bsd.h

gcc-you can use this code to learn something about gcc, and inquire further into linux,

/* Definitions for BSD assembler syntax for Intel 386
   (actually AT&T syntax for insns and operands,
   adapted to BSD conventions for symbol names and debugging.)
   Copyright (C) 1988, 1996, 2000, 2002 Free Software Foundation, Inc.

This file is part of GNU CC.

GNU CC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 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.  */

/* Use the Sequent Symmetry assembler syntax.  */

/* Define the syntax of pseudo-ops, labels and comments.  */

/* Prefix for internally generated assembler labels.  If we aren't using
   underscores, we are using prefix `.'s to identify labels that should
   be ignored, as in `i386/gas.h' [e-mail]  */

#define LPREFIX "L"

/* Assembler pseudos to introduce constants of various size.  */

#define ASM_SHORT "\t.word\t"
#define ASM_LONG "\t.long\t"
#define ASM_QUAD "\t.quad\t"  /* Should not be used for 32bit compilation.  */

/* Output at beginning of assembler file.
   ??? I am skeptical of this -- RMS.  */

#define ASM_FILE_START(FILE) \
  do {	output_file_directive (FILE, main_input_filename);	\
  } while (0)

/* This was suggested, but it shouldn't be right for DBX output. -- RMS
   #define ASM_OUTPUT_SOURCE_FILENAME(FILE, NAME) */


/* Define the syntax of labels and symbol definitions/declarations.  */

/* This is how to output an assembler line
   that says to advance the location counter by SIZE bytes.  */

#define ASM_OUTPUT_SKIP(FILE,SIZE)  \
  fprintf (FILE, "\t.space %u\n", (SIZE))

/* Define the syntax of labels and symbol definitions/declarations.  */

/* This says how to output an assembler line
   to define a global common symbol.  */

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

/* This says how to output an assembler line
   to define a local common symbol.  */

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

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

#define ASM_OUTPUT_ALIGN(FILE,LOG)	\
  if ((LOG)!=0) fprintf ((FILE), "\t.align %d\n", (LOG))

/* This is how to store into the string BUF
   the symbol_ref name of an internal numbered label where
   PREFIX is the class of label and NUM is the number within the class.
   This is suitable for output with `assemble_name'.  */

#define ASM_GENERATE_INTERNAL_LABEL(BUF,PREFIX,NUMBER)	\
    sprintf ((BUF), "*%s%ld", (PREFIX), (long)(NUMBER))

/* This is how to output an internal numbered label where
   PREFIX is the class of label and NUM is the number within the class.  */

#define ASM_OUTPUT_INTERNAL_LABEL(FILE,PREFIX,NUM)	\
  fprintf (FILE, "%s%d:\n", PREFIX, NUM)

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

#define USER_LABEL_PREFIX "_"

/* Sequent has some changes in the format of DBX symbols.  */
#define DBX_NO_XREFS 1

/* Don't split DBX symbols into continuations.  */
#define DBX_CONTIN_LENGTH 0