diff options
Diffstat (limited to 'gcc/stor-layout.c')
| -rw-r--r-- | gcc/stor-layout.c | 741 |
1 files changed, 388 insertions, 353 deletions
diff --git a/gcc/stor-layout.c b/gcc/stor-layout.c index 8773fa9..ada43a0 100644 --- a/gcc/stor-layout.c +++ b/gcc/stor-layout.c @@ -50,11 +50,10 @@ unsigned int maximum_field_alignment; May be overridden by front-ends. */ unsigned int set_alignment = 0; -static void finalize_record_size PARAMS ((record_layout_info)); -static void compute_record_mode PARAMS ((tree)); -static void finalize_type_size PARAMS ((tree)); -static void layout_union_field PARAMS ((record_layout_info, tree)); -static void finish_union_layout PARAMS ((record_layout_info)); +static void finalize_record_size PARAMS ((record_layout_info)); +static void compute_record_mode PARAMS ((tree)); +static void finalize_type_size PARAMS ((tree)); +static void place_union_field PARAMS ((record_layout_info, tree)); /* SAVE_EXPRs for sizes of types and decls, waiting to be expanded. */ @@ -65,6 +64,8 @@ static tree pending_sizes; int immediate_size_expand; +/* Get a list of all the objects put on the pending sizes list. */ + tree get_pending_sizes () { @@ -79,6 +80,9 @@ get_pending_sizes () return chain; } +/* Put a chain of objects into the pending sizes list, which must be + empty. */ + void put_pending_sizes (chain) tree chain; @@ -131,8 +135,7 @@ variable_size (size) Also, we would like to pass const0_rtx here, but don't have it. */ expand_expr (size, expand_expr (integer_zero_node, NULL_PTR, VOIDmode, 0), VOIDmode, 0); - else if (cfun != 0 - && cfun->x_dont_save_pending_sizes_p) + else if (cfun != 0 && cfun->x_dont_save_pending_sizes_p) /* The front-end doesn't want us to keep a list of the expressions that determine sizes for variable size objects. */ ; @@ -153,7 +156,7 @@ variable_size (size) enum machine_mode mode_for_size (size, class, limit) - int size; + unsigned int size; enum mode_class class; int limit; { @@ -194,7 +197,7 @@ mode_for_size_tree (size, class, limit) enum machine_mode smallest_mode_for_size (size, class) - int size; + unsigned int size; enum mode_class class; { register enum machine_mode mode; @@ -296,37 +299,37 @@ layout_decl (decl, known_align) if (type == error_mark_node) type = void_type_node; - /* Usually the size and mode come from the data type without change. */ + /* Usually the size and mode come from the data type without change, + however, the front-end may set the explicit width of the field, so its + size may not be the same as the size of its type. This happens with + bitfields, of course (an `int' bitfield may be only 2 bits, say), but it + also happens with other fields. For example, the C++ front-end creates + zero-sized fields corresponding to empty base classes, and depends on + layout_type setting DECL_FIELD_BITPOS correctly for the field. Set the + size in bytes from the size in bits. */ + DECL_MODE (decl) = TYPE_MODE (type); TREE_UNSIGNED (decl) = TREE_UNSIGNED (type); + if (DECL_SIZE (decl) == 0) { DECL_SIZE (decl) = TYPE_SIZE (type); DECL_SIZE_UNIT (decl) = TYPE_SIZE_UNIT (type); } - else if (code == FIELD_DECL) - { - HOST_WIDE_INT spec_size; - - /* Size is specified in number of bits. */ - spec_size = TREE_INT_CST_LOW (DECL_SIZE (decl)); - if (spec_size % BITS_PER_UNIT == 0) - DECL_SIZE_UNIT (decl) = size_int (spec_size / BITS_PER_UNIT); - else - DECL_SIZE_UNIT (decl) = 0; - } + else + DECL_SIZE_UNIT (decl) + = convert (sizetype, size_binop (CEIL_DIV_EXPR, DECL_SIZE (decl), + bitsize_unit_node)); /* Force alignment required for the data type. But if the decl itself wants greater alignment, don't override that. Likewise, if the decl is packed, don't override it. */ if (!(code == FIELD_DECL && DECL_BIT_FIELD (decl)) && (DECL_ALIGN (decl) == 0 - || (! DECL_PACKED (decl) && TYPE_ALIGN (type) > DECL_ALIGN (decl)))) + || (! DECL_PACKED (decl) && TYPE_ALIGN (type) > DECL_ALIGN (decl)))) DECL_ALIGN (decl) = TYPE_ALIGN (type); - /* See if we can use an ordinary integer mode for a bit-field. - Conditions are: a fixed size that is correct for another mode - and occupying a complete byte or bytes on proper boundary. */ + /* For fields, set the bit field type and update the alignment. */ if (code == FIELD_DECL) { DECL_BIT_FIELD_TYPE (decl) = DECL_BIT_FIELD (decl) ? type : 0; @@ -336,6 +339,9 @@ layout_decl (decl, known_align) DECL_ALIGN (decl) = MIN (DECL_ALIGN (decl), BITS_PER_UNIT); } + /* See if we can use an ordinary integer mode for a bit-field. + Conditions are: a fixed size that is correct for another mode + and occupying a complete byte or bytes on proper boundary. */ if (DECL_BIT_FIELD (decl) && TYPE_SIZE (type) != 0 && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST @@ -344,24 +350,21 @@ layout_decl (decl, known_align) register enum machine_mode xmode = mode_for_size_tree (DECL_SIZE (decl), MODE_INT, 1); - if (xmode != BLKmode - && known_align % GET_MODE_ALIGNMENT (xmode) == 0) + if (xmode != BLKmode && known_align > GET_MODE_ALIGNMENT (xmode)) { DECL_ALIGN (decl) = MAX (GET_MODE_ALIGNMENT (xmode), DECL_ALIGN (decl)); DECL_MODE (decl) = xmode; - DECL_SIZE (decl) = bitsize_int (GET_MODE_BITSIZE (xmode)); - DECL_SIZE_UNIT (decl) = size_int (GET_MODE_SIZE (xmode)); - /* This no longer needs to be accessed as a bit field. */ DECL_BIT_FIELD (decl) = 0; } } /* Turn off DECL_BIT_FIELD if we won't need it set. */ - if (DECL_BIT_FIELD (decl) && TYPE_MODE (type) == BLKmode - && known_align % TYPE_ALIGN (type) == 0 - && DECL_SIZE_UNIT (decl) != 0 - && DECL_ALIGN (decl) >= TYPE_ALIGN (type)) + if (DECL_BIT_FIELD (decl) + && TYPE_MODE (type) == BLKmode && DECL_MODE (decl) == BLKmode + && known_align > TYPE_ALIGN (type) + && DECL_ALIGN (decl) >= TYPE_ALIGN (type) + && DECL_SIZE_UNIT (decl) != 0) DECL_BIT_FIELD (decl) = 0; /* Evaluate nonconstant size only once, either now or as soon as safe. */ @@ -392,23 +395,28 @@ layout_decl (decl, known_align) } } -/* Create a new record_layout_info for T, which may be a RECORD_TYPE, - UNION_TYPE, or QUAL_UNION_TYPE. It is the responsibility of the - caller to call `free' for the storage the returned. */ +/* Begin laying out type T, which may be a RECORD_TYPE, UNION_TYPE, or + QUAL_UNION_TYPE. Return a pointer to a struct record_layout_info which + is to be passed to all other layout functions for this record. It is the + responsibility of the caller to call `free' for the storage returned. + Note that garbage collection is not permitted until we finish laying + out the record. */ record_layout_info -new_record_layout_info (t) +start_record_layout (t) tree t; { record_layout_info rli - = (record_layout_info) xcalloc (1, sizeof (struct record_layout_info_s)); + = (record_layout_info) xmalloc (sizeof (struct record_layout_info)); rli->t = t; + /* If the type has a minimum specified alignment (via an attribute declaration, for example) use it -- otherwise, start with a one-byte alignment. */ rli->record_align = MAX (BITS_PER_UNIT, TYPE_ALIGN (t)); rli->unpacked_align = rli->record_align; + rli->offset_align = MAX (rli->record_align, BIGGEST_ALIGNMENT); #ifdef STRUCTURE_SIZE_BOUNDARY /* Packed structures don't need to have minimum size. */ @@ -416,30 +424,96 @@ new_record_layout_info (t) rli->record_align = MAX (rli->record_align, STRUCTURE_SIZE_BOUNDARY); #endif + rli->offset = size_zero_node; + rli->bitpos = bitsize_zero_node; + rli->pending_statics = 0; + rli->packed_maybe_necessary = 0; + return rli; } -/* Like layout_field, but for unions. */ +/* Print debugging information about the information in RLI. */ -static void -layout_union_field (rli, field) +void +debug_rli (rli) record_layout_info rli; - tree field; { - tree dsize; - - /* This function should only be used for unions; use layout_field - for RECORD_TYPEs. */ - if (TREE_CODE (rli->t) != UNION_TYPE - && TREE_CODE (rli->t) != QUAL_UNION_TYPE) - abort (); + print_node_brief (stderr, "type", rli->t, 0); + print_node_brief (stderr, "\noffset", rli->offset, 0); + print_node_brief (stderr, " bitpos", rli->bitpos, 0); - /* By now, we should only be seeing FIELD_DECLs. */ - if (TREE_CODE (field) != FIELD_DECL) - abort (); + fprintf (stderr, "\nrec_align = %u, unpack_align = %u, off_align = %u\n", + rli->record_align, rli->unpacked_align, rli->offset_align); + if (rli->packed_maybe_necessary) + fprintf (stderr, "packed may be necessary\n"); + + if (rli->pending_statics) + { + fprintf (stderr, "pending statics:\n"); + debug_tree (rli->pending_statics); + } +} + +/* Given an RLI with a possibly-incremented BITPOS, adjust OFFSET and + BITPOS if necessary to keep BITPOS below OFFSET_ALIGN. */ + +void +normalize_rli (rli) + record_layout_info rli; +{ + /* If the bit position is now larger than it should be, adjust it + downwards. */ + if (compare_tree_int (rli->bitpos, rli->offset_align) >= 0) + { + tree extra_aligns = size_binop (FLOOR_DIV_EXPR, rli->bitpos, + bitsize_int (rli->offset_align)); + + rli->offset + = size_binop (PLUS_EXPR, rli->offset, + size_binop (MULT_EXPR, convert (sizetype, extra_aligns), + size_int (rli->offset_align + / BITS_PER_UNIT))); + + rli->bitpos = size_binop (FLOOR_MOD_EXPR, rli->bitpos, + bitsize_int (rli->offset_align)); + } +} +/* Returns the size in bytes allocated so far. */ + +tree +rli_size_unit_so_far (rli) + record_layout_info rli; +{ + return size_binop (PLUS_EXPR, rli->offset, + convert (sizetype, + size_binop (CEIL_DIV_EXPR, rli->bitpos, + bitsize_unit_node))); +} + +/* Returns the size in bits allocated so far. */ + +tree +rli_size_so_far (rli) + record_layout_info rli; +{ + return size_binop (PLUS_EXPR, rli->bitpos, + size_binop (MULT_EXPR, convert (bitsizetype, rli->offset), + bitsize_unit_node)); +} + +/* Called from place_field to handle unions. */ + +static void +place_union_field (rli, field) + record_layout_info rli; + tree field; +{ layout_decl (field, 0); - DECL_FIELD_BITPOS (field) = bitsize_int (0); + + DECL_FIELD_OFFSET (field) = size_zero_node; + DECL_FIELD_BIT_OFFSET (field) = bitsize_zero_node; + DECL_OFFSET_ALIGN (field) = BIGGEST_ALIGNMENT; /* Union must be at least as aligned as any field requires. */ rli->record_align = MAX (rli->record_align, DECL_ALIGN (field)); @@ -452,30 +526,14 @@ layout_union_field (rli, field) TYPE_ALIGN (TREE_TYPE (field))); #endif - dsize = DECL_SIZE (field); + /* We assume the union's size will be a multiple of a byte so we don't + bother with BITPOS. */ if (TREE_CODE (rli->t) == UNION_TYPE) - { - /* Set union_size to max (decl_size, union_size). There are - more and less general ways to do this. Use only CONST_SIZE - unless forced to use VAR_SIZE. */ - - if (TREE_CODE (dsize) == INTEGER_CST - && ! TREE_CONSTANT_OVERFLOW (dsize) - && TREE_INT_CST_HIGH (dsize) == 0) - rli->const_size - = MAX (rli->const_size, TREE_INT_CST_LOW (dsize)); - else if (rli->var_size == 0) - rli->var_size = dsize; - else - rli->var_size = size_binop (MAX_EXPR, rli->var_size, dsize); - } + rli->offset = size_binop (MAX_EXPR, rli->offset, DECL_SIZE_UNIT (field)); else if (TREE_CODE (rli->t) == QUAL_UNION_TYPE) - rli->var_size = fold (build (COND_EXPR, bitsizetype, - DECL_QUALIFIER (field), - DECL_SIZE (field), - (rli->var_size - ? rli->var_size - : bitsize_int (0)))); + rli->offset = fold (build (COND_EXPR, sizetype, + DECL_QUALIFIER (field), + DECL_SIZE_UNIT (field), rli->offset)); } /* RLI contains information about the layout of a RECORD_TYPE. FIELD @@ -484,7 +542,7 @@ layout_union_field (rli, field) callers that desire that behavior must manually perform that step.) */ void -layout_field (rli, field) +place_field (rli, field) record_layout_info rli; tree field; { @@ -493,11 +551,10 @@ layout_field (rli, field) /* The alignment FIELD would have if we just dropped it into the record as it presently stands. */ unsigned int known_align; + unsigned int actual_align; /* The type of this field. */ tree type = TREE_TYPE (field); - /* The size of this field, in bits. */ - tree dsize; - + /* If FIELD is static, then treat it like a separate variable, not really like a structure field. If it is a FUNCTION_DECL, it's a method. In both cases, all we do is lay out the decl, and we do @@ -508,29 +565,40 @@ layout_field (rli, field) rli->pending_statics); return; } + /* Enumerators and enum types which are local to this class need not be laid out. Likewise for initialized constant fields. */ else if (TREE_CODE (field) != FIELD_DECL) return; - /* This function should only be used for records; use - layout_union_field for unions. */ + + /* Unions are laid out very differently than records, so split + that code off to another function. */ else if (TREE_CODE (rli->t) != RECORD_TYPE) { - layout_union_field (rli, field); + place_union_field (rli, field); return; } - /* Work out the known alignment so far. */ - known_align = rli->var_size ? rli->var_align : rli->const_size; + /* Work out the known alignment so far. Note that A & (-A) is the + value of the least-significant bit in A that is one. */ + if (! integer_zerop (rli->bitpos) && TREE_CONSTANT (rli->offset)) + known_align = (tree_low_cst (rli->bitpos, 1) + & - tree_low_cst (rli->bitpos, 1)); + else if (host_integerp (rli->offset, 1)) + known_align = (BITS_PER_UNIT + * (tree_low_cst (rli->offset, 1) + & - tree_low_cst (rli->offset, 1))); + else + known_align = rli->offset_align; /* Lay out the field so we know what alignment it needs. For a packed field, use the alignment as specified, disregarding what the type would want. */ - if (DECL_PACKED (field)) - desired_align = DECL_ALIGN (field); + desired_align = DECL_ALIGN (field); layout_decl (field, known_align); if (! DECL_PACKED (field)) desired_align = DECL_ALIGN (field); + /* Some targets (i.e. VMS) limit struct field alignment to a lower boundary than alignment of variables. */ #ifdef BIGGEST_FIELD_ALIGNMENT @@ -556,6 +624,7 @@ layout_field (rli, field) rli->record_align = MAX (rli->record_align, desired_align); else if (! DECL_PACKED (field)) desired_align = TYPE_ALIGN (type); + /* A named bit field of declared type `int' forces the entire structure to have `int' alignment. */ if (DECL_NAME (field) != 0) @@ -577,15 +646,12 @@ layout_field (rli, field) #endif { rli->record_align = MAX (rli->record_align, desired_align); - if (warn_packed) - rli->unpacked_align = MAX (rli->unpacked_align, TYPE_ALIGN (type)); + rli->unpacked_align = MAX (rli->unpacked_align, TYPE_ALIGN (type)); } if (warn_packed && DECL_PACKED (field)) { - if (rli->const_size % TYPE_ALIGN (type) == 0 - || (rli->var_align % TYPE_ALIGN (type) == 0 - && rli->var_size != NULL_TREE)) + if (known_align > TYPE_ALIGN (type)) { if (TYPE_ALIGN (type) > desired_align) { @@ -601,9 +667,7 @@ layout_field (rli, field) /* Does this field automatically have alignment it needs by virtue of the fields that precede it and the record's own alignment? */ - if (rli->const_size % desired_align != 0 - || (rli->var_align % desired_align != 0 - && rli->var_size != NULL_TREE)) + if (known_align < desired_align) { /* No, we need to skip space before this field. Bump the cumulative size to multiple of field alignment. */ @@ -611,55 +675,72 @@ layout_field (rli, field) if (warn_padded) warning_with_decl (field, "padding struct to align `%s'"); - if (rli->var_size == NULL_TREE || rli->var_align % desired_align == 0) - rli->const_size - = CEIL (rli->const_size, desired_align) * desired_align; + /* If the alignment is still within offset_align, just align + the bit position. */ + if (desired_align < rli->offset_align) + rli->bitpos = round_up (rli->bitpos, desired_align); else { - if (rli->const_size > 0) - rli->var_size = size_binop (PLUS_EXPR, rli->var_size, - bitsize_int (rli->const_size)); - rli->const_size = 0; - rli->var_size = round_up (rli->var_size, desired_align); - rli->var_align = MIN (rli->var_align, desired_align); + /* First adjust OFFSET by the partial bits, then align. */ + rli->offset + = size_binop (PLUS_EXPR, rli->offset, + convert (sizetype, + size_binop (CEIL_DIV_EXPR, rli->bitpos, + bitsize_unit_node))); + rli->bitpos = bitsize_zero_node; + + rli->offset = round_up (rli->offset, desired_align / BITS_PER_UNIT); } + } + /* Handle compatibility with PCC. Note that if the record has any + variable-sized fields, we need not worry about compatibility. */ #ifdef PCC_BITFIELD_TYPE_MATTERS if (PCC_BITFIELD_TYPE_MATTERS && TREE_CODE (field) == FIELD_DECL && type != error_mark_node - && DECL_BIT_FIELD_TYPE (field) - && !DECL_PACKED (field) + && DECL_BIT_FIELD (field) + && ! DECL_PACKED (field) && maximum_field_alignment == 0 - && !integer_zerop (DECL_SIZE (field))) + && ! integer_zerop (DECL_SIZE (field)) + && host_integerp (DECL_SIZE (field), 1) + && host_integerp (rli->offset, 1) + && host_integerp (TYPE_SIZE (type), 1)) { unsigned int type_align = TYPE_ALIGN (type); - register tree dsize = DECL_SIZE (field); - unsigned int field_size = TREE_INT_CST_LOW (dsize); + tree dsize = DECL_SIZE (field); + HOST_WIDE_INT field_size = tree_low_cst (dsize, 1); + HOST_WIDE_INT offset = tree_low_cst (rli->offset, 0); + HOST_WIDE_INT bit_offset = tree_low_cst (rli->bitpos, 0); /* A bit field may not span more units of alignment of its type than its type itself. Advance to next boundary if necessary. */ - if (((rli->const_size + field_size + type_align - 1) / type_align - - rli->const_size / type_align) - > TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (field))) / type_align) - rli->const_size = CEIL (rli->const_size, type_align) * type_align; + if ((((offset * BITS_PER_UNIT + bit_offset + field_size + + type_align - 1) + / type_align) + - (offset * BITS_PER_UNIT + bit_offset) / type_align) + > tree_low_cst (TYPE_SIZE (type), 1) / type_align) + rli->bitpos = round_up (rli->bitpos, type_align); } #endif - /* No existing machine description uses this parameter. So I have - made it in this aspect identical to PCC_BITFIELD_TYPE_MATTERS. */ #ifdef BITFIELD_NBYTES_LIMITED if (BITFIELD_NBYTES_LIMITED && TREE_CODE (field) == FIELD_DECL && type != error_mark_node && DECL_BIT_FIELD_TYPE (field) - && !DECL_PACKED (field) - && !integer_zerop (DECL_SIZE (field))) + && ! DECL_PACKED (field) + && ! integer_zerop (DECL_SIZE (field)) + && host_integerp (DECL_SIZE (field), 1) + && host_integerp (rli->size, 1) + && host_integerp (TYPE_SIZE (type), 1)) { unsigned int type_align = TYPE_ALIGN (type); - register tree dsize = DECL_SIZE (field); - int field_size = TREE_INT_CST_LOW (dsize); + tree dsize = DECL_SIZE (field); + HOST_WIDE_INT field_size = tree_low_cst (dsize, 1); + HOST_WIDE_INT offset = tree_low_cst (rli->offset, 0); + HOST_WIDE_INT bit_offset = tree_low_cst (rli->bitpos, 0); if (maximum_field_alignment != 0) type_align = MIN (type_align, maximum_field_alignment); @@ -672,51 +753,63 @@ layout_field (rli, field) Advance to next boundary if necessary. */ /* ??? This code should match the code above for the PCC_BITFIELD_TYPE_MATTERS case. */ - if (rli->const_size / type_align - != (rli->const_size + field_size - 1) / type_align) - rli->const_size = CEIL (rli->const_size, type_align) * type_align; + if ((offset * BITS_PER_UNIT + bit_offset) / type_align + != ((offset * BITS_PER_UNIT + bit_offset + field_size - 1) + / type_align)) + rli->bitpos = round_up (rli->bitpos, type_align); } #endif - /* Size so far becomes the position of this field. */ - - if (rli->var_size && rli->const_size) - DECL_FIELD_BITPOS (field) - = size_binop (PLUS_EXPR, rli->var_size, bitsize_int (rli->const_size)); - else if (rli->var_size) - DECL_FIELD_BITPOS (field) = rli->var_size; + if (! TREE_CONSTANT (rli->offset)) + rli->offset_align = DECL_ALIGN (field); + + /* Offset so far becomes the position of this field after normalizing. */ + normalize_rli (rli); + DECL_FIELD_OFFSET (field) = rli->offset; + DECL_FIELD_BIT_OFFSET (field) = rli->bitpos; + DECL_OFFSET_ALIGN (field) = rli->offset_align; + + /* If this field ended up more aligned than we thought it would be (we + approximate this by seeing if its position changed), lay out the field + again; perhaps we can use an integral mode for it now. */ + if (! integer_zerop (DECL_FIELD_BIT_OFFSET (field)) + && TREE_CONSTANT (DECL_FIELD_OFFSET (field))) + actual_align = (tree_low_cst (DECL_FIELD_BIT_OFFSET (field), 1) + & - tree_low_cst (DECL_FIELD_BIT_OFFSET (field), 1)); + else if (host_integerp (DECL_FIELD_OFFSET (field), 1)) + actual_align = (BITS_PER_UNIT + * (tree_low_cst (DECL_FIELD_OFFSET (field), 1) + & - tree_low_cst (DECL_FIELD_OFFSET (field), 1))); else + actual_align = DECL_OFFSET_ALIGN (field); + + if (known_align != actual_align) + layout_decl (field, actual_align); + + /* Now add size of this field to the size of the record. If the size is + not constant, treat the field as being a multiple of bytes and just + adjust the offset, resetting the bit position. Otherwise, apportion the + size amongst the bit position and offset. First handle the case of an + unspecified size, which can happen when we have an invalid nested struct + definition, such as struct j { struct j { int i; } }. The error message + is printed in finish_struct. */ + if (DECL_SIZE (field) == 0) + /* Do nothing. */; + else if (! TREE_CONSTANT (DECL_SIZE_UNIT (field))) { - DECL_FIELD_BITPOS (field) = bitsize_int (rli->const_size); - - /* If this field ended up more aligned than we thought it - would be (we approximate this by seeing if its position - changed), lay out the field again; perhaps we can use an - integral mode for it now. */ - if (known_align != rli->const_size) - layout_decl (field, rli->const_size); + rli->offset + = size_binop (PLUS_EXPR, rli->offset, + convert (sizetype, + size_binop (CEIL_DIV_EXPR, rli->bitpos, + bitsize_unit_node))); + rli->offset + = size_binop (PLUS_EXPR, rli->offset, DECL_SIZE_UNIT (field)); + rli->bitpos = bitsize_zero_node; } - - /* Now add size of this field to the size of the record. */ - dsize = DECL_SIZE (field); - - /* This can happen when we have an invalid nested struct definition, - such as struct j { struct j { int i; } }. The error message is - printed in finish_struct. */ - if (dsize == 0) - /* Do nothing. */; - else if (TREE_CODE (dsize) == INTEGER_CST - && ! TREE_CONSTANT_OVERFLOW (dsize) - && TREE_INT_CST_HIGH (dsize) == 0 - && TREE_INT_CST_LOW (dsize) + rli->const_size >= rli->const_size) - /* Use const_size if there's no overflow. */ - rli->const_size += TREE_INT_CST_LOW (dsize); else { - if (rli->var_size == NULL_TREE) - rli->var_size = dsize; - else - rli->var_size = size_binop (PLUS_EXPR, rli->var_size, dsize); + rli->bitpos = size_binop (PLUS_EXPR, rli->bitpos, DECL_SIZE (field)); + normalize_rli (rli); } } @@ -728,18 +821,15 @@ static void finalize_record_size (rli) record_layout_info rli; { - /* Work out the total size and alignment of the record as one - expression and store in the record type. Round it up to a - multiple of the record's alignment. */ - if (rli->var_size == NULL_TREE) - TYPE_SIZE (rli->t) = bitsize_int (rli->const_size); - else - { - if (rli->const_size) - rli->var_size = size_binop (PLUS_EXPR, rli->var_size, - bitsize_int (rli->const_size)); - TYPE_SIZE (rli->t) = rli->var_size; - } + tree unpadded_size, unpadded_size_unit; + + /* Next move any full bytes of bits into the byte size. */ + rli->offset + = size_binop (PLUS_EXPR, rli->offset, + convert (sizetype, + size_binop (TRUNC_DIV_EXPR, rli->bitpos, + bitsize_unit_node))); + rli->bitpos = size_binop (TRUNC_MOD_EXPR, rli->bitpos, bitsize_unit_node); /* Determine the desired alignment. */ #ifdef ROUND_TYPE_ALIGN @@ -749,45 +839,55 @@ finalize_record_size (rli) TYPE_ALIGN (rli->t) = MAX (TYPE_ALIGN (rli->t), rli->record_align); #endif + unpadded_size + = size_binop (PLUS_EXPR, rli->bitpos, + size_binop (MULT_EXPR, convert (bitsizetype, rli->offset), + bitsize_unit_node)); + + unpadded_size_unit + = size_binop (PLUS_EXPR, rli->offset, + convert (sizetype, + size_binop (CEIL_DIV_EXPR, rli->bitpos, + bitsize_unit_node))); + /* Record the un-rounded size in the binfo node. But first we check the size of TYPE_BINFO to make sure that BINFO_SIZE is available. */ if (TYPE_BINFO (rli->t) && TREE_VEC_LENGTH (TYPE_BINFO (rli->t)) > 6) { - TYPE_BINFO_SIZE (rli->t) = TYPE_SIZE (rli->t); - TYPE_BINFO_SIZE_UNIT (rli->t) - = convert (sizetype, - size_binop (FLOOR_DIV_EXPR, TYPE_SIZE (rli->t), - bitsize_int (BITS_PER_UNIT))); + TYPE_BINFO_SIZE (rli->t) = unpadded_size; + TYPE_BINFO_SIZE_UNIT (rli->t) = unpadded_size_unit; } - - { - tree unpadded_size = TYPE_SIZE (rli->t); + /* Round the size up to be a multiple of the required alignment */ #ifdef ROUND_TYPE_SIZE - TYPE_SIZE (rli->t) = ROUND_TYPE_SIZE (rli->t, TYPE_SIZE (rli->t), - TYPE_ALIGN (rli->t)); + TYPE_SIZE (rli->t) = ROUND_TYPE_SIZE (rli->t, unpadded_size, + TYPE_ALIGN (rli->t)); + TYPE_SIZE_UNIT (rli->t) + = ROUND_TYPE_SIZE_UNIT (rli->t, unpaded_size_unit, + TYPE_ALIGN (rli->t) / BITS_PER_UNIT); #else - /* Round the size up to be a multiple of the required alignment */ - TYPE_SIZE (rli->t) = round_up (TYPE_SIZE (rli->t), TYPE_ALIGN (rli->t)); + TYPE_SIZE (rli->t) = round_up (unpadded_size, TYPE_ALIGN (rli->t)); + TYPE_SIZE_UNIT (rli->t) = round_up (unpadded_size_unit, + TYPE_ALIGN (rli->t) / BITS_PER_UNIT); #endif - if (warn_padded && rli->var_size == NULL_TREE - && simple_cst_equal (unpadded_size, TYPE_SIZE (rli->t)) == 0) - warning ("padding struct size to alignment boundary"); - } + if (warn_padded && TREE_CONSTANT (unpadded_size) + && simple_cst_equal (unpadded_size, TYPE_SIZE (rli->t)) == 0) + warning ("padding struct size to alignment boundary"); - if (warn_packed && TYPE_PACKED (rli->t) && !rli->packed_maybe_necessary - && rli->var_size == NULL_TREE) + if (warn_packed && TREE_CODE (rli->t) == RECORD_TYPE + && TYPE_PACKED (rli->t) && ! rli->packed_maybe_necessary + && TREE_CONSTANT (unpadded_size)) { tree unpacked_size; - TYPE_PACKED (rli->t) = 0; #ifdef ROUND_TYPE_ALIGN rli->unpacked_align = ROUND_TYPE_ALIGN (rli->t, TYPE_ALIGN (rli->t), rli->unpacked_align); #else rli->unpacked_align = MAX (TYPE_ALIGN (rli->t), rli->unpacked_align); #endif + #ifdef ROUND_TYPE_SIZE unpacked_size = ROUND_TYPE_SIZE (rli->t, TYPE_SIZE (rli->t), rli->unpacked_align); @@ -797,6 +897,8 @@ finalize_record_size (rli) if (simple_cst_equal (unpacked_size, TYPE_SIZE (rli->t))) { + TYPE_PACKED (rli->t) = 0; + if (TYPE_NAME (rli->t)) { char *name; @@ -805,6 +907,7 @@ finalize_record_size (rli) name = IDENTIFIER_POINTER (TYPE_NAME (rli->t)); else name = IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (rli->t))); + if (STRICT_ALIGNMENT) warning ("packed attribute causes inefficient alignment for `%s'", name); else @@ -818,7 +921,6 @@ finalize_record_size (rli) warning ("packed attribute is unnecessary"); } } - TYPE_PACKED (rli->t) = 1; } } @@ -828,79 +930,77 @@ static void compute_record_mode (type) tree type; { + tree field; + enum machine_mode mode = VOIDmode; + /* Most RECORD_TYPEs have BLKmode, so we start off assuming that. However, if possible, we use a mode that fits in a register instead, in order to allow for better optimization down the line. */ TYPE_MODE (type) = BLKmode; - if (TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST) - { - tree field; - enum machine_mode mode = VOIDmode; - - /* A record which has any BLKmode members must itself be - BLKmode; it can't go in a register. Unless the member is - BLKmode only because it isn't aligned. */ - for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) - { - unsigned HOST_WIDE_INT bitpos; - - if (TREE_CODE (field) != FIELD_DECL - || TREE_CODE (TREE_TYPE (field)) == ERROR_MARK) - continue; - if (TYPE_MODE (TREE_TYPE (field)) == BLKmode - && ! TYPE_NO_FORCE_BLK (TREE_TYPE (field))) - return; - - if (TREE_CODE (DECL_FIELD_BITPOS (field)) != INTEGER_CST) - return; + if (! host_integerp (TYPE_SIZE (type), 1)) + return; - bitpos = TREE_INT_CST_LOW (DECL_FIELD_BITPOS (field)); + /* A record which has any BLKmode members must itself be + BLKmode; it can't go in a register. Unless the member is + BLKmode only because it isn't aligned. */ + for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) + { + unsigned HOST_WIDE_INT bitpos; - /* Must be BLKmode if any field crosses a word boundary, - since extract_bit_field can't handle that in registers. */ - if (bitpos / BITS_PER_WORD - != ((TREE_INT_CST_LOW (DECL_SIZE (field)) + bitpos - 1) - / BITS_PER_WORD) - /* But there is no problem if the field is entire words. */ - && TREE_INT_CST_LOW (DECL_SIZE (field)) % BITS_PER_WORD != 0) - return; + if (TREE_CODE (field) != FIELD_DECL) + continue; - /* If this field is the whole struct, remember its mode so - that, say, we can put a double in a class into a DF - register instead of forcing it to live in the stack. */ - if (simple_cst_equal (TYPE_SIZE (type), DECL_SIZE (field))) - mode = DECL_MODE (field); + if (TREE_CODE (TREE_TYPE (field)) == ERROR_MARK + || (TYPE_MODE (TREE_TYPE (field)) == BLKmode + && ! TYPE_NO_FORCE_BLK (TREE_TYPE (field))) + || ! host_integerp (bit_position (field), 1) + || ! host_integerp (DECL_SIZE (field), 1)) + return; + + bitpos = int_bit_position (field); + + /* Must be BLKmode if any field crosses a word boundary, + since extract_bit_field can't handle that in registers. */ + if (bitpos / BITS_PER_WORD + != ((TREE_INT_CST_LOW (DECL_SIZE (field)) + bitpos - 1) + / BITS_PER_WORD) + /* But there is no problem if the field is entire words. */ + && tree_low_cst (DECL_SIZE (field), 1) % BITS_PER_WORD != 0) + return; + + /* If this field is the whole struct, remember its mode so + that, say, we can put a double in a class into a DF + register instead of forcing it to live in the stack. */ + if (field == TYPE_FIELDS (type) && TREE_CHAIN (field) == 0) + mode = DECL_MODE (field); #ifdef STRUCT_FORCE_BLK - /* With some targets, eg. c4x, it is sub-optimal - to access an aligned BLKmode structure as a scalar. */ - if (mode == VOIDmode && STRUCT_FORCE_BLK (field)) - return; + /* With some targets, eg. c4x, it is sub-optimal + to access an aligned BLKmode structure as a scalar. */ + if (mode == VOIDmode && STRUCT_FORCE_BLK (field)) + return; #endif /* STRUCT_FORCE_BLK */ - } + } - if (mode != VOIDmode) - /* We only have one real field; use its mode. */ - TYPE_MODE (type) = mode; - else - TYPE_MODE (type) - = mode_for_size_tree (TYPE_SIZE (type), MODE_INT, 1); - - /* If structure's known alignment is less than what the scalar - mode would need, and it matters, then stick with BLKmode. */ - if (TYPE_MODE (type) != BLKmode - && STRICT_ALIGNMENT - && ! (TYPE_ALIGN (type) >= BIGGEST_ALIGNMENT - || (TYPE_ALIGN (type) >= - GET_MODE_ALIGNMENT (TYPE_MODE (type))))) - { - /* If this is the only reason this type is BLKmode, then - don't force containing types to be BLKmode. */ - TYPE_NO_FORCE_BLK (type) = 1; - TYPE_MODE (type) = BLKmode; - } + if (mode != VOIDmode) + /* We only have one real field; use its mode. */ + TYPE_MODE (type) = mode; + else + TYPE_MODE (type) = mode_for_size_tree (TYPE_SIZE (type), MODE_INT, 1); + + /* If structure's known alignment is less than what the scalar + mode would need, and it matters, then stick with BLKmode. */ + if (TYPE_MODE (type) != BLKmode + && STRICT_ALIGNMENT + && ! (TYPE_ALIGN (type) >= BIGGEST_ALIGNMENT + || TYPE_ALIGN (type) >= GET_MODE_ALIGNMENT (TYPE_MODE (type)))) + { + /* If this is the only reason this type is BLKmode, then + don't force containing types to be BLKmode. */ + TYPE_NO_FORCE_BLK (type) = 1; + TYPE_MODE (type) = BLKmode; } } @@ -929,18 +1029,8 @@ finalize_type_size (type) = ROUND_TYPE_ALIGN (type, TYPE_ALIGN (type), BITS_PER_UNIT); #endif -#ifdef ROUND_TYPE_SIZE - if (TYPE_SIZE (type) != 0) - TYPE_SIZE (type) - = ROUND_TYPE_SIZE (type, TYPE_SIZE (type), TYPE_ALIGN (type)); -#endif - - /* Evaluate nonconstant size only once, either now or as soon as safe. */ - if (TYPE_SIZE (type) != 0 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST) - TYPE_SIZE (type) = variable_size (TYPE_SIZE (type)); - /* If we failed to find a simple way to calculate the unit size - of the type above, find it by division. */ + of the type, find it by division. */ if (TYPE_SIZE_UNIT (type) == 0 && TYPE_SIZE (type) != 0) /* TYPE_SIZE (type) is computed in bitsizetype. After the division, the result will fit in sizetype. We will get more efficient code using @@ -948,9 +1038,26 @@ finalize_type_size (type) TYPE_SIZE_UNIT (type) = convert (sizetype, size_binop (FLOOR_DIV_EXPR, TYPE_SIZE (type), - bitsize_int (BITS_PER_UNIT))); + bitsize_unit_node)); - /* Once again evaluate only once, either now or as soon as safe. */ + if (TYPE_SIZE (type) != 0) + { +#ifdef ROUND_TYPE_SIZE + TYPE_SIZE (type) + = ROUND_TYPE_SIZE (type, TYPE_SIZE (type), TYPE_ALIGN (type)); + TYPE_SIZE_UNIT (type) + = ROUND_TYPE_SIZE_UNIT (type, TYPE_SIZE_UNIT (type), + TYPE_ALIGN (type) / BITS_PER_UNIT); +#else + TYPE_SIZE (type) = round_up (TYPE_SIZE (type), TYPE_ALIGN (type)); + TYPE_SIZE_UNIT (type) + = round_up (TYPE_SIZE_UNIT (type), TYPE_ALIGN (type) / BITS_PER_UNIT); +#endif + } + + /* Evaluate nonconstant sizes only once, either now or as soon as safe. */ + if (TYPE_SIZE (type) != 0 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST) + TYPE_SIZE (type) = variable_size (TYPE_SIZE (type)); if (TYPE_SIZE_UNIT (type) != 0 && TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST) TYPE_SIZE_UNIT (type) = variable_size (TYPE_SIZE_UNIT (type)); @@ -987,16 +1094,11 @@ void finish_record_layout (rli) record_layout_info rli; { - /* Use finish_union_layout for unions. */ - if (TREE_CODE (rli->t) != RECORD_TYPE) - finish_union_layout (rli); - else - { - /* Compute the final size. */ - finalize_record_size (rli); - /* Compute the TYPE_MODE for the record. */ - compute_record_mode (rli->t); - } + /* Compute the final size. */ + finalize_record_size (rli); + + /* Compute the TYPE_MODE for the record. */ + compute_record_mode (rli->t); /* Lay out any static members. This is done now because their type may use the record's type. */ @@ -1008,83 +1110,10 @@ finish_record_layout (rli) /* Perform any last tweaks to the TYPE_SIZE, etc. */ finalize_type_size (rli->t); + /* Clean up. */ free (rli); } - -/* Like finish_record_layout, but for unions. */ - -static void -finish_union_layout (rli) - record_layout_info rli; -{ - /* This function should only be used for unions; use - finish_record_layout for RECORD_TYPEs. */ - if (TREE_CODE (rli->t) != UNION_TYPE - && TREE_CODE (rli->t) != QUAL_UNION_TYPE) - abort (); - - /* Determine the ultimate size of the union (in bytes). */ - if (NULL == rli->var_size) - TYPE_SIZE (rli->t) - = bitsize_int (CEIL (rli->const_size, BITS_PER_UNIT) * BITS_PER_UNIT); - - else if (rli->const_size == 0) - TYPE_SIZE (rli->t) = rli->var_size; - else - TYPE_SIZE (rli->t) = size_binop (MAX_EXPR, rli->var_size, - round_up (bitsize_int (rli->const_size), - BITS_PER_UNIT)); - - /* Determine the desired alignment. */ -#ifdef ROUND_TYPE_ALIGN - TYPE_ALIGN (rli->t) = ROUND_TYPE_ALIGN (rli->t, TYPE_ALIGN (rli->t), - rli->record_align); -#else - TYPE_ALIGN (rli->t) = MAX (TYPE_ALIGN (rli->t), rli->record_align); -#endif - -#ifdef ROUND_TYPE_SIZE - TYPE_SIZE (rli->t) = ROUND_TYPE_SIZE (rli->t, TYPE_SIZE (rli->t), - TYPE_ALIGN (rli->t)); -#else - /* Round the size up to be a multiple of the required alignment */ - TYPE_SIZE (rli->t) = round_up (TYPE_SIZE (rli->t), - TYPE_ALIGN (rli->t)); -#endif - - TYPE_MODE (rli->t) = BLKmode; - if (TREE_CODE (TYPE_SIZE (rli->t)) == INTEGER_CST - /* If structure's known alignment is less than - what the scalar mode would need, and it matters, - then stick with BLKmode. */ - && (! STRICT_ALIGNMENT - || TYPE_ALIGN (rli->t) >= BIGGEST_ALIGNMENT - || compare_tree_int (TYPE_SIZE (rli->t), - TYPE_ALIGN (rli->t)) <= 0)) - { - tree field; - - /* A union which has any BLKmode members must itself be BLKmode; - it can't go in a register. - Unless the member is BLKmode only because it isn't aligned. */ - for (field = TYPE_FIELDS (rli->t); - field; - field = TREE_CHAIN (field)) - { - if (TREE_CODE (field) != FIELD_DECL) - continue; - - if (TYPE_MODE (TREE_TYPE (field)) == BLKmode - && ! TYPE_NO_FORCE_BLK (TREE_TYPE (field))) - return; - } - - TYPE_MODE (rli->t) - = mode_for_size_tree (TYPE_SIZE (rli->t), MODE_INT, 1); - } -} - /* Calculate the mode, size, and alignment for TYPE. For an array type, calculate the element separation as well. @@ -1163,8 +1192,7 @@ layout_type (type) break; case VOID_TYPE: - /* VOID_TYPE is an incompletable type, it has no size */ - TYPE_SIZE_UNIT (type) = size_zero_node; + /* This is an incomplete type and so doesn't have a size. */ TYPE_ALIGN (type) = 1; TYPE_MODE (type) = VOIDmode; break; @@ -1325,17 +1353,21 @@ layout_type (type) record_layout_info rli; /* Initialize the layout information. */ - rli = new_record_layout_info (type); + rli = start_record_layout (type); + /* If this is a QUAL_UNION_TYPE, we want to process the fields in the reverse order in building the COND_EXPR that denotes its size. We reverse them again later. */ if (TREE_CODE (type) == QUAL_UNION_TYPE) TYPE_FIELDS (type) = nreverse (TYPE_FIELDS (type)); - /* Layout all the fields. */ + + /* Place all the fields. */ for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) - layout_field (rli, field); + place_field (rli, field); + if (TREE_CODE (type) == QUAL_UNION_TYPE) TYPE_FIELDS (type) = nreverse (TYPE_FIELDS (type)); + /* Finish laying out the record. */ finish_record_layout (rli); } @@ -1448,6 +1480,7 @@ initialize_sizetypes () TREE_UNSIGNED (t) = 1; TYPE_PRECISION (t) = GET_MODE_BITSIZE (SImode); TYPE_MIN_VALUE (t) = build_int_2 (0, 0); + TYPE_IS_SIZETYPE (t) = 1; /* 1000 avoids problems with possible overflow and is certainly larger than any size value we'd want to be storing. */ @@ -1483,9 +1516,11 @@ set_sizetype (type) /* Make copies of nodes since we'll be setting TYPE_IS_SIZETYPE. */ sizetype = copy_node (type); TYPE_DOMAIN (sizetype) = type; + TYPE_IS_SIZETYPE (sizetype) = 1; bitsizetype = make_node (INTEGER_TYPE); TYPE_NAME (bitsizetype) = TYPE_NAME (type); TYPE_PRECISION (bitsizetype) = precision; + TYPE_IS_SIZETYPE (bitsizetype) = 1; if (TREE_UNSIGNED (type)) fixup_unsigned_type (bitsizetype); @@ -1624,7 +1659,7 @@ get_best_mode (bitsize, bitpos, align, largest_mode, volatilep) int volatilep; { enum machine_mode mode; - int unit = 0; + unsigned int unit = 0; /* Find the narrowest integer mode that contains the bit field. */ for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT); mode != VOIDmode; @@ -1643,7 +1678,7 @@ get_best_mode (bitsize, bitpos, align, largest_mode, volatilep) if the extra 4th byte is past the end of memory. (Though at least one Unix compiler ignores this problem: that on the Sequent 386 machine. */ - || MIN (unit, BIGGEST_ALIGNMENT) > (int) align + || MIN (unit, BIGGEST_ALIGNMENT) > align || (largest_mode != VOIDmode && unit > GET_MODE_BITSIZE (largest_mode))) return VOIDmode; @@ -1657,7 +1692,7 @@ get_best_mode (bitsize, bitpos, align, largest_mode, volatilep) unit = GET_MODE_BITSIZE (tmode); if (bitpos / unit == (bitpos + bitsize - 1) / unit && unit <= BITS_PER_WORD - && unit <= (int) MIN (align, BIGGEST_ALIGNMENT) + && unit <= MIN (align, BIGGEST_ALIGNMENT) && (largest_mode == VOIDmode || unit <= GET_MODE_BITSIZE (largest_mode))) wide_mode = tmode; |