/* C-compiler utilities for types and variables storage layout
Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1996, 1998,
- 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
- Free Software Foundation, Inc.
+ 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
+ 2011 Free Software Foundation, Inc.
This file is part of GCC.
/* See if we can use an ordinary integer mode for a bit-field.
Conditions are: a fixed size that is correct for another mode,
occupying a complete byte or bytes on proper boundary,
- and not volatile or not -fstrict-volatile-bitfields. */
+ and not -fstrict-volatile-bitfields. If the latter is set,
+ we unfortunately can't check TREE_THIS_VOLATILE, as a cast
+ may make a volatile object later. */
if (TYPE_SIZE (type) != 0
&& TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST
&& GET_MODE_CLASS (TYPE_MODE (type)) == MODE_INT
- && !(TREE_THIS_VOLATILE (decl)
- && flag_strict_volatile_bitfields > 0))
+ && flag_strict_volatile_bitfields <= 0)
{
enum machine_mode xmode
= mode_for_size_tree (DECL_SIZE (decl), MODE_INT, 1);
applies if there was an immediately prior, nonzero-size
bitfield. (That's the way it is, experimentally.) */
if ((!is_bitfield && !DECL_PACKED (field))
- || (!integer_zerop (DECL_SIZE (field))
+ || ((DECL_SIZE (field) == NULL_TREE
+ || !integer_zerop (DECL_SIZE (field)))
? !DECL_PACKED (field)
: (rli->prev_field
&& DECL_BIT_FIELD_TYPE (rli->prev_field)
}
/* Does this field automatically have alignment it needs by virtue
- of the fields that precede it and the record's own alignment?
- We already align ms_struct fields, so don't re-align them. */
- if (known_align < desired_align
- && !targetm.ms_bitfield_layout_p (rli->t))
+ of the fields that precede it and the record's own alignment? */
+ if (known_align < desired_align)
{
/* No, we need to skip space before this field.
Bump the cumulative size to multiple of field alignment. */
- if (DECL_SOURCE_LOCATION (field) != BUILTINS_LOCATION)
+ if (!targetm.ms_bitfield_layout_p (rli->t)
+ && DECL_SOURCE_LOCATION (field) != BUILTINS_LOCATION)
warning (OPT_Wpadded, "padding struct to align %q+D", field);
/* If the alignment is still within offset_align, just align
if (! TREE_CONSTANT (rli->offset))
rli->offset_align = desired_align;
-
+ if (targetm.ms_bitfield_layout_p (rli->t))
+ rli->prev_field = NULL;
}
/* Handle compatibility with PCC. Note that if the record has any
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. */
+ /* The computation should happen in the original signedness so
+ that (possible) negative values are handled appropriately
+ when determining overflow. */
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)));
+ size_binop (PLUS_EXPR,
+ build_int_cst (TREE_TYPE (lb), 1),
+ size_binop (MINUS_EXPR, ub, lb)));
TYPE_SIZE (type) = size_binop (MULT_EXPR, element_size,
fold_convert (bitsizetype,
precision = LONG_TYPE_SIZE;
else if (strcmp (SIZE_TYPE, "long long unsigned int") == 0)
precision = LONG_LONG_TYPE_SIZE;
+ else if (strcmp (SIZE_TYPE, "short unsigned int") == 0)
+ precision = SHORT_TYPE_SIZE;
else
gcc_unreachable ();
= size_int (GET_MODE_SIZE (TYPE_MODE (bitsizetype)));
set_min_and_max_values_for_integral_type (bitsizetype, bprecision,
/*is_unsigned=*/true);
- /* ??? TYPE_MAX_VALUE is not properly sign-extended. */
+ /* bitsizetype is unsigned but we need to fix TYPE_MAX_VALUE so that it is
+ sign-extended in a way consistent with force_fit_type. */
+ TYPE_MAX_VALUE (bitsizetype)
+ = double_int_to_tree (bitsizetype,
+ tree_to_double_int (TYPE_MAX_VALUE (bitsizetype)));
/* Create the signed variants of *sizetype. */
ssizetype = make_signed_type (TYPE_PRECISION (sizetype));
/* Find the best machine mode to use when referencing a bit field of length
BITSIZE bits starting at BITPOS.
+ BITREGION_START is the bit position of the first bit in this
+ sequence of bit fields. BITREGION_END is the last bit in this
+ sequence. If these two fields are non-zero, we should restrict the
+ memory access to a maximum sized chunk of
+ BITREGION_END - BITREGION_START + 1. Otherwise, we are allowed to touch
+ any adjacent non bit-fields.
+
The underlying object is known to be aligned to a boundary of ALIGN bits.
If LARGEST_MODE is not VOIDmode, it means that we should not use a mode
larger than LARGEST_MODE (usually SImode).
decide which of the above modes should be used. */
enum machine_mode
-get_best_mode (int bitsize, int bitpos, unsigned int align,
+get_best_mode (int bitsize, int bitpos,
+ unsigned HOST_WIDE_INT bitregion_start,
+ unsigned HOST_WIDE_INT bitregion_end,
+ unsigned int align,
enum machine_mode largest_mode, int volatilep)
{
enum machine_mode mode;
unsigned int unit = 0;
+ unsigned HOST_WIDE_INT maxbits;
+
+ /* If unset, no restriction. */
+ if (!bitregion_end)
+ maxbits = MAX_FIXED_MODE_SIZE;
+ else
+ maxbits = (bitregion_end - bitregion_start) % align + 1;
/* Find the narrowest integer mode that contains the bit field. */
for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT); mode != VOIDmode;
&& bitpos / unit == (bitpos + bitsize - 1) / unit
&& unit <= BITS_PER_WORD
&& unit <= MIN (align, BIGGEST_ALIGNMENT)
+ && unit <= maxbits
&& (largest_mode == VOIDmode
|| unit <= GET_MODE_BITSIZE (largest_mode)))
wide_mode = tmode;
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