1 /* Output variables, constants and external declarations, for GNU compiler.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993 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> */
37 #include "hard-reg-set.h"
45 #ifdef XCOFF_DEBUGGING_INFO
52 #define ASM_STABS_OP ".stabs"
55 /* This macro gets just the user-specified name
56 out of the string in a SYMBOL_REF. On most machines,
57 we discard the * if any and that's all. */
58 #ifndef STRIP_NAME_ENCODING
59 #define STRIP_NAME_ENCODING(VAR,SYMBOL_NAME) \
60 (VAR) = ((SYMBOL_NAME) + ((SYMBOL_NAME)[0] == '*'))
63 /* File in which assembler code is being written. */
65 extern FILE *asm_out_file;
67 /* The (assembler) name of the first globally-visible object output. */
68 char *first_global_object_name;
70 extern struct obstack *current_obstack;
71 extern struct obstack *saveable_obstack;
72 extern struct obstack permanent_obstack;
73 #define obstack_chunk_alloc xmalloc
75 /* Number for making the label on the next
76 constant that is stored in memory. */
80 /* Number for making the label on the next
81 static variable internal to a function. */
85 /* Nonzero if at least one function definition has been seen. */
86 static int function_defined;
88 extern FILE *asm_out_file;
90 static char *compare_constant_1 ();
91 static void record_constant_1 ();
92 static void output_constant_def_contents ();
93 static int contains_pointers_p ();
95 void output_constant_pool ();
96 void assemble_name ();
97 int output_addressed_constants ();
98 void output_constant ();
99 void output_constructor ();
100 void output_byte_asm ();
101 void text_section ();
102 void readonly_data_section ();
103 void data_section ();
104 static void bc_assemble_integer ();
106 #ifdef EXTRA_SECTIONS
107 static enum in_section {no_section, in_text, in_data, EXTRA_SECTIONS} in_section
110 static enum in_section {no_section, in_text, in_data} in_section
114 /* Define functions like text_section for any extra sections. */
115 #ifdef EXTRA_SECTION_FUNCTIONS
116 EXTRA_SECTION_FUNCTIONS
119 /* Tell assembler to switch to text section. */
124 if (in_section != in_text)
129 fprintf (asm_out_file, "%s\n", TEXT_SECTION_ASM_OP);
131 in_section = in_text;
135 /* Tell assembler to switch to data section. */
140 if (in_section != in_data)
146 if (flag_shared_data)
148 #ifdef SHARED_SECTION_ASM_OP
149 fprintf (asm_out_file, "%s\n", SHARED_SECTION_ASM_OP);
151 fprintf (asm_out_file, "%s\n", DATA_SECTION_ASM_OP);
155 fprintf (asm_out_file, "%s\n", DATA_SECTION_ASM_OP);
158 in_section = in_data;
162 /* Tell assembler to switch to read-only data section. This is normally
166 readonly_data_section ()
168 #ifdef READONLY_DATA_SECTION
169 READONLY_DATA_SECTION (); /* Note this can call data_section. */
175 /* Determine if we're in the text section. */
180 return in_section == in_text;
183 /* Create the rtl to represent a function, for a function definition.
184 DECL is a FUNCTION_DECL node which describes which function.
185 The rtl is stored into DECL. */
188 make_function_rtl (decl)
191 char *name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
195 if (DECL_RTL (decl) == 0)
196 DECL_RTL (decl) = bc_gen_rtx (name, 0, (struct bc_label *) 0);
198 /* Record that at least one function has been defined. */
199 function_defined = 1;
203 /* Rename a nested function to avoid conflicts. */
204 if (decl_function_context (decl) != 0
205 && DECL_INITIAL (decl) != 0
206 && DECL_RTL (decl) == 0)
210 name = IDENTIFIER_POINTER (DECL_NAME (decl));
211 ASM_FORMAT_PRIVATE_NAME (label, name, var_labelno);
212 name = obstack_copy0 (saveable_obstack, label, strlen (label));
216 if (DECL_RTL (decl) == 0)
219 = gen_rtx (MEM, DECL_MODE (decl),
220 gen_rtx (SYMBOL_REF, Pmode, name));
222 /* Optionally set flags or add text to the name to record information
223 such as that it is a function name. If the name is changed, the macro
224 ASM_OUTPUT_LABELREF will have to know how to strip this information.
225 And if it finds a * at the beginning after doing so, it must handle
227 #ifdef ENCODE_SECTION_INFO
228 ENCODE_SECTION_INFO (decl);
232 /* Record at least one function has been defined. */
233 function_defined = 1;
236 /* Create the DECL_RTL for a declaration for a static or external
237 variable or static or external function.
238 ASMSPEC, if not 0, is the string which the user specified
239 as the assembler symbol name.
240 TOP_LEVEL is nonzero if this is a file-scope variable.
241 This is never called for PARM_DECLs. */
243 bc_make_decl_rtl (decl, asmspec, top_level)
248 register char *name = TREE_STRING_POINTER (DECL_ASSEMBLER_NAME (decl));
250 if (DECL_RTL (decl) == 0)
252 /* Print an error message for register variables. */
253 if (DECL_REGISTER (decl) && TREE_CODE (decl) == FUNCTION_DECL)
254 error ("function declared `register'");
255 else if (DECL_REGISTER (decl))
256 error ("global register variables not supported in the interpreter");
258 /* Handle ordinary static variables and functions. */
259 if (DECL_RTL (decl) == 0)
261 /* Can't use just the variable's own name for a variable
262 whose scope is less than the whole file.
263 Concatenate a distinguishing number. */
264 if (!top_level && !DECL_EXTERNAL (decl) && asmspec == 0)
268 ASM_FORMAT_PRIVATE_NAME (label, name, var_labelno);
269 name = obstack_copy0 (saveable_obstack, label, strlen (label));
273 DECL_RTL (decl) = bc_gen_rtx (name, 0, (struct bc_label *) 0);
278 /* Given NAME, a putative register name, discard any customary prefixes. */
281 strip_reg_name (name)
284 #ifdef REGISTER_PREFIX
285 if (!strncmp (name, REGISTER_PREFIX, strlen (REGISTER_PREFIX)))
286 name += strlen (REGISTER_PREFIX);
288 if (name[0] == '%' || name[0] == '#')
293 /* Decode an `asm' spec for a declaration as a register name.
294 Return the register number, or -1 if nothing specified,
295 or -2 if the ASMSPEC is not `cc' or `memory' and is not recognized,
296 or -3 if ASMSPEC is `cc' and is not recognized,
297 or -4 if ASMSPEC is `memory' and is not recognized.
298 Accept an exact spelling or a decimal number.
299 Prefixes such as % are optional. */
302 decode_reg_name (asmspec)
309 /* Get rid of confusing prefixes. */
310 asmspec = strip_reg_name (asmspec);
312 /* Allow a decimal number as a "register name". */
313 for (i = strlen (asmspec) - 1; i >= 0; i--)
314 if (! (asmspec[i] >= '0' && asmspec[i] <= '9'))
316 if (asmspec[0] != 0 && i < 0)
319 if (i < FIRST_PSEUDO_REGISTER && i >= 0)
325 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
327 && ! strcmp (asmspec, strip_reg_name (reg_names[i])))
330 #ifdef ADDITIONAL_REGISTER_NAMES
332 static struct { char *name; int number; } table[]
333 = ADDITIONAL_REGISTER_NAMES;
335 for (i = 0; i < sizeof (table) / sizeof (table[0]); i++)
336 if (! strcmp (asmspec, table[i].name))
337 return table[i].number;
339 #endif /* ADDITIONAL_REGISTER_NAMES */
341 if (!strcmp (asmspec, "memory"))
344 if (!strcmp (asmspec, "cc"))
353 /* Create the DECL_RTL for a declaration for a static or external variable
354 or static or external function.
355 ASMSPEC, if not 0, is the string which the user specified
356 as the assembler symbol name.
357 TOP_LEVEL is nonzero if this is a file-scope variable.
359 This is never called for PARM_DECL nodes. */
362 make_decl_rtl (decl, asmspec, top_level)
372 bc_make_decl_rtl (decl, asmspec, top_level);
376 reg_number = decode_reg_name (asmspec);
378 if (DECL_ASSEMBLER_NAME (decl) != NULL_TREE)
379 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
381 if (reg_number == -2)
383 /* ASMSPEC is given, and not the name of a register. */
384 name = (char *) obstack_alloc (saveable_obstack,
385 strlen (asmspec) + 2);
387 strcpy (&name[1], asmspec);
390 /* For a duplicate declaration, we can be called twice on the
391 same DECL node. Don't discard the RTL already made. */
392 if (DECL_RTL (decl) == 0)
396 /* First detect errors in declaring global registers. */
397 if (DECL_REGISTER (decl) && reg_number == -1)
398 error_with_decl (decl,
399 "register name not specified for `%s'");
400 else if (DECL_REGISTER (decl) && reg_number < 0)
401 error_with_decl (decl,
402 "invalid register name for `%s'");
403 else if ((reg_number >= 0 || reg_number == -3) && ! DECL_REGISTER (decl))
404 error_with_decl (decl,
405 "register name given for non-register variable `%s'");
406 else if (DECL_REGISTER (decl) && TREE_CODE (decl) == FUNCTION_DECL)
407 error ("function declared `register'");
408 else if (DECL_REGISTER (decl) && TYPE_MODE (TREE_TYPE (decl)) == BLKmode)
409 error_with_decl (decl, "data type of `%s' isn't suitable for a register");
410 else if (DECL_REGISTER (decl)
411 && ! HARD_REGNO_MODE_OK (reg_number, TYPE_MODE (TREE_TYPE (decl))))
412 error_with_decl (decl, "register number for `%s' isn't suitable for the data type");
413 /* Now handle properly declared static register variables. */
414 else if (DECL_REGISTER (decl))
417 #if 0 /* yylex should print the warning for this */
419 pedwarn ("ANSI C forbids global register variables");
421 if (DECL_INITIAL (decl) != 0 && top_level)
423 DECL_INITIAL (decl) = 0;
424 error ("global register variable has initial value");
426 if (fixed_regs[reg_number] == 0
427 && function_defined && top_level)
428 error ("global register variable follows a function definition");
429 if (TREE_THIS_VOLATILE (decl))
430 warning ("volatile register variables don't work as you might wish");
432 /* If the user specified one of the eliminables registers here,
433 e.g., FRAME_POINTER_REGNUM, we don't want to get this variable
434 confused with that register and be eliminated. Although this
435 usage is somewhat suspect, we nevertheless use the following
436 kludge to avoid setting DECL_RTL to frame_pointer_rtx. */
439 = gen_rtx (REG, DECL_MODE (decl), FIRST_PSEUDO_REGISTER);
440 REGNO (DECL_RTL (decl)) = reg_number;
441 REG_USERVAR_P (DECL_RTL (decl)) = 1;
445 /* Make this register fixed, so not usable for anything else. */
446 nregs = HARD_REGNO_NREGS (reg_number, DECL_MODE (decl));
448 global_regs[reg_number + --nregs] = 1;
453 /* Now handle ordinary static variables and functions (in memory).
454 Also handle vars declared register invalidly. */
455 if (DECL_RTL (decl) == 0)
457 /* Can't use just the variable's own name for a variable
458 whose scope is less than the whole file.
459 Concatenate a distinguishing number. */
460 if (!top_level && !DECL_EXTERNAL (decl) && asmspec == 0)
464 ASM_FORMAT_PRIVATE_NAME (label, name, var_labelno);
465 name = obstack_copy0 (saveable_obstack, label, strlen (label));
469 DECL_RTL (decl) = gen_rtx (MEM, DECL_MODE (decl),
470 gen_rtx (SYMBOL_REF, Pmode, name));
472 /* If this variable is to be treated as volatile, show its
473 tree node has side effects. If it has side effects, either
474 because of this test or from TREE_THIS_VOLATILE also
475 being set, show the MEM is volatile. */
476 if (flag_volatile_global && TREE_CODE (decl) == VAR_DECL
477 && TREE_PUBLIC (decl))
478 TREE_SIDE_EFFECTS (decl) = 1;
479 if (TREE_SIDE_EFFECTS (decl))
480 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
482 if (TREE_READONLY (decl))
483 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
484 MEM_IN_STRUCT_P (DECL_RTL (decl))
485 = (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
486 || TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE
487 || TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE
488 || TREE_CODE (TREE_TYPE (decl)) == QUAL_UNION_TYPE);
490 /* Optionally set flags or add text to the name to record information
491 such as that it is a function name.
492 If the name is changed, the macro ASM_OUTPUT_LABELREF
493 will have to know how to strip this information.
494 And if it finds a * at the beginning after doing so,
495 it must handle that too. */
496 #ifdef ENCODE_SECTION_INFO
497 ENCODE_SECTION_INFO (decl);
501 /* If the old RTL had the wrong mode, fix the mode. */
502 else if (GET_MODE (DECL_RTL (decl)) != DECL_MODE (decl))
504 rtx rtl = DECL_RTL (decl);
505 PUT_MODE (rtl, DECL_MODE (decl));
509 /* Make the rtl for variable VAR be volatile.
510 Use this only for static variables. */
513 make_var_volatile (var)
516 if (GET_CODE (DECL_RTL (var)) != MEM)
519 MEM_VOLATILE_P (DECL_RTL (var)) = 1;
522 /* Output alignment directive to align for constant expression EXP. */
525 assemble_constant_align (exp)
530 /* Align the location counter as required by EXP's data type. */
531 align = TYPE_ALIGN (TREE_TYPE (exp));
532 #ifdef CONSTANT_ALIGNMENT
533 align = CONSTANT_ALIGNMENT (exp, align);
536 if (align > BITS_PER_UNIT)
537 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
540 /* Output a string of literal assembler code
541 for an `asm' keyword used between functions. */
544 assemble_asm (string)
549 error ("asm statements not allowed in interpreter");
555 if (TREE_CODE (string) == ADDR_EXPR)
556 string = TREE_OPERAND (string, 0);
558 fprintf (asm_out_file, "\t%s\n", TREE_STRING_POINTER (string));
561 #if 0 /* This should no longer be needed, because
562 flag_gnu_linker should be 0 on these systems,
563 which should prevent any output
564 if ASM_OUTPUT_CONSTRUCTOR and ASM_OUTPUT_DESTRUCTOR are absent. */
565 #if !(defined(DBX_DEBUGGING_INFO) && !defined(FASCIST_ASSEMBLER))
566 #ifndef ASM_OUTPUT_CONSTRUCTOR
567 #define ASM_OUTPUT_CONSTRUCTOR(file, name)
569 #ifndef ASM_OUTPUT_DESTRUCTOR
570 #define ASM_OUTPUT_DESTRUCTOR(file, name)
575 /* Record an element in the table of global destructors.
576 How this is done depends on what sort of assembler and linker
579 NAME should be the name of a global function to be called
580 at exit time. This name is output using assemble_name. */
583 assemble_destructor (name)
586 #ifdef ASM_OUTPUT_DESTRUCTOR
587 ASM_OUTPUT_DESTRUCTOR (asm_out_file, name);
591 /* Now tell GNU LD that this is part of the static destructor set. */
592 /* This code works for any machine provided you use GNU as/ld. */
593 fprintf (asm_out_file, "%s \"___DTOR_LIST__\",22,0,0,", ASM_STABS_OP);
594 assemble_name (asm_out_file, name);
595 fputc ('\n', asm_out_file);
600 /* Likewise for global constructors. */
603 assemble_constructor (name)
606 #ifdef ASM_OUTPUT_CONSTRUCTOR
607 ASM_OUTPUT_CONSTRUCTOR (asm_out_file, name);
611 /* Now tell GNU LD that this is part of the static constructor set. */
612 /* This code works for any machine provided you use GNU as/ld. */
613 fprintf (asm_out_file, "%s \"___CTOR_LIST__\",22,0,0,", ASM_STABS_OP);
614 assemble_name (asm_out_file, name);
615 fputc ('\n', asm_out_file);
620 /* Likewise for entries we want to record for garbage collection.
621 Garbage collection is still under development. */
624 assemble_gc_entry (name)
627 #ifdef ASM_OUTPUT_GC_ENTRY
628 ASM_OUTPUT_GC_ENTRY (asm_out_file, name);
632 /* Now tell GNU LD that this is part of the static constructor set. */
633 fprintf (asm_out_file, "%s \"___PTR_LIST__\",22,0,0,", ASM_STABS_OP);
634 assemble_name (asm_out_file, name);
635 fputc ('\n', asm_out_file);
640 /* Output assembler code for the constant pool of a function and associated
641 with defining the name of the function. DECL describes the function.
642 NAME is the function's name. For the constant pool, we use the current
643 constant pool data. */
646 assemble_start_function (decl, fnname)
652 /* The following code does not need preprocessing in the assembler. */
656 output_constant_pool (fnname, decl);
661 /* Tell assembler to move to target machine's alignment for functions. */
662 align = floor_log2 (FUNCTION_BOUNDARY / BITS_PER_UNIT);
666 BC_OUTPUT_ALIGN (asm_out_file, align);
668 ASM_OUTPUT_ALIGN (asm_out_file, align);
671 #ifdef ASM_OUTPUT_FUNCTION_PREFIX
672 ASM_OUTPUT_FUNCTION_PREFIX (asm_out_file, fnname);
675 #ifdef SDB_DEBUGGING_INFO
676 /* Output SDB definition of the function. */
677 if (write_symbols == SDB_DEBUG)
678 sdbout_mark_begin_function ();
681 #ifdef DBX_DEBUGGING_INFO
682 /* Output DBX definition of the function. */
683 if (write_symbols == DBX_DEBUG)
684 dbxout_begin_function (decl);
687 /* Make function name accessible from other files, if appropriate. */
689 if (TREE_PUBLIC (decl))
691 if (!first_global_object_name)
692 STRIP_NAME_ENCODING (first_global_object_name, fnname);
694 BC_GLOBALIZE_LABEL (asm_out_file, fnname);
696 ASM_GLOBALIZE_LABEL (asm_out_file, fnname);
699 /* Do any machine/system dependent processing of the function name */
700 #ifdef ASM_DECLARE_FUNCTION_NAME
701 ASM_DECLARE_FUNCTION_NAME (asm_out_file, fnname, current_function_decl);
703 /* Standard thing is just output label for the function. */
705 BC_OUTPUT_LABEL (asm_out_file, fnname);
707 ASM_OUTPUT_LABEL (asm_out_file, fnname);
708 #endif /* ASM_DECLARE_FUNCTION_NAME */
711 /* Output assembler code associated with defining the size of the
712 function. DECL describes the function. NAME is the function's name. */
715 assemble_end_function (decl, fnname)
719 #ifdef ASM_DECLARE_FUNCTION_SIZE
720 ASM_DECLARE_FUNCTION_SIZE (asm_out_file, fnname, decl);
724 /* Assemble code to leave SIZE bytes of zeros. */
727 assemble_zeros (size)
732 bc_emit_const_skip (size);
736 #ifdef ASM_NO_SKIP_IN_TEXT
737 /* The `space' pseudo in the text section outputs nop insns rather than 0s,
738 so we must output 0s explicitly in the text section. */
739 if (ASM_NO_SKIP_IN_TEXT && in_text_section ())
743 for (i = 0; i < size - 20; i += 20)
746 fprintf (asm_out_file,
747 "%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);
749 fprintf (asm_out_file,
750 "\tbyte 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0\n");
756 fprintf (asm_out_file, "%s 0", ASM_BYTE_OP);
758 fprintf (asm_out_file, "\tbyte 0");
761 for (; i < size; i++)
762 fprintf (asm_out_file, ",0");
763 fprintf (asm_out_file, "\n");
771 BC_OUTPUT_SKIP (asm_out_file, size);
773 ASM_OUTPUT_SKIP (asm_out_file, size);
777 /* Assemble an alignment pseudo op for an ALIGN-bit boundary. */
780 assemble_align (align)
783 if (align > BITS_PER_UNIT)
784 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
787 /* Assemble a string constant with the specified C string as contents. */
790 assemble_string (p, size)
804 /* If the string is very long, split it up. */
808 int thissize = size - pos;
809 if (thissize > maximum)
813 BC_OUTPUT_ASCII (asm_out_file, p, thissize);
816 ASM_OUTPUT_ASCII (asm_out_file, p, thissize);
824 /* Assemble everything that is needed for a variable or function declaration.
825 Not used for automatic variables, and not used for function definitions.
826 Should not be called for variables of incomplete structure type.
828 TOP_LEVEL is nonzero if this variable has file scope.
829 AT_END is nonzero if this is the special handling, at end of compilation,
830 to define things that have had only tentative definitions.
831 DONT_OUTPUT_DATA if nonzero means don't actually output the
832 initial value (that will be done by the caller). */
835 assemble_variable (decl, top_level, at_end, dont_output_data)
844 enum in_section saved_in_section;
849 if (GET_CODE (DECL_RTL (decl)) == REG)
851 /* Do output symbol info for global register variables, but do nothing
854 if (TREE_ASM_WRITTEN (decl))
856 TREE_ASM_WRITTEN (decl) = 1;
858 if (!output_bytecode)
860 #if defined (DBX_DEBUGGING_INFO) || defined (XCOFF_DEBUGGING_INFO)
861 /* File-scope global variables are output here. */
862 if ((write_symbols == DBX_DEBUG || write_symbols == XCOFF_DEBUG)
864 dbxout_symbol (decl, 0);
866 #ifdef SDB_DEBUGGING_INFO
867 if (write_symbols == SDB_DEBUG && top_level
868 /* Leave initialized global vars for end of compilation;
869 see comment in compile_file. */
870 && (TREE_PUBLIC (decl) == 0 || DECL_INITIAL (decl) == 0))
871 sdbout_symbol (decl, 0);
875 /* Don't output any DWARF debugging information for variables here.
876 In the case of local variables, the information for them is output
877 when we do our recursive traversal of the tree representation for
878 the entire containing function. In the case of file-scope variables,
879 we output information for all of them at the very end of compilation
880 while we are doing our final traversal of the chain of file-scope
886 /* Normally no need to say anything here for external references,
887 since assemble_external is called by the langauge-specific code
888 when a declaration is first seen. */
890 if (DECL_EXTERNAL (decl))
893 /* Output no assembler code for a function declaration.
894 Only definitions of functions output anything. */
896 if (TREE_CODE (decl) == FUNCTION_DECL)
899 /* If type was incomplete when the variable was declared,
900 see if it is complete now. */
902 if (DECL_SIZE (decl) == 0)
903 layout_decl (decl, 0);
905 /* Still incomplete => don't allocate it; treat the tentative defn
906 (which is what it must have been) as an `extern' reference. */
908 if (!dont_output_data && DECL_SIZE (decl) == 0)
910 error_with_file_and_line (DECL_SOURCE_FILE (decl),
911 DECL_SOURCE_LINE (decl),
912 "storage size of `%s' isn't known",
913 IDENTIFIER_POINTER (DECL_NAME (decl)));
917 /* The first declaration of a variable that comes through this function
918 decides whether it is global (in C, has external linkage)
919 or local (in C, has internal linkage). So do nothing more
920 if this function has already run. */
922 if (TREE_ASM_WRITTEN (decl))
925 TREE_ASM_WRITTEN (decl) = 1;
927 /* If storage size is erroneously variable, just continue.
928 Error message was already made. */
930 if (DECL_SIZE (decl))
932 if (TREE_CODE (DECL_SIZE (decl)) != INTEGER_CST)
937 /* This is better than explicit arithmetic, since it avoids overflow. */
938 size_tree = size_binop (CEIL_DIV_EXPR,
939 DECL_SIZE (decl), size_int (BITS_PER_UNIT));
941 if (TREE_INT_CST_HIGH (size_tree) != 0)
943 error_with_decl (decl, "size of variable `%s' is too large");
948 name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
950 /* Handle uninitialized definitions. */
952 /* ANSI specifies that a tentative definition which is not merged with
953 a non-tentative definition behaves exactly like a definition with an
954 initializer equal to zero. (Section 3.7.2)
955 -fno-common gives strict ANSI behavior. Usually you don't want it.
956 This matters only for variables with external linkage. */
957 if ((! flag_no_common || ! TREE_PUBLIC (decl))
958 && ! dont_output_data
959 && (DECL_INITIAL (decl) == 0 || DECL_INITIAL (decl) == error_mark_node))
961 int size = TREE_INT_CST_LOW (size_tree);
964 if (TREE_INT_CST_HIGH (size_tree) != 0)
965 error_with_decl (decl, "size of variable `%s' is too large");
966 /* Don't allocate zero bytes of common,
967 since that means "undefined external" in the linker. */
968 if (size == 0) rounded = 1;
969 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
970 so that each uninitialized object starts on such a boundary. */
971 rounded += (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1;
972 rounded = (rounded / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
973 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
975 #ifdef DBX_DEBUGGING_INFO
976 /* File-scope global variables are output here. */
977 if (write_symbols == DBX_DEBUG && top_level)
978 dbxout_symbol (decl, 0);
980 #ifdef SDB_DEBUGGING_INFO
981 if (write_symbols == SDB_DEBUG && top_level
982 /* Leave initialized global vars for end of compilation;
983 see comment in compile_file. */
984 && (TREE_PUBLIC (decl) == 0 || DECL_INITIAL (decl) == 0))
985 sdbout_symbol (decl, 0);
988 /* Don't output any DWARF debugging information for variables here.
989 In the case of local variables, the information for them is output
990 when we do our recursive traversal of the tree representation for
991 the entire containing function. In the case of file-scope variables,
992 we output information for all of them at the very end of compilation
993 while we are doing our final traversal of the chain of file-scope
997 if (flag_shared_data)
1000 if (TREE_PUBLIC (decl))
1002 #ifdef ASM_OUTPUT_SHARED_COMMON
1003 if (flag_shared_data)
1004 ASM_OUTPUT_SHARED_COMMON (asm_out_file, name, size, rounded);
1007 if (output_bytecode)
1008 BC_OUTPUT_COMMON (asm_out_file, name, size, rounded);
1011 #ifdef ASM_OUTPUT_ALIGNED_COMMON
1012 ASM_OUTPUT_ALIGNED_COMMON (asm_out_file, name, size,
1015 ASM_OUTPUT_COMMON (asm_out_file, name, size, rounded);
1021 #ifdef ASM_OUTPUT_SHARED_LOCAL
1022 if (flag_shared_data)
1023 ASM_OUTPUT_SHARED_LOCAL (asm_out_file, name, size, rounded);
1026 if (output_bytecode)
1027 BC_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
1030 #ifdef ASM_OUTPUT_ALIGNED_LOCAL
1031 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size,
1034 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
1041 /* Handle initialized definitions. */
1043 /* First make the assembler name(s) global if appropriate. */
1044 if (TREE_PUBLIC (decl) && DECL_NAME (decl))
1046 if (!first_global_object_name)
1047 STRIP_NAME_ENCODING(first_global_object_name, name);
1048 ASM_GLOBALIZE_LABEL (asm_out_file, name);
1051 for (d = equivalents; d; d = TREE_CHAIN (d))
1053 tree e = TREE_VALUE (d);
1054 if (TREE_PUBLIC (e) && DECL_NAME (e))
1055 ASM_GLOBALIZE_LABEL (asm_out_file,
1056 XSTR (XEXP (DECL_RTL (e), 0), 0));
1060 /* Output any data that we will need to use the address of. */
1061 if (DECL_INITIAL (decl) == error_mark_node)
1062 reloc = contains_pointers_p (TREE_TYPE (decl));
1063 else if (DECL_INITIAL (decl))
1064 reloc = output_addressed_constants (DECL_INITIAL (decl));
1066 /* Switch to the proper section for this data. */
1067 #ifdef SELECT_SECTION
1068 SELECT_SECTION (decl, reloc);
1070 if (TREE_READONLY (decl)
1071 && ! TREE_THIS_VOLATILE (decl)
1072 && ! (flag_pic && reloc))
1073 readonly_data_section ();
1078 /* Record current section so we can restore it if dbxout.c clobbers it. */
1079 saved_in_section = in_section;
1081 /* Output the dbx info now that we have chosen the section. */
1083 #ifdef DBX_DEBUGGING_INFO
1084 /* File-scope global variables are output here. */
1085 if (write_symbols == DBX_DEBUG && top_level)
1086 dbxout_symbol (decl, 0);
1088 #ifdef SDB_DEBUGGING_INFO
1089 if (write_symbols == SDB_DEBUG && top_level
1090 /* Leave initialized global vars for end of compilation;
1091 see comment in compile_file. */
1092 && (TREE_PUBLIC (decl) == 0 || DECL_INITIAL (decl) == 0))
1093 sdbout_symbol (decl, 0);
1096 /* Don't output any DWARF debugging information for variables here.
1097 In the case of local variables, the information for them is output
1098 when we do our recursive traversal of the tree representation for
1099 the entire containing function. In the case of file-scope variables,
1100 we output information for all of them at the very end of compilation
1101 while we are doing our final traversal of the chain of file-scope
1104 if (in_section != saved_in_section)
1106 /* Switch to the proper section for this data. */
1107 #ifdef SELECT_SECTION
1108 SELECT_SECTION (decl, reloc);
1110 if (TREE_READONLY (decl)
1111 && ! TREE_THIS_VOLATILE (decl)
1112 && ! (flag_pic && reloc))
1113 readonly_data_section ();
1119 /* Compute and output the alignment of this data. */
1121 align = DECL_ALIGN (decl);
1122 /* In the case for initialing an array whose length isn't specified,
1123 where we have not yet been able to do the layout,
1124 figure out the proper alignment now. */
1125 if (dont_output_data && DECL_SIZE (decl) == 0
1126 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
1127 align = MAX (align, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
1129 /* Some object file formats have a maximum alignment which they support.
1130 In particular, a.out format supports a maximum alignment of 4. */
1131 #ifndef MAX_OFILE_ALIGNMENT
1132 #define MAX_OFILE_ALIGNMENT BIGGEST_ALIGNMENT
1134 if (align > MAX_OFILE_ALIGNMENT)
1136 warning_with_decl (decl,
1137 "alignment of `%s' is greater than maximum object file alignment");
1138 align = MAX_OFILE_ALIGNMENT;
1140 #ifdef DATA_ALIGNMENT
1141 /* On some machines, it is good to increase alignment sometimes. */
1142 align = DATA_ALIGNMENT (TREE_TYPE (decl), align);
1144 #ifdef CONSTANT_ALIGNMENT
1145 if (DECL_INITIAL (decl))
1146 align = CONSTANT_ALIGNMENT (DECL_INITIAL (decl), align);
1149 /* Reset the alignment in case we have made it tighter, so we can benefit
1150 from it in get_pointer_alignment. */
1151 DECL_ALIGN (decl) = align;
1153 if (align > BITS_PER_UNIT)
1155 if (output_bytecode)
1156 BC_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
1158 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
1161 /* Do any machine/system dependent processing of the object. */
1162 #ifdef ASM_DECLARE_OBJECT_NAME
1163 ASM_DECLARE_OBJECT_NAME (asm_out_file, name, decl);
1165 /* Standard thing is just output label for the object. */
1166 if (output_bytecode)
1167 BC_OUTPUT_LABEL (asm_out_file, name);
1169 ASM_OUTPUT_LABEL (asm_out_file, name);
1170 #endif /* ASM_DECLARE_OBJECT_NAME */
1172 if (!dont_output_data)
1174 if (DECL_INITIAL (decl))
1175 /* Output the actual data. */
1176 output_constant (DECL_INITIAL (decl),
1177 int_size_in_bytes (TREE_TYPE (decl)));
1179 /* Leave space for it. */
1180 assemble_zeros (int_size_in_bytes (TREE_TYPE (decl)));
1184 #ifdef XCOFF_DEBUGGING_INFO
1185 /* Unfortunately, the IBM assembler cannot handle stabx before the actual
1186 declaration. When something like ".stabx "aa:S-2",aa,133,0" is emitted
1187 and `aa' hasn't been output yet, the assembler generates a stab entry with
1188 a value of zero, in addition to creating an unnecessary external entry
1189 for `aa'. Hence, we must postpone dbxout_symbol to here at the end. */
1191 /* File-scope global variables are output here. */
1192 if (write_symbols == XCOFF_DEBUG && top_level)
1194 saved_in_section = in_section;
1196 dbxout_symbol (decl, 0);
1198 if (in_section != saved_in_section)
1200 /* Switch to the proper section for this data. */
1201 #ifdef SELECT_SECTION
1202 SELECT_SECTION (decl, reloc);
1204 if (TREE_READONLY (decl)
1205 && ! TREE_THIS_VOLATILE (decl)
1206 && ! (flag_pic && reloc))
1207 readonly_data_section ();
1214 /* There must be a statement after a label. */
1219 /* Return 1 if type TYPE contains any pointers. */
1222 contains_pointers_p (type)
1225 switch (TREE_CODE (type))
1228 case REFERENCE_TYPE:
1229 /* I'm not sure whether OFFSET_TYPE needs this treatment,
1230 so I'll play safe and return 1. */
1236 case QUAL_UNION_TYPE:
1239 /* For a type that has fields, see if the fields have pointers. */
1240 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
1241 if (contains_pointers_p (TREE_TYPE (fields)))
1247 /* An array type contains pointers if its element type does. */
1248 return contains_pointers_p (TREE_TYPE (type));
1255 /* Output text storage for constructor CONSTR. Returns rtx of
1259 bc_output_constructor (constr)
1264 /* Must always be a literal; non-literal constructors are handled
1267 if (!TREE_CONSTANT (constr))
1274 for (i = 0; TYPE_ALIGN (constr) >= BITS_PER_UNIT << (i + 1); i++);
1276 BC_OUTPUT_ALIGN (asm_out_file, i);
1279 output_constant (constr, int_size_in_bytes (TREE_TYPE (constr)));
1283 /* Create storage for constructor CONSTR. */
1286 bc_output_data_constructor (constr)
1291 /* Put in data section */
1295 for (i = 0; TYPE_ALIGN (constr) >= BITS_PER_UNIT << (i + 1); i++);
1297 BC_OUTPUT_ALIGN (asm_out_file, i);
1299 /* The constructor is filled in at runtime. */
1300 BC_OUTPUT_SKIP (asm_out_file, int_size_in_bytes (TREE_TYPE (constr)));
1304 /* Output something to declare an external symbol to the assembler.
1305 (Most assemblers don't need this, so we normally output nothing.)
1306 Do nothing if DECL is not external. */
1309 assemble_external (decl)
1312 if (output_bytecode)
1315 #ifdef ASM_OUTPUT_EXTERNAL
1316 if (TREE_CODE_CLASS (TREE_CODE (decl)) == 'd'
1317 && DECL_EXTERNAL (decl) && TREE_PUBLIC (decl))
1319 rtx rtl = DECL_RTL (decl);
1321 if (GET_CODE (rtl) == MEM && GET_CODE (XEXP (rtl, 0)) == SYMBOL_REF
1322 && ! SYMBOL_REF_USED (XEXP (rtl, 0)))
1324 /* Some systems do require some output. */
1325 SYMBOL_REF_USED (XEXP (rtl, 0)) = 1;
1326 ASM_OUTPUT_EXTERNAL (asm_out_file, decl, XSTR (XEXP (rtl, 0), 0));
1332 /* Similar, for calling a library function FUN. */
1335 assemble_external_libcall (fun)
1338 #ifdef ASM_OUTPUT_EXTERNAL_LIBCALL
1339 if (!output_bytecode)
1341 /* Declare library function name external when first used, if nec. */
1342 if (! SYMBOL_REF_USED (fun))
1344 SYMBOL_REF_USED (fun) = 1;
1345 ASM_OUTPUT_EXTERNAL_LIBCALL (asm_out_file, fun);
1351 /* Declare the label NAME global. */
1354 assemble_global (name)
1357 ASM_GLOBALIZE_LABEL (asm_out_file, name);
1360 /* Assemble a label named NAME. */
1363 assemble_label (name)
1366 if (output_bytecode)
1367 BC_OUTPUT_LABEL (asm_out_file, name);
1369 ASM_OUTPUT_LABEL (asm_out_file, name);
1372 /* Output to FILE a reference to the assembler name of a C-level name NAME.
1373 If NAME starts with a *, the rest of NAME is output verbatim.
1374 Otherwise NAME is transformed in an implementation-defined way
1375 (usually by the addition of an underscore).
1376 Many macros in the tm file are defined to call this function. */
1379 assemble_name (file, name)
1385 if (output_bytecode)
1386 bc_emit_labelref (name);
1388 fputs (&name[1], file);
1392 if (output_bytecode)
1393 BC_OUTPUT_LABELREF (file, name);
1395 ASM_OUTPUT_LABELREF (file, name);
1399 /* Allocate SIZE bytes writable static space with a gensym name
1400 and return an RTX to refer to its address. */
1403 assemble_static_space (size)
1409 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
1410 so that each uninitialized object starts on such a boundary. */
1411 int rounded = ((size + (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1)
1412 / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
1413 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
1416 if (flag_shared_data)
1420 ASM_GENERATE_INTERNAL_LABEL (name, "LF", const_labelno);
1423 namestring = (char *) obstack_alloc (saveable_obstack,
1425 strcpy (namestring, name);
1427 if (output_bytecode)
1428 x = bc_gen_rtx (namestring, 0, (struct bc_label *) 0);
1430 x = gen_rtx (SYMBOL_REF, Pmode, namestring);
1432 if (output_bytecode)
1433 BC_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
1436 #ifdef ASM_OUTPUT_ALIGNED_LOCAL
1437 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, BIGGEST_ALIGNMENT);
1439 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
1445 /* Assemble the static constant template for function entry trampolines.
1446 This is done at most once per compilation.
1447 Returns an RTX for the address of the template. */
1450 assemble_trampoline_template ()
1456 /* Shouldn't get here */
1457 if (output_bytecode)
1460 /* By default, put trampoline templates in read-only data section. */
1462 #ifdef TRAMPOLINE_SECTION
1463 TRAMPOLINE_SECTION ();
1465 readonly_data_section ();
1468 /* Write the assembler code to define one. */
1469 align = floor_log2 (FUNCTION_BOUNDARY / BITS_PER_UNIT);
1471 ASM_OUTPUT_ALIGN (asm_out_file, align);
1473 ASM_OUTPUT_INTERNAL_LABEL (asm_out_file, "LTRAMP", 0);
1474 TRAMPOLINE_TEMPLATE (asm_out_file);
1476 /* Record the rtl to refer to it. */
1477 ASM_GENERATE_INTERNAL_LABEL (label, "LTRAMP", 0);
1479 = (char *) obstack_copy0 (&permanent_obstack, label, strlen (label));
1480 return gen_rtx (SYMBOL_REF, Pmode, name);
1483 /* Assemble the integer constant X into an object of SIZE bytes.
1484 X must be either a CONST_INT or CONST_DOUBLE.
1486 Return 1 if we were able to output the constant, otherwise 0. If FORCE is
1487 non-zero, abort if we can't output the constant. */
1490 assemble_integer (x, size, force)
1495 /* First try to use the standard 1, 2, 4, 8, and 16 byte
1496 ASM_OUTPUT... macros. */
1500 #ifdef ASM_OUTPUT_CHAR
1502 ASM_OUTPUT_CHAR (asm_out_file, x);
1506 #ifdef ASM_OUTPUT_SHORT
1508 ASM_OUTPUT_SHORT (asm_out_file, x);
1512 #ifdef ASM_OUTPUT_INT
1514 ASM_OUTPUT_INT (asm_out_file, x);
1518 #ifdef ASM_OUTPUT_DOUBLE_INT
1520 ASM_OUTPUT_DOUBLE_INT (asm_out_file, x);
1524 #ifdef ASM_OUTPUT_QUADRUPLE_INT
1526 ASM_OUTPUT_QUADRUPLE_INT (asm_out_file, x);
1531 /* If we couldn't do it that way, there are two other possibilities: First,
1532 if the machine can output an explicit byte and this is a 1 byte constant,
1533 we can use ASM_OUTPUT_BYTE. */
1535 #ifdef ASM_OUTPUT_BYTE
1536 if (size == 1 && GET_CODE (x) == CONST_INT)
1538 ASM_OUTPUT_BYTE (asm_out_file, INTVAL (x));
1543 /* Finally, if SIZE is larger than a single word, try to output the constant
1544 one word at a time. */
1546 if (size > UNITS_PER_WORD)
1549 enum machine_mode mode
1550 = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
1553 for (i = 0; i < size / UNITS_PER_WORD; i++)
1555 word = operand_subword (x, i, 0, mode);
1560 if (! assemble_integer (word, UNITS_PER_WORD, 0))
1564 if (i == size / UNITS_PER_WORD)
1566 /* If we output at least one word and then could not finish,
1567 there is no valid way to continue. */
1578 /* Assemble the floating-point constant D into an object of size MODE. */
1581 assemble_real (d, mode)
1583 enum machine_mode mode;
1585 jmp_buf output_constant_handler;
1587 if (setjmp (output_constant_handler))
1589 error ("floating point trap outputting a constant");
1590 #ifdef REAL_IS_NOT_DOUBLE
1591 bzero (&d, sizeof d);
1598 set_float_handler (output_constant_handler);
1602 #ifdef ASM_OUTPUT_BYTE_FLOAT
1604 ASM_OUTPUT_BYTE_FLOAT (asm_out_file, d);
1607 #ifdef ASM_OUTPUT_SHORT_FLOAT
1609 ASM_OUTPUT_SHORT_FLOAT (asm_out_file, d);
1612 #ifdef ASM_OUTPUT_FLOAT
1614 ASM_OUTPUT_FLOAT (asm_out_file, d);
1618 #ifdef ASM_OUTPUT_DOUBLE
1620 ASM_OUTPUT_DOUBLE (asm_out_file, d);
1624 #ifdef ASM_OUTPUT_LONG_DOUBLE
1627 ASM_OUTPUT_LONG_DOUBLE (asm_out_file, d);
1635 set_float_handler (NULL_PTR);
1638 /* Here we combine duplicate floating constants to make
1639 CONST_DOUBLE rtx's, and force those out to memory when necessary. */
1641 /* Chain of all CONST_DOUBLE rtx's constructed for the current function.
1642 They are chained through the CONST_DOUBLE_CHAIN.
1643 A CONST_DOUBLE rtx has CONST_DOUBLE_MEM != cc0_rtx iff it is on this chain.
1644 In that case, CONST_DOUBLE_MEM is either a MEM,
1645 or const0_rtx if no MEM has been made for this CONST_DOUBLE yet.
1647 (CONST_DOUBLE_MEM is used only for top-level functions.
1648 See force_const_mem for explanation.) */
1650 static rtx const_double_chain;
1652 /* Return a CONST_DOUBLE for a value specified as a pair of ints.
1653 For an integer, I0 is the low-order word and I1 is the high-order word.
1654 For a real number, I0 is the word with the low address
1655 and I1 is the word with the high address. */
1658 immed_double_const (i0, i1, mode)
1659 HOST_WIDE_INT i0, i1;
1660 enum machine_mode mode;
1663 int in_current_obstack;
1665 if (GET_MODE_CLASS (mode) == MODE_INT
1666 || GET_MODE_CLASS (mode) == MODE_PARTIAL_INT)
1668 /* We clear out all bits that don't belong in MODE, unless they and our
1669 sign bit are all one. So we get either a reasonable negative value
1670 or a reasonable unsigned value for this mode. */
1671 int width = GET_MODE_BITSIZE (mode);
1672 if (width < HOST_BITS_PER_WIDE_INT
1673 && ((i0 & ((HOST_WIDE_INT) (-1) << (width - 1)))
1674 != ((HOST_WIDE_INT) (-1) << (width - 1))))
1675 i0 &= ((HOST_WIDE_INT) 1 << width) - 1, i1 = 0;
1676 else if (width == HOST_BITS_PER_WIDE_INT
1677 && ! (i1 == ~0 && i0 < 0))
1679 else if (width > 2 * HOST_BITS_PER_WIDE_INT)
1680 /* We cannot represent this value as a constant. */
1683 /* If MODE fits within HOST_BITS_PER_WIDE_INT, always use a CONST_INT.
1685 ??? Strictly speaking, this is wrong if we create a CONST_INT
1686 for a large unsigned constant with the size of MODE being
1687 HOST_BITS_PER_WIDE_INT and later try to interpret that constant in a
1688 wider mode. In that case we will mis-interpret it as a negative
1691 Unfortunately, the only alternative is to make a CONST_DOUBLE
1692 for any constant in any mode if it is an unsigned constant larger
1693 than the maximum signed integer in an int on the host. However,
1694 doing this will break everyone that always expects to see a CONST_INT
1695 for SImode and smaller.
1697 We have always been making CONST_INTs in this case, so nothing new
1700 if (width <= HOST_BITS_PER_WIDE_INT)
1701 i1 = (i0 < 0) ? ~0 : 0;
1703 /* If this integer fits in one word, return a CONST_INT. */
1704 if ((i1 == 0 && i0 >= 0)
1705 || (i1 == ~0 && i0 < 0))
1706 return GEN_INT (i0);
1708 /* We use VOIDmode for integers. */
1712 /* Search the chain for an existing CONST_DOUBLE with the right value.
1713 If one is found, return it. */
1715 for (r = const_double_chain; r; r = CONST_DOUBLE_CHAIN (r))
1716 if (CONST_DOUBLE_LOW (r) == i0 && CONST_DOUBLE_HIGH (r) == i1
1717 && GET_MODE (r) == mode)
1720 /* No; make a new one and add it to the chain.
1722 We may be called by an optimizer which may be discarding any memory
1723 allocated during its processing (such as combine and loop). However,
1724 we will be leaving this constant on the chain, so we cannot tolerate
1725 freed memory. So switch to saveable_obstack for this allocation
1726 and then switch back if we were in current_obstack. */
1728 push_obstacks_nochange ();
1729 rtl_in_saveable_obstack ();
1730 r = gen_rtx (CONST_DOUBLE, mode, 0, i0, i1);
1733 /* Don't touch const_double_chain in nested function; see force_const_mem.
1734 Also, don't touch it if not inside any function. */
1735 if (outer_function_chain == 0 && current_function_decl != 0)
1737 CONST_DOUBLE_CHAIN (r) = const_double_chain;
1738 const_double_chain = r;
1741 /* Store const0_rtx in mem-slot since this CONST_DOUBLE is on the chain.
1742 Actual use of mem-slot is only through force_const_mem. */
1744 CONST_DOUBLE_MEM (r) = const0_rtx;
1749 /* Return a CONST_DOUBLE for a specified `double' value
1750 and machine mode. */
1753 immed_real_const_1 (d, mode)
1755 enum machine_mode mode;
1757 union real_extract u;
1759 int in_current_obstack;
1761 /* Get the desired `double' value as a sequence of ints
1762 since that is how they are stored in a CONST_DOUBLE. */
1766 /* Detect special cases. */
1768 /* Avoid REAL_VALUES_EQUAL here in order to distinguish minus zero. */
1769 if (!bcmp (&dconst0, &d, sizeof d))
1770 return CONST0_RTX (mode);
1771 /* Check for NaN first, because some ports (specifically the i386) do not
1772 emit correct ieee-fp code by default, and thus will generate a core
1773 dump here if we pass a NaN to REAL_VALUES_EQUAL and if REAL_VALUES_EQUAL
1774 does a floating point comparison. */
1775 else if (! REAL_VALUE_ISNAN (d) && REAL_VALUES_EQUAL (dconst1, d))
1776 return CONST1_RTX (mode);
1778 if (sizeof u == 2 * sizeof (HOST_WIDE_INT))
1779 return immed_double_const (u.i[0], u.i[1], mode);
1781 /* The rest of this function handles the case where
1782 a float value requires more than 2 ints of space.
1783 It will be deleted as dead code on machines that don't need it. */
1785 /* Search the chain for an existing CONST_DOUBLE with the right value.
1786 If one is found, return it. */
1788 for (r = const_double_chain; r; r = CONST_DOUBLE_CHAIN (r))
1789 if (! bcmp (&CONST_DOUBLE_LOW (r), &u, sizeof u)
1790 && GET_MODE (r) == mode)
1793 /* No; make a new one and add it to the chain.
1795 We may be called by an optimizer which may be discarding any memory
1796 allocated during its processing (such as combine and loop). However,
1797 we will be leaving this constant on the chain, so we cannot tolerate
1798 freed memory. So switch to saveable_obstack for this allocation
1799 and then switch back if we were in current_obstack. */
1801 push_obstacks_nochange ();
1802 rtl_in_saveable_obstack ();
1803 r = rtx_alloc (CONST_DOUBLE);
1805 bcopy (&u, &CONST_DOUBLE_LOW (r), sizeof u);
1808 /* Don't touch const_double_chain in nested function; see force_const_mem.
1809 Also, don't touch it if not inside any function. */
1810 if (outer_function_chain == 0 && current_function_decl != 0)
1812 CONST_DOUBLE_CHAIN (r) = const_double_chain;
1813 const_double_chain = r;
1816 /* Store const0_rtx in CONST_DOUBLE_MEM since this CONST_DOUBLE is on the
1817 chain, but has not been allocated memory. Actual use of CONST_DOUBLE_MEM
1818 is only through force_const_mem. */
1820 CONST_DOUBLE_MEM (r) = const0_rtx;
1825 /* Return a CONST_DOUBLE rtx for a value specified by EXP,
1826 which must be a REAL_CST tree node. */
1829 immed_real_const (exp)
1832 return immed_real_const_1 (TREE_REAL_CST (exp), TYPE_MODE (TREE_TYPE (exp)));
1835 /* At the end of a function, forget the memory-constants
1836 previously made for CONST_DOUBLEs. Mark them as not on real_constant_chain.
1837 Also clear out real_constant_chain and clear out all the chain-pointers. */
1840 clear_const_double_mem ()
1842 register rtx r, next;
1844 /* Don't touch CONST_DOUBLE_MEM for nested functions.
1845 See force_const_mem for explanation. */
1846 if (outer_function_chain != 0)
1849 for (r = const_double_chain; r; r = next)
1851 next = CONST_DOUBLE_CHAIN (r);
1852 CONST_DOUBLE_CHAIN (r) = 0;
1853 CONST_DOUBLE_MEM (r) = cc0_rtx;
1855 const_double_chain = 0;
1858 /* Given an expression EXP with a constant value,
1859 reduce it to the sum of an assembler symbol and an integer.
1860 Store them both in the structure *VALUE.
1861 Abort if EXP does not reduce. */
1866 HOST_WIDE_INT offset;
1870 decode_addr_const (exp, value)
1872 struct addr_const *value;
1874 register tree target = TREE_OPERAND (exp, 0);
1875 register int offset = 0;
1880 if (TREE_CODE (target) == COMPONENT_REF
1881 && (TREE_CODE (DECL_FIELD_BITPOS (TREE_OPERAND (target, 1)))
1884 offset += TREE_INT_CST_LOW (DECL_FIELD_BITPOS (TREE_OPERAND (target, 1))) / BITS_PER_UNIT;
1885 target = TREE_OPERAND (target, 0);
1887 else if (TREE_CODE (target) == ARRAY_REF)
1889 if (TREE_CODE (TREE_OPERAND (target, 1)) != INTEGER_CST
1890 || TREE_CODE (TYPE_SIZE (TREE_TYPE (target))) != INTEGER_CST)
1892 offset += ((TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (target)))
1893 * TREE_INT_CST_LOW (TREE_OPERAND (target, 1)))
1895 target = TREE_OPERAND (target, 0);
1901 switch (TREE_CODE (target))
1905 x = DECL_RTL (target);
1909 if (output_bytecode)
1910 /* FIXME: this may not be correct, check it */
1911 x = bc_gen_rtx (TREE_STRING_POINTER (target), 0, (struct bc_label *) 0);
1913 x = gen_rtx (MEM, FUNCTION_MODE,
1914 gen_rtx (LABEL_REF, VOIDmode,
1915 label_rtx (TREE_OPERAND (exp, 0))));
1922 x = TREE_CST_RTL (target);
1929 if (!output_bytecode)
1931 if (GET_CODE (x) != MEM)
1937 value->offset = offset;
1940 /* Uniquize all constants that appear in memory.
1941 Each constant in memory thus far output is recorded
1942 in `const_hash_table' with a `struct constant_descriptor'
1943 that contains a polish representation of the value of
1946 We cannot store the trees in the hash table
1947 because the trees may be temporary. */
1949 struct constant_descriptor
1951 struct constant_descriptor *next;
1957 #define MAX_HASH_TABLE 1009
1958 static struct constant_descriptor *const_hash_table[MAX_HASH_TABLE];
1960 /* Compute a hash code for a constant expression. */
1967 register int len, hi, i;
1968 register enum tree_code code = TREE_CODE (exp);
1970 if (code == INTEGER_CST)
1972 p = (char *) &TREE_INT_CST_LOW (exp);
1973 len = 2 * sizeof TREE_INT_CST_LOW (exp);
1975 else if (code == REAL_CST)
1977 p = (char *) &TREE_REAL_CST (exp);
1978 len = sizeof TREE_REAL_CST (exp);
1980 else if (code == STRING_CST)
1981 p = TREE_STRING_POINTER (exp), len = TREE_STRING_LENGTH (exp);
1982 else if (code == COMPLEX_CST)
1983 return const_hash (TREE_REALPART (exp)) * 5
1984 + const_hash (TREE_IMAGPART (exp));
1985 else if (code == CONSTRUCTOR)
1989 /* For record type, include the type in the hashing.
1990 We do not do so for array types
1991 because (1) the sizes of the elements are sufficient
1992 and (2) distinct array types can have the same constructor.
1993 Instead, we include the array size because the constructor could
1995 if (TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE)
1996 hi = ((HOST_WIDE_INT) TREE_TYPE (exp) & ((1 << HASHBITS) - 1))
1999 hi = ((5 + int_size_in_bytes (TREE_TYPE (exp)))
2000 & ((1 << HASHBITS) - 1)) % MAX_HASH_TABLE;
2002 for (link = CONSTRUCTOR_ELTS (exp); link; link = TREE_CHAIN (link))
2003 if (TREE_VALUE (link))
2004 hi = (hi * 603 + const_hash (TREE_VALUE (link))) % MAX_HASH_TABLE;
2008 else if (code == ADDR_EXPR)
2010 struct addr_const value;
2011 decode_addr_const (exp, &value);
2012 if (GET_CODE (value.base) == SYMBOL_REF)
2014 /* Don't hash the address of the SYMBOL_REF;
2015 only use the offset and the symbol name. */
2017 p = XSTR (value.base, 0);
2018 for (i = 0; p[i] != 0; i++)
2019 hi = ((hi * 613) + (unsigned)(p[i]));
2021 else if (GET_CODE (value.base) == LABEL_REF)
2022 hi = value.offset + CODE_LABEL_NUMBER (XEXP (value.base, 0)) * 13;
2024 hi &= (1 << HASHBITS) - 1;
2025 hi %= MAX_HASH_TABLE;
2028 else if (code == PLUS_EXPR || code == MINUS_EXPR)
2029 return const_hash (TREE_OPERAND (exp, 0)) * 9
2030 + const_hash (TREE_OPERAND (exp, 1));
2031 else if (code == NOP_EXPR || code == CONVERT_EXPR)
2032 return const_hash (TREE_OPERAND (exp, 0)) * 7 + 2;
2034 /* Compute hashing function */
2036 for (i = 0; i < len; i++)
2037 hi = ((hi * 613) + (unsigned)(p[i]));
2039 hi &= (1 << HASHBITS) - 1;
2040 hi %= MAX_HASH_TABLE;
2044 /* Compare a constant expression EXP with a constant-descriptor DESC.
2045 Return 1 if DESC describes a constant with the same value as EXP. */
2048 compare_constant (exp, desc)
2050 struct constant_descriptor *desc;
2052 return 0 != compare_constant_1 (exp, desc->contents);
2055 /* Compare constant expression EXP with a substring P of a constant descriptor.
2056 If they match, return a pointer to the end of the substring matched.
2057 If they do not match, return 0.
2059 Since descriptors are written in polish prefix notation,
2060 this function can be used recursively to test one operand of EXP
2061 against a subdescriptor, and if it succeeds it returns the
2062 address of the subdescriptor for the next operand. */
2065 compare_constant_1 (exp, p)
2069 register char *strp;
2071 register enum tree_code code = TREE_CODE (exp);
2073 if (code != (enum tree_code) *p++)
2076 if (code == INTEGER_CST)
2078 /* Integer constants are the same only if the same width of type. */
2079 if (*p++ != TYPE_PRECISION (TREE_TYPE (exp)))
2081 strp = (char *) &TREE_INT_CST_LOW (exp);
2082 len = 2 * sizeof TREE_INT_CST_LOW (exp);
2084 else if (code == REAL_CST)
2086 /* Real constants are the same only if the same width of type. */
2087 if (*p++ != TYPE_PRECISION (TREE_TYPE (exp)))
2089 strp = (char *) &TREE_REAL_CST (exp);
2090 len = sizeof TREE_REAL_CST (exp);
2092 else if (code == STRING_CST)
2094 if (flag_writable_strings)
2096 strp = TREE_STRING_POINTER (exp);
2097 len = TREE_STRING_LENGTH (exp);
2098 if (bcmp (&TREE_STRING_LENGTH (exp), p,
2099 sizeof TREE_STRING_LENGTH (exp)))
2101 p += sizeof TREE_STRING_LENGTH (exp);
2103 else if (code == COMPLEX_CST)
2105 p = compare_constant_1 (TREE_REALPART (exp), p);
2106 if (p == 0) return 0;
2107 p = compare_constant_1 (TREE_IMAGPART (exp), p);
2110 else if (code == CONSTRUCTOR)
2113 int length = list_length (CONSTRUCTOR_ELTS (exp));
2116 if (bcmp (&length, p, sizeof length))
2120 /* For record constructors, insist that the types match.
2121 For arrays, just verify both constructors are for arrays. */
2122 if (TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE)
2123 type = TREE_TYPE (exp);
2126 if (bcmp (&type, p, sizeof type))
2130 /* For arrays, insist that the size in bytes match. */
2131 if (TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE)
2133 int size = int_size_in_bytes (TREE_TYPE (exp));
2134 if (bcmp (&size, p, sizeof size))
2139 for (link = CONSTRUCTOR_ELTS (exp); link; link = TREE_CHAIN (link))
2141 if (TREE_VALUE (link))
2143 if ((p = compare_constant_1 (TREE_VALUE (link), p)) == 0)
2150 if (bcmp (&zero, p, sizeof zero))
2158 else if (code == ADDR_EXPR)
2160 struct addr_const value;
2161 decode_addr_const (exp, &value);
2162 strp = (char *) &value.offset;
2163 len = sizeof value.offset;
2164 /* Compare the offset. */
2166 if (*p++ != *strp++)
2168 /* Compare symbol name. */
2169 strp = XSTR (value.base, 0);
2170 len = strlen (strp) + 1;
2172 else if (code == PLUS_EXPR || code == MINUS_EXPR)
2174 p = compare_constant_1 (TREE_OPERAND (exp, 0), p);
2175 if (p == 0) return 0;
2176 p = compare_constant_1 (TREE_OPERAND (exp, 1), p);
2179 else if (code == NOP_EXPR || code == CONVERT_EXPR)
2181 p = compare_constant_1 (TREE_OPERAND (exp, 0), p);
2185 /* Compare constant contents. */
2187 if (*p++ != *strp++)
2193 /* Construct a constant descriptor for the expression EXP.
2194 It is up to the caller to enter the descriptor in the hash table. */
2196 static struct constant_descriptor *
2197 record_constant (exp)
2200 struct constant_descriptor *next = 0;
2203 /* Make a struct constant_descriptor. The first two pointers will
2204 be filled in later. Here we just leave space for them. */
2206 obstack_grow (&permanent_obstack, (char *) &next, sizeof next);
2207 obstack_grow (&permanent_obstack, (char *) &label, sizeof label);
2208 record_constant_1 (exp);
2209 return (struct constant_descriptor *) obstack_finish (&permanent_obstack);
2212 /* Add a description of constant expression EXP
2213 to the object growing in `permanent_obstack'.
2214 No need to return its address; the caller will get that
2215 from the obstack when the object is complete. */
2218 record_constant_1 (exp)
2221 register char *strp;
2223 register enum tree_code code = TREE_CODE (exp);
2225 obstack_1grow (&permanent_obstack, (unsigned int) code);
2227 if (code == INTEGER_CST)
2229 obstack_1grow (&permanent_obstack, TYPE_PRECISION (TREE_TYPE (exp)));
2230 strp = (char *) &TREE_INT_CST_LOW (exp);
2231 len = 2 * sizeof TREE_INT_CST_LOW (exp);
2233 else if (code == REAL_CST)
2235 obstack_1grow (&permanent_obstack, TYPE_PRECISION (TREE_TYPE (exp)));
2236 strp = (char *) &TREE_REAL_CST (exp);
2237 len = sizeof TREE_REAL_CST (exp);
2239 else if (code == STRING_CST)
2241 if (flag_writable_strings)
2243 strp = TREE_STRING_POINTER (exp);
2244 len = TREE_STRING_LENGTH (exp);
2245 obstack_grow (&permanent_obstack, (char *) &TREE_STRING_LENGTH (exp),
2246 sizeof TREE_STRING_LENGTH (exp));
2248 else if (code == COMPLEX_CST)
2250 record_constant_1 (TREE_REALPART (exp));
2251 record_constant_1 (TREE_IMAGPART (exp));
2254 else if (code == CONSTRUCTOR)
2257 int length = list_length (CONSTRUCTOR_ELTS (exp));
2260 obstack_grow (&permanent_obstack, (char *) &length, sizeof length);
2262 /* For record constructors, insist that the types match.
2263 For arrays, just verify both constructors are for arrays. */
2264 if (TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE)
2265 type = TREE_TYPE (exp);
2268 obstack_grow (&permanent_obstack, (char *) &type, sizeof type);
2270 /* For arrays, insist that the size in bytes match. */
2271 if (TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE)
2273 int size = int_size_in_bytes (TREE_TYPE (exp));
2274 obstack_grow (&permanent_obstack, (char *) &size, sizeof size);
2277 for (link = CONSTRUCTOR_ELTS (exp); link; link = TREE_CHAIN (link))
2279 if (TREE_VALUE (link))
2280 record_constant_1 (TREE_VALUE (link));
2285 obstack_grow (&permanent_obstack, (char *) &zero, sizeof zero);
2291 else if (code == ADDR_EXPR)
2293 struct addr_const value;
2294 decode_addr_const (exp, &value);
2295 /* Record the offset. */
2296 obstack_grow (&permanent_obstack,
2297 (char *) &value.offset, sizeof value.offset);
2298 /* Record the symbol name. */
2299 obstack_grow (&permanent_obstack, XSTR (value.base, 0),
2300 strlen (XSTR (value.base, 0)) + 1);
2303 else if (code == PLUS_EXPR || code == MINUS_EXPR)
2305 record_constant_1 (TREE_OPERAND (exp, 0));
2306 record_constant_1 (TREE_OPERAND (exp, 1));
2309 else if (code == NOP_EXPR || code == CONVERT_EXPR)
2311 record_constant_1 (TREE_OPERAND (exp, 0));
2315 /* Record constant contents. */
2316 obstack_grow (&permanent_obstack, strp, len);
2319 /* Record a list of constant expressions that were passed to
2320 output_constant_def but that could not be output right away. */
2322 struct deferred_constant
2324 struct deferred_constant *next;
2330 static struct deferred_constant *deferred_constants;
2332 /* Nonzero means defer output of addressed subconstants
2333 (i.e., those for which output_constant_def is called.) */
2334 static int defer_addressed_constants_flag;
2336 /* Start deferring output of subconstants. */
2339 defer_addressed_constants ()
2341 defer_addressed_constants_flag++;
2344 /* Stop deferring output of subconstants,
2345 and output now all those that have been deferred. */
2348 output_deferred_addressed_constants ()
2350 struct deferred_constant *p, *next;
2352 defer_addressed_constants_flag--;
2354 if (defer_addressed_constants_flag > 0)
2357 for (p = deferred_constants; p; p = next)
2359 output_constant_def_contents (p->exp, p->reloc, p->labelno);
2364 deferred_constants = 0;
2367 /* Return an rtx representing a reference to constant data in memory
2368 for the constant expression EXP.
2370 If assembler code for such a constant has already been output,
2371 return an rtx to refer to it.
2372 Otherwise, output such a constant in memory (or defer it for later)
2373 and generate an rtx for it.
2375 The TREE_CST_RTL of EXP is set up to point to that rtx.
2376 The const_hash_table records which constants already have label strings. */
2379 output_constant_def (exp)
2383 register struct constant_descriptor *desc;
2389 if (TREE_CODE (exp) == INTEGER_CST)
2390 abort (); /* No TREE_CST_RTL slot in these. */
2392 if (TREE_CST_RTL (exp))
2393 return TREE_CST_RTL (exp);
2395 /* Make sure any other constants whose addresses appear in EXP
2396 are assigned label numbers. */
2398 reloc = output_addressed_constants (exp);
2400 /* Compute hash code of EXP. Search the descriptors for that hash code
2401 to see if any of them describes EXP. If yes, the descriptor records
2402 the label number already assigned. */
2404 if (!output_bytecode)
2406 hash = const_hash (exp) % MAX_HASH_TABLE;
2408 for (desc = const_hash_table[hash]; desc; desc = desc->next)
2409 if (compare_constant (exp, desc))
2411 found = desc->label;
2417 /* No constant equal to EXP is known to have been output.
2418 Make a constant descriptor to enter EXP in the hash table.
2419 Assign the label number and record it in the descriptor for
2420 future calls to this function to find. */
2422 /* Create a string containing the label name, in LABEL. */
2423 ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno);
2425 desc = record_constant (exp);
2426 desc->next = const_hash_table[hash];
2428 = (char *) obstack_copy0 (&permanent_obstack, label, strlen (label));
2429 const_hash_table[hash] = desc;
2433 /* Create a string containing the label name, in LABEL. */
2434 ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno);
2438 /* We have a symbol name; construct the SYMBOL_REF and the MEM. */
2440 push_obstacks_nochange ();
2441 if (TREE_PERMANENT (exp))
2442 end_temporary_allocation ();
2444 if (!output_bytecode)
2446 def = gen_rtx (SYMBOL_REF, Pmode, desc->label);
2449 = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (exp)), def);
2450 RTX_UNCHANGING_P (TREE_CST_RTL (exp)) = 1;
2451 if (TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE
2452 || TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE)
2453 MEM_IN_STRUCT_P (TREE_CST_RTL (exp)) = 1;
2457 /* Optionally set flags or add text to the name to record information
2458 such as that it is a function name. If the name is changed, the macro
2459 ASM_OUTPUT_LABELREF will have to know how to strip this information.
2460 And if it finds a * at the beginning after doing so, it must handle
2462 #ifdef ENCODE_SECTION_INFO
2463 ENCODE_SECTION_INFO (exp);
2466 /* If this is the first time we've seen this particular constant,
2467 output it (or defer its output for later). */
2470 if (defer_addressed_constants_flag)
2472 struct deferred_constant *p;
2473 p = (struct deferred_constant *) xmalloc (sizeof (struct deferred_constant));
2475 /* We really should copy trees in depth here,
2476 but since this case is the only one that should happen now,
2477 let's do it later. */
2478 if (TREE_CODE (exp) != STRING_CST)
2481 push_obstacks_nochange ();
2482 suspend_momentary ();
2483 p->exp = copy_node (exp);
2484 TREE_STRING_POINTER (p->exp)
2485 = obstack_copy0 (current_obstack, TREE_STRING_POINTER (p->exp),
2486 TREE_STRING_LENGTH (p->exp));
2489 p->labelno = const_labelno++;
2490 p->next = deferred_constants;
2491 deferred_constants = p;
2494 output_constant_def_contents (exp, reloc, const_labelno++);
2497 return TREE_CST_RTL (exp);
2500 /* Now output assembler code to define the label for EXP,
2501 and follow it with the data of EXP. */
2504 output_constant_def_contents (exp, reloc, labelno)
2511 /* First switch to text section, except for writable strings. */
2512 #ifdef SELECT_SECTION
2513 SELECT_SECTION (exp, reloc);
2515 if (((TREE_CODE (exp) == STRING_CST) && flag_writable_strings)
2516 || (flag_pic && reloc))
2519 readonly_data_section ();
2522 /* Align the location counter as required by EXP's data type. */
2523 align = TYPE_ALIGN (TREE_TYPE (exp));
2524 #ifdef CONSTANT_ALIGNMENT
2525 align = CONSTANT_ALIGNMENT (exp, align);
2528 if (align > BITS_PER_UNIT)
2530 if (!output_bytecode)
2532 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
2536 BC_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
2540 /* Output the label itself. */
2541 ASM_OUTPUT_INTERNAL_LABEL (asm_out_file, "LC", labelno);
2543 /* Output the value of EXP. */
2544 output_constant (exp,
2545 (TREE_CODE (exp) == STRING_CST
2546 ? TREE_STRING_LENGTH (exp)
2547 : int_size_in_bytes (TREE_TYPE (exp))));
2551 /* Similar hash facility for making memory-constants
2552 from constant rtl-expressions. It is used on RISC machines
2553 where immediate integer arguments and constant addresses are restricted
2554 so that such constants must be stored in memory.
2556 This pool of constants is reinitialized for each function
2557 so each function gets its own constants-pool that comes right before it.
2559 All structures allocated here are discarded when functions are saved for
2560 inlining, so they do not need to be allocated permanently. */
2562 #define MAX_RTX_HASH_TABLE 61
2563 static struct constant_descriptor **const_rtx_hash_table;
2565 /* Structure to represent sufficient information about a constant so that
2566 it can be output when the constant pool is output, so that function
2567 integration can be done, and to simplify handling on machines that reference
2568 constant pool as base+displacement. */
2570 struct pool_constant
2572 struct constant_descriptor *desc;
2573 struct pool_constant *next;
2574 enum machine_mode mode;
2581 /* Pointers to first and last constant in pool. */
2583 static struct pool_constant *first_pool, *last_pool;
2585 /* Current offset in constant pool (does not include any machine-specific
2588 static int pool_offset;
2590 /* Structure used to maintain hash table mapping symbols used to their
2591 corresponding constants. */
2596 struct pool_constant *pool;
2597 struct pool_sym *next;
2600 static struct pool_sym **const_rtx_sym_hash_table;
2602 /* Hash code for a SYMBOL_REF with CONSTANT_POOL_ADDRESS_P true.
2603 The argument is XSTR (... , 0) */
2605 #define SYMHASH(LABEL) \
2606 ((((HOST_WIDE_INT) (LABEL)) & ((1 << HASHBITS) - 1)) % MAX_RTX_HASH_TABLE)
2608 /* Initialize constant pool hashing for next function. */
2611 init_const_rtx_hash_table ()
2613 const_rtx_hash_table
2614 = ((struct constant_descriptor **)
2615 oballoc (MAX_RTX_HASH_TABLE * sizeof (struct constant_descriptor *)));
2616 const_rtx_sym_hash_table
2617 = ((struct pool_sym **)
2618 oballoc (MAX_RTX_HASH_TABLE * sizeof (struct pool_sym *)));
2619 bzero (const_rtx_hash_table,
2620 MAX_RTX_HASH_TABLE * sizeof (struct constant_descriptor *));
2621 bzero (const_rtx_sym_hash_table,
2622 MAX_RTX_HASH_TABLE * sizeof (struct pool_sym *));
2624 first_pool = last_pool = 0;
2628 /* Save and restore it for a nested function. */
2631 save_varasm_status (p)
2634 p->const_rtx_hash_table = const_rtx_hash_table;
2635 p->const_rtx_sym_hash_table = const_rtx_sym_hash_table;
2636 p->first_pool = first_pool;
2637 p->last_pool = last_pool;
2638 p->pool_offset = pool_offset;
2642 restore_varasm_status (p)
2645 const_rtx_hash_table = p->const_rtx_hash_table;
2646 const_rtx_sym_hash_table = p->const_rtx_sym_hash_table;
2647 first_pool = p->first_pool;
2648 last_pool = p->last_pool;
2649 pool_offset = p->pool_offset;
2652 enum kind { RTX_DOUBLE, RTX_INT };
2656 #ifdef ONLY_INT_FIELDS
2657 unsigned int kind : 16;
2658 unsigned int mode : 16;
2660 enum kind kind : 16;
2661 enum machine_mode mode : 16;
2664 union real_extract du;
2665 struct addr_const addr;
2669 /* Express an rtx for a constant integer (perhaps symbolic)
2670 as the sum of a symbol or label plus an explicit integer.
2671 They are stored into VALUE. */
2674 decode_rtx_const (mode, x, value)
2675 enum machine_mode mode;
2677 struct rtx_const *value;
2679 /* Clear the whole structure, including any gaps. */
2682 int *p = (int *) value;
2683 int *end = (int *) (value + 1);
2688 value->kind = RTX_INT; /* Most usual kind. */
2691 switch (GET_CODE (x))
2694 value->kind = RTX_DOUBLE;
2695 value->mode = GET_MODE (x);
2696 bcopy (&CONST_DOUBLE_LOW (x), &value->un.du, sizeof value->un.du);
2700 value->un.addr.offset = INTVAL (x);
2706 value->un.addr.base = x;
2711 if (GET_CODE (x) == PLUS)
2713 value->un.addr.base = XEXP (x, 0);
2714 if (GET_CODE (XEXP (x, 1)) != CONST_INT)
2716 value->un.addr.offset = INTVAL (XEXP (x, 1));
2718 else if (GET_CODE (x) == MINUS)
2720 value->un.addr.base = XEXP (x, 0);
2721 if (GET_CODE (XEXP (x, 1)) != CONST_INT)
2723 value->un.addr.offset = - INTVAL (XEXP (x, 1));
2733 if (value->kind == RTX_INT && value->un.addr.base != 0)
2734 switch (GET_CODE (value->un.addr.base))
2738 /* Use the string's address, not the SYMBOL_REF's address,
2739 for the sake of addresses of library routines.
2740 For a LABEL_REF, compare labels. */
2741 value->un.addr.base = XEXP (value->un.addr.base, 0);
2745 /* Given a MINUS expression, simplify it if both sides
2746 include the same symbol. */
2749 simplify_subtraction (x)
2752 struct rtx_const val0, val1;
2754 decode_rtx_const (GET_MODE (x), XEXP (x, 0), &val0);
2755 decode_rtx_const (GET_MODE (x), XEXP (x, 1), &val1);
2757 if (val0.un.addr.base == val1.un.addr.base)
2758 return GEN_INT (val0.un.addr.offset - val1.un.addr.offset);
2762 /* Compute a hash code for a constant RTL expression. */
2765 const_hash_rtx (mode, x)
2766 enum machine_mode mode;
2771 struct rtx_const value;
2772 decode_rtx_const (mode, x, &value);
2774 /* Compute hashing function */
2776 for (i = 0; i < sizeof value / sizeof (int); i++)
2777 hi += ((int *) &value)[i];
2779 hi &= (1 << HASHBITS) - 1;
2780 hi %= MAX_RTX_HASH_TABLE;
2784 /* Compare a constant rtl object X with a constant-descriptor DESC.
2785 Return 1 if DESC describes a constant with the same value as X. */
2788 compare_constant_rtx (mode, x, desc)
2789 enum machine_mode mode;
2791 struct constant_descriptor *desc;
2793 register int *p = (int *) desc->contents;
2796 struct rtx_const value;
2798 decode_rtx_const (mode, x, &value);
2799 strp = (int *) &value;
2800 len = sizeof value / sizeof (int);
2802 /* Compare constant contents. */
2804 if (*p++ != *strp++)
2810 /* Construct a constant descriptor for the rtl-expression X.
2811 It is up to the caller to enter the descriptor in the hash table. */
2813 static struct constant_descriptor *
2814 record_constant_rtx (mode, x)
2815 enum machine_mode mode;
2818 struct constant_descriptor *ptr;
2820 struct rtx_const value;
2822 decode_rtx_const (mode, x, &value);
2824 obstack_grow (current_obstack, &ptr, sizeof ptr);
2825 obstack_grow (current_obstack, &label, sizeof label);
2827 /* Record constant contents. */
2828 obstack_grow (current_obstack, &value, sizeof value);
2830 return (struct constant_descriptor *) obstack_finish (current_obstack);
2833 /* Given a constant rtx X, make (or find) a memory constant for its value
2834 and return a MEM rtx to refer to it in memory. */
2837 force_const_mem (mode, x)
2838 enum machine_mode mode;
2842 register struct constant_descriptor *desc;
2847 /* If we want this CONST_DOUBLE in the same mode as it is in memory
2848 (this will always be true for floating CONST_DOUBLEs that have been
2849 placed in memory, but not for VOIDmode (integer) CONST_DOUBLEs),
2850 use the previous copy. Otherwise, make a new one. Note that in
2851 the unlikely event that this same CONST_DOUBLE is used in two different
2852 modes in an alternating fashion, we will allocate a lot of different
2853 memory locations, but this should be extremely rare. */
2855 /* Don't use CONST_DOUBLE_MEM in a nested function.
2856 Nested functions have their own constant pools,
2857 so they can't share the same values in CONST_DOUBLE_MEM
2858 with the containing function. */
2859 if (outer_function_chain == 0)
2860 if (GET_CODE (x) == CONST_DOUBLE
2861 && GET_CODE (CONST_DOUBLE_MEM (x)) == MEM
2862 && GET_MODE (CONST_DOUBLE_MEM (x)) == mode)
2863 return CONST_DOUBLE_MEM (x);
2865 /* Compute hash code of X. Search the descriptors for that hash code
2866 to see if any of them describes X. If yes, the descriptor records
2867 the label number already assigned. */
2869 hash = const_hash_rtx (mode, x);
2871 for (desc = const_rtx_hash_table[hash]; desc; desc = desc->next)
2872 if (compare_constant_rtx (mode, x, desc))
2874 found = desc->label;
2880 register struct pool_constant *pool;
2881 register struct pool_sym *sym;
2884 /* No constant equal to X is known to have been output.
2885 Make a constant descriptor to enter X in the hash table.
2886 Assign the label number and record it in the descriptor for
2887 future calls to this function to find. */
2889 desc = record_constant_rtx (mode, x);
2890 desc->next = const_rtx_hash_table[hash];
2891 const_rtx_hash_table[hash] = desc;
2893 /* Align the location counter as required by EXP's data type. */
2894 align = (mode == VOIDmode) ? UNITS_PER_WORD : GET_MODE_SIZE (mode);
2895 if (align > BIGGEST_ALIGNMENT / BITS_PER_UNIT)
2896 align = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
2898 pool_offset += align - 1;
2899 pool_offset &= ~ (align - 1);
2901 /* Allocate a pool constant descriptor, fill it in, and chain it in. */
2903 pool = (struct pool_constant *) oballoc (sizeof (struct pool_constant));
2907 pool->labelno = const_labelno;
2908 pool->align = align;
2909 pool->offset = pool_offset;
2915 last_pool->next = pool;
2918 pool_offset += GET_MODE_SIZE (mode);
2920 /* Create a string containing the label name, in LABEL. */
2921 ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno);
2926 = (char *) obstack_copy0 (saveable_obstack, label, strlen (label));
2928 /* Add label to symbol hash table. */
2929 hash = SYMHASH (found);
2930 sym = (struct pool_sym *) oballoc (sizeof (struct pool_sym));
2933 sym->next = const_rtx_sym_hash_table[hash];
2934 const_rtx_sym_hash_table[hash] = sym;
2937 /* We have a symbol name; construct the SYMBOL_REF and the MEM. */
2939 def = gen_rtx (MEM, mode, gen_rtx (SYMBOL_REF, Pmode, found));
2941 RTX_UNCHANGING_P (def) = 1;
2942 /* Mark the symbol_ref as belonging to this constants pool. */
2943 CONSTANT_POOL_ADDRESS_P (XEXP (def, 0)) = 1;
2944 current_function_uses_const_pool = 1;
2946 if (outer_function_chain == 0)
2947 if (GET_CODE (x) == CONST_DOUBLE)
2949 if (CONST_DOUBLE_MEM (x) == cc0_rtx)
2951 CONST_DOUBLE_CHAIN (x) = const_double_chain;
2952 const_double_chain = x;
2954 CONST_DOUBLE_MEM (x) = def;
2960 /* Given a SYMBOL_REF with CONSTANT_POOL_ADDRESS_P true, return a pointer to
2961 the corresponding pool_constant structure. */
2963 static struct pool_constant *
2964 find_pool_constant (addr)
2967 struct pool_sym *sym;
2968 char *label = XSTR (addr, 0);
2970 for (sym = const_rtx_sym_hash_table[SYMHASH (label)]; sym; sym = sym->next)
2971 if (sym->label == label)
2977 /* Given a constant pool SYMBOL_REF, return the corresponding constant. */
2980 get_pool_constant (addr)
2983 return (find_pool_constant (addr))->constant;
2986 /* Similar, return the mode. */
2989 get_pool_mode (addr)
2992 return (find_pool_constant (addr))->mode;
2995 /* Similar, return the offset in the constant pool. */
2998 get_pool_offset (addr)
3001 return (find_pool_constant (addr))->offset;
3004 /* Return the size of the constant pool. */
3012 /* Write all the constants in the constant pool. */
3015 output_constant_pool (fnname, fndecl)
3019 struct pool_constant *pool;
3021 union real_extract u;
3023 #ifdef ASM_OUTPUT_POOL_PROLOGUE
3024 ASM_OUTPUT_POOL_PROLOGUE (asm_out_file, fnname, fndecl, pool_offset);
3027 for (pool = first_pool; pool; pool = pool->next)
3031 /* See if X is a LABEL_REF (or a CONST referring to a LABEL_REF)
3032 whose CODE_LABEL has been deleted. This can occur if a jump table
3033 is eliminated by optimization. If so, write a constant of zero
3034 instead. Note that this can also happen by turning the
3035 CODE_LABEL into a NOTE. */
3036 if (((GET_CODE (x) == LABEL_REF
3037 && (INSN_DELETED_P (XEXP (x, 0))
3038 || GET_CODE (XEXP (x, 0)) == NOTE)))
3039 || (GET_CODE (x) == CONST && GET_CODE (XEXP (x, 0)) == PLUS
3040 && GET_CODE (XEXP (XEXP (x, 0), 0)) == LABEL_REF
3041 && (INSN_DELETED_P (XEXP (XEXP (XEXP (x, 0), 0), 0))
3042 || GET_CODE (XEXP (XEXP (XEXP (x, 0), 0), 0)) == NOTE)))
3045 /* First switch to correct section. */
3046 #ifdef SELECT_RTX_SECTION
3047 SELECT_RTX_SECTION (pool->mode, x);
3049 readonly_data_section ();
3052 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3053 ASM_OUTPUT_SPECIAL_POOL_ENTRY (asm_out_file, x, pool->mode,
3054 pool->align, pool->labelno, done);
3057 if (pool->align > 1)
3058 ASM_OUTPUT_ALIGN (asm_out_file, exact_log2 (pool->align));
3060 /* Output the label. */
3061 ASM_OUTPUT_INTERNAL_LABEL (asm_out_file, "LC", pool->labelno);
3063 /* Output the value of the constant itself. */
3064 switch (GET_MODE_CLASS (pool->mode))
3067 if (GET_CODE (x) != CONST_DOUBLE)
3070 bcopy (&CONST_DOUBLE_LOW (x), &u, sizeof u);
3071 assemble_real (u.d, pool->mode);
3075 case MODE_PARTIAL_INT:
3076 assemble_integer (x, GET_MODE_SIZE (pool->mode), 1);
3086 /* Done with this pool. */
3087 first_pool = last_pool = 0;
3090 /* Find all the constants whose addresses are referenced inside of EXP,
3091 and make sure assembler code with a label has been output for each one.
3092 Indicate whether an ADDR_EXPR has been encountered. */
3095 output_addressed_constants (exp)
3100 switch (TREE_CODE (exp))
3104 register tree constant = TREE_OPERAND (exp, 0);
3106 while (TREE_CODE (constant) == COMPONENT_REF)
3108 constant = TREE_OPERAND (constant, 0);
3111 if (TREE_CODE_CLASS (TREE_CODE (constant)) == 'c'
3112 || TREE_CODE (constant) == CONSTRUCTOR)
3113 /* No need to do anything here
3114 for addresses of variables or functions. */
3115 output_constant_def (constant);
3122 reloc = output_addressed_constants (TREE_OPERAND (exp, 0));
3123 reloc |= output_addressed_constants (TREE_OPERAND (exp, 1));
3128 case NON_LVALUE_EXPR:
3129 reloc = output_addressed_constants (TREE_OPERAND (exp, 0));
3135 for (link = CONSTRUCTOR_ELTS (exp); link; link = TREE_CHAIN (link))
3136 if (TREE_VALUE (link) != 0)
3137 reloc |= output_addressed_constants (TREE_VALUE (link));
3148 /* Output assembler for byte constant */
3150 output_byte_asm (byte)
3153 if (output_bytecode)
3154 bc_emit_const ((char *) &byte, sizeof (char));
3155 #ifdef ASM_OUTPUT_BYTE
3158 ASM_OUTPUT_BYTE (asm_out_file, byte);
3163 /* Output assembler code for constant EXP to FILE, with no label.
3164 This includes the pseudo-op such as ".int" or ".byte", and a newline.
3165 Assumes output_addressed_constants has been done on EXP already.
3167 Generate exactly SIZE bytes of assembler data, padding at the end
3168 with zeros if necessary. SIZE must always be specified.
3170 SIZE is important for structure constructors,
3171 since trailing members may have been omitted from the constructor.
3172 It is also important for initialization of arrays from string constants
3173 since the full length of the string constant might not be wanted.
3174 It is also needed for initialization of unions, where the initializer's
3175 type is just one member, and that may not be as long as the union.
3177 There a case in which we would fail to output exactly SIZE bytes:
3178 for a structure constructor that wants to produce more than SIZE bytes.
3179 But such constructors will never be generated for any possible input. */
3182 output_constant (exp, size)
3186 register enum tree_code code = TREE_CODE (TREE_TYPE (exp));
3192 /* Allow a constructor with no elements for any data type.
3193 This means to fill the space with zeros. */
3194 if (TREE_CODE (exp) == CONSTRUCTOR && CONSTRUCTOR_ELTS (exp) == 0)
3196 if (output_bytecode)
3197 bc_emit_const_skip (size);
3199 assemble_zeros (size);
3203 /* Eliminate the NOP_EXPR that makes a cast not be an lvalue.
3204 That way we get the constant (we hope) inside it. */
3205 if (TREE_CODE (exp) == NOP_EXPR
3206 && TREE_TYPE (exp) == TREE_TYPE (TREE_OPERAND (exp, 0)))
3207 exp = TREE_OPERAND (exp, 0);
3216 case REFERENCE_TYPE:
3217 /* ??? What about (int)((float)(int)&foo + 4) */
3218 while (TREE_CODE (exp) == NOP_EXPR || TREE_CODE (exp) == CONVERT_EXPR
3219 || TREE_CODE (exp) == NON_LVALUE_EXPR)
3220 exp = TREE_OPERAND (exp, 0);
3222 if (! assemble_integer (expand_expr (exp, NULL_RTX, VOIDmode,
3223 EXPAND_INITIALIZER),
3225 error ("initializer for integer value is too complicated");
3230 if (TREE_CODE (exp) != REAL_CST)
3231 error ("initializer for floating value is not a floating constant");
3233 assemble_real (TREE_REAL_CST (exp),
3234 mode_for_size (size * BITS_PER_UNIT, MODE_FLOAT, 0));
3239 output_constant (TREE_REALPART (exp), size / 2);
3240 output_constant (TREE_IMAGPART (exp), size / 2);
3241 size -= (size / 2) * 2;
3245 if (TREE_CODE (exp) == CONSTRUCTOR)
3247 output_constructor (exp, size);
3250 else if (TREE_CODE (exp) == STRING_CST)
3254 if (size > TREE_STRING_LENGTH (exp))
3256 excess = size - TREE_STRING_LENGTH (exp);
3257 size = TREE_STRING_LENGTH (exp);
3260 assemble_string (TREE_STRING_POINTER (exp), size);
3269 if (TREE_CODE (exp) == CONSTRUCTOR)
3270 output_constructor (exp, size);
3277 assemble_zeros (size);
3281 /* Bytecode specific code to output assembler for integer. */
3283 bc_assemble_integer (exp, size)
3291 /* FIXME: is this fold() business going to be as good as the
3292 expand_expr() using EXPAND_SUM above in the RTL case? I
3294 FIXME: Copied as is from BC-GCC1; may need work. Don't hate. -bson */
3298 while (TREE_CODE (exp) == NOP_EXPR || TREE_CODE (exp) == CONVERT_EXPR)
3299 exp = TREE_OPERAND (exp, 0);
3300 if (TREE_CODE (exp) == INTEGER_CST)
3305 else if (TREE_CODE (exp) == PLUS_EXPR)
3307 const_part = TREE_OPERAND (exp, 0);
3308 while (TREE_CODE (const_part) == NOP_EXPR
3309 || TREE_CODE (const_part) == CONVERT_EXPR)
3310 const_part = TREE_OPERAND (const_part, 0);
3311 addr_part = TREE_OPERAND (exp, 1);
3312 while (TREE_CODE (addr_part) == NOP_EXPR
3313 || TREE_CODE (addr_part) == CONVERT_EXPR)
3314 addr_part = TREE_OPERAND (addr_part, 0);
3315 if (TREE_CODE (const_part) != INTEGER_CST)
3316 tmp = const_part, const_part = addr_part, addr_part = tmp;
3317 if (TREE_CODE (const_part) != INTEGER_CST
3318 || TREE_CODE (addr_part) != ADDR_EXPR)
3319 abort (); /* FIXME: we really haven't considered
3320 all the possible cases here. */
3322 else if (TREE_CODE (exp) == ADDR_EXPR)
3324 const_part = integer_zero_node;
3328 abort (); /* FIXME: ditto previous. */
3334 char c = TREE_INT_CST_LOW (const_part);
3340 short s = TREE_INT_CST_LOW (const_part);
3341 bc_emit ((char *) &s, 2);
3346 int i = TREE_INT_CST_LOW (const_part);
3347 bc_emit ((char *) &i, 4);
3352 #if WORDS_BIG_ENDIAN
3353 int i = TREE_INT_CST_HIGH (const_part);
3354 bc_emit ((char *) &i, 4);
3355 i = TREE_INT_CST_LOW (const_part);
3356 bc_emit ((char *) &i, 4);
3358 int i = TREE_INT_CST_LOW (const_part);
3359 bc_emit ((char *) &i, 4);
3360 i = TREE_INT_CST_HIGH (const_part);
3361 bc_emit ((char *) &i, 4);
3368 && TREE_CODE (TREE_OPERAND (addr_part, 0)) == VAR_DECL)
3369 bc_emit_labelref (DECL_ASSEMBLER_NAME (TREE_OPERAND (addr_part, 0)),
3370 TREE_INT_CST_LOW (const_part));
3372 abort (); /* FIXME: there may be more cases. */
3375 /* Subroutine of output_constant, used for CONSTRUCTORs
3376 (aggregate constants).
3377 Generate at least SIZE bytes, padding if necessary. */
3380 output_constructor (exp, size)
3384 register tree link, field = 0;
3385 /* Number of bytes output or skipped so far.
3386 In other words, current position within the constructor. */
3387 int total_bytes = 0;
3388 /* Non-zero means BYTE contains part of a byte, to be output. */
3389 int byte_buffer_in_use = 0;
3392 if (HOST_BITS_PER_WIDE_INT < BITS_PER_UNIT)
3395 if (TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE)
3396 field = TYPE_FIELDS (TREE_TYPE (exp));
3398 /* As LINK goes through the elements of the constant,
3399 FIELD goes through the structure fields, if the constant is a structure.
3400 if the constant is a union, then we override this,
3401 by getting the field from the TREE_LIST element.
3402 But the constant could also be an array. Then FIELD is zero. */
3403 for (link = CONSTRUCTOR_ELTS (exp);
3405 link = TREE_CHAIN (link),
3406 field = field ? TREE_CHAIN (field) : 0)
3408 tree val = TREE_VALUE (link);
3411 /* the element in a union constructor specifies the proper field. */
3413 if (TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE
3414 || TREE_CODE (TREE_TYPE (exp)) == UNION_TYPE)
3416 /* if available, use the type given by link */
3417 if (TREE_PURPOSE (link) != 0)
3418 field = TREE_PURPOSE (link);
3421 if (TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE)
3422 index = TREE_PURPOSE (link);
3424 /* Eliminate the marker that makes a cast not be an lvalue. */
3428 if (field == 0 || !DECL_BIT_FIELD (field))
3430 /* An element that is not a bit-field. */
3432 register int fieldsize;
3433 /* Since this structure is static,
3434 we know the positions are constant. */
3435 int bitpos = (field ? (TREE_INT_CST_LOW (DECL_FIELD_BITPOS (field))
3439 bitpos = (TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (val)))
3441 * TREE_INT_CST_LOW (index));
3443 /* Output any buffered-up bit-fields preceding this element. */
3444 if (byte_buffer_in_use)
3446 ASM_OUTPUT_BYTE (asm_out_file, byte);
3448 byte_buffer_in_use = 0;
3451 /* Advance to offset of this element.
3452 Note no alignment needed in an array, since that is guaranteed
3453 if each element has the proper size. */
3454 if ((field != 0 || index != 0) && bitpos != total_bytes)
3456 if (!output_bytecode)
3457 assemble_zeros (bitpos - total_bytes);
3459 bc_emit_const_skip (bitpos - total_bytes);
3460 total_bytes = bitpos;
3463 /* Determine size this element should occupy. */
3466 if (TREE_CODE (DECL_SIZE (field)) != INTEGER_CST)
3468 if (TREE_INT_CST_LOW (DECL_SIZE (field)) > 100000)
3470 /* This avoids overflow trouble. */
3471 tree size_tree = size_binop (CEIL_DIV_EXPR,
3473 size_int (BITS_PER_UNIT));
3474 fieldsize = TREE_INT_CST_LOW (size_tree);
3478 fieldsize = TREE_INT_CST_LOW (DECL_SIZE (field));
3479 fieldsize = (fieldsize + BITS_PER_UNIT - 1) / BITS_PER_UNIT;
3483 fieldsize = int_size_in_bytes (TREE_TYPE (TREE_TYPE (exp)));
3485 /* Output the element's initial value. */
3487 assemble_zeros (fieldsize);
3489 output_constant (val, fieldsize);
3491 /* Count its size. */
3492 total_bytes += fieldsize;
3494 else if (val != 0 && TREE_CODE (val) != INTEGER_CST)
3495 error ("invalid initial value for member `%s'",
3496 IDENTIFIER_POINTER (DECL_NAME (field)));
3499 /* Element that is a bit-field. */
3501 int next_offset = TREE_INT_CST_LOW (DECL_FIELD_BITPOS (field));
3503 = (next_offset + TREE_INT_CST_LOW (DECL_SIZE (field)));
3506 val = integer_zero_node;
3508 /* If this field does not start in this (or, next) byte,
3510 if (next_offset / BITS_PER_UNIT != total_bytes)
3512 /* Output remnant of any bit field in previous bytes. */
3513 if (byte_buffer_in_use)
3515 ASM_OUTPUT_BYTE (asm_out_file, byte);
3517 byte_buffer_in_use = 0;
3520 /* If still not at proper byte, advance to there. */
3521 if (next_offset / BITS_PER_UNIT != total_bytes)
3523 assemble_zeros (next_offset / BITS_PER_UNIT - total_bytes);
3524 total_bytes = next_offset / BITS_PER_UNIT;
3528 if (! byte_buffer_in_use)
3531 /* We must split the element into pieces that fall within
3532 separate bytes, and combine each byte with previous or
3533 following bit-fields. */
3535 /* next_offset is the offset n fbits from the beginning of
3536 the structure to the next bit of this element to be processed.
3537 end_offset is the offset of the first bit past the end of
3539 while (next_offset < end_offset)
3543 int next_byte = next_offset / BITS_PER_UNIT;
3544 int next_bit = next_offset % BITS_PER_UNIT;
3546 /* Advance from byte to byte
3547 within this element when necessary. */
3548 while (next_byte != total_bytes)
3550 ASM_OUTPUT_BYTE (asm_out_file, byte);
3555 /* Number of bits we can process at once
3556 (all part of the same byte). */
3557 this_time = MIN (end_offset - next_offset,
3558 BITS_PER_UNIT - next_bit);
3559 #if BYTES_BIG_ENDIAN
3560 /* On big-endian machine, take the most significant bits
3561 first (of the bits that are significant)
3562 and put them into bytes from the most significant end. */
3563 shift = end_offset - next_offset - this_time;
3564 /* Don't try to take a bunch of bits that cross
3565 the word boundary in the INTEGER_CST. */
3566 if (shift < HOST_BITS_PER_WIDE_INT
3567 && shift + this_time > HOST_BITS_PER_WIDE_INT)
3569 this_time -= (HOST_BITS_PER_WIDE_INT - shift);
3570 shift = HOST_BITS_PER_WIDE_INT;
3573 /* Now get the bits from the appropriate constant word. */
3574 if (shift < HOST_BITS_PER_WIDE_INT)
3576 value = TREE_INT_CST_LOW (val);
3578 else if (shift < 2 * HOST_BITS_PER_WIDE_INT)
3580 value = TREE_INT_CST_HIGH (val);
3581 shift -= HOST_BITS_PER_WIDE_INT;
3585 byte |= (((value >> shift)
3586 & (((HOST_WIDE_INT) 1 << this_time) - 1))
3587 << (BITS_PER_UNIT - this_time - next_bit));
3589 /* On little-endian machines,
3590 take first the least significant bits of the value
3591 and pack them starting at the least significant
3592 bits of the bytes. */
3593 shift = (next_offset
3594 - TREE_INT_CST_LOW (DECL_FIELD_BITPOS (field)));
3595 /* Don't try to take a bunch of bits that cross
3596 the word boundary in the INTEGER_CST. */
3597 if (shift < HOST_BITS_PER_WIDE_INT
3598 && shift + this_time > HOST_BITS_PER_WIDE_INT)
3600 this_time -= (HOST_BITS_PER_WIDE_INT - shift);
3601 shift = HOST_BITS_PER_WIDE_INT;
3604 /* Now get the bits from the appropriate constant word. */
3605 if (shift < HOST_BITS_PER_INT)
3606 value = TREE_INT_CST_LOW (val);
3607 else if (shift < 2 * HOST_BITS_PER_WIDE_INT)
3609 value = TREE_INT_CST_HIGH (val);
3610 shift -= HOST_BITS_PER_WIDE_INT;
3614 byte |= ((value >> shift)
3615 & (((HOST_WIDE_INT) 1 << this_time) - 1)) << next_bit;
3617 next_offset += this_time;
3618 byte_buffer_in_use = 1;
3622 if (byte_buffer_in_use)
3624 ASM_OUTPUT_BYTE (asm_out_file, byte);
3627 if (total_bytes < size)
3628 assemble_zeros (size - total_bytes);
3632 #ifdef HANDLE_SYSV_PRAGMA
3634 /* Support #pragma weak by default if WEAK_ASM_OP is defined. */
3635 #if defined (HANDLE_PRAGMA_WEAK) || (defined (WEAK_ASM_OP) && defined (SET_ASM_OP))
3637 /* Output asm to handle ``#pragma weak'' */
3639 handle_pragma_weak (what, asm_out_file, name, value)
3640 enum pragma_state what;
3644 if (what == ps_name || what == ps_value)
3646 fprintf (asm_out_file, "\t%s\t", WEAK_ASM_OP);
3648 if (output_bytecode)
3649 BC_OUTPUT_LABELREF (asm_out_file, name);
3651 ASM_OUTPUT_LABELREF (asm_out_file, name);
3653 fputc ('\n', asm_out_file);
3654 if (what == ps_value)
3656 fprintf (asm_out_file, "\t%s\t", SET_ASM_OP);
3657 if (output_bytecode)
3658 BC_OUTPUT_LABELREF (asm_out_file, name);
3660 ASM_OUTPUT_LABELREF (asm_out_file, name);
3662 fputc (',', asm_out_file);
3663 if (output_bytecode)
3664 BC_OUTPUT_LABELREF (asm_out_file, value);
3666 ASM_OUTPUT_LABELREF (asm_out_file, value);
3668 fputc ('\n', asm_out_file);
3671 else if (! (what == ps_done || what == ps_start))
3672 warning ("malformed `#pragma weak'");
3675 #endif /* HANDLE_PRAGMA_WEAK or (WEAK_ASM_OP and SET_ASM_OP) */
3677 #endif /* HANDLE_SYSV_PRAGMA */