build_int_cst (..., 1) returns actually -1 constant and that overflows
on the fold_build2, leading to ICEs later on.
This patch in that case adds resp. subtracts -1 instead of subtracting
resp. adding 1.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2011-11-24 Jakub Jelinek <ja...@redhat.com>
PR tree-optimization/51247
* tree-vrp.c (extract_range_from_assert): For signed 1-bit precision
types instead of adding 1 subtract -1 and instead of subtracting 1
add -1 to avoid overflows.
* gcc.c-torture/compile/pr51247.c: New test.
--- gcc/tree-vrp.c.jj 2011-10-17 22:27:42.000000000 +0200
+++ gcc/tree-vrp.c 2011-11-24 11:23:23.032335859 +0100
@@ -1693,8 +1693,13 @@ extract_range_from_assert (value_range_t
/* For LT_EXPR, we create the range [MIN, MAX - 1]. */
if (cond_code == LT_EXPR)
{
- tree one = build_int_cst (TREE_TYPE (max), 1);
- max = fold_build2 (MINUS_EXPR, TREE_TYPE (max), max, one);
+ if (TYPE_PRECISION (TREE_TYPE (max)) == 1
+ && !TYPE_UNSIGNED (TREE_TYPE (max)))
+ max = fold_build2 (PLUS_EXPR, TREE_TYPE (max), max,
+ build_int_cst (TREE_TYPE (max), -1));
+ else
+ max = fold_build2 (MINUS_EXPR, TREE_TYPE (max), max,
+ build_int_cst (TREE_TYPE (max), 1));
if (EXPR_P (max))
TREE_NO_WARNING (max) = 1;
}
@@ -1728,8 +1733,13 @@ extract_range_from_assert (value_range_t
/* For GT_EXPR, we create the range [MIN + 1, MAX]. */
if (cond_code == GT_EXPR)
{
- tree one = build_int_cst (TREE_TYPE (min), 1);
- min = fold_build2 (PLUS_EXPR, TREE_TYPE (min), min, one);
+ if (TYPE_PRECISION (TREE_TYPE (min)) == 1
+ && !TYPE_UNSIGNED (TREE_TYPE (min)))
+ min = fold_build2 (MINUS_EXPR, TREE_TYPE (min), min,
+ build_int_cst (TREE_TYPE (min), -1));
+ else
+ min = fold_build2 (PLUS_EXPR, TREE_TYPE (min), min,
+ build_int_cst (TREE_TYPE (min), 1));
if (EXPR_P (min))
TREE_NO_WARNING (min) = 1;
}
@@ -1915,9 +1925,19 @@ extract_range_from_assert (value_range_t
min = positive_overflow_infinity (TREE_TYPE (var_vr->min));
}
else if (!POINTER_TYPE_P (TREE_TYPE (var_vr->min)))
- min = fold_build2 (PLUS_EXPR, TREE_TYPE (var_vr->min),
- anti_max,
- build_int_cst (TREE_TYPE (var_vr->min), 1));
+ {
+ if (TYPE_PRECISION (TREE_TYPE (var_vr->min)) == 1
+ && !TYPE_UNSIGNED (TREE_TYPE (var_vr->min)))
+ min = fold_build2 (MINUS_EXPR, TREE_TYPE (var_vr->min),
+ anti_max,
+ build_int_cst (TREE_TYPE (var_vr->min),
+ -1));
+ else
+ min = fold_build2 (PLUS_EXPR, TREE_TYPE (var_vr->min),
+ anti_max,
+ build_int_cst (TREE_TYPE (var_vr->min),
+ 1));
+ }
else
min = fold_build_pointer_plus_hwi (anti_max, 1);
max = real_max;
@@ -1942,9 +1962,19 @@ extract_range_from_assert (value_range_t
max = negative_overflow_infinity (TREE_TYPE (var_vr->min));
}
else if (!POINTER_TYPE_P (TREE_TYPE (var_vr->min)))
- max = fold_build2 (MINUS_EXPR, TREE_TYPE (var_vr->min),
- anti_min,
- build_int_cst (TREE_TYPE (var_vr->min), 1));
+ {
+ if (TYPE_PRECISION (TREE_TYPE (var_vr->min)) == 1
+ && !TYPE_UNSIGNED (TREE_TYPE (var_vr->min)))
+ max = fold_build2 (PLUS_EXPR, TREE_TYPE (var_vr->min),
+ anti_min,
+ build_int_cst (TREE_TYPE (var_vr->min),
+ -1));
+ else
+ max = fold_build2 (MINUS_EXPR, TREE_TYPE (var_vr->min),
+ anti_min,
+ build_int_cst (TREE_TYPE (var_vr->min),
+ 1));
+ }
else
max = fold_build_pointer_plus_hwi (anti_min, -1);
min = real_min;
--- gcc/testsuite/gcc.c-torture/compile/pr51247.c.jj 2011-11-24
11:28:18.293592580 +0100
+++ gcc/testsuite/gcc.c-torture/compile/pr51247.c 2011-11-24
11:27:53.000000000 +0100
@@ -0,0 +1,16 @@
+/* PR tree-optimization/51247 */
+
+struct S { int s : 1; };
+int a;
+
+void
+foo (int x, int y)
+{
+ struct S s;
+ s.s = !!y;
+ while (1)
+ {
+ unsigned l = 94967295;
+ a = x || (s.s &= l);
+ }
+}
Jakub
