m68kelf.h

gcc-2.95.3 Linux下最常用的C编译器

/* m68kelf support, derived from m68kv4.h */

/* Target definitions for GNU compiler for mc680x0 running System V.4
   Copyright (C) 1991, 1993 Free Software Foundation, Inc.

   Written by Ron Guilmette ([e-mail]) and Fred Fish ([e-mail]).

This file is part of GNU CC.

GNU CC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU CC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU CC; see the file COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

/* #notinclude "m68k/sgs.h"	/* The m68k/SVR4 assembler is SGS based */

/* These are necessary for -fpic/-fPIC to work correctly.  */
#ifndef MOTOROLA
#define MOTOROLA                /* Use MOTOROLA syntax.  */
#endif
#ifdef  USE_GAS  /* when present, forces jsbr instead of jsr.  */
#undef  USE_GAS
#endif

#ifndef SWBEG_ASM_OP
#define SWBEG_ASM_OP ".swbeg"
#endif

/* Here are four prefixes that are used by asm_fprintf to
   facilitate customization for alternate assembler syntaxes.
   Machines with no likelihood of an alternate syntax need not
   define these and need not use asm_fprintf.  */

/* The prefix for register names.  Note that REGISTER_NAMES
   is supposed to include this prefix. Also note that this is NOT an
   fprintf format string, it is a literal string */

#undef REGISTER_PREFIX
#define REGISTER_PREFIX "%"

/* The prefix for local (compiler generated) labels.
   These labels will not appear in the symbol table. */

#undef LOCAL_LABEL_PREFIX
#define LOCAL_LABEL_PREFIX "."

/* The prefix to add to user-visible assembler symbols. */

#undef USER_LABEL_PREFIX
#define USER_LABEL_PREFIX ""

/* The prefix for immediate operands.  */

#undef  IMMEDIATE_PREFIX
#define IMMEDIATE_PREFIX "#"

/* In the machine description we can't use %R, because it will not be seen
   by ASM_FPRINTF.  (Isn't that a design bug?).  */

#undef REGISTER_PREFIX_MD
#define REGISTER_PREFIX_MD "%%"

/* config/m68k.md has an explicit reference to the program counter,
   prefix this by the register prefix.  */

#define ASM_RETURN_CASE_JUMP 			\
  do {						\
    if (TARGET_5200)				\
      return "ext%.l %0\n\tjmp %%pc@(2,%0:l)";	\
    else					\
      return "jmp %%pc@(2,%0:w)";		\
  } while (0)

/* How to refer to registers in assembler output.
   This sequence is indexed by compiler's hard-register-number.
   Motorola format uses different register names than defined 
   in m68k.h.  */

#undef REGISTER_NAMES

#define REGISTER_NAMES \
{"%d0",   "%d1",   "%d2",   "%d3",   "%d4",   "%d5",   "%d6",   "%d7",	     \
 "%a0",   "%a1",   "%a2",   "%a3",   "%a4",   "%a5",   "%a6",   "%sp",	     \
 "%fp0",  "%fp1",  "%fp2",  "%fp3",  "%fp4",  "%fp5",  "%fp6",  "%fp7" }

/* This is how to output an assembler line that says to advance the
   location counter to a multiple of 2**LOG bytes.  */

#undef ASM_OUTPUT_ALIGN
#define ASM_OUTPUT_ALIGN(FILE,LOG)				\
  if ((LOG) > 0)						\
    fprintf ((FILE), "\t%s \t%u\n", ALIGN_ASM_OP, 1 << (LOG));	\
  else if ((LOG) > 31)						\
    abort ();

/* Use proper assembler syntax for these macros.  */
#undef ASM_OUTPUT_REG_PUSH
#define ASM_OUTPUT_REG_PUSH(FILE,REGNO)  \
  asm_fprintf (FILE, "\t%Omove.l %s,-(%Rsp)\n", reg_names[REGNO])

#undef ASM_OUTPUT_REG_POP
#define ASM_OUTPUT_REG_POP(FILE,REGNO)  \
  asm_fprintf (FILE, "\t%Omove.l (%Rsp)+,%s\n", reg_names[REGNO])

/*  Override the definition of NO_DOLLAR_IN_LABEL in svr4.h, for special
    g++ assembler names.  When this is defined, g++ uses embedded '.'
    characters and some m68k assemblers have problems with this.  The
    chances are much greater that any particular assembler will permit
    embedded '$' characters. */

#undef NO_DOLLAR_IN_LABEL

/* Define PCC_STATIC_STRUCT_RETURN if the convention on the target machine
   is to use the nonreentrant technique for returning structure and union
   values, as commonly implemented by the AT&T Portable C Compiler (PCC).
   When defined, the gcc option -fpcc-struct-return can be used to cause
   this form to be generated.  When undefined, the option does nothing.
   For m68k SVR4, the convention is to use a reentrant technique compatible
   with the gcc default, so override the definition of this macro in m68k.h */

#undef PCC_STATIC_STRUCT_RETURN

/* Local common symbols are declared to the assembler with ".lcomm" rather
   than ".bss", so override the definition in svr4.h */

#undef BSS_ASM_OP
#define BSS_ASM_OP	".lcomm"

/* Register in which address to store a structure value is passed to a
   function.  The default in m68k.h is a1.  For m68k/SVR4 it is a0. */

#undef STRUCT_VALUE_REGNUM
#define STRUCT_VALUE_REGNUM 8

#define ASM_COMMENT_START "|"

#undef TYPE_OPERAND_FMT
#define TYPE_OPERAND_FMT      "@%s"

/* Define how the m68k registers should be numbered for Dwarf output.
   The numbering provided here should be compatible with the native
   SVR4 SDB debugger in the m68k/SVR4 reference port, where d0-d7
   are 0-7, a0-a8 are 8-15, and fp0-fp7 are 16-23. */

#undef DBX_REGISTER_NUMBER
#define DBX_REGISTER_NUMBER(REGNO) (REGNO)

/* The ASM_OUTPUT_SKIP macro is first defined in m68k.h, using ".skip".
   It is then overridden by m68k/sgs.h to use ".space", and again by svr4.h
   to use ".zero".  The m68k/SVR4 assembler uses ".space", so repeat the
   definition from m68k/sgs.h here.  Note that ASM_NO_SKIP_IN_TEXT is
   defined in m68k/sgs.h, so we don't have to repeat it here. */

#undef ASM_OUTPUT_SKIP
#define ASM_OUTPUT_SKIP(FILE,SIZE)  \
  fprintf (FILE, "\t%s %u\n", SPACE_ASM_OP, (SIZE))

#if 0
/* SVR4 m68k assembler is bitching on the `comm i,1,1' which askes for 
   1 byte alignment. Don't generate alignment for COMMON seems to be
   safer until we the assembler is fixed. */
#undef ASM_OUTPUT_ALIGNED_COMMON
/* Same problem with this one.  */
#undef ASM_OUTPUT_ALIGNED_LOCAL
#endif

/* The `string' directive on m68k svr4 does not handle string with
   escape char (ie., `\') right. Use normal way to output ASCII bytes
   seems to be safer. */
#undef ASM_OUTPUT_ASCII
#define ASM_OUTPUT_ASCII(FILE,PTR,LEN)				\
do {								\
  register int sp = 0, lp = 0, ch;				\
  fprintf ((FILE), "\t%s ", BYTE_ASM_OP);			\
  do {								\
    ch = (PTR)[sp];						\
    if (ch > ' ' && ! (ch & 0x80) && ch != '\\')		\
      {								\
	fprintf ((FILE), "'%c", ch);				\
      }								\
    else							\
      {								\
	fprintf ((FILE), "0x%x", ch);				\
      }								\
    if (++sp < (LEN))						\
      {								\
	if ((sp % 10) == 0)					\
	  {							\
	    fprintf ((FILE), "\n\t%s ", BYTE_ASM_OP);		\
	  }							\
	else							\
	  {							\
	    putc (',', (FILE));					\
	  }							\
      }								\
  } while (sp < (LEN));						\
  putc ('\n', (FILE));						\
} while (0)

/* SVR4 m68k assembler is bitching on the syntax `2.b'.
   So use the "LLDnnn-LLnnn" format.  Define LLDnnn after the table.  */

#undef ASM_OUTPUT_CASE_END
#define ASM_OUTPUT_CASE_END(FILE,NUM,TABLE)				\
do {									\
  if (switch_table_difference_label_flag)				\
    asm_fprintf ((FILE), "\t%s %LLD%d,%LL%d\n", SET_ASM_OP, (NUM), (NUM));\
  switch_table_difference_label_flag = 0;				\
} while (0)

extern int switch_table_difference_label_flag;

#undef ASM_OUTPUT_COMMON
#undef ASM_OUTPUT_LOCAL
#define ASM_OUTPUT_COMMON(FILE, NAME, SIZE, ROUNDED)  \
( fputs (".comm ", (FILE)),			\
  assemble_name ((FILE), (NAME)),		\
  fprintf ((FILE), ",%u\n", (SIZE)))

#define ASM_OUTPUT_LOCAL(FILE, NAME, SIZE, ROUNDED)  \
( fputs (".lcomm ", (FILE)),			\
  assemble_name ((FILE), (NAME)),		\
  fprintf ((FILE), ",%u\n", (SIZE)))

/* Currently, JUMP_TABLES_IN_TEXT_SECTION must be defined in order to
   keep switch tables in the text section. */
   
#define JUMP_TABLES_IN_TEXT_SECTION 1

/* Override the definition in svr4.h. In m68k svr4, using swbeg is the 
   standard way to do switch table. */
#undef ASM_OUTPUT_BEFORE_CASE_LABEL
#define ASM_OUTPUT_BEFORE_CASE_LABEL(FILE,PREFIX,NUM,TABLE)		\
  fprintf ((FILE), "\t%s &%d\n", SWBEG_ASM_OP, XVECLEN (PATTERN (TABLE), 1));

/* In m68k svr4, a symbol_ref rtx can be a valid PIC operand if it is an
   operand of a function call. */
#undef LEGITIMATE_PIC_OPERAND_P
#define LEGITIMATE_PIC_OPERAND_P(X) \
  (! symbolic_operand (X, VOIDmode) \
   || ((GET_CODE(X) == SYMBOL_REF) && SYMBOL_REF_FLAG(X)))

/* Turn off function cse if we are doing PIC. We always want function call
   to be done as `bsr foo@PLTPC', so it will force the assembler to create 
   the PLT entry for `foo'. Doing function cse will cause the address of `foo'
   to be loaded into a register, which is exactly what we want to avoid when
   we are doing PIC on svr4 m68k. */
#undef OVERRIDE_OPTIONS
#define OVERRIDE_OPTIONS		\
{					\
  if (flag_pic) flag_no_function_cse = 1; \
  if (! TARGET_68020 && flag_pic == 2)	\
    error("-fPIC is not currently supported on the 68000 or 68010\n");	\
}
/* end of stuff from m68kv4.h */

#undef SGS_CMP_ORDER

#undef ENDFILE_SPEC
#define ENDFILE_SPEC "crtend.o%s"

#undef	STARTFILE_SPEC
#define STARTFILE_SPEC "crtbegin.o%s"