This is another try at making sizetype behavior more consistent with
other integral types. In particular this series will eventually
succeed in making TYPE_UNSIGNED tell the truth for sizetypes ...
This first patch replaces a hack in the C frontend to handle
zero-sized arrays (int a[] = {}) by setting the upper bound of
the domain to integer_minus_one_node. This works by luck only
as the code later calls build_index_type which happily combines
(and converts) this with a sizetype zero lower bound. Simply
using an integer typed domain fixes this, so the patch makes
the C frontend use build_range_type instead.
Similarly the stor-layout.c code fails to properly use
signed arithmetic when it needs to. The present code presumably
already handles some cases, but not that special case of
adding one to -1.
The rest of the patch is simple stuff I noticed when going over
the code.
Bootstrapped and tested on x86_64-unknown-linux-gnu for all
languages including Ada and Objective-C++.
Are the c-family changes ok?
Thanks,
Richard.
2011-04-11 Richard Guenther <rguent...@suse.de>
* stor-layout.c (layout_type): Compute all array index size operations
in the original type.
(initialize_sizetypes): Add comment.
(set_sizetype): Do not set TREE_TYPE of a TREE_VEC.
c-family/
* c-common.c (complete_array_type): Build a range type of
proper type.
Index: trunk/gcc/stor-layout.c
===================================================================
*** trunk.orig/gcc/stor-layout.c 2011-04-06 10:51:40.000000000 +0200
--- trunk/gcc/stor-layout.c 2011-04-11 14:30:23.000000000 +0200
*************** layout_type (tree type)
*** 1996,2010 ****
if (integer_zerop (element_size))
length = size_zero_node;
! /* The initial subtraction should happen in the original type so
that (possible) negative values are handled appropriately. */
else
length
! = size_binop (PLUS_EXPR, size_one_node,
! fold_convert (sizetype,
! fold_build2 (MINUS_EXPR,
! TREE_TYPE (lb),
! ub, lb)));
TYPE_SIZE (type) = size_binop (MULT_EXPR, element_size,
fold_convert (bitsizetype,
--- 1996,2011 ----
if (integer_zerop (element_size))
length = size_zero_node;
! /* The computation should happen in the original type so
that (possible) negative values are handled appropriately. */
else
length
! = fold_convert (sizetype,
! fold_build2 (PLUS_EXPR, TREE_TYPE (lb),
! build_int_cst (TREE_TYPE (lb), 1),
! fold_build2 (MINUS_EXPR,
! TREE_TYPE (lb),
! ub, lb)));
TYPE_SIZE (type) = size_binop (MULT_EXPR, element_size,
fold_convert (bitsizetype,
*************** initialize_sizetypes (void)
*** 2249,2255 ****
TYPE_SIZE_UNIT (t) = build_int_cst (t, GET_MODE_SIZE (SImode));
TYPE_PRECISION (t) = precision;
! set_min_and_max_values_for_integral_type (t, precision, true);
sizetype = t;
bitsizetype = build_distinct_type_copy (t);
--- 2250,2257 ----
TYPE_SIZE_UNIT (t) = build_int_cst (t, GET_MODE_SIZE (SImode));
TYPE_PRECISION (t) = precision;
! set_min_and_max_values_for_integral_type (t, precision,
! /*is_unsinged=*/true);
sizetype = t;
bitsizetype = build_distinct_type_copy (t);
*************** set_sizetype (tree type)
*** 2284,2290 ****
/* We want to use sizetype's cache, as we will be replacing that type. */
TYPE_CACHED_VALUES (t) = TYPE_CACHED_VALUES (sizetype);
TYPE_CACHED_VALUES_P (t) = TYPE_CACHED_VALUES_P (sizetype);
- TREE_TYPE (TYPE_CACHED_VALUES (t)) = type;
TYPE_UID (t) = TYPE_UID (sizetype);
TYPE_IS_SIZETYPE (t) = 1;
--- 2286,2291 ----
Index: trunk/gcc/c-family/c-common.c
===================================================================
*** trunk.orig/gcc/c-family/c-common.c 2011-04-11 10:56:06.000000000 +0200
--- trunk/gcc/c-family/c-common.c 2011-04-11 14:27:17.000000000 +0200
*************** complete_array_type (tree *ptype, tree i
*** 8810,8816 ****
TYPE_LANG_FLAG_? bits that the front end may have set. */
main_type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type));
TREE_TYPE (main_type) = unqual_elt;
! TYPE_DOMAIN (main_type) = build_index_type (maxindex);
layout_type (main_type);
/* Make sure we have the canonical MAIN_TYPE. */
--- 8810,8818 ----
TYPE_LANG_FLAG_? bits that the front end may have set. */
main_type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type));
TREE_TYPE (main_type) = unqual_elt;
! TYPE_DOMAIN (main_type)
! = build_range_type (TREE_TYPE (maxindex),
! build_int_cst (TREE_TYPE (maxindex), 0), maxindex);
layout_type (main_type);
/* Make sure we have the canonical MAIN_TYPE. */
