1 /* Output variables, constants and external declarations, for GNU compiler.
2 Copyright (C) 1987, 1988, 1989, 1992 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
21 /* This file handles generation of all the assembler code
22 *except* the instructions of a function.
23 This includes declarations of variables and their initial values.
25 We also output the assembler code for constants stored in memory
26 and are responsible for combining constants with the same value. */
30 /* #include <stab.h> */
36 #include "hard-reg-set.h"
42 #ifdef XCOFF_DEBUGGING_INFO
47 #define ASM_STABS_OP ".stabs"
50 /* File in which assembler code is being written. */
52 extern FILE *asm_out_file;
54 /* The (assembler) name of the first globally-visible object output. */
55 char *first_global_object_name;
57 extern struct obstack *current_obstack;
58 extern struct obstack *saveable_obstack;
59 extern struct obstack permanent_obstack;
60 #define obstack_chunk_alloc xmalloc
62 /* Number for making the label on the next
63 constant that is stored in memory. */
67 /* Number for making the label on the next
68 static variable internal to a function. */
72 /* Nonzero if at least one function definition has been seen. */
73 static int function_defined;
75 extern FILE *asm_out_file;
77 static char *compare_constant_1 ();
78 static void record_constant_1 ();
79 void output_constant_pool ();
80 void assemble_name ();
81 int output_addressed_constants ();
82 void output_constant ();
83 void output_constructor ();
85 void readonly_data_section ();
89 static enum in_section {no_section, in_text, in_data, EXTRA_SECTIONS} in_section
92 static enum in_section {no_section, in_text, in_data} in_section
96 /* Define functions like text_section for any extra sections. */
97 #ifdef EXTRA_SECTION_FUNCTIONS
98 EXTRA_SECTION_FUNCTIONS
101 /* Tell assembler to switch to text section. */
106 if (in_section != in_text)
108 fprintf (asm_out_file, "%s\n", TEXT_SECTION_ASM_OP);
109 in_section = in_text;
113 /* Tell assembler to switch to data section. */
118 if (in_section != in_data)
120 if (flag_shared_data)
122 #ifdef SHARED_SECTION_ASM_OP
123 fprintf (asm_out_file, "%s\n", SHARED_SECTION_ASM_OP);
125 fprintf (asm_out_file, "%s\n", DATA_SECTION_ASM_OP);
129 fprintf (asm_out_file, "%s\n", DATA_SECTION_ASM_OP);
131 in_section = in_data;
135 /* Tell assembler to switch to read-only data section. This is normally
139 readonly_data_section ()
141 #ifdef READONLY_DATA_SECTION
142 READONLY_DATA_SECTION (); /* Note this can call data_section. */
148 /* Determine if we're in the text section. */
153 return in_section == in_text;
156 /* Create the rtl to represent a function, for a function definition.
157 DECL is a FUNCTION_DECL node which describes which function.
158 The rtl is stored into DECL. */
161 make_function_rtl (decl)
164 char *name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
166 /* Rename a nested function to avoid conflicts. */
167 if (decl_function_context (decl) != 0
168 && DECL_INITIAL (decl) != 0
169 && DECL_RTL (decl) == 0)
173 name = IDENTIFIER_POINTER (DECL_NAME (decl));
174 ASM_FORMAT_PRIVATE_NAME (label, name, var_labelno);
175 name = obstack_copy0 (saveable_obstack, label, strlen (label));
179 if (DECL_RTL (decl) == 0)
182 = gen_rtx (MEM, DECL_MODE (decl),
183 gen_rtx (SYMBOL_REF, Pmode, name));
185 /* Optionally set flags or add text to the name to record information
186 such as that it is a function name. If the name is changed, the macro
187 ASM_OUTPUT_LABELREF will have to know how to strip this information.
188 And if it finds a * at the beginning after doing so, it must handle
190 #ifdef ENCODE_SECTION_INFO
191 ENCODE_SECTION_INFO (decl);
195 /* Record at least one function has been defined. */
196 function_defined = 1;
199 /* Given NAME, a putative register name, discard any customary prefixes. */
202 strip_reg_name (name)
205 #ifdef REGISTER_PREFIX
206 if (!strncmp (name, REGISTER_PREFIX, strlen (REGISTER_PREFIX)))
207 name += strlen (REGISTER_PREFIX);
209 if (name[0] == '%' || name[0] == '#')
214 /* Decode an `asm' spec for a declaration as a register name.
215 Return the register number, or -1 if nothing specified,
216 or -2 if the ASMSPEC is not `cc' or `memory' and is not recognized,
217 or -3 if ASMSPEC is `cc' and is not recognized,
218 or -4 if ASMSPEC is `memory' and is not recognized.
219 Accept an exact spelling or a decimal number.
220 Prefixes such as % are optional. */
223 decode_reg_name (asmspec)
230 /* Get rid of confusing prefixes. */
231 asmspec = strip_reg_name (asmspec);
233 /* Allow a decimal number as a "register name". */
234 for (i = strlen (asmspec) - 1; i >= 0; i--)
235 if (! (asmspec[i] >= '0' && asmspec[i] <= '9'))
237 if (asmspec[0] != 0 && i < 0)
240 if (i < FIRST_PSEUDO_REGISTER && i >= 0)
246 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
248 && ! strcmp (asmspec, strip_reg_name (reg_names[i])))
251 #ifdef ADDITIONAL_REGISTER_NAMES
253 static struct { char *name; int number; } table[]
254 = ADDITIONAL_REGISTER_NAMES;
256 for (i = 0; i < sizeof (table) / sizeof (table[0]); i++)
257 if (! strcmp (asmspec, table[i].name))
258 return table[i].number;
260 #endif /* ADDITIONAL_REGISTER_NAMES */
262 if (!strcmp (asmspec, "memory"))
265 if (!strcmp (asmspec, "cc"))
274 /* Create the DECL_RTL for a declaration for a static or external variable
275 or static or external function.
276 ASMSPEC, if not 0, is the string which the user specified
277 as the assembler symbol name.
278 TOP_LEVEL is nonzero if this is a file-scope variable.
280 This is never called for PARM_DECL nodes. */
283 make_decl_rtl (decl, asmspec, top_level)
289 int reg_number = decode_reg_name (asmspec);
291 if (DECL_ASSEMBLER_NAME (decl) != NULL_TREE)
292 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
294 if (reg_number == -2)
296 /* ASMSPEC is given, and not the name of a register. */
297 name = (char *) obstack_alloc (saveable_obstack,
298 strlen (asmspec) + 2);
300 strcpy (&name[1], asmspec);
303 /* For a duplicate declaration, we can be called twice on the
304 same DECL node. Don't alter the RTL already made
305 unless the old mode is wrong (which can happen when
306 the previous rtl was made when the type was incomplete). */
307 if (DECL_RTL (decl) == 0
308 || GET_MODE (DECL_RTL (decl)) != DECL_MODE (decl))
312 /* First detect errors in declaring global registers. */
313 if (DECL_REGISTER (decl) && reg_number == -1)
314 error_with_decl (decl,
315 "register name not specified for `%s'");
316 else if (DECL_REGISTER (decl) && reg_number < 0)
317 error_with_decl (decl,
318 "invalid register name for `%s'");
319 else if ((reg_number >= 0 || reg_number == -3) && ! DECL_REGISTER (decl))
320 error_with_decl (decl,
321 "register name given for non-register variable `%s'");
322 else if (DECL_REGISTER (decl) && TREE_CODE (decl) == FUNCTION_DECL)
323 error ("function declared `register'");
324 else if (DECL_REGISTER (decl) && TYPE_MODE (TREE_TYPE (decl)) == BLKmode)
325 error_with_decl (decl, "data type of `%s' isn't suitable for a register");
326 /* Now handle properly declared static register variables. */
327 else if (DECL_REGISTER (decl))
330 #if 0 /* yylex should print the warning for this */
332 pedwarn ("ANSI C forbids global register variables");
334 if (DECL_INITIAL (decl) != 0 && top_level)
336 DECL_INITIAL (decl) = 0;
337 error ("global register variable has initial value");
339 if (fixed_regs[reg_number] == 0
340 && function_defined && top_level)
341 error ("global register variable follows a function definition");
342 if (TREE_THIS_VOLATILE (decl))
343 warning ("volatile register variables don't work as you might wish");
344 DECL_RTL (decl) = gen_rtx (REG, DECL_MODE (decl), reg_number);
345 REG_USERVAR_P (DECL_RTL (decl)) = 1;
349 /* Make this register fixed, so not usable for anything else. */
350 nregs = HARD_REGNO_NREGS (reg_number, DECL_MODE (decl));
352 global_regs[reg_number + --nregs] = 1;
357 /* Now handle ordinary static variables and functions (in memory).
358 Also handle vars declared register invalidly. */
359 if (DECL_RTL (decl) == 0)
361 /* Can't use just the variable's own name for a variable
362 whose scope is less than the whole file.
363 Concatenate a distinguishing number. */
364 if (!top_level && !DECL_EXTERNAL (decl) && asmspec == 0)
368 ASM_FORMAT_PRIVATE_NAME (label, name, var_labelno);
369 name = obstack_copy0 (saveable_obstack, label, strlen (label));
373 DECL_RTL (decl) = gen_rtx (MEM, DECL_MODE (decl),
374 gen_rtx (SYMBOL_REF, Pmode, name));
375 if (TREE_THIS_VOLATILE (decl))
376 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
377 if (TREE_READONLY (decl))
378 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
379 MEM_IN_STRUCT_P (DECL_RTL (decl))
380 = (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
381 || TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE
382 || TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE);
384 /* Optionally set flags or add text to the name to record information
385 such as that it is a function name.
386 If the name is changed, the macro ASM_OUTPUT_LABELREF
387 will have to know how to strip this information.
388 And if it finds a * at the beginning after doing so,
389 it must handle that too. */
390 #ifdef ENCODE_SECTION_INFO
391 ENCODE_SECTION_INFO (decl);
397 /* Make the rtl for variable VAR be volatile.
398 Use this only for static variables. */
400 make_var_volatile (var)
403 if (GET_CODE (DECL_RTL (var)) != MEM)
406 MEM_VOLATILE_P (DECL_RTL (var)) = 1;
409 /* Output a string of literal assembler code
410 for an `asm' keyword used between functions. */
413 assemble_asm (string)
418 if (TREE_CODE (string) == ADDR_EXPR)
419 string = TREE_OPERAND (string, 0);
421 fprintf (asm_out_file, "\t%s\n", TREE_STRING_POINTER (string));
424 #if 0 /* This should no longer be needed, because
425 flag_gnu_linker should be 0 on these systems,
426 which should prevent any output
427 if ASM_OUTPUT_CONSTRUCTOR and ASM_OUTPUT_DESTRUCTOR are absent. */
428 #if !(defined(DBX_DEBUGGING_INFO) && !defined(FASCIST_ASSEMBLER))
429 #ifndef ASM_OUTPUT_CONSTRUCTOR
430 #define ASM_OUTPUT_CONSTRUCTOR(file, name)
432 #ifndef ASM_OUTPUT_DESTRUCTOR
433 #define ASM_OUTPUT_DESTRUCTOR(file, name)
438 /* Record an element in the table of global destructors.
439 How this is done depends on what sort of assembler and linker
442 NAME should be the name of a global function to be called
443 at exit time. This name is output using assemble_name. */
446 assemble_destructor (name)
449 #ifdef ASM_OUTPUT_DESTRUCTOR
450 ASM_OUTPUT_DESTRUCTOR (asm_out_file, name);
454 /* Now tell GNU LD that this is part of the static destructor set. */
455 /* This code works for any machine provided you use GNU as/ld. */
456 fprintf (asm_out_file, "%s \"___DTOR_LIST__\",22,0,0,", ASM_STABS_OP);
457 assemble_name (asm_out_file, name);
458 fputc ('\n', asm_out_file);
463 /* Likewise for global constructors. */
466 assemble_constructor (name)
469 #ifdef ASM_OUTPUT_CONSTRUCTOR
470 ASM_OUTPUT_CONSTRUCTOR (asm_out_file, name);
474 /* Now tell GNU LD that this is part of the static constructor set. */
475 /* This code works for any machine provided you use GNU as/ld. */
476 fprintf (asm_out_file, "%s \"___CTOR_LIST__\",22,0,0,", ASM_STABS_OP);
477 assemble_name (asm_out_file, name);
478 fputc ('\n', asm_out_file);
483 /* Likewise for entries we want to record for garbage collection.
484 Garbage collection is still under development. */
487 assemble_gc_entry (name)
490 #ifdef ASM_OUTPUT_GC_ENTRY
491 ASM_OUTPUT_GC_ENTRY (asm_out_file, name);
495 /* Now tell GNU LD that this is part of the static constructor set. */
496 fprintf (asm_out_file, "%s \"___PTR_LIST__\",22,0,0,", ASM_STABS_OP);
497 assemble_name (asm_out_file, name);
498 fputc ('\n', asm_out_file);
503 /* Output assembler code for the constant pool of a function and associated
504 with defining the name of the function. DECL describes the function.
505 NAME is the function's name. For the constant pool, we use the current
506 constant pool data. */
509 assemble_start_function (decl, fnname)
515 /* The following code does not need preprocessing in the assembler. */
519 output_constant_pool (fnname, decl);
524 /* Tell assembler to move to target machine's alignment for functions. */
525 align = floor_log2 (FUNCTION_BOUNDARY / BITS_PER_UNIT);
527 ASM_OUTPUT_ALIGN (asm_out_file, align);
529 #ifdef ASM_OUTPUT_FUNCTION_PREFIX
530 ASM_OUTPUT_FUNCTION_PREFIX (asm_out_file, fnname);
533 #ifdef SDB_DEBUGGING_INFO
534 /* Output SDB definition of the function. */
535 if (write_symbols == SDB_DEBUG)
536 sdbout_mark_begin_function ();
539 #ifdef DBX_DEBUGGING_INFO
540 /* Output DBX definition of the function. */
541 if (write_symbols == DBX_DEBUG)
542 dbxout_begin_function (decl);
545 /* Make function name accessible from other files, if appropriate. */
547 if (TREE_PUBLIC (decl))
549 if (!first_global_object_name)
550 first_global_object_name = fnname + (fnname[0] == '*');
551 ASM_GLOBALIZE_LABEL (asm_out_file, fnname);
554 /* Do any machine/system dependent processing of the function name */
555 #ifdef ASM_DECLARE_FUNCTION_NAME
556 ASM_DECLARE_FUNCTION_NAME (asm_out_file, fnname, current_function_decl);
558 /* Standard thing is just output label for the function. */
559 ASM_OUTPUT_LABEL (asm_out_file, fnname);
560 #endif /* ASM_DECLARE_FUNCTION_NAME */
563 /* Output assembler code associated with defining the size of the
564 function. DECL describes the function. NAME is the function's name. */
567 assemble_end_function (decl, fnname)
571 #ifdef ASM_DECLARE_FUNCTION_SIZE
572 ASM_DECLARE_FUNCTION_SIZE (asm_out_file, fnname, decl);
576 /* Assemble code to leave SIZE bytes of zeros. */
579 assemble_zeros (size)
582 #ifdef ASM_NO_SKIP_IN_TEXT
583 /* The `space' pseudo in the text section outputs nop insns rather than 0s,
584 so we must output 0s explicitly in the text section. */
585 if (ASM_NO_SKIP_IN_TEXT && in_text_section ())
589 for (i = 0; i < size - 20; i += 20)
592 fprintf (asm_out_file,
593 "%s 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0\n", ASM_BYTE_OP);
595 fprintf (asm_out_file,
596 "\tbyte 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0\n");
602 fprintf (asm_out_file, "%s 0", ASM_BYTE_OP);
604 fprintf (asm_out_file, "\tbyte 0");
607 for (; i < size; i++)
608 fprintf (asm_out_file, ",0");
609 fprintf (asm_out_file, "\n");
614 ASM_OUTPUT_SKIP (asm_out_file, size);
617 /* Assemble a string constant with the specified C string as contents. */
620 assemble_string (p, size)
628 /* If the string is very long, split it up. */
632 int thissize = size - pos;
633 if (thissize > maximum)
636 ASM_OUTPUT_ASCII (asm_out_file, p, thissize);
643 /* Assemble everything that is needed for a variable or function declaration.
644 Not used for automatic variables, and not used for function definitions.
645 Should not be called for variables of incomplete structure type.
647 TOP_LEVEL is nonzero if this variable has file scope.
648 AT_END is nonzero if this is the special handling, at end of compilation,
649 to define things that have had only tentative definitions. */
652 assemble_variable (decl, top_level, at_end)
662 if (GET_CODE (DECL_RTL (decl)) == REG)
664 /* Do output symbol info for global register variables, but do nothing
667 if (TREE_ASM_WRITTEN (decl))
669 TREE_ASM_WRITTEN (decl) = 1;
671 #if defined (DBX_DEBUGGING_INFO) || defined (XCOFF_DEBUGGING_INFO)
672 /* File-scope global variables are output here. */
673 if ((write_symbols == DBX_DEBUG || write_symbols == XCOFF_DEBUG)
675 dbxout_symbol (decl, 0);
677 #ifdef SDB_DEBUGGING_INFO
678 if (write_symbols == SDB_DEBUG && top_level
679 /* Leave initialized global vars for end of compilation;
680 see comment in compile_file. */
681 && (TREE_PUBLIC (decl) == 0 || DECL_INITIAL (decl) == 0))
682 sdbout_symbol (decl, 0);
685 /* Don't output any DWARF debugging information for variables here.
686 In the case of local variables, the information for them is output
687 when we do our recursive traversal of the tree representation for
688 the entire containing function. In the case of file-scope variables,
689 we output information for all of them at the very end of compilation
690 while we are doing our final traversal of the chain of file-scope
696 /* Normally no need to say anything for external references,
697 since assembler considers all undefined symbols external. */
699 if (DECL_EXTERNAL (decl))
702 /* Output no assembler code for a function declaration.
703 Only definitions of functions output anything. */
705 if (TREE_CODE (decl) == FUNCTION_DECL)
708 /* If type was incomplete when the variable was declared,
709 see if it is complete now. */
711 if (DECL_SIZE (decl) == 0)
712 layout_decl (decl, 0);
714 /* Still incomplete => don't allocate it; treat the tentative defn
715 (which is what it must have been) as an `extern' reference. */
717 if (DECL_SIZE (decl) == 0)
719 error_with_file_and_line (DECL_SOURCE_FILE (decl),
720 DECL_SOURCE_LINE (decl),
721 "storage size of static var `%s' isn't known",
722 IDENTIFIER_POINTER (DECL_NAME (decl)));
726 /* The first declaration of a variable that comes through this function
727 decides whether it is global (in C, has external linkage)
728 or local (in C, has internal linkage). So do nothing more
729 if this function has already run. */
731 if (TREE_ASM_WRITTEN (decl))
734 TREE_ASM_WRITTEN (decl) = 1;
736 #ifdef DBX_DEBUGGING_INFO
737 /* File-scope global variables are output here. */
738 if (write_symbols == DBX_DEBUG && top_level)
739 dbxout_symbol (decl, 0);
741 #ifdef SDB_DEBUGGING_INFO
742 if (write_symbols == SDB_DEBUG && top_level
743 /* Leave initialized global vars for end of compilation;
744 see comment in compile_file. */
745 && (TREE_PUBLIC (decl) == 0 || DECL_INITIAL (decl) == 0))
746 sdbout_symbol (decl, 0);
749 /* Don't output any DWARF debugging information for variables here.
750 In the case of local variables, the information for them is output
751 when we do our recursive traversal of the tree representation for
752 the entire containing function. In the case of file-scope variables,
753 we output information for all of them at the very end of compilation
754 while we are doing our final traversal of the chain of file-scope
757 /* If storage size is erroneously variable, just continue.
758 Error message was already made. */
760 if (TREE_CODE (DECL_SIZE (decl)) != INTEGER_CST)
765 /* This is better than explicit arithmetic, since it avoids overflow. */
766 size_tree = size_binop (CEIL_DIV_EXPR,
767 DECL_SIZE (decl), size_int (BITS_PER_UNIT));
769 if (TREE_INT_CST_HIGH (size_tree) != 0)
771 error_with_decl (decl, "size of variable `%s' is too large");
775 name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
777 /* Handle uninitialized definitions. */
779 /* ANSI specifies that a tentative definition which is not merged with
780 a non-tentative definition behaves exactly like a definition with an
781 initializer equal to zero. (Section 3.7.2)
782 -fno-common gives strict ANSI behavior. Usually you don't want it. */
784 && (DECL_INITIAL (decl) == 0 || DECL_INITIAL (decl) == error_mark_node))
786 int size = TREE_INT_CST_LOW (size_tree);
789 if (TREE_INT_CST_HIGH (size_tree) != 0)
790 error_with_decl (decl, "size of variable `%s' is too large");
791 /* Don't allocate zero bytes of common,
792 since that means "undefined external" in the linker. */
793 if (size == 0) rounded = 1;
794 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
795 so that each uninitialized object starts on such a boundary. */
796 rounded += (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1;
797 rounded = (rounded / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
798 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
800 if (flag_shared_data)
803 if (TREE_PUBLIC (decl))
805 #ifdef ASM_OUTPUT_SHARED_COMMON
806 if (flag_shared_data)
807 ASM_OUTPUT_SHARED_COMMON (asm_out_file, name, size, rounded);
810 #ifdef ASM_OUTPUT_ALIGNED_COMMON
811 ASM_OUTPUT_ALIGNED_COMMON (asm_out_file, name, size,
814 ASM_OUTPUT_COMMON (asm_out_file, name, size, rounded);
819 #ifdef ASM_OUTPUT_SHARED_LOCAL
820 if (flag_shared_data)
821 ASM_OUTPUT_SHARED_LOCAL (asm_out_file, name, size, rounded);
824 #ifdef ASM_OUTPUT_ALIGNED_LOCAL
825 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size,
828 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
834 /* Handle initialized definitions. */
836 /* First make the assembler name(s) global if appropriate. */
837 if (TREE_PUBLIC (decl) && DECL_NAME (decl))
839 if (!first_global_object_name)
840 first_global_object_name = name + (name[0] == '*');
841 ASM_GLOBALIZE_LABEL (asm_out_file, name);
844 for (d = equivalents; d; d = TREE_CHAIN (d))
846 tree e = TREE_VALUE (d);
847 if (TREE_PUBLIC (e) && DECL_NAME (e))
848 ASM_GLOBALIZE_LABEL (asm_out_file,
849 XSTR (XEXP (DECL_RTL (e), 0), 0));
853 /* Output any data that we will need to use the address of. */
854 if (DECL_INITIAL (decl))
855 reloc = output_addressed_constants (DECL_INITIAL (decl));
857 /* Switch to the proper section for this data. */
858 #ifdef SELECT_SECTION
859 SELECT_SECTION (decl, reloc);
861 if (TREE_READONLY (decl)
862 && ! TREE_THIS_VOLATILE (decl)
863 && ! (flag_pic && reloc))
864 readonly_data_section ();
869 /* Compute and output the alignment of this data. */
871 align = DECL_ALIGN (decl);
872 /* Some object file formats have a maximum alignment which they support.
873 In particular, a.out format supports a maximum alignment of 4. */
874 #ifndef MAX_OFILE_ALIGNMENT
875 #define MAX_OFILE_ALIGNMENT BIGGEST_ALIGNMENT
877 if (align > MAX_OFILE_ALIGNMENT)
879 warning_with_decl (decl,
880 "alignment of `%s' is greater than maximum object file alignment");
881 align = MAX_OFILE_ALIGNMENT;
883 #ifdef DATA_ALIGNMENT
884 /* On some machines, it is good to increase alignment sometimes. */
885 align = DATA_ALIGNMENT (TREE_TYPE (decl), align);
887 #ifdef CONSTANT_ALIGNMENT
888 if (DECL_INITIAL (decl))
889 align = CONSTANT_ALIGNMENT (DECL_INITIAL (decl), align);
892 /* Reset the alignment in case we have made it tighter, so we can benefit
893 from it in get_pointer_alignment. */
894 DECL_ALIGN (decl) = align;
896 if (align > BITS_PER_UNIT)
897 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
899 /* Do any machine/system dependent processing of the object. */
900 #ifdef ASM_DECLARE_OBJECT_NAME
901 ASM_DECLARE_OBJECT_NAME (asm_out_file, name, decl);
903 /* Standard thing is just output label for the object. */
904 ASM_OUTPUT_LABEL (asm_out_file, name);
905 #endif /* ASM_DECLARE_OBJECT_NAME */
908 for (d = equivalents; d; d = TREE_CHAIN (d))
910 tree e = TREE_VALUE (d);
911 ASM_OUTPUT_LABEL (asm_out_file, XSTR (XEXP (DECL_RTL (e), 0), 0));
915 if (DECL_INITIAL (decl))
916 /* Output the actual data. */
917 output_constant (DECL_INITIAL (decl),
918 int_size_in_bytes (TREE_TYPE (decl)));
920 /* Leave space for it. */
921 assemble_zeros (int_size_in_bytes (TREE_TYPE (decl)));
924 #ifdef XCOFF_DEBUGGING_INFO
925 /* Unfortunately, the IBM assembler cannot handle stabx before the actual
926 declaration. When something like ".stabx "aa:S-2",aa,133,0" is emitted
927 and `aa' hasn't been output yet, the assembler generates a stab entry with
928 a value of zero, in addition to creating an unnecessary external entry
929 for `aa'. Hence, we must postpone dbxout_symbol to here at the end. */
931 /* File-scope global variables are output here. */
932 if (write_symbols == XCOFF_DEBUG && top_level)
933 dbxout_symbol (decl, 0);
935 /* There must be a statement after a label. */
940 /* Output something to declare an external symbol to the assembler.
941 (Most assemblers don't need this, so we normally output nothing.)
942 Do nothing if DECL is not external. */
945 assemble_external (decl)
948 #ifdef ASM_OUTPUT_EXTERNAL
949 if (TREE_CODE_CLASS (TREE_CODE (decl)) == 'd'
950 && DECL_EXTERNAL (decl) && TREE_PUBLIC (decl))
952 rtx rtl = DECL_RTL (decl);
954 if (GET_CODE (rtl) == MEM && GET_CODE (XEXP (rtl, 0)) == SYMBOL_REF
955 && ! SYMBOL_REF_USED (XEXP (rtl, 0)))
957 /* Some systems do require some output. */
958 SYMBOL_REF_USED (XEXP (rtl, 0)) = 1;
959 ASM_OUTPUT_EXTERNAL (asm_out_file, decl, XSTR (XEXP (rtl, 0), 0));
965 /* Similar, for calling a library function FUN. */
968 assemble_external_libcall (fun)
971 #ifdef ASM_OUTPUT_EXTERNAL_LIBCALL
972 /* Declare library function name external when first used, if nec. */
973 if (! SYMBOL_REF_USED (fun))
975 SYMBOL_REF_USED (fun) = 1;
976 ASM_OUTPUT_EXTERNAL_LIBCALL (asm_out_file, fun);
981 /* Declare the label NAME global. */
984 assemble_global (name)
987 ASM_GLOBALIZE_LABEL (asm_out_file, name);
990 /* Assemble a label named NAME. */
993 assemble_label (name)
996 ASM_OUTPUT_LABEL (asm_out_file, name);
999 /* Output to FILE a reference to the assembler name of a C-level name NAME.
1000 If NAME starts with a *, the rest of NAME is output verbatim.
1001 Otherwise NAME is transformed in an implementation-defined way
1002 (usually by the addition of an underscore).
1003 Many macros in the tm file are defined to call this function. */
1006 assemble_name (file, name)
1011 fputs (&name[1], file);
1013 ASM_OUTPUT_LABELREF (file, name);
1016 /* Allocate SIZE bytes writable static space with a gensym name
1017 and return an RTX to refer to its address. */
1020 assemble_static_space (size)
1026 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
1027 so that each uninitialized object starts on such a boundary. */
1028 int rounded = ((size + (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1)
1029 / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
1030 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
1033 if (flag_shared_data)
1037 ASM_GENERATE_INTERNAL_LABEL (name, "LF", const_labelno);
1040 namestring = (char *) obstack_alloc (saveable_obstack,
1042 strcpy (namestring, name);
1044 x = gen_rtx (SYMBOL_REF, Pmode, namestring);
1045 #ifdef ASM_OUTPUT_ALIGNED_LOCAL
1046 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, BIGGEST_ALIGNMENT);
1048 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
1053 /* Assemble the static constant template for function entry trampolines.
1054 This is done at most once per compilation.
1055 Returns an RTX for the address of the template. */
1058 assemble_trampoline_template ()
1064 /* Write the assembler code to define one. */
1065 align = floor_log2 (FUNCTION_BOUNDARY / BITS_PER_UNIT);
1067 ASM_OUTPUT_ALIGN (asm_out_file, align);
1069 ASM_OUTPUT_INTERNAL_LABEL (asm_out_file, "LTRAMP", 0);
1070 TRAMPOLINE_TEMPLATE (asm_out_file);
1072 /* Record the rtl to refer to it. */
1073 ASM_GENERATE_INTERNAL_LABEL (label, "LTRAMP", 0);
1075 = (char *) obstack_copy0 (&permanent_obstack, label, strlen (label));
1076 return gen_rtx (SYMBOL_REF, Pmode, name);
1079 /* Assemble the integer constant X into an object of SIZE bytes.
1080 X must be either a CONST_INT or CONST_DOUBLE.
1082 Return 1 if we were able to output the constant, otherwise 0. If FORCE is
1083 non-zero, abort if we can't output the constant. */
1086 assemble_integer (x, size, force)
1091 /* First try to use the standard 1, 2, 4, 8, and 16 byte
1092 ASM_OUTPUT... macros. */
1096 #ifdef ASM_OUTPUT_CHAR
1098 ASM_OUTPUT_CHAR (asm_out_file, x);
1102 #ifdef ASM_OUTPUT_SHORT
1104 ASM_OUTPUT_SHORT (asm_out_file, x);
1108 #ifdef ASM_OUTPUT_INT
1110 ASM_OUTPUT_INT (asm_out_file, x);
1114 #ifdef ASM_OUTPUT_DOUBLE_INT
1116 ASM_OUTPUT_DOUBLE_INT (asm_out_file, x);
1120 #ifdef ASM_OUTPUT_QUADRUPLE_INT
1122 ASM_OUTPUT_QUADRUPLE_INT (asm_out_file, x);
1127 /* If we couldn't do it that way, there are two other possibilities: First,
1128 if the machine can output an explicit byte and this is a 1 byte constant,
1129 we can use ASM_OUTPUT_BYTE. */
1131 #ifdef ASM_OUTPUT_BYTE
1132 if (size == 1 && GET_CODE (x) == CONST_INT)
1134 ASM_OUTPUT_BYTE (asm_out_file, INTVAL (x));
1139 /* Finally, if SIZE is larger than a single word, try to output the constant
1140 one word at a time. */
1142 if (size > UNITS_PER_WORD)
1145 enum machine_mode mode
1146 = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
1149 for (i = 0; i < size / UNITS_PER_WORD; i++)
1151 word = operand_subword (x, i, 0, mode);
1156 if (! assemble_integer (word, UNITS_PER_WORD, 0))
1160 if (i == size / UNITS_PER_WORD)
1162 /* If we output at least one word and then could not finish,
1163 there is no valid way to continue. */
1174 /* Assemble the floating-point constant D into an object of size MODE. */
1177 assemble_real (d, mode)
1179 enum machine_mode mode;
1181 jmp_buf output_constant_handler;
1183 if (setjmp (output_constant_handler))
1185 error ("floating point trap outputting a constant");
1186 #ifdef REAL_IS_NOT_DOUBLE
1187 bzero (&d, sizeof d);
1194 set_float_handler (output_constant_handler);
1198 #ifdef ASM_OUTPUT_FLOAT
1200 ASM_OUTPUT_FLOAT (asm_out_file, d);
1204 #ifdef ASM_OUTPUT_DOUBLE
1206 ASM_OUTPUT_DOUBLE (asm_out_file, d);
1210 #ifdef ASM_OUTPUT_LONG_DOUBLE
1212 ASM_OUTPUT_LONG_DOUBLE (asm_out_file, d);
1220 set_float_handler (NULL_PTR);
1223 /* Here we combine duplicate floating constants to make
1224 CONST_DOUBLE rtx's, and force those out to memory when necessary. */
1226 /* Chain of all CONST_DOUBLE rtx's constructed for the current function.
1227 They are chained through the CONST_DOUBLE_CHAIN.
1228 A CONST_DOUBLE rtx has CONST_DOUBLE_MEM != cc0_rtx iff it is on this chain.
1229 In that case, CONST_DOUBLE_MEM is either a MEM,
1230 or const0_rtx if no MEM has been made for this CONST_DOUBLE yet. */
1232 static rtx const_double_chain;
1234 /* Return a CONST_DOUBLE for a value specified as a pair of ints.
1235 For an integer, I0 is the low-order word and I1 is the high-order word.
1236 For a real number, I0 is the word with the low address
1237 and I1 is the word with the high address. */
1240 immed_double_const (i0, i1, mode)
1241 HOST_WIDE_INT i0, i1;
1242 enum machine_mode mode;
1245 int in_current_obstack;
1247 if (GET_MODE_CLASS (mode) == MODE_INT)
1249 /* We clear out all bits that don't belong in MODE, unless they and our
1250 sign bit are all one. So we get either a reasonable negative value
1251 or a reasonable unsigned value for this mode. */
1252 int width = GET_MODE_BITSIZE (mode);
1253 if (width < HOST_BITS_PER_WIDE_INT
1254 && ((i0 & ((HOST_WIDE_INT) (-1) << (width - 1)))
1255 != ((HOST_WIDE_INT) (-1) << (width - 1))))
1256 i0 &= ((HOST_WIDE_INT) 1 << width) - 1, i1 = 0;
1257 else if (width == HOST_BITS_PER_WIDE_INT
1258 && ! (i1 == ~0 && i0 < 0))
1260 else if (width > 2 * HOST_BITS_PER_WIDE_INT)
1261 /* We cannot represent this value as a constant. */
1264 /* If MODE fits within HOST_BITS_PER_WIDE_INT, always use a CONST_INT.
1266 ??? Strictly speaking, this is wrong if we create a CONST_INT
1267 for a large unsigned constant with the size of MODE being
1268 HOST_BITS_PER_WIDE_INT and later try to interpret that constant in a
1269 wider mode. In that case we will mis-interpret it as a negative
1272 Unfortunately, the only alternative is to make a CONST_DOUBLE
1273 for any constant in any mode if it is an unsigned constant larger
1274 than the maximum signed integer in an int on the host. However,
1275 doing this will break everyone that always expects to see a CONST_INT
1276 for SImode and smaller.
1278 We have always been making CONST_INTs in this case, so nothing new
1281 if (width <= HOST_BITS_PER_WIDE_INT)
1282 i1 = (i0 < 0) ? ~0 : 0;
1284 /* If this integer fits in one word, return a CONST_INT. */
1285 if ((i1 == 0 && i0 >= 0)
1286 || (i1 == ~0 && i0 < 0))
1287 return GEN_INT (i0);
1289 /* We use VOIDmode for integers. */
1293 /* Search the chain for an existing CONST_DOUBLE with the right value.
1294 If one is found, return it. */
1296 for (r = const_double_chain; r; r = CONST_DOUBLE_CHAIN (r))
1297 if (CONST_DOUBLE_LOW (r) == i0 && CONST_DOUBLE_HIGH (r) == i1
1298 && GET_MODE (r) == mode)
1301 /* No; make a new one and add it to the chain.
1303 We may be called by an optimizer which may be discarding any memory
1304 allocated during its processing (such as combine and loop). However,
1305 we will be leaving this constant on the chain, so we cannot tolerate
1306 freed memory. So switch to saveable_obstack for this allocation
1307 and then switch back if we were in current_obstack. */
1309 in_current_obstack = rtl_in_saveable_obstack ();
1310 r = gen_rtx (CONST_DOUBLE, mode, 0, i0, i1);
1311 if (in_current_obstack)
1312 rtl_in_current_obstack ();
1314 CONST_DOUBLE_CHAIN (r) = const_double_chain;
1315 const_double_chain = r;
1317 /* Store const0_rtx in mem-slot since this CONST_DOUBLE is on the chain.
1318 Actual use of mem-slot is only through force_const_mem. */
1320 CONST_DOUBLE_MEM (r) = const0_rtx;
1325 /* Return a CONST_DOUBLE for a specified `double' value
1326 and machine mode. */
1329 immed_real_const_1 (d, mode)
1331 enum machine_mode mode;
1333 union real_extract u;
1335 int in_current_obstack;
1337 /* Get the desired `double' value as a sequence of ints
1338 since that is how they are stored in a CONST_DOUBLE. */
1342 /* Detect special cases. */
1344 /* Avoid REAL_VALUES_EQUAL here in order to distinguish minus zero. */
1345 if (!bcmp (&dconst0, &d, sizeof d))
1346 return CONST0_RTX (mode);
1347 else if (REAL_VALUES_EQUAL (dconst1, d))
1348 return CONST1_RTX (mode);
1350 if (sizeof u == 2 * sizeof (HOST_WIDE_INT))
1351 return immed_double_const (u.i[0], u.i[1], mode);
1353 /* The rest of this function handles the case where
1354 a float value requires more than 2 ints of space.
1355 It will be deleted as dead code on machines that don't need it. */
1357 /* Search the chain for an existing CONST_DOUBLE with the right value.
1358 If one is found, return it. */
1360 for (r = const_double_chain; r; r = CONST_DOUBLE_CHAIN (r))
1361 if (! bcmp (&CONST_DOUBLE_LOW (r), &u, sizeof u)
1362 && GET_MODE (r) == mode)
1365 /* No; make a new one and add it to the chain.
1367 We may be called by an optimizer which may be discarding any memory
1368 allocated during its processing (such as combine and loop). However,
1369 we will be leaving this constant on the chain, so we cannot tolerate
1370 freed memory. So switch to saveable_obstack for this allocation
1371 and then switch back if we were in current_obstack. */
1373 in_current_obstack = rtl_in_saveable_obstack ();
1374 r = rtx_alloc (CONST_DOUBLE);
1376 bcopy (&u, &CONST_DOUBLE_LOW (r), sizeof u);
1377 if (in_current_obstack)
1378 rtl_in_current_obstack ();
1380 CONST_DOUBLE_CHAIN (r) = const_double_chain;
1381 const_double_chain = r;
1383 /* Store const0_rtx in CONST_DOUBLE_MEM since this CONST_DOUBLE is on the
1384 chain, but has not been allocated memory. Actual use of CONST_DOUBLE_MEM
1385 is only through force_const_mem. */
1387 CONST_DOUBLE_MEM (r) = const0_rtx;
1392 /* Return a CONST_DOUBLE rtx for a value specified by EXP,
1393 which must be a REAL_CST tree node. */
1396 immed_real_const (exp)
1399 return immed_real_const_1 (TREE_REAL_CST (exp), TYPE_MODE (TREE_TYPE (exp)));
1402 /* At the end of a function, forget the memory-constants
1403 previously made for CONST_DOUBLEs. Mark them as not on real_constant_chain.
1404 Also clear out real_constant_chain and clear out all the chain-pointers. */
1407 clear_const_double_mem ()
1409 register rtx r, next;
1411 for (r = const_double_chain; r; r = next)
1413 next = CONST_DOUBLE_CHAIN (r);
1414 CONST_DOUBLE_CHAIN (r) = 0;
1415 CONST_DOUBLE_MEM (r) = cc0_rtx;
1417 const_double_chain = 0;
1420 /* Given an expression EXP with a constant value,
1421 reduce it to the sum of an assembler symbol and an integer.
1422 Store them both in the structure *VALUE.
1423 Abort if EXP does not reduce. */
1428 HOST_WIDE_INT offset;
1432 decode_addr_const (exp, value)
1434 struct addr_const *value;
1436 register tree target = TREE_OPERAND (exp, 0);
1437 register int offset = 0;
1442 if (TREE_CODE (target) == COMPONENT_REF
1443 && (TREE_CODE (DECL_FIELD_BITPOS (TREE_OPERAND (target, 1)))
1446 offset += TREE_INT_CST_LOW (DECL_FIELD_BITPOS (TREE_OPERAND (target, 1))) / BITS_PER_UNIT;
1447 target = TREE_OPERAND (target, 0);
1449 else if (TREE_CODE (target) == ARRAY_REF)
1451 if (TREE_CODE (TREE_OPERAND (target, 1)) != INTEGER_CST
1452 || TREE_CODE (TYPE_SIZE (TREE_TYPE (target))) != INTEGER_CST)
1454 offset += ((TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (target)))
1455 * TREE_INT_CST_LOW (TREE_OPERAND (target, 1)))
1457 target = TREE_OPERAND (target, 0);
1463 switch (TREE_CODE (target))
1467 x = DECL_RTL (target);
1471 x = gen_rtx (MEM, FUNCTION_MODE,
1472 gen_rtx (LABEL_REF, VOIDmode,
1473 label_rtx (TREE_OPERAND (exp, 0))));
1480 x = TREE_CST_RTL (target);
1487 if (GET_CODE (x) != MEM)
1492 value->offset = offset;
1495 /* Uniquize all constants that appear in memory.
1496 Each constant in memory thus far output is recorded
1497 in `const_hash_table' with a `struct constant_descriptor'
1498 that contains a polish representation of the value of
1501 We cannot store the trees in the hash table
1502 because the trees may be temporary. */
1504 struct constant_descriptor
1506 struct constant_descriptor *next;
1512 #define MAX_HASH_TABLE 1009
1513 static struct constant_descriptor *const_hash_table[MAX_HASH_TABLE];
1515 /* Compute a hash code for a constant expression. */
1522 register int len, hi, i;
1523 register enum tree_code code = TREE_CODE (exp);
1525 if (code == INTEGER_CST)
1527 p = (char *) &TREE_INT_CST_LOW (exp);
1528 len = 2 * sizeof TREE_INT_CST_LOW (exp);
1530 else if (code == REAL_CST)
1532 p = (char *) &TREE_REAL_CST (exp);
1533 len = sizeof TREE_REAL_CST (exp);
1535 else if (code == STRING_CST)
1536 p = TREE_STRING_POINTER (exp), len = TREE_STRING_LENGTH (exp);
1537 else if (code == COMPLEX_CST)
1538 return const_hash (TREE_REALPART (exp)) * 5
1539 + const_hash (TREE_IMAGPART (exp));
1540 else if (code == CONSTRUCTOR)
1544 /* For record type, include the type in the hashing.
1545 We do not do so for array types
1546 because (1) the sizes of the elements are sufficient
1547 and (2) distinct array types can have the same constructor.
1548 Instead, we include the array size because the constructor could
1550 if (TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE)
1551 hi = ((HOST_WIDE_INT) TREE_TYPE (exp) & ((1 << HASHBITS) - 1))
1554 hi = ((5 + int_size_in_bytes (TREE_TYPE (exp)))
1555 & ((1 << HASHBITS) - 1)) % MAX_HASH_TABLE;
1557 for (link = CONSTRUCTOR_ELTS (exp); link; link = TREE_CHAIN (link))
1558 if (TREE_VALUE (link))
1559 hi = (hi * 603 + const_hash (TREE_VALUE (link))) % MAX_HASH_TABLE;
1563 else if (code == ADDR_EXPR)
1565 struct addr_const value;
1566 decode_addr_const (exp, &value);
1567 if (GET_CODE (value.base) == SYMBOL_REF)
1569 /* Don't hash the address of the SYMBOL_REF;
1570 only use the offset and the symbol name. */
1572 p = XSTR (value.base, 0);
1573 for (i = 0; p[i] != 0; i++)
1574 hi = ((hi * 613) + (unsigned)(p[i]));
1576 else if (GET_CODE (value.base) == LABEL_REF)
1577 hi = value.offset + CODE_LABEL_NUMBER (XEXP (value.base, 0)) * 13;
1579 hi &= (1 << HASHBITS) - 1;
1580 hi %= MAX_HASH_TABLE;
1583 else if (code == PLUS_EXPR || code == MINUS_EXPR)
1584 return const_hash (TREE_OPERAND (exp, 0)) * 9
1585 + const_hash (TREE_OPERAND (exp, 1));
1586 else if (code == NOP_EXPR || code == CONVERT_EXPR)
1587 return const_hash (TREE_OPERAND (exp, 0)) * 7 + 2;
1589 /* Compute hashing function */
1591 for (i = 0; i < len; i++)
1592 hi = ((hi * 613) + (unsigned)(p[i]));
1594 hi &= (1 << HASHBITS) - 1;
1595 hi %= MAX_HASH_TABLE;
1599 /* Compare a constant expression EXP with a constant-descriptor DESC.
1600 Return 1 if DESC describes a constant with the same value as EXP. */
1603 compare_constant (exp, desc)
1605 struct constant_descriptor *desc;
1607 return 0 != compare_constant_1 (exp, desc->contents);
1610 /* Compare constant expression EXP with a substring P of a constant descriptor.
1611 If they match, return a pointer to the end of the substring matched.
1612 If they do not match, return 0.
1614 Since descriptors are written in polish prefix notation,
1615 this function can be used recursively to test one operand of EXP
1616 against a subdescriptor, and if it succeeds it returns the
1617 address of the subdescriptor for the next operand. */
1620 compare_constant_1 (exp, p)
1624 register char *strp;
1626 register enum tree_code code = TREE_CODE (exp);
1628 if (code != (enum tree_code) *p++)
1631 if (code == INTEGER_CST)
1633 /* Integer constants are the same only if the same width of type. */
1634 if (*p++ != TYPE_PRECISION (TREE_TYPE (exp)))
1636 strp = (char *) &TREE_INT_CST_LOW (exp);
1637 len = 2 * sizeof TREE_INT_CST_LOW (exp);
1639 else if (code == REAL_CST)
1641 /* Real constants are the same only if the same width of type. */
1642 if (*p++ != TYPE_PRECISION (TREE_TYPE (exp)))
1644 strp = (char *) &TREE_REAL_CST (exp);
1645 len = sizeof TREE_REAL_CST (exp);
1647 else if (code == STRING_CST)
1649 if (flag_writable_strings)
1651 strp = TREE_STRING_POINTER (exp);
1652 len = TREE_STRING_LENGTH (exp);
1653 if (bcmp (&TREE_STRING_LENGTH (exp), p,
1654 sizeof TREE_STRING_LENGTH (exp)))
1656 p += sizeof TREE_STRING_LENGTH (exp);
1658 else if (code == COMPLEX_CST)
1660 p = compare_constant_1 (TREE_REALPART (exp), p);
1661 if (p == 0) return 0;
1662 p = compare_constant_1 (TREE_IMAGPART (exp), p);
1665 else if (code == CONSTRUCTOR)
1668 int length = list_length (CONSTRUCTOR_ELTS (exp));
1671 if (bcmp (&length, p, sizeof length))
1675 /* For record constructors, insist that the types match.
1676 For arrays, just verify both constructors are for arrays. */
1677 if (TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE)
1678 type = TREE_TYPE (exp);
1681 if (bcmp (&type, p, sizeof type))
1685 /* For arrays, insist that the size in bytes match. */
1686 if (TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE)
1688 int size = int_size_in_bytes (TREE_TYPE (exp));
1689 if (bcmp (&size, p, sizeof size))
1694 for (link = CONSTRUCTOR_ELTS (exp); link; link = TREE_CHAIN (link))
1696 if (TREE_VALUE (link))
1698 if ((p = compare_constant_1 (TREE_VALUE (link), p)) == 0)
1705 if (bcmp (&zero, p, sizeof zero))
1713 else if (code == ADDR_EXPR)
1715 struct addr_const value;
1716 decode_addr_const (exp, &value);
1717 strp = (char *) &value.offset;
1718 len = sizeof value.offset;
1719 /* Compare the offset. */
1721 if (*p++ != *strp++)
1723 /* Compare symbol name. */
1724 strp = XSTR (value.base, 0);
1725 len = strlen (strp) + 1;
1727 else if (code == PLUS_EXPR || code == MINUS_EXPR)
1729 p = compare_constant_1 (TREE_OPERAND (exp, 0), p);
1730 if (p == 0) return 0;
1731 p = compare_constant_1 (TREE_OPERAND (exp, 1), p);
1734 else if (code == NOP_EXPR || code == CONVERT_EXPR)
1736 p = compare_constant_1 (TREE_OPERAND (exp, 0), p);
1740 /* Compare constant contents. */
1742 if (*p++ != *strp++)
1748 /* Construct a constant descriptor for the expression EXP.
1749 It is up to the caller to enter the descriptor in the hash table. */
1751 static struct constant_descriptor *
1752 record_constant (exp)
1755 struct constant_descriptor *ptr = 0;
1758 obstack_grow (&permanent_obstack, &ptr, sizeof ptr);
1759 obstack_grow (&permanent_obstack, &buf, sizeof buf);
1760 record_constant_1 (exp);
1761 return (struct constant_descriptor *) obstack_finish (&permanent_obstack);
1764 /* Add a description of constant expression EXP
1765 to the object growing in `permanent_obstack'.
1766 No need to return its address; the caller will get that
1767 from the obstack when the object is complete. */
1770 record_constant_1 (exp)
1773 register char *strp;
1775 register enum tree_code code = TREE_CODE (exp);
1777 obstack_1grow (&permanent_obstack, (unsigned int) code);
1779 if (code == INTEGER_CST)
1781 obstack_1grow (&permanent_obstack, TYPE_PRECISION (TREE_TYPE (exp)));
1782 strp = (char *) &TREE_INT_CST_LOW (exp);
1783 len = 2 * sizeof TREE_INT_CST_LOW (exp);
1785 else if (code == REAL_CST)
1787 obstack_1grow (&permanent_obstack, TYPE_PRECISION (TREE_TYPE (exp)));
1788 strp = (char *) &TREE_REAL_CST (exp);
1789 len = sizeof TREE_REAL_CST (exp);
1791 else if (code == STRING_CST)
1793 if (flag_writable_strings)
1795 strp = TREE_STRING_POINTER (exp);
1796 len = TREE_STRING_LENGTH (exp);
1797 obstack_grow (&permanent_obstack, (char *) &TREE_STRING_LENGTH (exp),
1798 sizeof TREE_STRING_LENGTH (exp));
1800 else if (code == COMPLEX_CST)
1802 record_constant_1 (TREE_REALPART (exp));
1803 record_constant_1 (TREE_IMAGPART (exp));
1806 else if (code == CONSTRUCTOR)
1809 int length = list_length (CONSTRUCTOR_ELTS (exp));
1812 obstack_grow (&permanent_obstack, (char *) &length, sizeof length);
1814 /* For record constructors, insist that the types match.
1815 For arrays, just verify both constructors are for arrays. */
1816 if (TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE)
1817 type = TREE_TYPE (exp);
1820 obstack_grow (&permanent_obstack, (char *) &type, sizeof type);
1822 /* For arrays, insist that the size in bytes match. */
1823 if (TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE)
1825 int size = int_size_in_bytes (TREE_TYPE (exp));
1826 obstack_grow (&permanent_obstack, (char *) &size, sizeof size);
1829 for (link = CONSTRUCTOR_ELTS (exp); link; link = TREE_CHAIN (link))
1831 if (TREE_VALUE (link))
1832 record_constant_1 (TREE_VALUE (link));
1837 obstack_grow (&permanent_obstack, (char *) &zero, sizeof zero);
1843 else if (code == ADDR_EXPR)
1845 struct addr_const value;
1846 decode_addr_const (exp, &value);
1847 /* Record the offset. */
1848 obstack_grow (&permanent_obstack,
1849 (char *) &value.offset, sizeof value.offset);
1850 /* Record the symbol name. */
1851 obstack_grow (&permanent_obstack, XSTR (value.base, 0),
1852 strlen (XSTR (value.base, 0)) + 1);
1855 else if (code == PLUS_EXPR || code == MINUS_EXPR)
1857 record_constant_1 (TREE_OPERAND (exp, 0));
1858 record_constant_1 (TREE_OPERAND (exp, 1));
1861 else if (code == NOP_EXPR || code == CONVERT_EXPR)
1863 record_constant_1 (TREE_OPERAND (exp, 0));
1867 /* Record constant contents. */
1868 obstack_grow (&permanent_obstack, strp, len);
1871 /* Return an rtx representing a reference to constant data in memory
1872 for the constant expression EXP.
1873 If assembler code for such a constant has already been output,
1874 return an rtx to refer to it.
1875 Otherwise, output such a constant in memory and generate
1876 an rtx for it. The TREE_CST_RTL of EXP is set up to point to that rtx.
1877 The const_hash_table records which constants already have label strings. */
1880 output_constant_def (exp)
1883 register int hash, align;
1884 register struct constant_descriptor *desc;
1890 if (TREE_CODE (exp) == INTEGER_CST)
1891 abort (); /* No TREE_CST_RTL slot in these. */
1893 if (TREE_CST_RTL (exp))
1894 return TREE_CST_RTL (exp);
1896 /* Make sure any other constants whose addresses appear in EXP
1897 are assigned label numbers. */
1899 reloc = output_addressed_constants (exp);
1901 /* Compute hash code of EXP. Search the descriptors for that hash code
1902 to see if any of them describes EXP. If yes, the descriptor records
1903 the label number already assigned. */
1905 hash = const_hash (exp) % MAX_HASH_TABLE;
1907 for (desc = const_hash_table[hash]; desc; desc = desc->next)
1908 if (compare_constant (exp, desc))
1910 found = desc->label;
1916 /* No constant equal to EXP is known to have been output.
1917 Make a constant descriptor to enter EXP in the hash table.
1918 Assign the label number and record it in the descriptor for
1919 future calls to this function to find. */
1921 /* Create a string containing the label name, in LABEL. */
1922 ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno);
1924 desc = record_constant (exp);
1925 desc->next = const_hash_table[hash];
1927 = (char *) obstack_copy0 (&permanent_obstack, label, strlen (label));
1928 const_hash_table[hash] = desc;
1931 /* We have a symbol name; construct the SYMBOL_REF and the MEM. */
1933 push_obstacks_nochange ();
1934 if (TREE_PERMANENT (exp))
1935 end_temporary_allocation ();
1937 def = gen_rtx (SYMBOL_REF, Pmode, desc->label);
1940 = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (exp)), def);
1941 RTX_UNCHANGING_P (TREE_CST_RTL (exp)) = 1;
1942 if (TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE
1943 || TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE)
1944 MEM_IN_STRUCT_P (TREE_CST_RTL (exp)) = 1;
1948 /* Optionally set flags or add text to the name to record information
1949 such as that it is a function name. If the name is changed, the macro
1950 ASM_OUTPUT_LABELREF will have to know how to strip this information.
1951 And if it finds a * at the beginning after doing so, it must handle
1953 #ifdef ENCODE_SECTION_INFO
1954 ENCODE_SECTION_INFO (exp);
1959 /* Now output assembler code to define that label
1960 and follow it with the data of EXP. */
1962 /* First switch to text section, except for writable strings. */
1963 #ifdef SELECT_SECTION
1964 SELECT_SECTION (exp, reloc);
1966 if (((TREE_CODE (exp) == STRING_CST) && flag_writable_strings)
1967 || (flag_pic && reloc))
1970 readonly_data_section ();
1973 /* Align the location counter as required by EXP's data type. */
1974 align = TYPE_ALIGN (TREE_TYPE (exp));
1975 #ifdef CONSTANT_ALIGNMENT
1976 align = CONSTANT_ALIGNMENT (exp, align);
1979 if (align > BITS_PER_UNIT)
1980 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
1982 /* Output the label itself. */
1983 ASM_OUTPUT_INTERNAL_LABEL (asm_out_file, "LC", const_labelno);
1985 /* Output the value of EXP. */
1986 output_constant (exp,
1987 (TREE_CODE (exp) == STRING_CST
1988 ? TREE_STRING_LENGTH (exp)
1989 : int_size_in_bytes (TREE_TYPE (exp))));
1994 return TREE_CST_RTL (exp);
1997 /* Similar hash facility for making memory-constants
1998 from constant rtl-expressions. It is used on RISC machines
1999 where immediate integer arguments and constant addresses are restricted
2000 so that such constants must be stored in memory.
2002 This pool of constants is reinitialized for each function
2003 so each function gets its own constants-pool that comes right before it.
2005 All structures allocated here are discarded when functions are saved for
2006 inlining, so they do not need to be allocated permanently. */
2008 #define MAX_RTX_HASH_TABLE 61
2009 static struct constant_descriptor *const_rtx_hash_table[MAX_RTX_HASH_TABLE];
2011 /* Structure to represent sufficient information about a constant so that
2012 it can be output when the constant pool is output, so that function
2013 integration can be done, and to simplify handling on machines that reference
2014 constant pool as base+displacement. */
2016 struct pool_constant
2018 struct constant_descriptor *desc;
2019 struct pool_constant *next;
2020 enum machine_mode mode;
2027 /* Pointers to first and last constant in pool. */
2029 static struct pool_constant *first_pool, *last_pool;
2031 /* Current offset in constant pool (does not include any machine-specific
2034 static int pool_offset;
2036 /* Structure used to maintain hash table mapping symbols used to their
2037 corresponding constants. */
2042 struct pool_constant *pool;
2043 struct pool_sym *next;
2046 static struct pool_sym *const_rtx_sym_hash_table[MAX_RTX_HASH_TABLE];
2048 /* Hash code for a SYMBOL_REF with CONSTANT_POOL_ADDRESS_P true.
2049 The argument is XSTR (... , 0) */
2051 #define SYMHASH(LABEL) \
2052 ((((HOST_WIDE_INT) (LABEL)) & ((1 << HASHBITS) - 1)) % MAX_RTX_HASH_TABLE)
2054 /* Initialize constant pool hashing for next function. */
2057 init_const_rtx_hash_table ()
2059 bzero (const_rtx_hash_table, sizeof const_rtx_hash_table);
2060 bzero (const_rtx_sym_hash_table, sizeof const_rtx_sym_hash_table);
2062 first_pool = last_pool = 0;
2066 enum kind { RTX_DOUBLE, RTX_INT };
2070 #ifdef ONLY_INT_FIELDS
2071 unsigned int kind : 16;
2072 unsigned int mode : 16;
2074 enum kind kind : 16;
2075 enum machine_mode mode : 16;
2078 union real_extract du;
2079 struct addr_const addr;
2083 /* Express an rtx for a constant integer (perhaps symbolic)
2084 as the sum of a symbol or label plus an explicit integer.
2085 They are stored into VALUE. */
2088 decode_rtx_const (mode, x, value)
2089 enum machine_mode mode;
2091 struct rtx_const *value;
2093 /* Clear the whole structure, including any gaps. */
2096 int *p = (int *) value;
2097 int *end = (int *) (value + 1);
2102 value->kind = RTX_INT; /* Most usual kind. */
2105 switch (GET_CODE (x))
2108 value->kind = RTX_DOUBLE;
2109 value->mode = GET_MODE (x);
2110 bcopy (&CONST_DOUBLE_LOW (x), &value->un.du, sizeof value->un.du);
2114 value->un.addr.offset = INTVAL (x);
2119 value->un.addr.base = x;
2124 if (GET_CODE (x) == PLUS)
2126 value->un.addr.base = XEXP (x, 0);
2127 if (GET_CODE (XEXP (x, 1)) != CONST_INT)
2129 value->un.addr.offset = INTVAL (XEXP (x, 1));
2131 else if (GET_CODE (x) == MINUS)
2133 value->un.addr.base = XEXP (x, 0);
2134 if (GET_CODE (XEXP (x, 1)) != CONST_INT)
2136 value->un.addr.offset = - INTVAL (XEXP (x, 1));
2146 if (value->kind == RTX_INT && value->un.addr.base != 0)
2147 switch (GET_CODE (value->un.addr.base))
2151 /* Use the string's address, not the SYMBOL_REF's address,
2152 for the sake of addresses of library routines.
2153 For a LABEL_REF, compare labels. */
2154 value->un.addr.base = XEXP (value->un.addr.base, 0);
2158 /* Compute a hash code for a constant RTL expression. */
2161 const_hash_rtx (mode, x)
2162 enum machine_mode mode;
2167 struct rtx_const value;
2168 decode_rtx_const (mode, x, &value);
2170 /* Compute hashing function */
2172 for (i = 0; i < sizeof value / sizeof (int); i++)
2173 hi += ((int *) &value)[i];
2175 hi &= (1 << HASHBITS) - 1;
2176 hi %= MAX_RTX_HASH_TABLE;
2180 /* Compare a constant rtl object X with a constant-descriptor DESC.
2181 Return 1 if DESC describes a constant with the same value as X. */
2184 compare_constant_rtx (mode, x, desc)
2185 enum machine_mode mode;
2187 struct constant_descriptor *desc;
2189 register int *p = (int *) desc->contents;
2192 struct rtx_const value;
2194 decode_rtx_const (mode, x, &value);
2195 strp = (int *) &value;
2196 len = sizeof value / sizeof (int);
2198 /* Compare constant contents. */
2200 if (*p++ != *strp++)
2206 /* Construct a constant descriptor for the rtl-expression X.
2207 It is up to the caller to enter the descriptor in the hash table. */
2209 static struct constant_descriptor *
2210 record_constant_rtx (mode, x)
2211 enum machine_mode mode;
2214 struct constant_descriptor *ptr;
2216 struct rtx_const value;
2218 decode_rtx_const (mode, x, &value);
2220 obstack_grow (current_obstack, &ptr, sizeof ptr);
2221 obstack_grow (current_obstack, &label, sizeof label);
2223 /* Record constant contents. */
2224 obstack_grow (current_obstack, &value, sizeof value);
2226 return (struct constant_descriptor *) obstack_finish (current_obstack);
2229 /* Given a constant rtx X, make (or find) a memory constant for its value
2230 and return a MEM rtx to refer to it in memory. */
2233 force_const_mem (mode, x)
2234 enum machine_mode mode;
2238 register struct constant_descriptor *desc;
2243 /* If we want this CONST_DOUBLE in the same mode as it is in memory
2244 (this will always be true for floating CONST_DOUBLEs that have been
2245 placed in memory, but not for VOIDmode (integer) CONST_DOUBLEs),
2246 use the previous copy. Otherwise, make a new one. Note that in
2247 the unlikely event that this same CONST_DOUBLE is used in two different
2248 modes in an alternating fashion, we will allocate a lot of different
2249 memory locations, but this should be extremely rare. */
2251 if (GET_CODE (x) == CONST_DOUBLE
2252 && GET_CODE (CONST_DOUBLE_MEM (x)) == MEM
2253 && GET_MODE (CONST_DOUBLE_MEM (x)) == mode)
2254 return CONST_DOUBLE_MEM (x);
2256 /* Compute hash code of X. Search the descriptors for that hash code
2257 to see if any of them describes X. If yes, the descriptor records
2258 the label number already assigned. */
2260 hash = const_hash_rtx (mode, x);
2262 for (desc = const_rtx_hash_table[hash]; desc; desc = desc->next)
2263 if (compare_constant_rtx (mode, x, desc))
2265 found = desc->label;
2271 register struct pool_constant *pool;
2272 register struct pool_sym *sym;
2275 /* No constant equal to X is known to have been output.
2276 Make a constant descriptor to enter X in the hash table.
2277 Assign the label number and record it in the descriptor for
2278 future calls to this function to find. */
2280 desc = record_constant_rtx (mode, x);
2281 desc->next = const_rtx_hash_table[hash];
2282 const_rtx_hash_table[hash] = desc;
2284 /* Align the location counter as required by EXP's data type. */
2285 align = (mode == VOIDmode) ? UNITS_PER_WORD : GET_MODE_SIZE (mode);
2286 if (align > BIGGEST_ALIGNMENT / BITS_PER_UNIT)
2287 align = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
2289 pool_offset += align - 1;
2290 pool_offset &= ~ (align - 1);
2292 /* Allocate a pool constant descriptor, fill it in, and chain it in. */
2294 pool = (struct pool_constant *) oballoc (sizeof (struct pool_constant));
2298 pool->labelno = const_labelno;
2299 pool->align = align;
2300 pool->offset = pool_offset;
2306 last_pool->next = pool;
2309 pool_offset += GET_MODE_SIZE (mode);
2311 /* Create a string containing the label name, in LABEL. */
2312 ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno);
2317 = (char *) obstack_copy0 (saveable_obstack, label, strlen (label));
2319 /* Add label to symbol hash table. */
2320 hash = SYMHASH (found);
2321 sym = (struct pool_sym *) oballoc (sizeof (struct pool_sym));
2324 sym->next = const_rtx_sym_hash_table[hash];
2325 const_rtx_sym_hash_table[hash] = sym;
2328 /* We have a symbol name; construct the SYMBOL_REF and the MEM. */
2330 def = gen_rtx (MEM, mode, gen_rtx (SYMBOL_REF, Pmode, found));
2332 RTX_UNCHANGING_P (def) = 1;
2333 /* Mark the symbol_ref as belonging to this constants pool. */
2334 CONSTANT_POOL_ADDRESS_P (XEXP (def, 0)) = 1;
2335 current_function_uses_const_pool = 1;
2337 if (GET_CODE (x) == CONST_DOUBLE)
2339 if (CONST_DOUBLE_MEM (x) == cc0_rtx)
2341 CONST_DOUBLE_CHAIN (x) = const_double_chain;
2342 const_double_chain = x;
2344 CONST_DOUBLE_MEM (x) = def;
2350 /* Given a SYMBOL_REF with CONSTANT_POOL_ADDRESS_P true, return a pointer to
2351 the corresponding pool_constant structure. */
2353 static struct pool_constant *
2354 find_pool_constant (addr)
2357 struct pool_sym *sym;
2358 char *label = XSTR (addr, 0);
2360 for (sym = const_rtx_sym_hash_table[SYMHASH (label)]; sym; sym = sym->next)
2361 if (sym->label == label)
2367 /* Given a constant pool SYMBOL_REF, return the corresponding constant. */
2370 get_pool_constant (addr)
2373 return (find_pool_constant (addr))->constant;
2376 /* Similar, return the mode. */
2379 get_pool_mode (addr)
2382 return (find_pool_constant (addr))->mode;
2385 /* Similar, return the offset in the constant pool. */
2388 get_pool_offset (addr)
2391 return (find_pool_constant (addr))->offset;
2394 /* Return the size of the constant pool. */
2402 /* Write all the constants in the constant pool. */
2405 output_constant_pool (fnname, fndecl)
2409 struct pool_constant *pool;
2411 union real_extract u;
2413 #ifdef ASM_OUTPUT_POOL_PROLOGUE
2414 ASM_OUTPUT_POOL_PROLOGUE (asm_out_file, fnname, fndecl, pool_offset);
2417 for (pool = first_pool; pool; pool = pool->next)
2421 /* See if X is a LABEL_REF (or a CONST referring to a LABEL_REF)
2422 whose CODE_LABEL has been deleted. This can occur if a jump table
2423 is eliminated by optimization. If so, write a constant of zero
2425 if ((GET_CODE (x) == LABEL_REF && INSN_DELETED_P (XEXP (x, 0)))
2426 || (GET_CODE (x) == CONST && GET_CODE (XEXP (x, 0)) == PLUS
2427 && GET_CODE (XEXP (XEXP (x, 0), 0)) == LABEL_REF
2428 && INSN_DELETED_P (XEXP (XEXP (XEXP (x, 0), 0), 0))))
2431 /* First switch to correct section. */
2432 #ifdef SELECT_RTX_SECTION
2433 SELECT_RTX_SECTION (pool->mode, x);
2435 readonly_data_section ();
2438 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
2439 ASM_OUTPUT_SPECIAL_POOL_ENTRY (asm_out_file, x, pool->mode,
2440 pool->align, pool->labelno, done);
2443 if (pool->align > 1)
2444 ASM_OUTPUT_ALIGN (asm_out_file, exact_log2 (pool->align));
2446 /* Output the label. */
2447 ASM_OUTPUT_INTERNAL_LABEL (asm_out_file, "LC", pool->labelno);
2449 /* Output the value of the constant itself. */
2450 switch (GET_MODE_CLASS (pool->mode))
2453 if (GET_CODE (x) != CONST_DOUBLE)
2456 bcopy (&CONST_DOUBLE_LOW (x), &u, sizeof u);
2457 assemble_real (u.d, pool->mode);
2461 assemble_integer (x, GET_MODE_SIZE (pool->mode), 1);
2471 /* Done with this pool. */
2472 first_pool = last_pool = 0;
2475 /* Find all the constants whose addresses are referenced inside of EXP,
2476 and make sure assembler code with a label has been output for each one.
2477 Indicate whether an ADDR_EXPR has been encountered. */
2480 output_addressed_constants (exp)
2485 switch (TREE_CODE (exp))
2489 register tree constant = TREE_OPERAND (exp, 0);
2491 while (TREE_CODE (constant) == COMPONENT_REF)
2493 constant = TREE_OPERAND (constant, 0);
2496 if (TREE_CODE_CLASS (TREE_CODE (constant)) == 'c'
2497 || TREE_CODE (constant) == CONSTRUCTOR)
2498 /* No need to do anything here
2499 for addresses of variables or functions. */
2500 output_constant_def (constant);
2507 reloc = output_addressed_constants (TREE_OPERAND (exp, 0));
2508 reloc |= output_addressed_constants (TREE_OPERAND (exp, 1));
2513 reloc = output_addressed_constants (TREE_OPERAND (exp, 0));
2519 for (link = CONSTRUCTOR_ELTS (exp); link; link = TREE_CHAIN (link))
2520 if (TREE_VALUE (link) != 0)
2521 reloc |= output_addressed_constants (TREE_VALUE (link));
2531 /* Output assembler code for constant EXP to FILE, with no label.
2532 This includes the pseudo-op such as ".int" or ".byte", and a newline.
2533 Assumes output_addressed_constants has been done on EXP already.
2535 Generate exactly SIZE bytes of assembler data, padding at the end
2536 with zeros if necessary. SIZE must always be specified.
2538 SIZE is important for structure constructors,
2539 since trailing members may have been omitted from the constructor.
2540 It is also important for initialization of arrays from string constants
2541 since the full length of the string constant might not be wanted.
2542 It is also needed for initialization of unions, where the initializer's
2543 type is just one member, and that may not be as long as the union.
2545 There a case in which we would fail to output exactly SIZE bytes:
2546 for a structure constructor that wants to produce more than SIZE bytes.
2547 But such constructors will never be generated for any possible input. */
2550 output_constant (exp, size)
2554 register enum tree_code code = TREE_CODE (TREE_TYPE (exp));
2560 /* Allow a constructor with no elements for any data type.
2561 This means to fill the space with zeros. */
2562 if (TREE_CODE (exp) == CONSTRUCTOR && CONSTRUCTOR_ELTS (exp) == 0)
2564 assemble_zeros (size);
2568 /* Eliminate the NOP_EXPR that makes a cast not be an lvalue.
2569 That way we get the constant (we hope) inside it. */
2570 if (TREE_CODE (exp) == NOP_EXPR
2571 && TREE_TYPE (exp) == TREE_TYPE (TREE_OPERAND (exp, 0)))
2572 exp = TREE_OPERAND (exp, 0);
2579 case REFERENCE_TYPE:
2580 /* ??? What about (int)((float)(int)&foo + 4) */
2581 while (TREE_CODE (exp) == NOP_EXPR || TREE_CODE (exp) == CONVERT_EXPR
2582 || TREE_CODE (exp) == NON_LVALUE_EXPR)
2583 exp = TREE_OPERAND (exp, 0);
2585 if (! assemble_integer (expand_expr (exp, NULL_RTX, VOIDmode,
2586 EXPAND_INITIALIZER),
2588 error ("initializer for integer value is too complicated");
2593 if (TREE_CODE (exp) != REAL_CST)
2594 error ("initializer for floating value is not a floating constant");
2596 assemble_real (TREE_REAL_CST (exp),
2597 mode_for_size (size * BITS_PER_UNIT, MODE_FLOAT, 0));
2602 output_constant (TREE_REALPART (exp), size / 2);
2603 output_constant (TREE_IMAGPART (exp), size / 2);
2604 size -= (size / 2) * 2;
2608 if (TREE_CODE (exp) == CONSTRUCTOR)
2610 output_constructor (exp, size);
2613 else if (TREE_CODE (exp) == STRING_CST)
2617 if (size > TREE_STRING_LENGTH (exp))
2619 excess = size - TREE_STRING_LENGTH (exp);
2620 size = TREE_STRING_LENGTH (exp);
2623 assemble_string (TREE_STRING_POINTER (exp), size);
2632 if (TREE_CODE (exp) == CONSTRUCTOR)
2633 output_constructor (exp, size);
2640 assemble_zeros (size);
2643 /* Subroutine of output_constant, used for CONSTRUCTORs
2644 (aggregate constants).
2645 Generate at least SIZE bytes, padding if necessary. */
2648 output_constructor (exp, size)
2652 register tree link, field = 0;
2653 /* Number of bytes output or skipped so far.
2654 In other words, current position within the constructor. */
2655 int total_bytes = 0;
2656 /* Non-zero means BYTE contains part of a byte, to be output. */
2657 int byte_buffer_in_use = 0;
2660 if (HOST_BITS_PER_WIDE_INT < BITS_PER_UNIT)
2663 if (TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE)
2664 field = TYPE_FIELDS (TREE_TYPE (exp));
2666 /* As LINK goes through the elements of the constant,
2667 FIELD goes through the structure fields, if the constant is a structure.
2668 if the constant is a union, then we override this,
2669 by getting the field from the TREE_LIST element.
2670 But the constant could also be an array. Then FIELD is zero. */
2671 for (link = CONSTRUCTOR_ELTS (exp);
2673 link = TREE_CHAIN (link),
2674 field = field ? TREE_CHAIN (field) : 0)
2676 tree val = TREE_VALUE (link);
2677 /* the element in a union constructor specifies the proper field. */
2678 if (TREE_PURPOSE (link) != 0)
2679 field = TREE_PURPOSE (link);
2681 /* Eliminate the marker that makes a cast not be an lvalue. */
2685 if (field == 0 || !DECL_BIT_FIELD (field))
2687 register int fieldsize;
2688 /* Since this structure is static,
2689 we know the positions are constant. */
2690 int bitpos = (field ? (TREE_INT_CST_LOW (DECL_FIELD_BITPOS (field))
2694 /* An element that is not a bit-field.
2695 Output any buffered-up bit-fields preceding it. */
2696 if (byte_buffer_in_use)
2698 ASM_OUTPUT_BYTE (asm_out_file, byte);
2700 byte_buffer_in_use = 0;
2703 /* Advance to offset of this element.
2704 Note no alignment needed in an array, since that is guaranteed
2705 if each element has the proper size. */
2706 if (field != 0 && bitpos != total_bytes)
2708 assemble_zeros (bitpos - total_bytes);
2709 total_bytes = bitpos;
2712 /* Determine size this element should occupy. */
2715 if (TREE_CODE (DECL_SIZE (field)) != INTEGER_CST)
2717 if (TREE_INT_CST_LOW (DECL_SIZE (field)) > 100000)
2719 /* This avoids overflow trouble. */
2720 tree size_tree = size_binop (CEIL_DIV_EXPR,
2722 size_int (BITS_PER_UNIT));
2723 fieldsize = TREE_INT_CST_LOW (size_tree);
2727 fieldsize = TREE_INT_CST_LOW (DECL_SIZE (field));
2728 fieldsize = (fieldsize + BITS_PER_UNIT - 1) / BITS_PER_UNIT;
2732 fieldsize = int_size_in_bytes (TREE_TYPE (TREE_TYPE (exp)));
2734 /* Output the element's initial value. */
2736 assemble_zeros (fieldsize);
2738 output_constant (val, fieldsize);
2740 /* Count its size. */
2741 total_bytes += fieldsize;
2743 else if (val != 0 && TREE_CODE (val) != INTEGER_CST)
2744 error ("invalid initial value for member `%s'",
2745 IDENTIFIER_POINTER (DECL_NAME (field)));
2748 /* Element that is a bit-field. */
2750 int next_offset = TREE_INT_CST_LOW (DECL_FIELD_BITPOS (field));
2752 = (next_offset + TREE_INT_CST_LOW (DECL_SIZE (field)));
2755 val = integer_zero_node;
2757 /* If this field does not start in this (or, next) byte,
2759 if (next_offset / BITS_PER_UNIT != total_bytes)
2761 /* Output remnant of any bit field in previous bytes. */
2762 if (byte_buffer_in_use)
2764 ASM_OUTPUT_BYTE (asm_out_file, byte);
2766 byte_buffer_in_use = 0;
2769 /* If still not at proper byte, advance to there. */
2770 if (next_offset / BITS_PER_UNIT != total_bytes)
2772 assemble_zeros (next_offset / BITS_PER_UNIT - total_bytes);
2773 total_bytes = next_offset / BITS_PER_UNIT;
2777 if (! byte_buffer_in_use)
2780 /* We must split the element into pieces that fall within
2781 separate bytes, and combine each byte with previous or
2782 following bit-fields. */
2784 /* next_offset is the offset n fbits from the beginning of
2785 the structure to the next bit of this element to be processed.
2786 end_offset is the offset of the first bit past the end of
2788 while (next_offset < end_offset)
2792 int next_byte = next_offset / BITS_PER_UNIT;
2793 int next_bit = next_offset % BITS_PER_UNIT;
2795 /* Advance from byte to byte
2796 within this element when necessary. */
2797 while (next_byte != total_bytes)
2799 ASM_OUTPUT_BYTE (asm_out_file, byte);
2804 /* Number of bits we can process at once
2805 (all part of the same byte). */
2806 this_time = MIN (end_offset - next_offset,
2807 BITS_PER_UNIT - next_bit);
2808 #if BYTES_BIG_ENDIAN
2809 /* On big-endian machine, take the most significant bits
2810 first (of the bits that are significant)
2811 and put them into bytes from the most significant end. */
2812 shift = end_offset - next_offset - this_time;
2813 /* Don't try to take a bunch of bits that cross
2814 the word boundary in the INTEGER_CST. */
2815 if (shift < HOST_BITS_PER_WIDE_INT
2816 && shift + this_time > HOST_BITS_PER_WIDE_INT)
2818 this_time -= (HOST_BITS_PER_WIDE_INT - shift);
2819 shift = HOST_BITS_PER_WIDE_INT;
2822 /* Now get the bits from the appropriate constant word. */
2823 if (shift < HOST_BITS_PER_WIDE_INT)
2825 value = TREE_INT_CST_LOW (val);
2827 else if (shift < 2 * HOST_BITS_PER_WIDE_INT)
2829 value = TREE_INT_CST_HIGH (val);
2830 shift -= HOST_BITS_PER_WIDE_INT;
2834 byte |= (((value >> shift)
2835 & (((HOST_WIDE_INT) 1 << this_time) - 1))
2836 << (BITS_PER_UNIT - this_time - next_bit));
2838 /* On little-endian machines,
2839 take first the least significant bits of the value
2840 and pack them starting at the least significant
2841 bits of the bytes. */
2842 shift = (next_offset
2843 - TREE_INT_CST_LOW (DECL_FIELD_BITPOS (field)));
2844 /* Don't try to take a bunch of bits that cross
2845 the word boundary in the INTEGER_CST. */
2846 if (shift < HOST_BITS_PER_WIDE_INT
2847 && shift + this_time > HOST_BITS_PER_WIDE_INT)
2849 this_time -= (HOST_BITS_PER_WIDE_INT - shift);
2850 shift = HOST_BITS_PER_WIDE_INT;
2853 /* Now get the bits from the appropriate constant word. */
2854 if (shift < HOST_BITS_PER_INT)
2855 value = TREE_INT_CST_LOW (val);
2856 else if (shift < 2 * HOST_BITS_PER_WIDE_INT)
2858 value = TREE_INT_CST_HIGH (val);
2859 shift -= HOST_BITS_PER_WIDE_INT;
2863 byte |= ((value >> shift)
2864 & (((HOST_WIDE_INT) 1 << this_time) - 1)) << next_bit;
2866 next_offset += this_time;
2867 byte_buffer_in_use = 1;
2871 if (byte_buffer_in_use)
2873 ASM_OUTPUT_BYTE (asm_out_file, byte);
2876 if (total_bytes < size)
2877 assemble_zeros (size - total_bytes);