Google Git
Sign in
gnu / gcc / cd99b30c7cf1e68ef76ed2af7a41ac74c78116fe / . / gcc / tree.c
blob: a33596d6be3f1e4ce0415ff0842a44c2ae85dbb3 [file] [log] [blame]
/* Language-independent node constructors for parse phase of GNU compiler.
Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
Free Software Foundation, Inc.
This file is part of GCC.
GCC 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 3, or (at your option) any later
version.
GCC 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 GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
/* This file contains the low level primitives for operating on tree nodes,
including allocation, list operations, interning of identifiers,
construction of data type nodes and statement nodes,
and construction of type conversion nodes. It also contains
tables index by tree code that describe how to take apart
nodes of that code.
It is intended to be language-independent, but occasionally
calls language-dependent routines defined (for C) in typecheck.c. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "flags.h"
#include "tree.h"
#include "real.h"
#include "tm_p.h"
#include "function.h"
#include "obstack.h"
#include "toplev.h"
#include "ggc.h"
#include "hashtab.h"
#include "output.h"
#include "target.h"
#include "langhooks.h"
#include "tree-iterator.h"
#include "basic-block.h"
#include "tree-flow.h"
#include "params.h"
#include "pointer-set.h"
#include "fixed-value.h"
/* Tree code classes. */
#define DEFTREECODE(SYM, NAME, TYPE, LENGTH) TYPE,
#define END_OF_BASE_TREE_CODES tcc_exceptional,
const enum tree_code_class tree_code_type[] = {
#include "all-tree.def"
};
#undef DEFTREECODE
#undef END_OF_BASE_TREE_CODES
/* Table indexed by tree code giving number of expression
operands beyond the fixed part of the node structure.
Not used for types or decls. */
#define DEFTREECODE(SYM, NAME, TYPE, LENGTH) LENGTH,
#define END_OF_BASE_TREE_CODES 0,
const unsigned char tree_code_length[] = {
#include "all-tree.def"
};
#undef DEFTREECODE
#undef END_OF_BASE_TREE_CODES
/* Names of tree components.
Used for printing out the tree and error messages. */
#define DEFTREECODE(SYM, NAME, TYPE, LEN) NAME,
#define END_OF_BASE_TREE_CODES "@dummy",
const char *const tree_code_name[] = {
#include "all-tree.def"
};
#undef DEFTREECODE
#undef END_OF_BASE_TREE_CODES
/* Each tree code class has an associated string representation.
These must correspond to the tree_code_class entries. */
const char *const tree_code_class_strings[] =
{
"exceptional",
"constant",
"type",
"declaration",
"reference",
"comparison",
"unary",
"binary",
"statement",
"vl_exp",
"expression"
};
/* obstack.[ch] explicitly declined to prototype this. */
extern int _obstack_allocated_p (struct obstack *h, void *obj);
#ifdef GATHER_STATISTICS
/* Statistics-gathering stuff. */
int tree_node_counts[(int) all_kinds];
int tree_node_sizes[(int) all_kinds];
/* Keep in sync with tree.h:enum tree_node_kind. */
static const char * const tree_node_kind_names[] = {
"decls",
"types",
"blocks",
"stmts",
"refs",
"exprs",
"constants",
"identifiers",
"perm_tree_lists",
"temp_tree_lists",
"vecs",
"binfos",
"ssa names",
"constructors",
"random kinds",
"lang_decl kinds",
"lang_type kinds",
"omp clauses",
};
#endif /* GATHER_STATISTICS */
/* Unique id for next decl created. */
static GTY(()) int next_decl_uid;
/* Unique id for next type created. */
static GTY(()) int next_type_uid = 1;
/* Since we cannot rehash a type after it is in the table, we have to
keep the hash code. */
struct type_hash GTY(())
{
unsigned long hash;
tree type;
};
/* Initial size of the hash table (rounded to next prime). */
#define TYPE_HASH_INITIAL_SIZE 1000
/* Now here is the hash table. When recording a type, it is added to
the slot whose index is the hash code. Note that the hash table is
used for several kinds of types (function types, array types and
array index range types, for now). While all these live in the
same table, they are completely independent, and the hash code is
computed differently for each of these. */
static GTY ((if_marked ("type_hash_marked_p"), param_is (struct type_hash)))
htab_t type_hash_table;
/* Hash table and temporary node for larger integer const values. */
static GTY (()) tree int_cst_node;
static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node)))
htab_t int_cst_hash_table;
/* Hash table for optimization flags and target option flags. Use the same
hash table for both sets of options. Nodes for building the current
optimization and target option nodes. The assumption is most of the time
the options created will already be in the hash table, so we avoid
allocating and freeing up a node repeatably. */
static GTY (()) tree cl_optimization_node;
static GTY (()) tree cl_target_option_node;
static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node)))
htab_t cl_option_hash_table;
/* General tree->tree mapping structure for use in hash tables. */
static GTY ((if_marked ("tree_map_marked_p"), param_is (struct tree_map)))
htab_t debug_expr_for_decl;
static GTY ((if_marked ("tree_map_marked_p"), param_is (struct tree_map)))
htab_t value_expr_for_decl;
static GTY ((if_marked ("tree_priority_map_marked_p"),
param_is (struct tree_priority_map)))
htab_t init_priority_for_decl;
static GTY ((if_marked ("tree_map_marked_p"), param_is (struct tree_map)))
htab_t restrict_base_for_decl;
static void set_type_quals (tree, int);
static int type_hash_eq (const void *, const void *);
static hashval_t type_hash_hash (const void *);
static hashval_t int_cst_hash_hash (const void *);
static int int_cst_hash_eq (const void *, const void *);
static hashval_t cl_option_hash_hash (const void *);
static int cl_option_hash_eq (const void *, const void *);
static void print_type_hash_statistics (void);
static void print_debug_expr_statistics (void);
static void print_value_expr_statistics (void);
static int type_hash_marked_p (const void *);
static unsigned int type_hash_list (const_tree, hashval_t);
static unsigned int attribute_hash_list (const_tree, hashval_t);
tree global_trees[TI_MAX];
tree integer_types[itk_none];
unsigned char tree_contains_struct[MAX_TREE_CODES][64];
/* Number of operands for each OpenMP clause. */
unsigned const char omp_clause_num_ops[] =
{
0, /* OMP_CLAUSE_ERROR */
1, /* OMP_CLAUSE_PRIVATE */
1, /* OMP_CLAUSE_SHARED */
1, /* OMP_CLAUSE_FIRSTPRIVATE */
2, /* OMP_CLAUSE_LASTPRIVATE */
4, /* OMP_CLAUSE_REDUCTION */
1, /* OMP_CLAUSE_COPYIN */
1, /* OMP_CLAUSE_COPYPRIVATE */
1, /* OMP_CLAUSE_IF */
1, /* OMP_CLAUSE_NUM_THREADS */
1, /* OMP_CLAUSE_SCHEDULE */
0, /* OMP_CLAUSE_NOWAIT */
0, /* OMP_CLAUSE_ORDERED */
0, /* OMP_CLAUSE_DEFAULT */
3, /* OMP_CLAUSE_COLLAPSE */
0 /* OMP_CLAUSE_UNTIED */
};
const char * const omp_clause_code_name[] =
{
"error_clause",
"private",
"shared",
"firstprivate",
"lastprivate",
"reduction",
"copyin",
"copyprivate",
"if",
"num_threads",
"schedule",
"nowait",
"ordered",
"default",
"collapse",
"untied"
};
/* Init tree.c. */
void
init_ttree (void)
{
/* Initialize the hash table of types. */
type_hash_table = htab_create_ggc (TYPE_HASH_INITIAL_SIZE, type_hash_hash,
type_hash_eq, 0);
debug_expr_for_decl = htab_create_ggc (512, tree_map_hash,
tree_map_eq, 0);
value_expr_for_decl = htab_create_ggc (512, tree_map_hash,
tree_map_eq, 0);
init_priority_for_decl = htab_create_ggc (512, tree_priority_map_hash,
tree_priority_map_eq, 0);
restrict_base_for_decl = htab_create_ggc (256, tree_map_hash,
tree_map_eq, 0);
int_cst_hash_table = htab_create_ggc (1024, int_cst_hash_hash,
int_cst_hash_eq, NULL);
int_cst_node = make_node (INTEGER_CST);
cl_option_hash_table = htab_create_ggc (64, cl_option_hash_hash,
cl_option_hash_eq, NULL);
cl_optimization_node = make_node (OPTIMIZATION_NODE);
cl_target_option_node = make_node (TARGET_OPTION_NODE);
tree_contains_struct[FUNCTION_DECL][TS_DECL_NON_COMMON] = 1;
tree_contains_struct[TRANSLATION_UNIT_DECL][TS_DECL_NON_COMMON] = 1;
tree_contains_struct[TYPE_DECL][TS_DECL_NON_COMMON] = 1;
tree_contains_struct[CONST_DECL][TS_DECL_COMMON] = 1;
tree_contains_struct[VAR_DECL][TS_DECL_COMMON] = 1;
tree_contains_struct[PARM_DECL][TS_DECL_COMMON] = 1;
tree_contains_struct[RESULT_DECL][TS_DECL_COMMON] = 1;
tree_contains_struct[FUNCTION_DECL][TS_DECL_COMMON] = 1;
tree_contains_struct[TYPE_DECL][TS_DECL_COMMON] = 1;
tree_contains_struct[TRANSLATION_UNIT_DECL][TS_DECL_COMMON] = 1;
tree_contains_struct[LABEL_DECL][TS_DECL_COMMON] = 1;
tree_contains_struct[FIELD_DECL][TS_DECL_COMMON] = 1;
tree_contains_struct[CONST_DECL][TS_DECL_WRTL] = 1;
tree_contains_struct[VAR_DECL][TS_DECL_WRTL] = 1;
tree_contains_struct[PARM_DECL][TS_DECL_WRTL] = 1;
tree_contains_struct[RESULT_DECL][TS_DECL_WRTL] = 1;
tree_contains_struct[FUNCTION_DECL][TS_DECL_WRTL] = 1;
tree_contains_struct[LABEL_DECL][TS_DECL_WRTL] = 1;
tree_contains_struct[CONST_DECL][TS_DECL_MINIMAL] = 1;
tree_contains_struct[VAR_DECL][TS_DECL_MINIMAL] = 1;
tree_contains_struct[PARM_DECL][TS_DECL_MINIMAL] = 1;
tree_contains_struct[RESULT_DECL][TS_DECL_MINIMAL] = 1;
tree_contains_struct[FUNCTION_DECL][TS_DECL_MINIMAL] = 1;
tree_contains_struct[TYPE_DECL][TS_DECL_MINIMAL] = 1;
tree_contains_struct[TRANSLATION_UNIT_DECL][TS_DECL_MINIMAL] = 1;
tree_contains_struct[LABEL_DECL][TS_DECL_MINIMAL] = 1;
tree_contains_struct[FIELD_DECL][TS_DECL_MINIMAL] = 1;
tree_contains_struct[NAME_MEMORY_TAG][TS_DECL_MINIMAL] = 1;
tree_contains_struct[SYMBOL_MEMORY_TAG][TS_DECL_MINIMAL] = 1;
tree_contains_struct[MEMORY_PARTITION_TAG][TS_DECL_MINIMAL] = 1;
tree_contains_struct[NAME_MEMORY_TAG][TS_MEMORY_TAG] = 1;
tree_contains_struct[SYMBOL_MEMORY_TAG][TS_MEMORY_TAG] = 1;
tree_contains_struct[MEMORY_PARTITION_TAG][TS_MEMORY_TAG] = 1;
tree_contains_struct[MEMORY_PARTITION_TAG][TS_MEMORY_PARTITION_TAG] = 1;
tree_contains_struct[VAR_DECL][TS_DECL_WITH_VIS] = 1;
tree_contains_struct[FUNCTION_DECL][TS_DECL_WITH_VIS] = 1;
tree_contains_struct[TYPE_DECL][TS_DECL_WITH_VIS] = 1;
tree_contains_struct[TRANSLATION_UNIT_DECL][TS_DECL_WITH_VIS] = 1;
tree_contains_struct[VAR_DECL][TS_VAR_DECL] = 1;
tree_contains_struct[FIELD_DECL][TS_FIELD_DECL] = 1;
tree_contains_struct[PARM_DECL][TS_PARM_DECL] = 1;
tree_contains_struct[LABEL_DECL][TS_LABEL_DECL] = 1;
tree_contains_struct[RESULT_DECL][TS_RESULT_DECL] = 1;
tree_contains_struct[CONST_DECL][TS_CONST_DECL] = 1;
tree_contains_struct[TYPE_DECL][TS_TYPE_DECL] = 1;
tree_contains_struct[FUNCTION_DECL][TS_FUNCTION_DECL] = 1;
tree_contains_struct[IMPORTED_DECL][TS_DECL_MINIMAL] = 1;
tree_contains_struct[IMPORTED_DECL][TS_DECL_COMMON] = 1;
lang_hooks.init_ts ();
}
/* The name of the object as the assembler will see it (but before any
translations made by ASM_OUTPUT_LABELREF). Often this is the same
as DECL_NAME. It is an IDENTIFIER_NODE. */
tree
decl_assembler_name (tree decl)
{
if (!DECL_ASSEMBLER_NAME_SET_P (decl))
lang_hooks.set_decl_assembler_name (decl);
return DECL_WITH_VIS_CHECK (decl)->decl_with_vis.assembler_name;
}
/* Compare ASMNAME with the DECL_ASSEMBLER_NAME of DECL. */
bool
decl_assembler_name_equal (tree decl, const_tree asmname)
{
tree decl_asmname = DECL_ASSEMBLER_NAME (decl);
const char *decl_str;
const char *asmname_str;
bool test = false;
if (decl_asmname == asmname)
return true;
decl_str = IDENTIFIER_POINTER (decl_asmname);
asmname_str = IDENTIFIER_POINTER (asmname);
/* If the target assembler name was set by the user, things are trickier.
We have a leading '*' to begin with. After that, it's arguable what
is the correct thing to do with -fleading-underscore. Arguably, we've
historically been doing the wrong thing in assemble_alias by always
printing the leading underscore. Since we're not changing that, make
sure user_label_prefix follows the '*' before matching. */
if (decl_str[0] == '*')
{
size_t ulp_len = strlen (user_label_prefix);
decl_str ++;
if (ulp_len == 0)
test = true;
else if (strncmp (decl_str, user_label_prefix, ulp_len) == 0)
decl_str += ulp_len, test=true;
else
decl_str --;
}
if (asmname_str[0] == '*')
{
size_t ulp_len = strlen (user_label_prefix);
asmname_str ++;
if (ulp_len == 0)
test = true;
else if (strncmp (asmname_str, user_label_prefix, ulp_len) == 0)
asmname_str += ulp_len, test=true;
else
asmname_str --;
}
if (!test)
return false;
return strcmp (decl_str, asmname_str) == 0;
}
/* Hash asmnames ignoring the user specified marks. */
hashval_t
decl_assembler_name_hash (const_tree asmname)
{
if (IDENTIFIER_POINTER (asmname)[0] == '*')
{
const char *decl_str = IDENTIFIER_POINTER (asmname) + 1;
size_t ulp_len = strlen (user_label_prefix);
if (ulp_len == 0)
;
else if (strncmp (decl_str, user_label_prefix, ulp_len) == 0)
decl_str += ulp_len;
return htab_hash_string (decl_str);
}
return htab_hash_string (IDENTIFIER_POINTER (asmname));
}
/* Compute the number of bytes occupied by a tree with code CODE.
This function cannot be used for nodes that have variable sizes,
including TREE_VEC, STRING_CST, and CALL_EXPR. */
size_t
tree_code_size (enum tree_code code)
{
switch (TREE_CODE_CLASS (code))
{
case tcc_declaration: /* A decl node */
{
switch (code)
{
case FIELD_DECL:
return sizeof (struct tree_field_decl);
case PARM_DECL:
return sizeof (struct tree_parm_decl);
case VAR_DECL:
return sizeof (struct tree_var_decl);
case LABEL_DECL:
return sizeof (struct tree_label_decl);
case RESULT_DECL:
return sizeof (struct tree_result_decl);
case CONST_DECL:
return sizeof (struct tree_const_decl);
case TYPE_DECL:
return sizeof (struct tree_type_decl);
case FUNCTION_DECL:
return sizeof (struct tree_function_decl);
case NAME_MEMORY_TAG:
case SYMBOL_MEMORY_TAG:
return sizeof (struct tree_memory_tag);
case MEMORY_PARTITION_TAG:
return sizeof (struct tree_memory_partition_tag);
default:
return sizeof (struct tree_decl_non_common);
}
}
case tcc_type: /* a type node */
return sizeof (struct tree_type);
case tcc_reference: /* a reference */
case tcc_expression: /* an expression */
case tcc_statement: /* an expression with side effects */
case tcc_comparison: /* a comparison expression */
case tcc_unary: /* a unary arithmetic expression */
case tcc_binary: /* a binary arithmetic expression */
return (sizeof (struct tree_exp)
+ (TREE_CODE_LENGTH (code) - 1) * sizeof (tree));
case tcc_constant: /* a constant */
switch (code)
{
case INTEGER_CST: return sizeof (struct tree_int_cst);
case REAL_CST: return sizeof (struct tree_real_cst);
case FIXED_CST: return sizeof (struct tree_fixed_cst);
case COMPLEX_CST: return sizeof (struct tree_complex);
case VECTOR_CST: return sizeof (struct tree_vector);
case STRING_CST: gcc_unreachable ();
default:
return lang_hooks.tree_size (code);
}
case tcc_exceptional: /* something random, like an identifier. */
switch (code)
{
case IDENTIFIER_NODE: return lang_hooks.identifier_size;
case TREE_LIST: return sizeof (struct tree_list);
case ERROR_MARK:
case PLACEHOLDER_EXPR: return sizeof (struct tree_common);
case TREE_VEC:
case OMP_CLAUSE: gcc_unreachable ();
case SSA_NAME: return sizeof (struct tree_ssa_name);
case STATEMENT_LIST: return sizeof (struct tree_statement_list);
case BLOCK: return sizeof (struct tree_block);
case CONSTRUCTOR: return sizeof (struct tree_constructor);
case OPTIMIZATION_NODE: return sizeof (struct tree_optimization_option);
case TARGET_OPTION_NODE: return sizeof (struct tree_target_option);
default:
return lang_hooks.tree_size (code);
}
default:
gcc_unreachable ();
}
}
/* Compute the number of bytes occupied by NODE. This routine only
looks at TREE_CODE, except for those nodes that have variable sizes. */
size_t
tree_size (const_tree node)
{
const enum tree_code code = TREE_CODE (node);
switch (code)
{
case TREE_BINFO:
return (offsetof (struct tree_binfo, base_binfos)
+ VEC_embedded_size (tree, BINFO_N_BASE_BINFOS (node)));
case TREE_VEC:
return (sizeof (struct tree_vec)
+ (TREE_VEC_LENGTH (node) - 1) * sizeof (tree));
case STRING_CST:
return TREE_STRING_LENGTH (node) + offsetof (struct tree_string, str) + 1;
case OMP_CLAUSE:
return (sizeof (struct tree_omp_clause)
+ (omp_clause_num_ops[OMP_CLAUSE_CODE (node)] - 1)
* sizeof (tree));
default:
if (TREE_CODE_CLASS (code) == tcc_vl_exp)
return (sizeof (struct tree_exp)
+ (VL_EXP_OPERAND_LENGTH (node) - 1) * sizeof (tree));
else
return tree_code_size (code);
}
}
/* Return a newly allocated node of code CODE. For decl and type
nodes, some other fields are initialized. The rest of the node is
initialized to zero. This function cannot be used for TREE_VEC or
OMP_CLAUSE nodes, which is enforced by asserts in tree_code_size.
Achoo! I got a code in the node. */
tree
make_node_stat (enum tree_code code MEM_STAT_DECL)
{
tree t;
enum tree_code_class type = TREE_CODE_CLASS (code);
size_t length = tree_code_size (code);
#ifdef GATHER_STATISTICS
tree_node_kind kind;
switch (type)
{
case tcc_declaration: /* A decl node */
kind = d_kind;
break;
case tcc_type: /* a type node */
kind = t_kind;
break;
case tcc_statement: /* an expression with side effects */
kind = s_kind;
break;
case tcc_reference: /* a reference */
kind = r_kind;
break;
case tcc_expression: /* an expression */
case tcc_comparison: /* a comparison expression */
case tcc_unary: /* a unary arithmetic expression */
case tcc_binary: /* a binary arithmetic expression */
kind = e_kind;
break;
case tcc_constant: /* a constant */
kind = c_kind;
break;
case tcc_exceptional: /* something random, like an identifier. */
switch (code)
{
case IDENTIFIER_NODE:
kind = id_kind;
break;
case TREE_VEC:
kind = vec_kind;
break;
case TREE_BINFO:
kind = binfo_kind;
break;
case SSA_NAME:
kind = ssa_name_kind;
break;
case BLOCK:
kind = b_kind;
break;
case CONSTRUCTOR:
kind = constr_kind;
break;
default:
kind = x_kind;
break;
}
break;
default:
gcc_unreachable ();
}
tree_node_counts[(int) kind]++;
tree_node_sizes[(int) kind] += length;
#endif
if (code == IDENTIFIER_NODE)
t = (tree) ggc_alloc_zone_pass_stat (length, &tree_id_zone);
else
t = (tree) ggc_alloc_zone_pass_stat (length, &tree_zone);
memset (t, 0, length);
TREE_SET_CODE (t, code);
switch (type)
{
case tcc_statement:
TREE_SIDE_EFFECTS (t) = 1;
break;
case tcc_declaration:
if (CODE_CONTAINS_STRUCT (code, TS_DECL_COMMON))
{
if (code == FUNCTION_DECL)
{
DECL_ALIGN (t) = FUNCTION_BOUNDARY;
DECL_MODE (t) = FUNCTION_MODE;
}
else
DECL_ALIGN (t) = 1;
/* We have not yet computed the alias set for this declaration. */
DECL_POINTER_ALIAS_SET (t) = -1;
}
DECL_SOURCE_LOCATION (t) = input_location;
DECL_UID (t) = next_decl_uid++;
break;
case tcc_type:
TYPE_UID (t) = next_type_uid++;
TYPE_ALIGN (t) = BITS_PER_UNIT;
TYPE_USER_ALIGN (t) = 0;
TYPE_MAIN_VARIANT (t) = t;
TYPE_CANONICAL (t) = t;
/* Default to no attributes for type, but let target change that. */
TYPE_ATTRIBUTES (t) = NULL_TREE;
targetm.set_default_type_attributes (t);
/* We have not yet computed the alias set for this type. */
TYPE_ALIAS_SET (t) = -1;
break;
case tcc_constant:
TREE_CONSTANT (t) = 1;
break;
case tcc_expression:
switch (code)
{
case INIT_EXPR:
case MODIFY_EXPR:
case VA_ARG_EXPR:
case PREDECREMENT_EXPR:
case PREINCREMENT_EXPR:
case POSTDECREMENT_EXPR:
case POSTINCREMENT_EXPR:
/* All of these have side-effects, no matter what their
operands are. */
TREE_SIDE_EFFECTS (t) = 1;
break;
default:
break;
}
break;
default:
/* Other classes need no special treatment. */
break;
}
return t;
}
/* Return a new node with the same contents as NODE except that its
TREE_CHAIN is zero and it has a fresh uid. */
tree
copy_node_stat (tree node MEM_STAT_DECL)
{
tree t;
enum tree_code code = TREE_CODE (node);
size_t length;
gcc_assert (code != STATEMENT_LIST);
length = tree_size (node);
t = (tree) ggc_alloc_zone_pass_stat (length, &tree_zone);
memcpy (t, node, length);
TREE_CHAIN (t) = 0;
TREE_ASM_WRITTEN (t) = 0;
TREE_VISITED (t) = 0;
t->base.ann = 0;
if (TREE_CODE_CLASS (code) == tcc_declaration)
{
DECL_UID (t) = next_decl_uid++;
if ((TREE_CODE (node) == PARM_DECL || TREE_CODE (node) == VAR_DECL)
&& DECL_HAS_VALUE_EXPR_P (node))
{
SET_DECL_VALUE_EXPR (t, DECL_VALUE_EXPR (node));
DECL_HAS_VALUE_EXPR_P (t) = 1;
}
if (TREE_CODE (node) == VAR_DECL && DECL_HAS_INIT_PRIORITY_P (node))
{
SET_DECL_INIT_PRIORITY (t, DECL_INIT_PRIORITY (node));
DECL_HAS_INIT_PRIORITY_P (t) = 1;
}
if (TREE_CODE (node) == VAR_DECL && DECL_BASED_ON_RESTRICT_P (node))
{
SET_DECL_RESTRICT_BASE (t, DECL_GET_RESTRICT_BASE (node));
DECL_BASED_ON_RESTRICT_P (t) = 1;
}
}
else if (TREE_CODE_CLASS (code) == tcc_type)
{
TYPE_UID (t) = next_type_uid++;
/* The following is so that the debug code for
the copy is different from the original type.
The two statements usually duplicate each other
(because they clear fields of the same union),
but the optimizer should catch that. */
TYPE_SYMTAB_POINTER (t) = 0;
TYPE_SYMTAB_ADDRESS (t) = 0;
/* Do not copy the values cache. */
if (TYPE_CACHED_VALUES_P(t))
{
TYPE_CACHED_VALUES_P (t) = 0;
TYPE_CACHED_VALUES (t) = NULL_TREE;
}
}
return t;
}
/* Return a copy of a chain of nodes, chained through the TREE_CHAIN field.
For example, this can copy a list made of TREE_LIST nodes. */
tree
copy_list (tree list)
{
tree head;
tree prev, next;
if (list == 0)
return 0;
head = prev = copy_node (list);
next = TREE_CHAIN (list);
while (next)
{
TREE_CHAIN (prev) = copy_node (next);
prev = TREE_CHAIN (prev);
next = TREE_CHAIN (next);
}
return head;
}
/* Create an INT_CST node with a LOW value sign extended. */
tree
build_int_cst (tree type, HOST_WIDE_INT low)
{
/* Support legacy code. */
if (!type)
type = integer_type_node;
return build_int_cst_wide (type, low, low < 0 ? -1 : 0);
}
/* Create an INT_CST node with a LOW value zero extended. */
tree
build_int_cstu (tree type, unsigned HOST_WIDE_INT low)
{
return build_int_cst_wide (type, low, 0);
}
/* Create an INT_CST node with a LOW value in TYPE. The value is sign extended
if it is negative. This function is similar to build_int_cst, but
the extra bits outside of the type precision are cleared. Constants
with these extra bits may confuse the fold so that it detects overflows
even in cases when they do not occur, and in general should be avoided.
We cannot however make this a default behavior of build_int_cst without
more intrusive changes, since there are parts of gcc that rely on the extra
precision of the integer constants. */
tree
build_int_cst_type (tree type, HOST_WIDE_INT low)
{
unsigned HOST_WIDE_INT low1;
HOST_WIDE_INT hi;
gcc_assert (type);
fit_double_type (low, low < 0 ? -1 : 0, &low1, &hi, type);
return build_int_cst_wide (type, low1, hi);
}
/* Create an INT_CST node of TYPE and value HI:LOW. The value is truncated
and sign extended according to the value range of TYPE. */
tree
build_int_cst_wide_type (tree type,
unsigned HOST_WIDE_INT low, HOST_WIDE_INT high)
{
fit_double_type (low, high, &low, &high, type);
return build_int_cst_wide (type, low, high);
}
/* These are the hash table functions for the hash table of INTEGER_CST
nodes of a sizetype. */
/* Return the hash code code X, an INTEGER_CST. */
static hashval_t
int_cst_hash_hash (const void *x)
{
const_tree const t = (const_tree) x;
return (TREE_INT_CST_HIGH (t) ^ TREE_INT_CST_LOW (t)
^ htab_hash_pointer (TREE_TYPE (t)));
}
/* Return nonzero if the value represented by *X (an INTEGER_CST tree node)
is the same as that given by *Y, which is the same. */
static int
int_cst_hash_eq (const void *x, const void *y)
{
const_tree const xt = (const_tree) x;
const_tree const yt = (const_tree) y;
return (TREE_TYPE (xt) == TREE_TYPE (yt)
&& TREE_INT_CST_HIGH (xt) == TREE_INT_CST_HIGH (yt)
&& TREE_INT_CST_LOW (xt) == TREE_INT_CST_LOW (yt));
}
/* Create an INT_CST node of TYPE and value HI:LOW.
The returned node is always shared. For small integers we use a
per-type vector cache, for larger ones we use a single hash table. */
tree
build_int_cst_wide (tree type, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
{
tree t;
int ix = -1;
int limit = 0;
gcc_assert (type);
switch (TREE_CODE (type))
{
case POINTER_TYPE:
case REFERENCE_TYPE:
/* Cache NULL pointer. */
if (!hi && !low)
{
limit = 1;
ix = 0;
}
break;
case BOOLEAN_TYPE:
/* Cache false or true. */
limit = 2;
if (!hi && low < 2)
ix = low;
break;
case INTEGER_TYPE:
case OFFSET_TYPE:
if (TYPE_UNSIGNED (type))
{
/* Cache 0..N */
limit = INTEGER_SHARE_LIMIT;
if (!hi && low < (unsigned HOST_WIDE_INT)INTEGER_SHARE_LIMIT)
ix = low;
}
else
{
/* Cache -1..N */
limit = INTEGER_SHARE_LIMIT + 1;
if (!hi && low < (unsigned HOST_WIDE_INT)INTEGER_SHARE_LIMIT)
ix = low + 1;
else if (hi == -1 && low == -(unsigned HOST_WIDE_INT)1)
ix = 0;
}
break;
case ENUMERAL_TYPE:
break;
default:
gcc_unreachable ();
}
if (ix >= 0)
{
/* Look for it in the type's vector of small shared ints. */
if (!TYPE_CACHED_VALUES_P (type))
{
TYPE_CACHED_VALUES_P (type) = 1;
TYPE_CACHED_VALUES (type) = make_tree_vec (limit);
}
t = TREE_VEC_ELT (TYPE_CACHED_VALUES (type), ix);
if (t)
{
/* Make sure no one is clobbering the shared constant. */
gcc_assert (TREE_TYPE (t) == type);
gcc_assert (TREE_INT_CST_LOW (t) == low);
gcc_assert (TREE_INT_CST_HIGH (t) == hi);
}
else
{
/* Create a new shared int. */
t = make_node (INTEGER_CST);
TREE_INT_CST_LOW (t) = low;
TREE_INT_CST_HIGH (t) = hi;
TREE_TYPE (t) = type;
TREE_VEC_ELT (TYPE_CACHED_VALUES (type), ix) = t;
}
}
else
{
/* Use the cache of larger shared ints. */
void **slot;
TREE_INT_CST_LOW (int_cst_node) = low;
TREE_INT_CST_HIGH (int_cst_node) = hi;
TREE_TYPE (int_cst_node) = type;
slot = htab_find_slot (int_cst_hash_table, int_cst_node, INSERT);
t = (tree) *slot;
if (!t)
{
/* Insert this one into the hash table. */
t = int_cst_node;
*slot = t;
/* Make a new node for next time round. */
int_cst_node = make_node (INTEGER_CST);
}
}
return t;
}
/* Builds an integer constant in TYPE such that lowest BITS bits are ones
and the rest are zeros. */
tree
build_low_bits_mask (tree type, unsigned bits)
{
unsigned HOST_WIDE_INT low;
HOST_WIDE_INT high;
unsigned HOST_WIDE_INT all_ones = ~(unsigned HOST_WIDE_INT) 0;
gcc_assert (bits <= TYPE_PRECISION (type));
if (bits == TYPE_PRECISION (type)
&& !TYPE_UNSIGNED (type))
{
/* Sign extended all-ones mask. */
low = all_ones;
high = -1;
}
else if (bits <= HOST_BITS_PER_WIDE_INT)
{
low = all_ones >> (HOST_BITS_PER_WIDE_INT - bits);
high = 0;
}
else
{
bits -= HOST_BITS_PER_WIDE_INT;
low = all_ones;
high = all_ones >> (HOST_BITS_PER_WIDE_INT - bits);
}
return build_int_cst_wide (type, low, high);
}
/* Checks that X is integer constant that can be expressed in (unsigned)
HOST_WIDE_INT without loss of precision. */
bool
cst_and_fits_in_hwi (const_tree x)
{
if (TREE_CODE (x) != INTEGER_CST)
return false;
if (TYPE_PRECISION (TREE_TYPE (x)) > HOST_BITS_PER_WIDE_INT)
return false;
return (TREE_INT_CST_HIGH (x) == 0
|| TREE_INT_CST_HIGH (x) == -1);
}
/* Return a new VECTOR_CST node whose type is TYPE and whose values
are in a list pointed to by VALS. */
tree
build_vector (tree type, tree vals)
{
tree v = make_node (VECTOR_CST);
int over = 0;
tree link;
TREE_VECTOR_CST_ELTS (v) = vals;
TREE_TYPE (v) = type;
/* Iterate through elements and check for overflow. */
for (link = vals; link; link = TREE_CHAIN (link))
{
tree value = TREE_VALUE (link);
/* Don't crash if we get an address constant. */
if (!CONSTANT_CLASS_P (value))
continue;
over |= TREE_OVERFLOW (value);
}
TREE_OVERFLOW (v) = over;
return v;
}
/* Return a new VECTOR_CST node whose type is TYPE and whose values
are extracted from V, a vector of CONSTRUCTOR_ELT. */
tree
build_vector_from_ctor (tree type, VEC(constructor_elt,gc) *v)
{
tree list = NULL_TREE;
unsigned HOST_WIDE_INT idx;
tree value;
FOR_EACH_CONSTRUCTOR_VALUE (v, idx, value)
list = tree_cons (NULL_TREE, value, list);
return build_vector (type, nreverse (list));
}
/* Return a new CONSTRUCTOR node whose type is TYPE and whose values
are in the VEC pointed to by VALS. */
tree
build_constructor (tree type, VEC(constructor_elt,gc) *vals)
{
tree c = make_node (CONSTRUCTOR);
TREE_TYPE (c) = type;
CONSTRUCTOR_ELTS (c) = vals;
return c;
}
/* Build a CONSTRUCTOR node made of a single initializer, with the specified
INDEX and VALUE. */
tree
build_constructor_single (tree type, tree index, tree value)
{
VEC(constructor_elt,gc) *v;
constructor_elt *elt;
tree t;
v = VEC_alloc (constructor_elt, gc, 1);
elt = VEC_quick_push (constructor_elt, v, NULL);
elt->index = index;
elt->value = value;
t = build_constructor (type, v);
TREE_CONSTANT (t) = TREE_CONSTANT (value);
return t;
}
/* Return a new CONSTRUCTOR node whose type is TYPE and whose values
are in a list pointed to by VALS. */
tree
build_constructor_from_list (tree type, tree vals)
{
tree t, val;
VEC(constructor_elt,gc) *v = NULL;
bool constant_p = true;
if (vals)
{
v = VEC_alloc (constructor_elt, gc, list_length (vals));
for (t = vals; t; t = TREE_CHAIN (t))
{
constructor_elt *elt = VEC_quick_push (constructor_elt, v, NULL);
val = TREE_VALUE (t);
elt->index = TREE_PURPOSE (t);
elt->value = val;
if (!TREE_CONSTANT (val))
constant_p = false;
}
}
t = build_constructor (type, v);
TREE_CONSTANT (t) = constant_p;
return t;
}
/* Return a new FIXED_CST node whose type is TYPE and value is F. */
tree
build_fixed (tree type, FIXED_VALUE_TYPE f)
{
tree v;
FIXED_VALUE_TYPE *fp;
v = make_node (FIXED_CST);
fp = GGC_NEW (FIXED_VALUE_TYPE);
memcpy (fp, &f, sizeof (FIXED_VALUE_TYPE));
TREE_TYPE (v) = type;
TREE_FIXED_CST_PTR (v) = fp;
return v;
}
/* Return a new REAL_CST node whose type is TYPE and value is D. */
tree
build_real (tree type, REAL_VALUE_TYPE d)
{
tree v;
REAL_VALUE_TYPE *dp;
int overflow = 0;
/* ??? Used to check for overflow here via CHECK_FLOAT_TYPE.
Consider doing it via real_convert now. */
v = make_node (REAL_CST);
dp = GGC_NEW (REAL_VALUE_TYPE);
memcpy (dp, &d, sizeof (REAL_VALUE_TYPE));
TREE_TYPE (v) = type;
TREE_REAL_CST_PTR (v) = dp;
TREE_OVERFLOW (v) = overflow;
return v;
}
/* Return a new REAL_CST node whose type is TYPE
and whose value is the integer value of the INTEGER_CST node I. */
REAL_VALUE_TYPE
real_value_from_int_cst (const_tree type, const_tree i)
{
REAL_VALUE_TYPE d;
/* Clear all bits of the real value type so that we can later do
bitwise comparisons to see if two values are the same. */
memset (&d, 0, sizeof d);
real_from_integer (&d, type ? TYPE_MODE (type) : VOIDmode,
TREE_INT_CST_LOW (i), TREE_INT_CST_HIGH (i),
TYPE_UNSIGNED (TREE_TYPE (i)));
return d;
}
/* Given a tree representing an integer constant I, return a tree
representing the same value as a floating-point constant of type TYPE. */
tree
build_real_from_int_cst (tree type, const_tree i)
{
tree v;
int overflow = TREE_OVERFLOW (i);
v = build_real (type, real_value_from_int_cst (type, i));
TREE_OVERFLOW (v) |= overflow;
return v;
}
/* Return a newly constructed STRING_CST node whose value is
the LEN characters at STR.
The TREE_TYPE is not initialized. */
tree
build_string (int len, const char *str)
{
tree s;
size_t length;
/* Do not waste bytes provided by padding of struct tree_string. */
length = len + offsetof (struct tree_string, str) + 1;
#ifdef GATHER_STATISTICS
tree_node_counts[(int) c_kind]++;
tree_node_sizes[(int) c_kind] += length;
#endif
s = ggc_alloc_tree (length);
memset (s, 0, sizeof (struct tree_common));
TREE_SET_CODE (s, STRING_CST);
TREE_CONSTANT (s) = 1;
TREE_STRING_LENGTH (s) = len;
memcpy (s->string.str, str, len);
s->string.str[len] = '\0';
return s;
}
/* Return a newly constructed COMPLEX_CST node whose value is
specified by the real and imaginary parts REAL and IMAG.
Both REAL and IMAG should be constant nodes. TYPE, if specified,
will be the type of the COMPLEX_CST; otherwise a new type will be made. */
tree
build_complex (tree type, tree real, tree imag)
{
tree t = make_node (COMPLEX_CST);
TREE_REALPART (t) = real;
TREE_IMAGPART (t) = imag;
TREE_TYPE (t) = type ? type : build_complex_type (TREE_TYPE (real));
TREE_OVERFLOW (t) = TREE_OVERFLOW (real) | TREE_OVERFLOW (imag);
return t;
}
/* Return a constant of arithmetic type TYPE which is the
multiplicative identity of the set TYPE. */
tree
build_one_cst (tree type)
{
switch (TREE_CODE (type))
{
case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
case POINTER_TYPE: case REFERENCE_TYPE:
case OFFSET_TYPE:
return build_int_cst (type, 1);
case REAL_TYPE:
return build_real (type, dconst1);
case FIXED_POINT_TYPE:
/* We can only generate 1 for accum types. */
gcc_assert (ALL_SCALAR_ACCUM_MODE_P (TYPE_MODE (type)));
return build_fixed (type, FCONST1(TYPE_MODE (type)));
case VECTOR_TYPE:
{
tree scalar, cst;
int i;
scalar = build_one_cst (TREE_TYPE (type));
/* Create 'vect_cst_ = {cst,cst,...,cst}' */
cst = NULL_TREE;
for (i = TYPE_VECTOR_SUBPARTS (type); --i >= 0; )
cst = tree_cons (NULL_TREE, scalar, cst);
return build_vector (type, cst);
}
case COMPLEX_TYPE:
return build_complex (type,
build_one_cst (TREE_TYPE (type)),
fold_convert (TREE_TYPE (type), integer_zero_node));
default:
gcc_unreachable ();
}
}
/* Build a BINFO with LEN language slots. */
tree
make_tree_binfo_stat (unsigned base_binfos MEM_STAT_DECL)
{
tree t;
size_t length = (offsetof (struct tree_binfo, base_binfos)
+ VEC_embedded_size (tree, base_binfos));
#ifdef GATHER_STATISTICS
tree_node_counts[(int) binfo_kind]++;
tree_node_sizes[(int) binfo_kind] += length;
#endif
t = (tree) ggc_alloc_zone_pass_stat (length, &tree_zone);
memset (t, 0, offsetof (struct tree_binfo, base_binfos));
TREE_SET_CODE (t, TREE_BINFO);
VEC_embedded_init (tree, BINFO_BASE_BINFOS (t), base_binfos);
return t;
}
/* Build a newly constructed TREE_VEC node of length LEN. */
tree
make_tree_vec_stat (int len MEM_STAT_DECL)
{
tree t;
int length = (len - 1) * sizeof (tree) + sizeof (struct tree_vec);
#ifdef GATHER_STATISTICS
tree_node_counts[(int) vec_kind]++;
tree_node_sizes[(int) vec_kind] += length;
#endif
t = (tree) ggc_alloc_zone_pass_stat (length, &tree_zone);
memset (t, 0, length);
TREE_SET_CODE (t, TREE_VEC);
TREE_VEC_LENGTH (t) = len;
return t;
}
/* Return 1 if EXPR is the integer constant zero or a complex constant
of zero. */
int
integer_zerop (const_tree expr)
{
STRIP_NOPS (expr);
return ((TREE_CODE (expr) == INTEGER_CST
&& TREE_INT_CST_LOW (expr) == 0
&& TREE_INT_CST_HIGH (expr) == 0)
|| (TREE_CODE (expr) == COMPLEX_CST
&& integer_zerop (TREE_REALPART (expr))
&& integer_zerop (TREE_IMAGPART (expr))));
}
/* Return 1 if EXPR is the integer constant one or the corresponding
complex constant. */
int
integer_onep (const_tree expr)
{
STRIP_NOPS (expr);
return ((TREE_CODE (expr) == INTEGER_CST
&& TREE_INT_CST_LOW (expr) == 1
&& TREE_INT_CST_HIGH (expr) == 0)
|| (TREE_CODE (expr) == COMPLEX_CST
&& integer_onep (TREE_REALPART (expr))
&& integer_zerop (TREE_IMAGPART (expr))));
}
/* Return 1 if EXPR is an integer containing all 1's in as much precision as
it contains. Likewise for the corresponding complex constant. */
int
integer_all_onesp (const_tree expr)
{
int prec;
int uns;
STRIP_NOPS (expr);
if (TREE_CODE (expr) == COMPLEX_CST
&& integer_all_onesp (TREE_REALPART (expr))
&& integer_zerop (TREE_IMAGPART (expr)))
return 1;
else if (TREE_CODE (expr) != INTEGER_CST)
return 0;
uns = TYPE_UNSIGNED (TREE_TYPE (expr));
if (TREE_INT_CST_LOW (expr) == ~(unsigned HOST_WIDE_INT) 0
&& TREE_INT_CST_HIGH (expr) == -1)
return 1;
if (!uns)
return 0;
/* Note that using TYPE_PRECISION here is wrong. We care about the
actual bits, not the (arbitrary) range of the type. */
prec = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (expr)));
if (prec >= HOST_BITS_PER_WIDE_INT)
{
HOST_WIDE_INT high_value;
int shift_amount;
shift_amount = prec - HOST_BITS_PER_WIDE_INT;
/* Can not handle precisions greater than twice the host int size. */
gcc_assert (shift_amount <= HOST_BITS_PER_WIDE_INT);
if (shift_amount == HOST_BITS_PER_WIDE_INT)
/* Shifting by the host word size is undefined according to the ANSI
standard, so we must handle this as a special case. */
high_value = -1;
else
high_value = ((HOST_WIDE_INT) 1 << shift_amount) - 1;
return (TREE_INT_CST_LOW (expr) == ~(unsigned HOST_WIDE_INT) 0
&& TREE_INT_CST_HIGH (expr) == high_value);
}
else
return TREE_INT_CST_LOW (expr) == ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
}
/* Return 1 if EXPR is an integer constant that is a power of 2 (i.e., has only
one bit on). */
int
integer_pow2p (const_tree expr)
{
int prec;
HOST_WIDE_INT high, low;
STRIP_NOPS (expr);
if (TREE_CODE (expr) == COMPLEX_CST
&& integer_pow2p (TREE_REALPART (expr))
&& integer_zerop (TREE_IMAGPART (expr)))
return 1;
if (TREE_CODE (expr) != INTEGER_CST)
return 0;
prec = (POINTER_TYPE_P (TREE_TYPE (expr))
? POINTER_SIZE : TYPE_PRECISION (TREE_TYPE (expr)));
high = TREE_INT_CST_HIGH (expr);
low = TREE_INT_CST_LOW (expr);
/* First clear all bits that are beyond the type's precision in case
we've been sign extended. */
if (prec == 2 * HOST_BITS_PER_WIDE_INT)
;
else if (prec > HOST_BITS_PER_WIDE_INT)
high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
else
{
high = 0;
if (prec < HOST_BITS_PER_WIDE_INT)
low &= ~((HOST_WIDE_INT) (-1) << prec);
}
if (high == 0 && low == 0)
return 0;
return ((high == 0 && (low & (low - 1)) == 0)
|| (low == 0 && (high & (high - 1)) == 0));
}
/* Return 1 if EXPR is an integer constant other than zero or a
complex constant other than zero. */
int
integer_nonzerop (const_tree expr)
{
STRIP_NOPS (expr);
return ((TREE_CODE (expr) == INTEGER_CST
&& (TREE_INT_CST_LOW (expr) != 0
|| TREE_INT_CST_HIGH (expr) != 0))
|| (TREE_CODE (expr) == COMPLEX_CST
&& (integer_nonzerop (TREE_REALPART (expr))
|| integer_nonzerop (TREE_IMAGPART (expr)))));
}
/* Return 1 if EXPR is the fixed-point constant zero. */
int
fixed_zerop (const_tree expr)
{
return (TREE_CODE (expr) == FIXED_CST
&& double_int_zero_p (TREE_FIXED_CST (expr).data));
}
/* Return the power of two represented by a tree node known to be a
power of two. */
int
tree_log2 (const_tree expr)
{
int prec;
HOST_WIDE_INT high, low;
STRIP_NOPS (expr);
if (TREE_CODE (expr) == COMPLEX_CST)
return tree_log2 (TREE_REALPART (expr));
prec = (POINTER_TYPE_P (TREE_TYPE (expr))
? POINTER_SIZE : TYPE_PRECISION (TREE_TYPE (expr)));
high = TREE_INT_CST_HIGH (expr);
low = TREE_INT_CST_LOW (expr);
/* First clear all bits that are beyond the type's precision in case
we've been sign extended. */
if (prec == 2 * HOST_BITS_PER_WIDE_INT)
;
else if (prec > HOST_BITS_PER_WIDE_INT)
high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
else
{
high = 0;
if (prec < HOST_BITS_PER_WIDE_INT)
low &= ~((HOST_WIDE_INT) (-1) << prec);
}
return (high != 0 ? HOST_BITS_PER_WIDE_INT + exact_log2 (high)
: exact_log2 (low));
}
/* Similar, but return the largest integer Y such that 2 ** Y is less
than or equal to EXPR. */
int
tree_floor_log2 (const_tree expr)
{
int prec;
HOST_WIDE_INT high, low;
STRIP_NOPS (expr);
if (TREE_CODE (expr) == COMPLEX_CST)
return tree_log2 (TREE_REALPART (expr));
prec = (POINTER_TYPE_P (TREE_TYPE (expr))
? POINTER_SIZE : TYPE_PRECISION (TREE_TYPE (expr)));
high = TREE_INT_CST_HIGH (expr);
low = TREE_INT_CST_LOW (expr);
/* First clear all bits that are beyond the type's precision in case
we've been sign extended. Ignore if type's precision hasn't been set
since what we are doing is setting it. */
if (prec == 2 * HOST_BITS_PER_WIDE_INT || prec == 0)
;
else if (prec > HOST_BITS_PER_WIDE_INT)
high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
else
{
high = 0;
if (prec < HOST_BITS_PER_WIDE_INT)
low &= ~((HOST_WIDE_INT) (-1) << prec);
}
return (high != 0 ? HOST_BITS_PER_WIDE_INT + floor_log2 (high)
: floor_log2 (low));
}
/* Return 1 if EXPR is the real constant zero. Trailing zeroes matter for
decimal float constants, so don't return 1 for them. */
int
real_zerop (const_tree expr)
{
STRIP_NOPS (expr);
return ((TREE_CODE (expr) == REAL_CST
&& REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst0)
&& !(DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (expr)))))
|| (TREE_CODE (expr) == COMPLEX_CST
&& real_zerop (TREE_REALPART (expr))
&& real_zerop (TREE_IMAGPART (expr))));
}
/* Return 1 if EXPR is the real constant one in real or complex form.
Trailing zeroes matter for decimal float constants, so don't return
1 for them. */
int
real_onep (const_tree expr)
{
STRIP_NOPS (expr);
return ((TREE_CODE (expr) == REAL_CST
&& REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst1)
&& !(DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (expr)))))
|| (TREE_CODE (expr) == COMPLEX_CST
&& real_onep (TREE_REALPART (expr))
&& real_zerop (TREE_IMAGPART (expr))));
}
/* Return 1 if EXPR is the real constant two. Trailing zeroes matter
for decimal float constants, so don't return 1 for them. */
int
real_twop (const_tree expr)
{
STRIP_NOPS (expr);
return ((TREE_CODE (expr) == REAL_CST
&& REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst2)
&& !(DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (expr)))))
|| (TREE_CODE (expr) == COMPLEX_CST
&& real_twop (TREE_REALPART (expr))
&& real_zerop (TREE_IMAGPART (expr))));
}
/* Return 1 if EXPR is the real constant minus one. Trailing zeroes
matter for decimal float constants, so don't return 1 for them. */
int
real_minus_onep (const_tree expr)
{
STRIP_NOPS (expr);
return ((TREE_CODE (expr) == REAL_CST
&& REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconstm1)
&& !(DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (expr)))))
|| (TREE_CODE (expr) == COMPLEX_CST
&& real_minus_onep (TREE_REALPART (expr))
&& real_zerop (TREE_IMAGPART (expr))));
}
/* Nonzero if EXP is a constant or a cast of a constant. */
int
really_constant_p (const_tree exp)
{
/* This is not quite the same as STRIP_NOPS. It does more. */
while (CONVERT_EXPR_P (exp)
|| TREE_CODE (exp) == NON_LVALUE_EXPR)
exp = TREE_OPERAND (exp, 0);
return TREE_CONSTANT (exp);
}
/* Return first list element whose TREE_VALUE is ELEM.
Return 0 if ELEM is not in LIST. */
tree
value_member (tree elem, tree list)
{
while (list)
{
if (elem == TREE_VALUE (list))
return list;
list = TREE_CHAIN (list);
}
return NULL_TREE;
}
/* Return first list element whose TREE_PURPOSE is ELEM.
Return 0 if ELEM is not in LIST. */
tree
purpose_member (const_tree elem, tree list)
{
while (list)
{
if (elem == TREE_PURPOSE (list))
return list;
list = TREE_CHAIN (list);
}
return NULL_TREE;
}
/* Return nonzero if ELEM is part of the chain CHAIN. */
int
chain_member (const_tree elem, const_tree chain)
{
while (chain)
{
if (elem == chain)
return 1;
chain = TREE_CHAIN (chain);
}
return 0;
}
/* Return the length of a chain of nodes chained through TREE_CHAIN.
We expect a null pointer to mark the end of the chain.
This is the Lisp primitive `length'. */
int
list_length (const_tree t)
{
const_tree p = t;
#ifdef ENABLE_TREE_CHECKING
const_tree q = t;
#endif
int len = 0;
while (p)
{
p = TREE_CHAIN (p);
#ifdef ENABLE_TREE_CHECKING
if (len % 2)
q = TREE_CHAIN (q);
gcc_assert (p != q);
#endif
len++;
}
return len;
}
/* Returns the number of FIELD_DECLs in TYPE. */
int
fields_length (const_tree type)
{
tree t = TYPE_FIELDS (type);
int count = 0;
for (; t; t = TREE_CHAIN (t))
if (TREE_CODE (t) == FIELD_DECL)
++count;
return count;
}
/* Concatenate two chains of nodes (chained through TREE_CHAIN)
by modifying the last node in chain 1 to point to chain 2.
This is the Lisp primitive `nconc'. */
tree
chainon (tree op1, tree op2)
{
tree t1;
if (!op1)
return op2;
if (!op2)
return op1;
for (t1 = op1; TREE_CHAIN (t1); t1 = TREE_CHAIN (t1))
continue;
TREE_CHAIN (t1) = op2;
#ifdef ENABLE_TREE_CHECKING
{
tree t2;
for (t2 = op2; t2; t2 = TREE_CHAIN (t2))
gcc_assert (t2 != t1);
}
#endif
return op1;
}
/* Return the last node in a chain of nodes (chained through TREE_CHAIN). */
tree
tree_last (tree chain)
{
tree next;
if (chain)
while ((next = TREE_CHAIN (chain)))
chain = next;
return chain;
}
/* Reverse the order of elements in the chain T,
and return the new head of the chain (old last element). */
tree
nreverse (tree t)
{
tree prev = 0, decl, next;
for (decl = t; decl; decl = next)
{
next = TREE_CHAIN (decl);
TREE_CHAIN (decl) = prev;
prev = decl;
}
return prev;
}
/* Return a newly created TREE_LIST node whose
purpose and value fields are PARM and VALUE. */
tree
build_tree_list_stat (tree parm, tree value MEM_STAT_DECL)
{
tree t = make_node_stat (TREE_LIST PASS_MEM_STAT);
TREE_PURPOSE (t) = parm;
TREE_VALUE (t) = value;
return t;
}
/* Return a newly created TREE_LIST node whose
purpose and value fields are PURPOSE and VALUE
and whose TREE_CHAIN is CHAIN. */
tree
tree_cons_stat (tree purpose, tree value, tree chain MEM_STAT_DECL)
{
tree node;
node = (tree) ggc_alloc_zone_pass_stat (sizeof (struct tree_list), &tree_zone);
memset (node, 0, sizeof (struct tree_common));
#ifdef GATHER_STATISTICS
tree_node_counts[(int) x_kind]++;
tree_node_sizes[(int) x_kind] += sizeof (struct tree_list);
#endif
TREE_SET_CODE (node, TREE_LIST);
TREE_CHAIN (node) = chain;
TREE_PURPOSE (node) = purpose;
TREE_VALUE (node) = value;
return node;
}
/* Return the elements of a CONSTRUCTOR as a TREE_LIST. */
tree
ctor_to_list (tree ctor)
{
tree list = NULL_TREE;
tree *p = &list;
unsigned ix;
tree purpose, val;
FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), ix, purpose, val)
{
*p = build_tree_list (purpose, val);
p = &TREE_CHAIN (*p);
}
return list;
}
/* Return the size nominally occupied by an object of type TYPE
when it resides in memory. The value is measured in units of bytes,
and its data type is that normally used for type sizes
(which is the first type created by make_signed_type or
make_unsigned_type). */
tree
size_in_bytes (const_tree type)
{
tree t;
if (type == error_mark_node)
return integer_zero_node;
type = TYPE_MAIN_VARIANT (type);
t = TYPE_SIZE_UNIT (type);
if (t == 0)
{
lang_hooks.types.incomplete_type_error (NULL_TREE, type);
return size_zero_node;
}
return t;
}
/* Return the size of TYPE (in bytes) as a wide integer
or return -1 if the size can vary or is larger than an integer. */
HOST_WIDE_INT
int_size_in_bytes (const_tree type)
{
tree t;
if (type == error_mark_node)
return 0;
type = TYPE_MAIN_VARIANT (type);
t = TYPE_SIZE_UNIT (type);
if (t == 0
|| TREE_CODE (t) != INTEGER_CST
|| TREE_INT_CST_HIGH (t) != 0
/* If the result would appear negative, it's too big to represent. */
|| (HOST_WIDE_INT) TREE_INT_CST_LOW (t) < 0)
return -1;
return TREE_INT_CST_LOW (t);
}
/* Return the maximum size of TYPE (in bytes) as a wide integer
or return -1 if the size can vary or is larger than an integer. */
HOST_WIDE_INT
max_int_size_in_bytes (const_tree type)
{
HOST_WIDE_INT size = -1;
tree size_tree;
/* If this is an array type, check for a possible MAX_SIZE attached. */
if (TREE_CODE (type) == ARRAY_TYPE)
{
size_tree = TYPE_ARRAY_MAX_SIZE (type);
if (size_tree && host_integerp (size_tree, 1))
size = tree_low_cst (size_tree, 1);
}
/* If we still haven't been able to get a size, see if the language
can compute a maximum size. */
if (size == -1)
{
size_tree = lang_hooks.types.max_size (type);
if (size_tree && host_integerp (size_tree, 1))
size = tree_low_cst (size_tree, 1);
}
return size;
}
/* Return the bit position of FIELD, in bits from the start of the record.
This is a tree of type bitsizetype. */
tree
bit_position (const_tree field)
{
return bit_from_pos (DECL_FIELD_OFFSET (field),
DECL_FIELD_BIT_OFFSET (field));
}
/* Likewise, but return as an integer. It must be representable in
that way (since it could be a signed value, we don't have the
option of returning -1 like int_size_in_byte can. */
HOST_WIDE_INT
int_bit_position (const_tree field)
{
return tree_low_cst (bit_position (field), 0);
}
/* Return the byte position of FIELD, in bytes from the start of the record.
This is a tree of type sizetype. */
tree
byte_position (const_tree field)
{
return byte_from_pos (DECL_FIELD_OFFSET (field),
DECL_FIELD_BIT_OFFSET (field));
}
/* Likewise, but return as an integer. It must be representable in
that way (since it could be a signed value, we don't have the
option of returning -1 like int_size_in_byte can. */
HOST_WIDE_INT
int_byte_position (const_tree field)
{
return tree_low_cst (byte_position (field), 0);
}
/* Return the strictest alignment, in bits, that T is known to have. */
unsigned int
expr_align (const_tree t)
{
unsigned int align0, align1;
switch (TREE_CODE (t))
{
CASE_CONVERT: case NON_LVALUE_EXPR:
/* If we have conversions, we know that the alignment of the
object must meet each of the alignments of the types. */
align0 = expr_align (TREE_OPERAND (t, 0));
align1 = TYPE_ALIGN (TREE_TYPE (t));
return MAX (align0, align1);
case SAVE_EXPR: case COMPOUND_EXPR: case MODIFY_EXPR:
case INIT_EXPR: case TARGET_EXPR: case WITH_CLEANUP_EXPR:
case CLEANUP_POINT_EXPR:
/* These don't change the alignment of an object. */
return expr_align (TREE_OPERAND (t, 0));
case COND_EXPR:
/* The best we can do is say that the alignment is the least aligned
of the two arms. */
align0 = expr_align (TREE_OPERAND (t, 1));
align1 = expr_align (TREE_OPERAND (t, 2));
return MIN (align0, align1);
/* FIXME: LABEL_DECL and CONST_DECL never have DECL_ALIGN set
meaningfully, it's always 1. */
case LABEL_DECL: case CONST_DECL:
case VAR_DECL: case PARM_DECL: case RESULT_DECL:
case FUNCTION_DECL:
gcc_assert (DECL_ALIGN (t) != 0);
return DECL_ALIGN (t);
default:
break;
}
/* Otherwise take the alignment from that of the type. */
return TYPE_ALIGN (TREE_TYPE (t));
}
/* Return, as a tree node, the number of elements for TYPE (which is an
ARRAY_TYPE) minus one. This counts only elements of the top array. */
tree
array_type_nelts (const_tree type)
{
tree index_type, min, max;
/* If they did it with unspecified bounds, then we should have already
given an error about it before we got here. */
if (! TYPE_DOMAIN (type))
return error_mark_node;
index_type = TYPE_DOMAIN (type);
min = TYPE_MIN_VALUE (index_type);
max = TYPE_MAX_VALUE (index_type);
return (integer_zerop (min)
? max
: fold_build2 (MINUS_EXPR, TREE_TYPE (max), max, min));
}
/* If arg is static -- a reference to an object in static storage -- then
return the object. This is not the same as the C meaning of `static'.
If arg isn't static, return NULL. */
tree
staticp (tree arg)
{
switch (TREE_CODE (arg))
{
case FUNCTION_DECL:
/* Nested functions are static, even though taking their address will
involve a trampoline as we unnest the nested function and create
the trampoline on the tree level. */
return arg;
case VAR_DECL:
return ((TREE_STATIC (arg) || DECL_EXTERNAL (arg))
&& ! DECL_THREAD_LOCAL_P (arg)
&& ! DECL_DLLIMPORT_P (arg)
? arg : NULL);
case CONST_DECL:
return ((TREE_STATIC (arg) || DECL_EXTERNAL (arg))
? arg : NULL);
case CONSTRUCTOR:
return TREE_STATIC (arg) ? arg : NULL;
case LABEL_DECL:
case STRING_CST:
return arg;
case COMPONENT_REF:
/* If the thing being referenced is not a field, then it is
something language specific. */
if (TREE_CODE (TREE_OPERAND (arg, 1)) != FIELD_DECL)
return (*lang_hooks.staticp) (arg);
/* If we are referencing a bitfield, we can't evaluate an
ADDR_EXPR at compile time and so it isn't a constant. */
if (DECL_BIT_FIELD (TREE_OPERAND (arg, 1)))
return NULL;
return staticp (TREE_OPERAND (arg, 0));
case BIT_FIELD_REF:
return NULL;
case MISALIGNED_INDIRECT_REF:
case ALIGN_INDIRECT_REF:
case INDIRECT_REF:
return TREE_CONSTANT (TREE_OPERAND (arg, 0)) ? arg : NULL;
case ARRAY_REF:
case ARRAY_RANGE_REF:
if (TREE_CODE (TYPE_SIZE (TREE_TYPE (arg))) == INTEGER_CST
&& TREE_CODE (TREE_OPERAND (arg, 1)) == INTEGER_CST)
return staticp (TREE_OPERAND (arg, 0));
else
return false;
default:
if ((unsigned int) TREE_CODE (arg)
>= (unsigned int) LAST_AND_UNUSED_TREE_CODE)
return lang_hooks.staticp (arg);
else
return NULL;
}
}
/* Return whether OP is a DECL whose address is function-invariant. */
bool
decl_address_invariant_p (const_tree op)
{
/* The conditions below are slightly less strict than the one in
staticp. */
switch (TREE_CODE (op))
{
case PARM_DECL:
case RESULT_DECL:
case LABEL_DECL:
case FUNCTION_DECL:
return true;
case VAR_DECL:
if (((TREE_STATIC (op) || DECL_EXTERNAL (op))
&& !DECL_DLLIMPORT_P (op))
|| DECL_THREAD_LOCAL_P (op)
|| DECL_CONTEXT (op) == current_function_decl
|| decl_function_context (op) == current_function_decl)
return true;
break;
case CONST_DECL:
if ((TREE_STATIC (op) || DECL_EXTERNAL (op))
|| decl_function_context (op) == current_function_decl)
return true;
break;
default:
break;
}
return false;
}
/* Return whether OP is a DECL whose address is interprocedural-invariant. */
bool
decl_address_ip_invariant_p (const_tree op)
{
/* The conditions below are slightly less strict than the one in
staticp. */
switch (TREE_CODE (op))
{
case LABEL_DECL:
case FUNCTION_DECL:
case STRING_CST:
return true;
case VAR_DECL:
if (((TREE_STATIC (op) || DECL_EXTERNAL (op))
&& !DECL_DLLIMPORT_P (op))
|| DECL_THREAD_LOCAL_P (op))
return true;
break;
case CONST_DECL:
if ((TREE_STATIC (op) || DECL_EXTERNAL (op)))
return true;
break;
default:
break;
}
return false;
}
/* Return true if T is function-invariant (internal function, does
not handle arithmetic; that's handled in skip_simple_arithmetic and
tree_invariant_p). */
static bool tree_invariant_p (tree t);
static bool
tree_invariant_p_1 (tree t)
{
tree op;
if (TREE_CONSTANT (t)
|| (TREE_READONLY (t) && !TREE_SIDE_EFFECTS (t)))
return true;
switch (TREE_CODE (t))
{
case SAVE_EXPR:
return true;
case ADDR_EXPR:
op = TREE_OPERAND (t, 0);
while (handled_component_p (op))
{
switch (TREE_CODE (op))
{
case ARRAY_REF:
case ARRAY_RANGE_REF:
if (!tree_invariant_p (TREE_OPERAND (op, 1))
|| TREE_OPERAND (op, 2) != NULL_TREE
|| TREE_OPERAND (op, 3) != NULL_TREE)
return false;
break;
case COMPONENT_REF:
if (TREE_OPERAND (op, 2) != NULL_TREE)
return false;
break;
default:;
}
op = TREE_OPERAND (op, 0);
}
return CONSTANT_CLASS_P (op) || decl_address_invariant_p (op);
default:
break;
}
return false;
}
/* Return true if T is function-invariant. */
static bool
tree_invariant_p (tree t)
{
tree inner = skip_simple_arithmetic (t);
return tree_invariant_p_1 (inner);
}
/* Wrap a SAVE_EXPR around EXPR, if appropriate.
Do this to any expression which may be used in more than one place,
but must be evaluated only once.
Normally, expand_expr would reevaluate the expression each time.
Calling save_expr produces something that is evaluated and recorded
the first time expand_expr is called on it. Subsequent calls to
expand_expr just reuse the recorded value.
The call to expand_expr that generates code that actually computes
the value is the first call *at compile time*. Subsequent calls
*at compile time* generate code to use the saved value.
This produces correct result provided that *at run time* control
always flows through the insns made by the first expand_expr
before reaching the other places where the save_expr was evaluated.
You, the caller of save_expr, must make sure this is so.
Constants, and certain read-only nodes, are returned with no
SAVE_EXPR because that is safe. Expressions containing placeholders
are not touched; see tree.def for an explanation of what these
are used for. */
tree
save_expr (tree expr)
{
tree t = fold (expr);
tree inner;
/* If the tree evaluates to a constant, then we don't want to hide that
fact (i.e. this allows further folding, and direct checks for constants).
However, a read-only object that has side effects cannot be bypassed.
Since it is no problem to reevaluate literals, we just return the
literal node. */
inner = skip_simple_arithmetic (t);
if (TREE_CODE (inner) == ERROR_MARK)
return inner;
if (tree_invariant_p_1 (inner))
return t;
/* If INNER contains a PLACEHOLDER_EXPR, we must evaluate it each time, since
it means that the size or offset of some field of an object depends on
the value within another field.
Note that it must not be the case that T contains both a PLACEHOLDER_EXPR
and some variable since it would then need to be both evaluated once and
evaluated more than once. Front-ends must assure this case cannot
happen by surrounding any such subexpressions in their own SAVE_EXPR
and forcing evaluation at the proper time. */
if (contains_placeholder_p (inner))
return t;
t = build1 (SAVE_EXPR, TREE_TYPE (expr), t);
/* This expression might be placed ahead of a jump to ensure that the
value was computed on both sides of the jump. So make sure it isn't
eliminated as dead. */
TREE_SIDE_EFFECTS (t) = 1;
return t;
}
/* Look inside EXPR and into any simple arithmetic operations. Return
the innermost non-arithmetic node. */
tree
skip_simple_arithmetic (tree expr)
{
tree inner;
/* We don't care about whether this can be used as an lvalue in this
context. */
while (TREE_CODE (expr) == NON_LVALUE_EXPR)
expr = TREE_OPERAND (expr, 0);
/* If we have simple operations applied to a SAVE_EXPR or to a SAVE_EXPR and
a constant, it will be more efficient to not make another SAVE_EXPR since
it will allow better simplification and GCSE will be able to merge the
computations if they actually occur. */
inner = expr;
while (1)
{
if (UNARY_CLASS_P (inner))
inner = TREE_OPERAND (inner, 0);
else if (BINARY_CLASS_P (inner))
{
if (tree_invariant_p (TREE_OPERAND (inner, 1)))
inner = TREE_OPERAND (inner, 0);
else if (tree_invariant_p (TREE_OPERAND (inner, 0)))
inner = TREE_OPERAND (inner, 1);
else
break;
}
else
break;
}
return inner;
}
/* Return which tree structure is used by T. */
enum tree_node_structure_enum
tree_node_structure (const_tree t)
{
const enum tree_code code = TREE_CODE (t);
switch (TREE_CODE_CLASS (code))
{
case tcc_declaration:
{
switch (code)
{
case FIELD_DECL:
return TS_FIELD_DECL;
case PARM_DECL:
return TS_PARM_DECL;
case VAR_DECL:
return TS_VAR_DECL;
case LABEL_DECL:
return TS_LABEL_DECL;
case RESULT_DECL:
return TS_RESULT_DECL;
case CONST_DECL:
return TS_CONST_DECL;
case TYPE_DECL:
return TS_TYPE_DECL;
case FUNCTION_DECL:
return TS_FUNCTION_DECL;
case SYMBOL_MEMORY_TAG:
case NAME_MEMORY_TAG:
case MEMORY_PARTITION_TAG:
return TS_MEMORY_TAG;
default:
return TS_DECL_NON_COMMON;
}
}
case tcc_type:
return TS_TYPE;
case tcc_reference:
case tcc_comparison:
case tcc_unary:
case tcc_binary:
case tcc_expression:
case tcc_statement:
case tcc_vl_exp:
return TS_EXP;
default: /* tcc_constant and tcc_exceptional */
break;
}
switch (code)
{
/* tcc_constant cases. */
case INTEGER_CST: return TS_INT_CST;
case REAL_CST: return TS_REAL_CST;
case FIXED_CST: return TS_FIXED_CST;
case COMPLEX_CST: return TS_COMPLEX;
case VECTOR_CST: return TS_VECTOR;
case STRING_CST: return TS_STRING;
/* tcc_exceptional cases. */
case ERROR_MARK: return TS_COMMON;
case IDENTIFIER_NODE: return TS_IDENTIFIER;
case TREE_LIST: return TS_LIST;
case TREE_VEC: return TS_VEC;
case SSA_NAME: return TS_SSA_NAME;
case PLACEHOLDER_EXPR: return TS_COMMON;
case STATEMENT_LIST: return TS_STATEMENT_LIST;
case BLOCK: return TS_BLOCK;
case CONSTRUCTOR: return TS_CONSTRUCTOR;
case TREE_BINFO: return TS_BINFO;
case OMP_CLAUSE: return TS_OMP_CLAUSE;
case OPTIMIZATION_NODE: return TS_OPTIMIZATION;
case TARGET_OPTION_NODE: return TS_TARGET_OPTION;
default:
gcc_unreachable ();
}
}
/* Return 1 if EXP contains a PLACEHOLDER_EXPR; i.e., if it represents a size
or offset that depends on a field within a record. */
bool
contains_placeholder_p (const_tree exp)
{
enum tree_code code;
if (!exp)
return 0;
code = TREE_CODE (exp);
if (code == PLACEHOLDER_EXPR)
return 1;
switch (TREE_CODE_CLASS (code))
{
case tcc_reference:
/* Don't look at any PLACEHOLDER_EXPRs that might be in index or bit
position computations since they will be converted into a
WITH_RECORD_EXPR involving the reference, which will assume
here will be valid. */
return CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 0));
case tcc_exceptional:
if (code == TREE_LIST)
return (CONTAINS_PLACEHOLDER_P (TREE_VALUE (exp))
|| CONTAINS_PLACEHOLDER_P (TREE_CHAIN (exp)));
break;
case tcc_unary:
case tcc_binary:
case tcc_comparison:
case tcc_expression:
switch (code)
{
case COMPOUND_EXPR:
/* Ignoring the first operand isn't quite right, but works best. */
return CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 1));
case COND_EXPR:
return (CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 0))
|| CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 1))
|| CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 2)));
case SAVE_EXPR:
/* The save_expr function never wraps anything containing
a PLACEHOLDER_EXPR. */
return 0;
default:
break;
}
switch (TREE_CODE_LENGTH (code))
{
case 1:
return CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 0));
case 2:
return (CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 0))
|| CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 1)));
default:
return 0;
}
case tcc_vl_exp:
switch (code)
{
case CALL_EXPR:
{
const_tree arg;
const_call_expr_arg_iterator iter;
FOR_EACH_CONST_CALL_EXPR_ARG (arg, iter, exp)
if (CONTAINS_PLACEHOLDER_P (arg))
return 1;
return 0;
}
default:
return 0;
}
default:
return 0;
}
return 0;
}
/* Return true if any part of the computation of TYPE involves a
PLACEHOLDER_EXPR. This includes size, bounds, qualifiers
(for QUAL_UNION_TYPE) and field positions. */
static bool
type_contains_placeholder_1 (const_tree type)
{
/* If the size contains a placeholder or the parent type (component type in
the case of arrays) type involves a placeholder, this type does. */
if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (type))
|| CONTAINS_PLACEHOLDER_P (TYPE_SIZE_UNIT (type))
|| (TREE_TYPE (type) != 0
&& type_contains_placeholder_p (TREE_TYPE (type))))
return true;
/* Now do type-specific checks. Note that the last part of the check above
greatly limits what we have to do below. */
switch (TREE_CODE (type))
{
case VOID_TYPE:
case COMPLEX_TYPE:
case ENUMERAL_TYPE:
case BOOLEAN_TYPE:
case POINTER_TYPE:
case OFFSET_TYPE:
case REFERENCE_TYPE:
case METHOD_TYPE:
case FUNCTION_TYPE:
case VECTOR_TYPE:
return false;
case INTEGER_TYPE:
case REAL_TYPE:
case FIXED_POINT_TYPE:
/* Here we just check the bounds. */
return (CONTAINS_PLACEHOLDER_P (TYPE_MIN_VALUE (type))
|| CONTAINS_PLACEHOLDER_P (TYPE_MAX_VALUE (type)));
case ARRAY_TYPE:
/* We're already checked the component type (TREE_TYPE), so just check
the index type. */
return type_contains_placeholder_p (TYPE_DOMAIN (type));
case RECORD_TYPE:
case UNION_TYPE:
case QUAL_UNION_TYPE:
{
tree field;
for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
if (TREE_CODE (field) == FIELD_DECL
&& (CONTAINS_PLACEHOLDER_P (DECL_FIELD_OFFSET (field))
|| (TREE_CODE (type) == QUAL_UNION_TYPE
&& CONTAINS_PLACEHOLDER_P (DECL_QUALIFIER (field)))
|| type_contains_placeholder_p (TREE_TYPE (field))))
return true;
return false;
}
default:
gcc_unreachable ();
}
}
bool
type_contains_placeholder_p (tree type)
{
bool result;
/* If the contains_placeholder_bits field has been initialized,
then we know the answer. */
if (TYPE_CONTAINS_PLACEHOLDER_INTERNAL (type) > 0)
return TYPE_CONTAINS_PLACEHOLDER_INTERNAL (type) - 1;
/* Indicate that we've seen this type node, and the answer is false.
This is what we want to return if we run into recursion via fields. */
TYPE_CONTAINS_PLACEHOLDER_INTERNAL (type) = 1;
/* Compute the real value. */
result = type_contains_placeholder_1 (type);
/* Store the real value. */
TYPE_CONTAINS_PLACEHOLDER_INTERNAL (type) = result + 1;
return result;
}
/* Given a tree EXP, a FIELD_DECL F, and a replacement value R,
return a tree with all occurrences of references to F in a
PLACEHOLDER_EXPR replaced by R. Note that we assume here that EXP
contains only arithmetic expressions or a CALL_EXPR with a
PLACEHOLDER_EXPR occurring only in its arglist. */
tree
substitute_in_expr (tree exp, tree f, tree r)
{
enum tree_code code = TREE_CODE (exp);
tree op0, op1, op2, op3;
tree new_tree, inner;
/* We handle TREE_LIST and COMPONENT_REF separately. */
if (code == TREE_LIST)
{
op0 = SUBSTITUTE_IN_EXPR (TREE_CHAIN (exp), f, r);
op1 = SUBSTITUTE_IN_EXPR (TREE_VALUE (exp), f, r);
if (op0 == TREE_CHAIN (exp) && op1 == TREE_VALUE (exp))
return exp;
return tree_cons (TREE_PURPOSE (exp), op1, op0);
}
else if (code == COMPONENT_REF)
{
/* If this expression is getting a value from a PLACEHOLDER_EXPR
and it is the right field, replace it with R. */
for (inner = TREE_OPERAND (exp, 0);
REFERENCE_CLASS_P (inner);
inner = TREE_OPERAND (inner, 0))
;
if (TREE_CODE (inner) == PLACEHOLDER_EXPR
&& TREE_OPERAND (exp, 1) == f)
return r;
/* If this expression hasn't been completed let, leave it alone. */
if (TREE_CODE (inner) == PLACEHOLDER_EXPR && TREE_TYPE (inner) == 0)
return exp;
op0 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 0), f, r);
if (op0 == TREE_OPERAND (exp, 0))
return exp;
new_tree = fold_build3 (COMPONENT_REF, TREE_TYPE (exp),
op0, TREE_OPERAND (exp, 1), NULL_TREE);
}
else
switch (TREE_CODE_CLASS (code))
{
case tcc_constant:
case tcc_declaration:
return exp;
case tcc_exceptional:
case tcc_unary:
case tcc_binary:
case tcc_comparison:
case tcc_expression:
case tcc_reference:
switch (TREE_CODE_LENGTH (code))
{
case 0:
return exp;
case 1:
op0 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 0), f, r);
if (op0 == TREE_OPERAND (exp, 0))
return exp;
new_tree = fold_build1 (code, TREE_TYPE (exp), op0);
break;
case 2:
op0 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 0), f, r);
op1 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 1), f, r);
if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1))
return exp;
new_tree = fold_build2 (code, TREE_TYPE (exp), op0, op1);
break;
case 3:
op0 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 0), f, r);
op1 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 1), f, r);
op2 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 2), f, r);
if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
&& op2 == TREE_OPERAND (exp, 2))
return exp;
new_tree = fold_build3 (code, TREE_TYPE (exp), op0, op1, op2);
break;
case 4:
op0 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 0), f, r);
op1 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 1), f, r);
op2 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 2), f, r);
op3 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 3), f, r);
if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
&& op2 == TREE_OPERAND (exp, 2)
&& op3 == TREE_OPERAND (exp, 3))
return exp;
new_tree = fold (build4 (code, TREE_TYPE (exp), op0, op1, op2, op3));
break;
default:
gcc_unreachable ();
}
break;
case tcc_vl_exp:
{
tree copy = NULL_TREE;
int i;
for (i = 1; i < TREE_OPERAND_LENGTH (exp); i++)
{
tree op = TREE_OPERAND (exp, i);
tree new_op = SUBSTITUTE_IN_EXPR (op, f, r);
if (new_op != op)
{
if (!copy)
copy = copy_node (exp);
TREE_OPERAND (copy, i) = new_op;
}
}
if (copy)
new_tree = fold (copy);
else
return exp;
}
break;
default:
gcc_unreachable ();
}
TREE_READONLY (new_tree) = TREE_READONLY (exp);
return new_tree;
}
/* Similar, but look for a PLACEHOLDER_EXPR in EXP and find a replacement
for it within OBJ, a tree that is an object or a chain of references. */
tree
substitute_placeholder_in_expr (tree exp, tree obj)
{
enum tree_code code = TREE_CODE (exp);
tree op0, op1, op2, op3;
/* If this is a PLACEHOLDER_EXPR, see if we find a corresponding type
in the chain of OBJ. */
if (code == PLACEHOLDER_EXPR)
{
tree need_type = TYPE_MAIN_VARIANT (TREE_TYPE (exp));
tree elt;
for (elt = obj; elt != 0;
elt = ((TREE_CODE (elt) == COMPOUND_EXPR
|| TREE_CODE (elt) == COND_EXPR)
? TREE_OPERAND (elt, 1)
: (REFERENCE_CLASS_P (elt)
|| UNARY_CLASS_P (elt)
|| BINARY_CLASS_P (elt)
|| VL_EXP_CLASS_P (elt)
|| EXPRESSION_CLASS_P (elt))
? TREE_OPERAND (elt, 0) : 0))
if (TYPE_MAIN_VARIANT (TREE_TYPE (elt)) == need_type)
return elt;
for (elt = obj; elt != 0;
elt = ((TREE_CODE (elt) == COMPOUND_EXPR
|| TREE_CODE (elt) == COND_EXPR)
? TREE_OPERAND (elt, 1)
: (REFERENCE_CLASS_P (elt)
|| UNARY_CLASS_P (elt)
|| BINARY_CLASS_P (elt)
|| VL_EXP_CLASS_P (elt)
|| EXPRESSION_CLASS_P (elt))
? TREE_OPERAND (elt, 0) : 0))
if (POINTER_TYPE_P (TREE_TYPE (elt))
&& (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (elt)))
== need_type))
return fold_build1 (INDIRECT_REF, need_type, elt);
/* If we didn't find it, return the original PLACEHOLDER_EXPR. If it
survives until RTL generation, there will be an error. */
return exp;
}
/* TREE_LIST is special because we need to look at TREE_VALUE
and TREE_CHAIN, not TREE_OPERANDS. */
else if (code == TREE_LIST)
{
op0 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_CHAIN (exp), obj);
op1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_VALUE (exp), obj);
if (op0 == TREE_CHAIN (exp) && op1 == TREE_VALUE (exp))
return exp;
return tree_cons (TREE_PURPOSE (exp), op1, op0);
}
else
switch (TREE_CODE_CLASS (code))
{
case tcc_constant:
case tcc_declaration:
return exp;
case tcc_exceptional:
case tcc_unary:
case tcc_binary:
case tcc_comparison:
case tcc_expression:
case tcc_reference:
case tcc_statement:
switch (TREE_CODE_LENGTH (code))
{
case 0:
return exp;
case 1:
op0 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 0), obj);
if (op0 == TREE_OPERAND (exp, 0))
return exp;
else
return fold_build1 (code, TREE_TYPE (exp), op0);
case 2:
op0 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 0), obj);
op1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 1), obj);
if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1))
return exp;
else
return fold_build2 (code, TREE_TYPE (exp), op0, op1);
case 3:
op0 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 0), obj);
op1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 1), obj);
op2 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 2), obj);
if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
&& op2 == TREE_OPERAND (exp, 2))
return exp;
else
return fold_build3 (code, TREE_TYPE (exp), op0, op1, op2);
case 4:
op0 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 0), obj);
op1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 1), obj);
op2 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 2), obj);
op3 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 3), obj);
if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
&& op2 == TREE_OPERAND (exp, 2)
&& op3 == TREE_OPERAND (exp, 3))
return exp;
else
return fold (build4 (code, TREE_TYPE (exp), op0, op1, op2, op3));
default:
gcc_unreachable ();
}
break;
case tcc_vl_exp:
{
tree copy = NULL_TREE;
int i;
for (i = 1; i < TREE_OPERAND_LENGTH (exp); i++)
{
tree op = TREE_OPERAND (exp, i);
tree new_op = SUBSTITUTE_PLACEHOLDER_IN_EXPR (op, obj);
if (new_op != op)
{
if (!copy)
copy = copy_node (exp);
TREE_OPERAND (copy, i) = new_op;
}
}
if (copy)
return fold (copy);
else
return exp;
}
default:
gcc_unreachable ();
}
}
/* Stabilize a reference so that we can use it any number of times
without causing its operands to be evaluated more than once.
Returns the stabilized reference. This works by means of save_expr,
so see the caveats in the comments about save_expr.
Also allows conversion expressions whose operands are references.
Any other kind of expression is returned unchanged. */
tree
stabilize_reference (tree ref)
{
tree result;
enum tree_code code = TREE_CODE (ref);
switch (code)
{
case VAR_DECL:
case PARM_DECL:
case RESULT_DECL:
/* No action is needed in this case. */
return ref;
CASE_CONVERT:
case FLOAT_EXPR:
case FIX_TRUNC_EXPR:
result = build_nt (code, stabilize_reference (TREE_OPERAND (ref, 0)));
break;
case INDIRECT_REF:
result = build_nt (INDIRECT_REF,
stabilize_reference_1 (TREE_OPERAND (ref, 0)));
break;
case COMPONENT_REF:
result = build_nt (COMPONENT_REF,
stabilize_reference (TREE_OPERAND (ref, 0)),
TREE_OPERAND (ref, 1), NULL_TREE);
break;
case BIT_FIELD_REF:
result = build_nt (BIT_FIELD_REF,
stabilize_reference (TREE_OPERAND (ref, 0)),
stabilize_reference_1 (TREE_OPERAND (ref, 1)),
stabilize_reference_1 (TREE_OPERAND (ref, 2)));
break;
case ARRAY_REF:
result = build_nt (ARRAY_REF,
stabilize_reference (TREE_OPERAND (ref, 0)),
stabilize_reference_1 (TREE_OPERAND (ref, 1)),
TREE_OPERAND (ref, 2), TREE_OPERAND (ref, 3));
break;
case ARRAY_RANGE_REF:
result = build_nt (ARRAY_RANGE_REF,
stabilize_reference (TREE_OPERAND (ref, 0)),
stabilize_reference_1 (TREE_OPERAND (ref, 1)),
TREE_OPERAND (ref, 2), TREE_OPERAND (ref, 3));
break;
case COMPOUND_EXPR:
/* We cannot wrap the first expression in a SAVE_EXPR, as then
it wouldn't be ignored. This matters when dealing with
volatiles. */
return stabilize_reference_1 (ref);
/* If arg isn't a kind of lvalue we recognize, make no change.
Caller should recognize the error for an invalid lvalue. */
default:
return ref;
case ERROR_MARK:
return error_mark_node;
}
TREE_TYPE (result) = TREE_TYPE (ref);
TREE_READONLY (result) = TREE_READONLY (ref);
TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (ref);
TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (ref);
return result;
}
/* Subroutine of stabilize_reference; this is called for subtrees of
references. Any expression with side-effects must be put in a SAVE_EXPR
to ensure that it is only evaluated once.
We don't put SAVE_EXPR nodes around everything, because assigning very
simple expressions to temporaries causes us to miss good opportunities
for optimizations. Among other things, the opportunity to fold in the
addition of a constant into an addressing mode often gets lost, e.g.
"y[i+1] += x;". In general, we take the approach that we should not make
an assignment unless we are forced into it - i.e., that any non-side effect
operator should be allowed, and that cse should take care of coalescing
multiple utterances of the same expression should that prove fruitful. */
tree
stabilize_reference_1 (tree e)
{
tree result;
enum tree_code code = TREE_CODE (e);
/* We cannot ignore const expressions because it might be a reference
to a const array but whose index contains side-effects. But we can
ignore things that are actual constant or that already have been
handled by this function. */
if (tree_invariant_p (e))
return e;
switch (TREE_CODE_CLASS (code))
{
case tcc_exceptional:
case tcc_type:
case tcc_declaration:
case tcc_comparison:
case tcc_statement:
case tcc_expression:
case tcc_reference:
case tcc_vl_exp:
/* If the expression has side-effects, then encase it in a SAVE_EXPR
so that it will only be evaluated once. */
/* The reference (r) and comparison (<) classes could be handled as
below, but it is generally faster to only evaluate them once. */
if (TREE_SIDE_EFFECTS (e))
return save_expr (e);
return e;
case tcc_constant:
/* Constants need no processing. In fact, we should never reach
here. */
return e;
case tcc_binary:
/* Division is slow and tends to be compiled with jumps,
especially the division by powers of 2 that is often
found inside of an array reference. So do it just once. */
if (code == TRUNC_DIV_EXPR || code == TRUNC_MOD_EXPR
|| code == FLOOR_DIV_EXPR || code == FLOOR_MOD_EXPR
|| code == CEIL_DIV_EXPR || code == CEIL_MOD_EXPR
|| code == ROUND_DIV_EXPR || code == ROUND_MOD_EXPR)
return save_expr (e);
/* Recursively stabilize each operand. */
result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)),
stabilize_reference_1 (TREE_OPERAND (e, 1)));
break;
case tcc_unary:
/* Recursively stabilize each operand. */
result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)));
break;
default:
gcc_unreachable ();
}
TREE_TYPE (result) = TREE_TYPE (e);
TREE_READONLY (result) = TREE_READONLY (e);
TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (e);
TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (e);
return result;
}
/* Low-level constructors for expressions. */
/* A helper function for build1 and constant folders. Set TREE_CONSTANT,
and TREE_SIDE_EFFECTS for an ADDR_EXPR. */
void
recompute_tree_invariant_for_addr_expr (tree t)
{
tree node;
bool tc = true, se = false;
/* We started out assuming this address is both invariant and constant, but
does not have side effects. Now go down any handled components and see if
any of them involve offsets that are either non-constant or non-invariant.
Also check for side-effects.
??? Note that this code makes no attempt to deal with the case where
taking the address of something causes a copy due to misalignment. */
#define UPDATE_FLAGS(NODE) \
do { tree _node = (NODE); \
if (_node && !TREE_CONSTANT (_node)) tc = false; \
if (_node && TREE_SIDE_EFFECTS (_node)) se = true; } while (0)
for (node = TREE_OPERAND (t, 0); handled_component_p (node);
node = TREE_OPERAND (node, 0))
{
/* If the first operand doesn't have an ARRAY_TYPE, this is a bogus
array reference (probably made temporarily by the G++ front end),
so ignore all the operands. */
if ((TREE_CODE (node) == ARRAY_REF
|| TREE_CODE (node) == ARRAY_RANGE_REF)
&& TREE_CODE (TREE_TYPE (TREE_OPERAND (node, 0))) == ARRAY_TYPE)
{
UPDATE_FLAGS (TREE_OPERAND (node, 1));
if (TREE_OPERAND (node, 2))
UPDATE_FLAGS (TREE_OPERAND (node, 2));
if (TREE_OPERAND (node, 3))
UPDATE_FLAGS (TREE_OPERAND (node, 3));
}
/* Likewise, just because this is a COMPONENT_REF doesn't mean we have a
FIELD_DECL, apparently. The G++ front end can put something else
there, at least temporarily. */
else if (TREE_CODE (node) == COMPONENT_REF
&& TREE_CODE (TREE_OPERAND (node, 1)) == FIELD_DECL)
{
if (TREE_OPERAND (node, 2))
UPDATE_FLAGS (TREE_OPERAND (node, 2));
}
else if (TREE_CODE (node) == BIT_FIELD_REF)
UPDATE_FLAGS (TREE_OPERAND (node, 2));
}
node = lang_hooks.expr_to_decl (node, &tc, &se);
/* Now see what's inside. If it's an INDIRECT_REF, copy our properties from
the address, since &(*a)->b is a form of addition. If it's a constant, the
address is constant too. If it's a decl, its address is constant if the
decl is static. Everything else is not constant and, furthermore,
taking the address of a volatile variable is not volatile. */
if (TREE_CODE (node) == INDIRECT_REF)
UPDATE_FLAGS (TREE_OPERAND (node, 0));
else if (CONSTANT_CLASS_P (node))
;
else if (DECL_P (node))
tc &= (staticp (node) != NULL_TREE);
else
{
tc = false;
se |= TREE_SIDE_EFFECTS (node);
}
TREE_CONSTANT (t) = tc;
TREE_SIDE_EFFECTS (t) = se;
#undef UPDATE_FLAGS
}
/* Build an expression of code CODE, data type TYPE, and operands as
specified. Expressions and reference nodes can be created this way.
Constants, decls, types and misc nodes cannot be.
We define 5 non-variadic functions, from 0 to 4 arguments. This is
enough for all extant tree codes. */
tree
build0_stat (enum tree_code code, tree tt MEM_STAT_DECL)
{
tree t;
gcc_assert (TREE_CODE_LENGTH (code) == 0);
t = make_node_stat (code PASS_MEM_STAT);
TREE_TYPE (t) = tt;
return t;
}
tree
build1_stat (enum tree_code code, tree type, tree node MEM_STAT_DECL)
{
int length = sizeof (struct tree_exp);
#ifdef GATHER_STATISTICS
tree_node_kind kind;
#endif
tree t;
#ifdef GATHER_STATISTICS
switch (TREE_CODE_CLASS (code))
{
case tcc_statement: /* an expression with side effects */
kind = s_kind;
break;
case tcc_reference: /* a reference */
kind = r_kind;
break;
default:
kind = e_kind;
break;
}
tree_node_counts[(int) kind]++;
tree_node_sizes[(int) kind] += length;
#endif
gcc_assert (TREE_CODE_LENGTH (code) == 1);
t = (tree) ggc_alloc_zone_pass_stat (length, &tree_zone);
memset (t, 0, sizeof (struct tree_common));
TREE_SET_CODE (t, code);
TREE_TYPE (t) = type;
SET_EXPR_LOCATION (t, UNKNOWN_LOCATION);
TREE_OPERAND (t, 0) = node;
TREE_BLOCK (t) = NULL_TREE;
if (node && !TYPE_P (node))
{
TREE_SIDE_EFFECTS (t) = TREE_SIDE_EFFECTS (node);
TREE_READONLY (t) = TREE_READONLY (node);
}
if (TREE_CODE_CLASS (code) == tcc_statement)
TREE_SIDE_EFFECTS (t) = 1;
else switch (code)
{
case VA_ARG_EXPR:
/* All of these have side-effects, no matter what their
operands are. */
TREE_SIDE_EFFECTS (t) = 1;
TREE_READONLY (t) = 0;
break;
case MISALIGNED_INDIRECT_REF:
case ALIGN_INDIRECT_REF:
case INDIRECT_REF:
/* Whether a dereference is readonly has nothing to do with whether
its operand is readonly. */</