mirror/gcc
2
0
Fork 0
mirror of git://gcc.gnu.org/git/gcc.git synced 2025-03-10 09:16:47 +08:00
Code Issues Packages Projects Releases Wiki Activity

dwarf2out.c (simple_decl_align_in_bits): new

Browse Source 
* dwarf2out.c (simple_decl_align_in_bits): new
(field_byte_offset): Try both the type align and the
decl align, use whichever works, preferring the type align.

From-SVN: r38418
This commit is contained in:
DJ Delorie 2000-12-21 13:20:39 -05:00 committed by DJ Delorie
parent 477f6664a4
commit 5f446d2172
2 changed files with 36 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
gcc/ChangeLog
View File

@ -1,3 +1,9 @@
2000-12-21 DJ Delorie <dj@redhat.com>
* dwarf2out.c (simple_decl_align_in_bits): new
(field_byte_offset): Try both the type align and the
decl align, use whichever works, preferring the type align.
2000-12-21 Joseph S. Myers <jsm28@cam.ac.uk>
* gccbug.in: Fix typo.

43
gcc/dwarf2out.c
View File

@ -3460,6 +3460,7 @@ static dw_loc_descr_ref loc_descriptor_from_tree PARAMS ((tree, int));
static HOST_WIDE_INT ceiling PARAMS ((HOST_WIDE_INT, unsigned int));
static tree field_type PARAMS ((tree));
static unsigned int simple_type_align_in_bits PARAMS ((tree));
static unsigned int simple_decl_align_in_bits PARAMS ((tree));
static unsigned HOST_WIDE_INT simple_type_size_in_bits PARAMS ((tree));
static HOST_WIDE_INT field_byte_offset PARAMS ((tree));
static void add_AT_location_description PARAMS ((dw_die_ref,
@ -8050,10 +8051,9 @@ field_type (decl)
return type;
}
/* Given a pointer to a tree node, assumed to be some kind of a ..._TYPE
node, return the alignment in bits for the type, or else return
BITS_PER_WORD if the node actually turns out to be an
ERROR_MARK node. */
/* Given a pointer to a tree node, return the alignment in bits for
it, or else return BITS_PER_WORD if the node actually turns out to
be an ERROR_MARK node. */
static inline unsigned
simple_type_align_in_bits (type)
@ -8062,6 +8062,13 @@ simple_type_align_in_bits (type)
return (TREE_CODE (type) != ERROR_MARK) ? TYPE_ALIGN (type) : BITS_PER_WORD;
}
static inline unsigned
simple_decl_align_in_bits (decl)
register tree decl;
{
return (TREE_CODE (decl) != ERROR_MARK) ? DECL_ALIGN (decl) : BITS_PER_WORD;
}
/* Given a pointer to a tree node, assumed to be some kind of a ..._TYPE
node, return the size in bits for the type if it is a constant, or else
return the alignment for the type if the type's size is not constant, or
@ -8096,10 +8103,9 @@ static HOST_WIDE_INT
field_byte_offset (decl)
register tree decl;
{
unsigned int type_align_in_bytes;
unsigned int type_align_in_bits;
unsigned int decl_align_in_bits;
unsigned HOST_WIDE_INT type_size_in_bits;
HOST_WIDE_INT object_offset_in_align_units;
HOST_WIDE_INT object_offset_in_bits;
HOST_WIDE_INT object_offset_in_bytes;
tree type;
@ -8138,7 +8144,7 @@ field_byte_offset (decl)
type_size_in_bits = simple_type_size_in_bits (type);
type_align_in_bits = simple_type_align_in_bits (type);
type_align_in_bytes = type_align_in_bits / BITS_PER_UNIT;
decl_align_in_bits = simple_decl_align_in_bits (decl);
/* Note that the GCC front-end doesn't make any attempt to keep track of
the starting bit offset (relative to the start of the containing
@ -8185,14 +8191,25 @@ field_byte_offset (decl)
/* This is the tricky part. Use some fancy footwork to deduce where the
lowest addressed bit of the containing object must be. */
object_offset_in_bits
= ceiling (deepest_bitpos, type_align_in_bits) - type_size_in_bits;
object_offset_in_bits = deepest_bitpos - type_size_in_bits;
/* Compute the offset of the containing object in "alignment units". */
object_offset_in_align_units = object_offset_in_bits / type_align_in_bits;
/* Round up to type_align by default. This works best for bitfields. */
object_offset_in_bits += type_align_in_bits - 1;
object_offset_in_bits /= type_align_in_bits;
object_offset_in_bits *= type_align_in_bits;
/* Compute the offset of the containing object in bytes. */
object_offset_in_bytes = object_offset_in_align_units * type_align_in_bytes;
if (object_offset_in_bits > bitpos_int)
{
/* Sigh, the decl must be packed. */
object_offset_in_bits = deepest_bitpos - type_size_in_bits;
/* Round up to decl_align instead. */
object_offset_in_bits += decl_align_in_bits - 1;
object_offset_in_bits /= decl_align_in_bits;
object_offset_in_bits *= decl_align_in_bits;
}
object_offset_in_bytes = object_offset_in_bits / BITS_PER_UNIT;
return object_offset_in_bytes;
}