Hi!
My recent commit to tree-vrp.c on the trunk caused the following
testcase to fail, the problem is that we would insert <= 255
assertion for unsigned char expression (which doesn't say anything)
and VRP insist that such ASSERT_EXPRs aren't added.
Fixed thusly, in addition the patch cleans the code slightly,
e.g. by using double_int instead of a pair of uHWIs.
Bootstrapped/regtested on x86_64-linux and i686-linux,
ok for trunk?
2012-03-09 Jakub Jelinek <ja...@redhat.com>
PR tree-optimization/52533
* tree-vrp.c (register_edge_assert_for_2): Use double_int
type for mask, only handle shifts by non-zero in-range
shift count, for LE_EXPR and GT_EXPR if new_val is
maximum, don't add the assertion.
* gcc.c-torture/compile/pr52533.c: New test.
--- gcc/tree-vrp.c.jj 2012-03-09 10:26:26.000000000 +0100
+++ gcc/tree-vrp.c 2012-03-09 12:30:19.348501480 +0100
@@ -4470,7 +4470,8 @@ register_edge_assert_for_2 (tree name, e
gimple def_stmt = SSA_NAME_DEF_STMT (name);
tree name2 = NULL_TREE, cst2 = NULL_TREE;
tree val2 = NULL_TREE;
- unsigned HOST_WIDE_INT mask[2] = { 0, 0 };
+ double_int mask = double_int_zero;
+ unsigned int prec = TYPE_PRECISION (TREE_TYPE (val));
/* Extract CST2 from the right shift. */
if (is_gimple_assign (def_stmt)
@@ -4480,23 +4481,13 @@ register_edge_assert_for_2 (tree name, e
cst2 = gimple_assign_rhs2 (def_stmt);
if (TREE_CODE (name2) == SSA_NAME
&& host_integerp (cst2, 1)
- && (unsigned HOST_WIDE_INT) tree_low_cst (cst2, 1)
- < 2 * HOST_BITS_PER_WIDE_INT
&& INTEGRAL_TYPE_P (TREE_TYPE (name2))
+ && IN_RANGE (tree_low_cst (cst2, 1), 1, prec - 1)
+ && prec <= 2 * HOST_BITS_PER_WIDE_INT
&& live_on_edge (e, name2)
&& !has_single_use (name2))
{
- if ((unsigned HOST_WIDE_INT) tree_low_cst (cst2, 1)
- < HOST_BITS_PER_WIDE_INT)
- mask[0] = ((unsigned HOST_WIDE_INT) 1
- << tree_low_cst (cst2, 1)) - 1;
- else
- {
- mask[1] = ((unsigned HOST_WIDE_INT) 1
- << (tree_low_cst (cst2, 1)
- - HOST_BITS_PER_WIDE_INT)) - 1;
- mask[0] = -1;
- }
+ mask = double_int_mask (tree_low_cst (cst2, 1));
val2 = fold_binary (LSHIFT_EXPR, TREE_TYPE (val), val, cst2);
}
}
@@ -4515,37 +4506,40 @@ register_edge_assert_for_2 (tree name, e
{
if (!TYPE_UNSIGNED (TREE_TYPE (val)))
{
- unsigned int prec = TYPE_PRECISION (TREE_TYPE (val));
tree type = build_nonstandard_integer_type (prec, 1);
tmp = build1 (NOP_EXPR, type, name2);
val2 = fold_convert (type, val2);
}
tmp = fold_build2 (MINUS_EXPR, TREE_TYPE (tmp), tmp, val2);
- new_val = build_int_cst_wide (TREE_TYPE (tmp), mask[0], mask[1]);
+ new_val = double_int_to_tree (TREE_TYPE (tmp), mask);
new_comp_code = comp_code == EQ_EXPR ? LE_EXPR : GT_EXPR;
}
else if (comp_code == LT_EXPR || comp_code == GE_EXPR)
new_val = val2;
else
{
- new_val = build_int_cst_wide (TREE_TYPE (val2),
- mask[0], mask[1]);
- new_val = fold_binary (BIT_IOR_EXPR, TREE_TYPE (val2),
- val2, new_val);
+ mask = double_int_ior (tree_to_double_int (val2), mask);
+ if (double_int_minus_one_p (double_int_sext (mask, prec)))
+ new_val = NULL_TREE;
+ else
+ new_val = double_int_to_tree (TREE_TYPE (val2), mask);
}
- if (dump_file)
+ if (new_val)
{
- fprintf (dump_file, "Adding assert for ");
- print_generic_expr (dump_file, name2, 0);
- fprintf (dump_file, " from ");
- print_generic_expr (dump_file, tmp, 0);
- fprintf (dump_file, "\n");
- }
+ if (dump_file)
+ {
+ fprintf (dump_file, "Adding assert for ");
+ print_generic_expr (dump_file, name2, 0);
+ fprintf (dump_file, " from ");
+ print_generic_expr (dump_file, tmp, 0);
+ fprintf (dump_file, "\n");
+ }
- register_new_assert_for (name2, tmp, new_comp_code, new_val,
- NULL, e, bsi);
- retval = true;
+ register_new_assert_for (name2, tmp, new_comp_code, new_val,
+ NULL, e, bsi);
+ retval = true;
+ }
}
}
--- gcc/testsuite/gcc.c-torture/compile/pr52533.c.jj 2012-03-09
12:20:39.189877465 +0100
+++ gcc/testsuite/gcc.c-torture/compile/pr52533.c 2012-03-09
09:22:35.000000000 +0100
@@ -0,0 +1,19 @@
+/* PR tree-optimization/52533 */
+
+int
+foo (unsigned char x)
+{
+ if (x <= 9)
+ return '0' + x;
+ else if (x <= 15)
+ return 'a' + (x - 10);
+ else
+ return 0;
+}
+
+void
+bar (unsigned char x, unsigned char *y)
+{
+ y[0] = foo ((unsigned char) (x >> 4));
+ y[1] = foo ((unsigned char) (x & 0x0f));
+}
Jakub
