On Fri, Aug 19, 2016 at 7:30 PM, Patrick Palka <[email protected]> wrote:
> integer_nonzerop() currently unconditionally returns false for a
> VECTOR_CST argument. This is confusing because one would expect that
> integer_onep(x) => integer_nonzerop(x) for all x but that is currently
> not the case. For a VECTOR_CST of all ones i.e. {1,1,1,1},
> integer_onep() returns true but integer_nonzerop() returns false.
>
> This patch makes integer_nonzerop() handle VECTOR_CSTs in the obvious
> way and also adds some self tests (the last of which fails without the
> change). Does this look OK to commit afetr bootstrap + regtesting on
> x86_64-pc-linux-gnu?
Actually I guess there is some ambiguity as to whether
integer_nonzerop() should return true for a VECTOR_CST only if it has
at least one non-zero element or only if all of its elements are
non-zero...
>
> gcc/ChangeLog:
>
> * tree.c (integer_nonzerop): Rewrite to use a switch. Handle
> VECTOR_CSTs.
> (test_vector_constants): New static function.
> (tree_c_tests): Call it.
> ---
> gcc/tree.c | 43 ++++++++++++++++++++++++++++++++++++++-----
> 1 file changed, 38 insertions(+), 5 deletions(-)
>
> diff --git a/gcc/tree.c b/gcc/tree.c
> index 33e6f97..48795c7 100644
> --- a/gcc/tree.c
> +++ b/gcc/tree.c
> @@ -2439,11 +2439,24 @@ integer_pow2p (const_tree expr)
> int
> integer_nonzerop (const_tree expr)
> {
> - return ((TREE_CODE (expr) == INTEGER_CST
> - && !wi::eq_p (expr, 0))
> - || (TREE_CODE (expr) == COMPLEX_CST
> - && (integer_nonzerop (TREE_REALPART (expr))
> - || integer_nonzerop (TREE_IMAGPART (expr)))));
> + switch (TREE_CODE (expr))
> + {
> + case INTEGER_CST:
> + return !wi::eq_p (expr, 0);
> + case COMPLEX_CST:
> + return (integer_nonzerop (TREE_REALPART (expr))
> + || integer_nonzerop (TREE_IMAGPART (expr)));
> + case VECTOR_CST:
> + {
> + unsigned i;
> + for (i = 0; i < VECTOR_CST_NELTS (expr); ++i)
> + if (integer_nonzerop (VECTOR_CST_ELT (expr, i)))
> + return true;
> + return false;
> + }
> + default:
> + return false;
> + }
> }
>
> /* Return 1 if EXPR is the integer constant one. For vector,
> @@ -14230,6 +14243,25 @@ test_integer_constants ()
> ASSERT_EQ (type, TREE_TYPE (zero));
> }
>
> +/* Verify various predicates and operations on vector constants. */
> +
> +static void
> +test_vector_constants ()
> +{
> + tree inner_type = integer_type_node;
> + tree type = build_vector_type (inner_type, 8);
> + tree zero = build_zero_cst (type);
> + tree one = build_one_cst (type);
> +
> + ASSERT_TRUE (integer_zerop (zero));
> + ASSERT_FALSE (integer_onep (zero));
> + ASSERT_FALSE (integer_nonzerop (zero));
> +
> + ASSERT_FALSE (integer_zerop (one));
> + ASSERT_TRUE (integer_onep (one));
> + ASSERT_TRUE (integer_nonzerop (one));
> +}
> +
> /* Verify identifiers. */
>
> static void
> @@ -14258,6 +14290,7 @@ void
> tree_c_tests ()
> {
> test_integer_constants ();
> + test_vector_constants ();
> test_identifiers ();
> test_labels ();
> }
> --
> 2.9.3.650.g20ba99f
>
