+/* C-compiler utilities for types and variables storage layout
+ Copyright (C) 1987, 1988 Free Software Foundation, Inc.
+
+This file is part of GNU CC.
+
+GNU CC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 1, or (at your option)
+any later version.
+
+GNU CC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU CC; see the file COPYING. If not, write to
+the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+
+#include "config.h"
+#include <stdio.h>
+
+#include "tree.h"
+#include "rtl.h" /* For GET_MODE_SIZE */
+
+#define MAX(x,y) ((x) > (y) ? (x) : (y))
+#define MIN(x,y) ((x) < (y) ? (x) : (y))
+#define CEIL(x,y) (((x) + (y) - 1) / (y))
+
+/* Data type for the expressions representing sizes of data types.
+ It is the first integer type laid out.
+ In C, this is int. */
+
+tree sizetype;
+
+/* An integer constant with value 0 whose type is sizetype. */
+
+tree size_zero_node;
+
+/* An integer constant with value 1 whose type is sizetype. */
+
+tree size_one_node;
+
+/* Integer constants with sizes for pointers and reference types,
+ function types, and method types respectively. */
+static tree ptr_size_node, function_size_node, method_size_node;
+
+#define GET_MODE_ALIGNMENT(MODE) \
+ MIN (BIGGEST_ALIGNMENT, \
+ MAX (1, (GET_MODE_UNIT_SIZE (MODE) * BITS_PER_UNIT)))
+\f
+/* Chain of all permanent types we have allocated since last
+ call to get_permanent_types. */
+
+tree permanent_type_chain;
+
+/* Chain of all temporary types we have allocated in this function. */
+
+tree temporary_type_chain;
+
+/* When the chains is not null, these point at the last
+ types on the two chains. These help us tell whether a type
+ is already on a chain. */
+tree permanent_type_end;
+tree temporary_type_end;
+
+/* Put the newly-made type T
+ on either permanent_type_chain or temporary_type_chain.
+ Types that are const or volatile variants of other types
+ are not put on any chain, since in the gdb symbol segment
+ we do not make those distinctions.
+
+ If T is already on the chain, we do nothing. */
+
+void
+chain_type (t)
+ tree t;
+{
+ if (TYPE_MAIN_VARIANT (t) != t)
+ return;
+ if (TREE_CHAIN (t) != 0)
+ return;
+ if (TREE_PERMANENT (t))
+ {
+ /* If T is on the chain at the end, don't chain it to itself! */
+ if (t == permanent_type_end)
+ return;
+ /* Add T to the end of the chain. */
+ if (permanent_type_chain == 0)
+ permanent_type_chain = t;
+ else
+ TREE_CHAIN (permanent_type_end) = t;
+ permanent_type_end = t;
+ }
+ else
+ {
+ if (t == temporary_type_end)
+ return;
+ if (temporary_type_chain == 0)
+ temporary_type_chain = t;
+ else
+ TREE_CHAIN (temporary_type_end) = t;
+ temporary_type_end = t;
+ }
+}
+
+/* Get a chain of all permanent types made since this function
+ was last called. */
+
+tree
+get_permanent_types ()
+{
+ register tree tem = permanent_type_chain;
+ permanent_type_chain = 0;
+ permanent_type_end = 0;
+ return tem;
+}
+
+/* Get a chain of all temporary types made since this function
+ was last called. */
+
+tree
+get_temporary_types ()
+{
+ register tree tem = temporary_type_chain;
+ temporary_type_chain = 0;
+ temporary_type_end = 0;
+ return tem;
+}
+\f
+/* SAVE_EXPRs for sizes of types and decls, waiting to be expanded. */
+
+static tree pending_sizes;
+
+/* Nonzero means cannot safely call expand_expr now,
+ so put variable sizes onto `pending_sizes' instead. */
+
+int immediate_size_expand;
+
+tree
+get_pending_sizes ()
+{
+ tree chain = pending_sizes;
+ pending_sizes = 0;
+ return chain;
+}
+
+/* Given a size SIZE that isn't constant, return a SAVE_EXPR
+ to serve as the actual size-expression for a type or decl. */
+
+static tree
+variable_size (size)
+ tree size;
+{
+ size = save_expr (size);
+
+ if (global_bindings_p ())
+ {
+ error ("variable-size type declared outside of any function");
+ return build_int (1);
+ }
+
+ if (immediate_size_expand)
+ expand_expr (size, 0, VOIDmode, 0);
+ else
+ pending_sizes = tree_cons (0, size, pending_sizes);
+
+ return size;
+}
+\f
+/* Return the machine mode to use for an aggregate of SIZE bits.
+
+ Note!!! We only use a non-BLKmode mode if the size matches exactly.
+ There used to be the idea of using DImode for anything whose
+ size was less than DImode but more than SImode. This does not work
+ because DImode moves cannot be used to store such objects in memory. */
+
+#ifndef MAX_FIXED_MODE_SIZE
+#define MAX_FIXED_MODE_SIZE GET_MODE_BITSIZE (DImode)
+#endif
+
+static
+enum machine_mode
+agg_mode (size)
+ unsigned int size;
+{
+ register int units = size / BITS_PER_UNIT;
+ register enum machine_mode t, val;
+
+ if (size % BITS_PER_UNIT != 0)
+ return BLKmode;
+
+ if (size > MAX_FIXED_MODE_SIZE)
+ return BLKmode;
+
+ /* Get the last mode which has this size. */
+ val = BLKmode;
+ for (t = QImode; GET_MODE_CLASS (t) == MODE_INT;
+ t = (enum machine_mode) ((int) t + 1))
+ if (GET_MODE_SIZE (t) == units)
+ val = t;
+
+ return val;
+}
+\f
+/* Return an INTEGER_CST with value V and type from `sizetype'. */
+
+tree
+build_int (v)
+ int v;
+{
+ register tree t;
+
+ t = build_int_2 (v, 0);
+ TREE_TYPE (t) = sizetype;
+ return t;
+}
+
+/* Combine operands OP1 and OP2 with arithmetic operation OPC.
+ OPC is a tree code. Data type is taken from `sizetype',
+ If the operands are constant, so is the result. */
+
+tree
+genop (opc, op1, op2)
+ enum tree_code opc;
+ tree op1, op2;
+{
+ /* Handle the special case of two integer constants faster. */
+ if (TREE_CODE (op1) == INTEGER_CST && TREE_CODE (op2) == INTEGER_CST)
+ {
+ /* And some specific cases even faster than that. */
+ if (opc == PLUS_EXPR
+ && TREE_INT_CST_LOW (op1) == 0
+ && TREE_INT_CST_HIGH (op1) == 0)
+ return op2;
+ if (opc == MINUS_EXPR
+ && TREE_INT_CST_LOW (op2) == 0
+ && TREE_INT_CST_HIGH (op2) == 0)
+ return op1;
+ if (opc == MULT_EXPR
+ && TREE_INT_CST_LOW (op1) == 1
+ && TREE_INT_CST_HIGH (op1) == 0)
+ return op2;
+ if (opc == CEIL_DIV_EXPR
+ && TREE_INT_CST_LOW (op1) == TREE_INT_CST_LOW (op2)
+ && TREE_INT_CST_HIGH (op1) == TREE_INT_CST_HIGH (op2))
+ return size_one_node;
+ /* Handle general case of two integer constants. */
+ return combine (opc, op1, op2);
+ }
+
+ if (op1 == error_mark_node || op2 == error_mark_node)
+ return error_mark_node;
+
+ return fold (build (opc, sizetype, op1, op2));
+}
+
+/* Convert a size which is SIZE when expressed in unit INUNITS
+ into the units OUTUNITS. Rounds up if conversion is not exact.
+ If SIZE is constant, so is the result. */
+
+tree
+convert_units (size, inunits, outunits)
+ tree size;
+ register int inunits, outunits;
+{
+ register tree t;
+
+ if (inunits == outunits)
+ return size;
+ /* Check for inunits divisible by outunits.
+ In that case, just multiply by their ratio. */
+ if (0 == (inunits % outunits))
+ return genop (MULT_EXPR, size, build_int (inunits / outunits));
+ /* The inverse case. */
+ if (0 == (outunits % inunits))
+ {
+ /* Discard anything in SIZE to round it up to a multiple
+ of a number N that divides our current divisor. */
+ if (TREE_CODE (size) == MULT_EXPR
+ && TREE_CODE (TREE_OPERAND (size, 1)) == INTEGER_CST
+ && 0 == (outunits / inunits) % TREE_INT_CST_LOW (TREE_OPERAND (size, 1))
+ && TREE_CODE (TREE_OPERAND (size, 0)) == CEIL_DIV_EXPR
+ && tree_int_cst_equal (TREE_OPERAND (size, 1),
+ TREE_OPERAND (TREE_OPERAND (size, 0), 1)))
+ size = TREE_OPERAND (TREE_OPERAND (size, 0), 0);
+ return genop (CEIL_DIV_EXPR, size, build_int (outunits / inunits));
+ }
+ /* The general case. */
+ t = genop (MULT_EXPR, size,
+ build_int (inunits)); /* convert to bits */
+ return genop (CEIL_DIV_EXPR, t,
+ build_int (outunits)); /* then to outunits */
+}
+\f
+/* Set the size, mode and alignment of a ..._DECL node.
+ TYPE_DECL does need this for C++. It is up to language-specific
+ code to intialize the DECL_OFFSET of TYPE_DECL nodes.
+ Note that LABEL_DECL and CONST_DECL nodes do not need this,
+ and FUNCTION_DECL nodes have them set up in a special (and simple) way.
+ Don't call layout_decl for them.
+
+ KNOWN_ALIGN is the amount of alignment we can assume this
+ decl has with no special effort. It is relevant only for FIELD_DECLs
+ and depends on the previous fields.
+ All that matters about KNOWN_ALIGN is which powers of 2 divide it.
+ If KNOWN_ALIGN is 0, it means, "as much alignment as you like":
+ the record will be aligned to suit. */
+
+void
+layout_decl (decl, known_align)
+ tree decl;
+ unsigned known_align;
+{
+ register tree type = TREE_TYPE (decl);
+ register enum tree_code code = TREE_CODE (decl);
+ int spec_size = DECL_SIZE_UNIT (decl);
+ int bitsize;
+
+ if (code == CONST_DECL)
+ return;
+
+ if (code != VAR_DECL && code != PARM_DECL && code != RESULT_DECL
+ && code != FIELD_DECL && code != TYPE_DECL)
+ abort ();
+
+ if (type == error_mark_node)
+ {
+ type = void_type_node;
+ spec_size = 0;
+ }
+ if (TYPE_SIZE_UNIT (type) == 0)
+ abort ();
+
+ /* Usually the size and mode come from the data type without change. */
+
+ DECL_MODE (decl) = TYPE_MODE (type);
+ DECL_SIZE (decl) = TYPE_SIZE (type);
+ DECL_SIZE_UNIT (decl) = TYPE_SIZE_UNIT (type);
+ TREE_UNSIGNED (decl) = TREE_UNSIGNED (type);
+
+ if (code == FIELD_DECL && TREE_PACKED (decl))
+ {
+ /* This is a bit-field. We don't know how to handle
+ them except for integers and enums, and front end should
+ never generate them otherwise. */
+
+ if (! (TREE_CODE (type) == INTEGER_TYPE
+ || TREE_CODE (type) == ENUMERAL_TYPE))
+ abort ();
+
+ if (spec_size == 0)
+ abort ();
+
+ /* Mode is "integer bit field". */
+ DECL_MODE (decl) = BImode;
+ /* Size is specified number of bits. */
+ DECL_SIZE (decl) = size_one_node;
+ DECL_SIZE_UNIT (decl) = spec_size;
+ }
+ /* Force alignment required for the data type.
+ But if the decl itself wants greater alignment, don't override that. */
+ else if (TYPE_ALIGN (type) > DECL_ALIGN (decl))
+ DECL_ALIGN (decl) = TYPE_ALIGN (type);
+
+ if (DECL_SIZE (decl))
+ bitsize = TREE_INT_CST_LOW (DECL_SIZE (decl)) * DECL_SIZE_UNIT (decl);
+
+ /* See if we can use a scalar mode such as QImode or SImode
+ in place of BLKmode or a packed byte mode. */
+ /* Conditions are: a fixed size that is correct for another mode
+ and occupying a complete byte or bytes on proper boundary. */
+ if ((DECL_MODE (decl) == BLKmode
+ || DECL_MODE (decl) == BImode)
+ /* Don't do this if DECL's type requires it to be BLKmode. */
+ && TYPE_MODE (type) != BLKmode
+ && TYPE_SIZE (type) != 0
+ && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST)
+ {
+ register enum machine_mode xmode = agg_mode (bitsize);
+
+ if (xmode != BLKmode
+ && known_align % GET_MODE_ALIGNMENT (xmode) == 0)
+ {
+ DECL_ALIGN (decl) = MAX (GET_MODE_ALIGNMENT (xmode),
+ DECL_ALIGN (decl));
+ DECL_MODE (decl) = xmode;
+ DECL_SIZE (decl) = build_int (GET_MODE_SIZE (xmode));
+ DECL_SIZE_UNIT (decl) = BITS_PER_UNIT;
+ bitsize = GET_MODE_BITSIZE (xmode);
+ }
+ }
+
+ /* Don't let more than one word of an aggregate occupy one register,
+ since then the SUBREG used to access the high part would malfunction.
+ Check that the expected # of registers is big enough that they
+ seem to hold this variable with just a word per register. */
+ if (DECL_SIZE (decl) != 0
+ && (TREE_CODE (type) == RECORD_TYPE
+ || TREE_CODE (type) == UNION_TYPE
+ || TREE_CODE (type) == ARRAY_TYPE))
+ {
+ /* This test is not exactly right, since we really want the minimum
+ number of regs in any class that can hold this mode.
+ But it does distinguish the machines we need to distinguish,
+ for now. */
+ if (CLASS_MAX_NREGS (ALL_REGS, TYPE_MODE (type)) * BITS_PER_WORD
+ < bitsize)
+ TREE_ADDRESSABLE (decl) = 1;
+ }
+
+ /* Evaluate nonconstant size only once, either now or as soon as safe. */
+ if (DECL_SIZE (decl) != 0 && ! TREE_LITERAL (DECL_SIZE (decl)))
+ DECL_SIZE (decl) = variable_size (DECL_SIZE (decl));
+}
+\f
+/* Lay out a RECORD_TYPE type (a C struct).
+ This means laying out the fields, determining their offsets,
+ and computing the overall size and required alignment of the record.
+ Note that if you set the TYPE_ALIGN before calling this
+ then the struct is aligned to at least that boundary.
+
+ If the type has basetypes, you must call layout_basetypes
+ before calling this function. */
+
+static void
+layout_record (rec)
+ tree rec;
+{
+ register tree field;
+#ifdef STRUCTURE_SIZE_BOUNDARY
+ int record_align = MAX (STRUCTURE_SIZE_BOUNDARY, TYPE_ALIGN (rec));
+#else
+ int record_align = MAX (BITS_PER_UNIT, TYPE_ALIGN (rec));
+#endif
+ /* These must be laid out *after* the record is. */
+ tree pending_statics = NULL_TREE;
+ /* Record size so far is CONST_SIZE + VAR_SIZE * SIZE_UNIT bits,
+ where CONST_SIZE is an integer
+ and VAR_SIZE is a tree expression.
+ If VAR_SIZE is null, the size is just CONST_SIZE.
+ Naturally we try to avoid using VAR_SIZE. */
+ register int const_size = 0;
+ register tree var_size = 0;
+ register int size_unit = BITS_PER_UNIT;
+
+ for (field = TYPE_FIELDS (rec); field; field = TREE_CHAIN (field))
+ {
+ register int desired_align;
+
+ /* If FIELD is a VAR_DECL, 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 it *after* the record is laid out. */
+
+ if (TREE_STATIC (field))
+ {
+ pending_statics = tree_cons (NULL, field, pending_statics);
+ continue;
+ }
+ /* Enumerators and enum types which are local to this class need not
+ be laid out. Same with initialized constant fields. */
+ if (TREE_CODE (field) != FIELD_DECL)
+ continue;
+
+ /* Lay out the field so we know what alignment it needs.
+ For KNOWN_ALIGN, pass the number of bits from start of record
+ or some divisor of it. */
+
+ layout_decl (field, var_size ? size_unit : const_size);
+ desired_align = DECL_ALIGN (field);
+
+ /* Record must have at least as much alignment as any field.
+ Otherwise, the alignment of the field within the record
+ is meaningless. */
+
+ record_align = MAX (record_align, desired_align);
+#ifdef PCC_BITFIELD_TYPE_MATTERS
+ /* In PCC on Vax, Sony, etc., a bit field of declare type `int'
+ forces the entire structure to have `int' alignment. */
+ if (DECL_NAME (field) != 0)
+ record_align = MAX (record_align, TYPE_ALIGN (TREE_TYPE (field)));
+#endif
+
+ /* Does this field automatically have alignment it needs
+ by virtue of the fields that precede it and the record's
+ own alignment? */
+
+ if (const_size % desired_align != 0
+ || (size_unit % desired_align != 0
+ && var_size))
+ {
+ /* No, we need to skip space before this field.
+ Bump the cumulative size to multiple of field alignment. */
+
+ if (var_size == 0
+ || size_unit % desired_align == 0)
+ const_size
+ = CEIL (const_size, desired_align) * desired_align;
+ else
+ {
+ var_size
+ = genop (PLUS_EXPR, var_size,
+ build_int (CEIL (const_size, size_unit)));
+ const_size = 0;
+ var_size = convert_units (var_size, size_unit, desired_align);
+ size_unit = desired_align;
+ }
+ }
+
+#ifdef PCC_BITFIELD_TYPE_MATTERS
+ if (TREE_CODE (field) == FIELD_DECL
+ && TREE_TYPE (field) != error_mark_node)
+ {
+ int type_align = TYPE_ALIGN (TREE_TYPE (field));
+ register tree dsize = DECL_SIZE (field);
+ int field_size = TREE_INT_CST_LOW (dsize) * DECL_SIZE_UNIT (field);
+
+ /* A bit field may not span the unit of alignment of its type.
+ Advance to next boundary if necessary. */
+ if (const_size / type_align
+ != (const_size + field_size - 1) / type_align)
+ const_size = CEIL (const_size, type_align) * type_align;
+ }
+#endif
+
+ /* Size so far becomes the offset of this field. */
+
+ DECL_OFFSET (field) = const_size;
+ DECL_VOFFSET (field) = var_size;
+ DECL_VOFFSET_UNIT (field) = size_unit;
+
+ /* If this field is an anonymous union,
+ give each union-member the same offset as the union has. */
+
+ if (DECL_NAME (field) == 0
+ && TREE_CODE (TREE_TYPE (field)) == UNION_TYPE)
+ {
+ tree uelt = TYPE_FIELDS (TREE_TYPE (field));
+ for (; uelt; uelt = TREE_CHAIN (uelt))
+ {
+ DECL_FIELD_CONTEXT (uelt) = DECL_FIELD_CONTEXT (field);
+ DECL_OFFSET (uelt) = DECL_OFFSET (field);
+ DECL_VOFFSET (uelt) = DECL_VOFFSET (field);
+ DECL_VOFFSET_UNIT (uelt) = DECL_VOFFSET_UNIT (field);
+ }
+ }
+
+ /* Now add size of this field to the size of the record. */
+
+ {
+ register tree dsize = DECL_SIZE (field);
+
+ if (TREE_LITERAL (dsize))
+ const_size += TREE_INT_CST_LOW (dsize) * DECL_SIZE_UNIT (field);
+ else if (var_size == 0)
+ {
+ var_size = dsize;
+ size_unit = DECL_SIZE_UNIT (field);
+ }
+ else
+ {
+ register int tunits = MIN (size_unit, DECL_SIZE_UNIT (field));
+ var_size
+ = genop (PLUS_EXPR,
+ convert_units (var_size, size_unit, tunits),
+ convert_units (dsize, DECL_SIZE_UNIT (field), tunits));
+ }
+ }
+ }
+
+ /* 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 (var_size == 0)
+ TYPE_SIZE (rec)
+ = build_int (CEIL (CEIL (const_size, record_align) * record_align,
+ size_unit));
+ else
+ {
+ if (const_size)
+ var_size
+ = genop (PLUS_EXPR, var_size,
+ build_int (CEIL (const_size, size_unit)));
+ TYPE_SIZE (rec)
+ = convert_units (var_size,
+ size_unit,
+ record_align);
+ size_unit = record_align;
+ }
+
+ TYPE_SIZE (rec) = convert_units (TYPE_SIZE (rec), size_unit,
+ BITS_PER_UNIT);
+ TYPE_SIZE_UNIT (rec) = BITS_PER_UNIT;
+ TYPE_ALIGN (rec) = MIN (BIGGEST_ALIGNMENT, record_align);
+
+ /* Lay out any static members. This is done now
+ because their type may use the record's type. */
+
+ for (field = pending_statics; field; field = TREE_CHAIN (field))
+ layout_decl (TREE_VALUE (field), 0);
+}
+\f
+/* Lay out a UNION_TYPE type.
+ Lay out all the fields, set their offsets to zero,
+ and compute the size and alignment of the union (maximum of any field).
+ Note that if you set the TYPE_ALIGN before calling this
+ then the union align is aligned to at least that boundary. */
+
+static void
+layout_union (rec)
+ tree rec;
+{
+ register tree field;
+#ifdef STRUCTURE_SIZE_BOUNDARY
+ int union_align = STRUCTURE_SIZE_BOUNDARY;
+#else
+ int union_align = BITS_PER_UNIT;
+#endif
+
+ /* The size of the union, based on the fields scanned so far,
+ is max (CONST_SIZE, VAR_SIZE).
+ VAR_SIZE may be null; then CONST_SIZE by itself is the size. */
+ register int const_size = 0;
+ register tree var_size = 0;
+
+ for (field = TYPE_FIELDS (rec); field; field = TREE_CHAIN (field))
+ {
+ /* Enums which are local to this class need not
+ be laid out. */
+ if (TREE_CODE (field) != FIELD_DECL)
+ continue;
+
+ layout_decl (field, 0);
+ DECL_OFFSET (field) = 0;
+ DECL_VOFFSET (field) = 0;
+ DECL_VOFFSET_UNIT (field) = BITS_PER_UNIT;
+
+ /* Union must be at least as aligned as any field requires. */
+
+ union_align = MAX (union_align, DECL_ALIGN (field));
+
+#ifdef PCC_BITFIELD_TYPE_MATTERS
+ /* On the m88000, a bit field of declare type `int'
+ forces the entire union to have `int' alignment. */
+ union_align = MAX (union_align, TYPE_ALIGN (TREE_TYPE (field)));
+#endif
+
+ /* 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_LITERAL (DECL_SIZE (field)))
+ const_size = MAX (const_size,
+ TREE_INT_CST_LOW (DECL_SIZE (field))
+ * DECL_SIZE_UNIT (field));
+ else if (var_size == 0)
+ var_size = convert_units (DECL_SIZE (field),
+ DECL_SIZE_UNIT (field),
+ BITS_PER_UNIT);
+ else
+ var_size = genop (MAX_EXPR,
+ convert_units (DECL_SIZE (field),
+ DECL_SIZE_UNIT (field),
+ BITS_PER_UNIT),
+ var_size);
+ }
+
+ /* Determine the ultimate size of the union (in bytes). */
+ if (NULL == var_size)
+ TYPE_SIZE (rec) = build_int (CEIL (const_size, BITS_PER_UNIT));
+ else if (const_size == 0)
+ TYPE_SIZE (rec) = var_size;
+ else
+ TYPE_SIZE (rec) = genop (MAX_EXPR, var_size,
+ build_int (CEIL (const_size, BITS_PER_UNIT)));
+
+ /* Determine the desired alignment. */
+ union_align = MIN (BIGGEST_ALIGNMENT, union_align);
+ TYPE_ALIGN (rec) = MAX (TYPE_ALIGN (rec), union_align);
+
+ /* Round the size up to be a multiple of the required alignment */
+ TYPE_SIZE (rec)
+ = convert_units (TYPE_SIZE (rec), BITS_PER_UNIT, TYPE_ALIGN (rec));
+ TYPE_SIZE_UNIT (rec) = TYPE_ALIGN (rec);
+}
+\f
+/* Calculate the mode, size, and alignment for TYPE.
+ For an array type, calculate the element separation as well.
+ Record TYPE on the chain of permanent or temporary types
+ so that dbxout will find out about it.
+
+ TYPE_SIZE of a type is nonzero if the type has been laid out already.
+ layout_type does nothing on such a type.
+
+ If the type is incomplete, its TYPE_SIZE remains zero. */
+
+void
+layout_type (type)
+ tree type;
+{
+ int old;
+ int temporary = 0;
+
+ if (type == 0)
+ abort ();
+
+ /* Do nothing if type has been laid out before. */
+ if (TYPE_SIZE (type))
+ return;
+
+ /* Make sure all nodes we allocate are not momentary;
+ they must last past the current statement. */
+ old = suspend_momentary ();
+ if (TREE_PERMANENT (type) && allocation_temporary_p ())
+ {
+ temporary = 1;
+ end_temporary_allocation ();
+ }
+
+ chain_type (type);
+
+ switch (TREE_CODE (type))
+ {
+ case LANG_TYPE:
+ /* This kind of type is the responsibility
+ of the languge-specific code. */
+ abort ();
+
+ case VOID_TYPE:
+ TYPE_SIZE (type) = size_zero_node;
+ TYPE_SIZE_UNIT (type) = BITS_PER_UNIT;
+ TYPE_ALIGN (type) = 1;
+ TYPE_MODE (type) = VOIDmode;
+ break;
+
+ case INTEGER_TYPE:
+ case ENUMERAL_TYPE:
+ if (TREE_INT_CST_HIGH (TYPE_MIN_VALUE (type)) >= 0)
+ TREE_UNSIGNED (type) = 1;
+
+ /* What follows is like agg_mode except that it ignores
+ MAX_FIXED_MODE_SIZE. That applies only to structures. */
+ {
+ enum machine_mode mode, t;
+
+ /* Get the last mode which has this size. */
+ mode = BLKmode;
+ for (t = QImode; GET_MODE_CLASS (t) == MODE_INT;
+ t = (enum machine_mode) ((int) t + 1))
+ if (GET_MODE_BITSIZE (t) == TYPE_PRECISION (type))
+ mode = t;
+
+ TYPE_MODE (type) = mode;
+ }
+ TYPE_SIZE (type) = build_int (GET_MODE_SIZE (TYPE_MODE (type)));
+ TYPE_SIZE_UNIT (type) = BITS_PER_UNIT;
+ TYPE_ALIGN (type) = GET_MODE_ALIGNMENT (TYPE_MODE (type));
+ break;
+
+ case REAL_TYPE:
+ {
+ register int prec = TYPE_PRECISION (type);
+ if (prec <= GET_MODE_BITSIZE (SFmode))
+ TYPE_MODE (type) = SFmode;
+ else if (prec <= GET_MODE_BITSIZE (DFmode))
+ TYPE_MODE (type) = DFmode;
+ else if (prec <= GET_MODE_BITSIZE (TFmode))
+ TYPE_MODE (type) = TFmode;
+ else
+ abort ();
+ }
+ TYPE_SIZE (type) = build_int (GET_MODE_SIZE (TYPE_MODE (type)));
+ TYPE_SIZE_UNIT (type) = BITS_PER_UNIT;
+ TYPE_ALIGN (type) = GET_MODE_ALIGNMENT (TYPE_MODE (type));
+ break;
+
+ case POINTER_TYPE:
+ case REFERENCE_TYPE:
+ TYPE_MODE (type) = Pmode;
+ TYPE_SIZE (type) = ptr_size_node;
+ TYPE_SIZE_UNIT (type) = BITS_PER_UNIT;
+ TYPE_ALIGN (type) = POINTER_BOUNDARY;
+ TREE_UNSIGNED (type) = 1;
+ TYPE_PRECISION (type) = POINTER_SIZE;
+ break;
+
+ case ARRAY_TYPE:
+ {
+ register tree index = TYPE_DOMAIN (type);
+ register tree length;
+ register tree element = TREE_TYPE (type);
+
+/* layout_type (element); */
+ build_pointer_type (element);
+
+ if (index == 0)
+ length = 0;
+ else
+ length = genop (PLUS_EXPR, size_one_node,
+ genop (MINUS_EXPR, TYPE_MAX_VALUE (index),
+ TYPE_MIN_VALUE (index)));
+
+ if (TREE_PACKED (type))
+ abort (); /* ??? Not written yet since not needed for C. */
+
+ TYPE_SIZE_UNIT (type) = TYPE_SIZE_UNIT (element);
+ if (length && TYPE_SIZE (element))
+ TYPE_SIZE (type) = genop (MULT_EXPR, TYPE_SIZE (element), length);
+ TYPE_SEP (type) = TYPE_SIZE (element);
+ TYPE_SEP_UNIT (type) = TYPE_SIZE_UNIT (element);
+ TYPE_ALIGN (type) = MAX (TYPE_ALIGN (element), BITS_PER_UNIT);
+ TYPE_MODE (type) = BLKmode;
+ if (TYPE_SIZE (type) != 0
+ && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST
+ /* BLKmode elements force BLKmode aggregate;
+ else extract/store fields may lose. */
+ && TYPE_MODE (TREE_TYPE (type)) != BLKmode
+#ifdef STRICT_ALIGNMENT
+ && (TYPE_ALIGN (type) >= BIGGEST_ALIGNMENT
+ || TYPE_ALIGN (type) >= (TREE_INT_CST_LOW (TYPE_SIZE (type))
+ * TYPE_SIZE_UNIT (type)))
+#endif
+ )
+ {
+ TYPE_MODE (type)
+ = agg_mode (TREE_INT_CST_LOW (TYPE_SIZE (type))
+ * TYPE_SIZE_UNIT (type));
+ }
+ break;
+ }
+
+ case RECORD_TYPE:
+ layout_record (type);
+ TYPE_MODE (type) = BLKmode;
+ if (TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST
+ /* If structure's known alignment is less than
+ what the scalar mode would need, and it matters,
+ then stick with BLKmode. */
+#ifdef STRICT_ALIGNMENT
+ && (TYPE_ALIGN (type) >= BIGGEST_ALIGNMENT
+ || TYPE_ALIGN (type) >= (TREE_INT_CST_LOW (TYPE_SIZE (type))
+ * TYPE_SIZE_UNIT (type)))
+#endif
+ )
+ {
+ tree field;
+ /* A record which has any BLKmode members must itself be BLKmode;
+ it can't go in a register. */
+ for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
+ {
+ if (TREE_CODE (field) != FIELD_DECL)
+ continue;
+
+ if (TYPE_MODE (TREE_TYPE (field)) == BLKmode)
+ goto record_lose;
+
+ /* Must be BLKmode if any field crosses a word boundary,
+ since extract_bit_field can't handle that in registers. */
+ if (DECL_OFFSET (field) / BITS_PER_WORD
+ != ((TREE_INT_CST_LOW (DECL_SIZE (field)) * DECL_SIZE_UNIT (field)
+ + DECL_OFFSET (field) - 1)
+ / BITS_PER_WORD))
+ goto record_lose;
+ }
+
+ TYPE_MODE (type)
+ = agg_mode (TREE_INT_CST_LOW (TYPE_SIZE (type))
+ * TYPE_SIZE_UNIT (type));
+ record_lose: ;
+ }
+ break;
+
+ case UNION_TYPE:
+ layout_union (type);
+ TYPE_MODE (type) = BLKmode;
+ if (TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST
+ /* If structure's known alignment is less than
+ what the scalar mode would need, and it matters,
+ then stick with BLKmode. */
+#ifdef STRICT_ALIGNMENT
+ && (TYPE_ALIGN (type) >= BIGGEST_ALIGNMENT
+ || TYPE_ALIGN (type) >= (TREE_INT_CST_LOW (TYPE_SIZE (type))
+ * TYPE_SIZE_UNIT (type)))
+#endif
+ )
+ {
+ tree field;
+ /* A union which has any BLKmode members must itself be BLKmode;
+ it can't go in a register. */
+ for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
+ if (TYPE_MODE (TREE_TYPE (field)) == BLKmode)
+ goto union_lose;
+
+ TYPE_MODE (type)
+ = agg_mode (TREE_INT_CST_LOW (TYPE_SIZE (type))
+ * TYPE_SIZE_UNIT (type));
+ union_lose: ;
+ }
+ break;
+
+ case FUNCTION_TYPE:
+ TYPE_MODE (type) = EPmode;
+ TYPE_SIZE (type) = function_size_node;
+ TYPE_SIZE_UNIT (type) = BITS_PER_UNIT;
+ TYPE_ALIGN (type) = POINTER_BOUNDARY;
+ break;
+
+ case METHOD_TYPE:
+ TYPE_MODE (type) = EPmode;
+ TYPE_SIZE (type) = method_size_node;
+ TYPE_SIZE_UNIT (type) = BITS_PER_UNIT;
+ TYPE_ALIGN (type) = POINTER_BOUNDARY;
+ break;
+
+ default:
+ abort ();
+ } /* end switch */
+
+ /* Evaluate nonconstant size only once, either now or as soon as safe. */
+ if (TYPE_SIZE (type) != 0 && ! TREE_LITERAL (TYPE_SIZE (type)))
+ TYPE_SIZE (type) = variable_size (TYPE_SIZE (type));
+
+ /* Also layout any other variants of the type. */
+ if (TYPE_NEXT_VARIANT (type)
+ || type != TYPE_MAIN_VARIANT (type))
+ {
+ tree variant;
+ /* Record layout info of this variant. */
+ tree size = TYPE_SIZE (type);
+ int size_unit = TYPE_SIZE_UNIT (type);
+ int align = TYPE_ALIGN (type);
+ enum machine_mode mode = TYPE_MODE (type);
+
+ /* Copy it into all variants. */
+ for (variant = TYPE_MAIN_VARIANT (type);
+ variant;
+ variant = TYPE_NEXT_VARIANT (variant))
+ {
+ TYPE_SIZE (variant) = size;
+ TYPE_SIZE_UNIT (variant) = size_unit;
+ TYPE_ALIGN (variant) = align;
+ TYPE_MODE (variant) = mode;
+ }
+ }
+
+ if (temporary)
+ resume_temporary_allocation ();
+ resume_momentary (old);
+}
+\f
+/* Create and return a type for signed integers of PRECISION bits. */
+
+tree
+make_signed_type (precision)
+ int precision;
+{
+ register tree type = make_node (INTEGER_TYPE);
+
+ TYPE_PRECISION (type) = precision;
+
+ /* Create the extreme values based on the number of bits. */
+
+ TYPE_MIN_VALUE (type)
+ = build_int_2 ((precision-HOST_BITS_PER_INT > 0 ? 0 : (-1)<<(precision-1)),
+ (-1)<<(precision-HOST_BITS_PER_INT-1 > 0
+ ? precision-HOST_BITS_PER_INT-1
+ : 0));
+ TYPE_MAX_VALUE (type)
+ = build_int_2 ((precision-HOST_BITS_PER_INT > 0 ? -1 : (1<<(precision-1))-1),
+ (precision-HOST_BITS_PER_INT-1 > 0
+ ? (1<<(precision-HOST_BITS_PER_INT-1))-1
+ : 0));
+
+ /* Give this type's extreme values this type as their type. */
+
+ TREE_TYPE (TYPE_MIN_VALUE (type)) = type;
+ TREE_TYPE (TYPE_MAX_VALUE (type)) = type;
+
+ /* The first type made with this or `make_unsigned_type'
+ is the type for size values. */
+
+ if (sizetype == 0)
+ {
+ sizetype = type;
+ ptr_size_node = build_int (POINTER_SIZE / BITS_PER_UNIT);
+ function_size_node = ptr_size_node;
+ method_size_node = build_int (2 * POINTER_SIZE / BITS_PER_UNIT);
+ }
+
+ /* Lay out the type: set its alignment, size, etc. */
+
+ layout_type (type);
+
+ return type;
+}
+
+/* Create and return a type for unsigned integers of PRECISION bits. */
+
+tree
+make_unsigned_type (precision)
+ int precision;
+{
+ register tree type = make_node (INTEGER_TYPE);
+
+ TYPE_PRECISION (type) = precision;
+
+ /* The first type made with this or `make_unsigned_type'
+ is the type for size values. */
+
+ if (sizetype == 0)
+ {
+ sizetype = type;
+ ptr_size_node = build_int (POINTER_SIZE / BITS_PER_UNIT);
+ function_size_node = ptr_size_node;
+ method_size_node = build_int (2 * POINTER_SIZE / BITS_PER_UNIT);
+ }
+
+ fixup_unsigned_type (type);
+ return type;
+}
+
+/* Set the extreme values of TYPE based on its precision in bits,
+ the lay it out. This is used both in `make_unsigned_type'
+ and for enumeral types. */
+
+void
+fixup_unsigned_type (type)
+ tree type;
+{
+ register int precision = TYPE_PRECISION (type);
+
+ TYPE_MIN_VALUE (type) = build_int_2 (0, 0);
+ TYPE_MAX_VALUE (type)
+ = build_int_2 (precision-HOST_BITS_PER_INT >= 0 ? -1 : (1<<precision)-1,
+ precision-HOST_BITS_PER_INT > 0
+ ? ((unsigned) ~0
+ >> (HOST_BITS_PER_INT - (precision - HOST_BITS_PER_INT)))
+ : 0);
+ TREE_TYPE (TYPE_MIN_VALUE (type)) = type;
+ TREE_TYPE (TYPE_MAX_VALUE (type)) = type;
+
+ /* Lay out the type: set its alignment, size, etc. */
+
+ layout_type (type);
+}
projects / unix-history / commitdiff