On Fri, 9 Mar 2012, Jakub Jelinek wrote:
> 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?
Ok.
Thanks,
Richard.
> 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
>
>
--
Richard Guenther <rguent...@suse.de>
SUSE / SUSE Labs
SUSE LINUX Products GmbH - Nuernberg - AG Nuernberg - HRB 16746
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer
