poly_int: bit_field_size/offset

verify_expr ensured that the size and offset in gimple BIT_FIELD_REFs
satisfied tree_fits_uhwi_p.  This patch extends that so that they can
be poly_uint64s, and adds helper routines for accessing them when the
verify_expr requirements apply.

2017-12-21  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* tree.h (bit_field_size, bit_field_offset): New functions.
	* hsa-gen.c (gen_hsa_addr): Use them.
	* tree-ssa-forwprop.c (simplify_bitfield_ref): Likewise.
	(simplify_vector_constructor): Likewise.
	* tree-ssa-sccvn.c (copy_reference_ops_from_ref): Likewise.
	* tree-cfg.c (verify_expr): Require the sizes and offsets of a
	BIT_FIELD_REF to be poly_uint64s rather than uhwis.
	* fold-const.c (fold_ternary_loc): Protect tree_to_uhwi with
	tree_fits_uhwi_p.

Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>

From-SVN: r255926

1 files changed, 18 insertions, 0 deletions

diff --git a/gcc/tree.h b/gcc/tree.h
index 5ac1f2594f0..e8a2470106e 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -4784,6 +4784,24 @@ poly_int_tree_p (const_tree t)
   return (TREE_CODE (t) == INTEGER_CST || POLY_INT_CST_P (t));
 }
 
+/* Return the bit size of BIT_FIELD_REF T, in cases where it is known
+   to be a poly_uint64.  (This is always true at the gimple level.)  */
+
+inline poly_uint64
+bit_field_size (const_tree t)
+{
+  return tree_to_poly_uint64 (TREE_OPERAND (t, 1));
+}
+
+/* Return the starting bit offset of BIT_FIELD_REF T, in cases where it is
+   known to be a poly_uint64.  (This is always true at the gimple level.)  */
+
+inline poly_uint64
+bit_field_offset (const_tree t)
+{
+  return tree_to_poly_uint64 (TREE_OPERAND (t, 2));
+}
+
 extern tree strip_float_extensions (tree);
 extern int really_constant_p (const_tree);
 extern bool ptrdiff_tree_p (const_tree, poly_int64_pod *);