gcc/config/i386/isc.h

/* Assembler-independent definitions for an Intel 386 running
   Interactive Unix System V. Specifically, this is for recent versions
   that support POSIX.  */

/* Use crt1.o, not crt0.o, as a startup file, and crtn.o as a closing file.  */
#undef STARTFILE_SPEC
#define STARTFILE_SPEC \
  "%{!shlib:%{posix:%{pg:mcrtp1.o%s}%{!pg:%{p:mcrtp1.o%s}%{!p:crtp1.o%s}}}\
   %{Xp:%{pg:mcrtp1.o%s}%{!pg:%{p:mcrtp1.o%s}%{!p:crtp1.o%s}}}\
   %{!posix:%{!Xp:%{pg:mcrt1.o%s}%{!pg:%{p:mcrt1.o%s}%{!p:crt1.o%s}}\
   %{p:-L/lib/libp} %{pg:-L/lib/libp}}}}\
   %{shlib:%{Xp:crtp1.o%s}%{posix:crtp1.o%s}%{!posix:%{!Xp:crt1.o%s}}}\
   crtbegin.o%s"
  
#define ENDFILE_SPEC "crtend.o%s crtn.o%s"

/* Library spec */
#undef LIB_SPEC
#define LIB_SPEC "%{shlib:-lc_s} %{posix:-lcposix} %{Xp:-lcposix} -lc -lg"

#undef CPP_SPEC
#define CPP_SPEC "%(cpp_cpu) %{posix:-D_POSIX_SOURCE} %{Xp:-D_POSIX_SOURCE}"

/* ISC 2.2 uses `char' for `wchar_t'.  */
#undef WCHAR_TYPE
#define WCHAR_TYPE "char"

#undef WCHAR_TYPE_SIZE
#define WCHAR_TYPE_SIZE BITS_PER_UNIT

#if 0
/* This is apparently not true: ISC versions up to 3.0, at least, use
   the standard calling sequence in which the called function pops the
   extra arg.  */
/* caller has to pop the extra argument passed to functions that return
   structures.  */

#undef RETURN_POPS_ARGS
#define RETURN_POPS_ARGS(FUNDECL,FUNTYPE,SIZE)   \
  ((FUNDECL) && TREE_CODE (FUNDECL) == IDENTIFIER_NODE ? 0	\
   : (TARGET_RTD						\
      && (TYPE_ARG_TYPES (FUNTYPE) == 0				\
	  || (TREE_VALUE (tree_last (TYPE_ARG_TYPES (FUNTYPE)))	\
	      == void_type_node))) ? (SIZE)			\
   : 0)
/* On other 386 systems, the last line looks like this:
   : (aggregate_value_p (TREE_TYPE (FUNTYPE))) ? GET_MODE_SIZE (Pmode) : 0)  */
#endif

/* Handle #pragma pack and #pragma weak.  */
#define HANDLE_SYSV_PRAGMA

/* By default, target has a 80387, uses IEEE compatible arithmetic,
   and returns float values in the 387, ie,
   (TARGET_80387 | TARGET_FLOAT_RETURNS_IN_80387)

   ISC's software emulation of a 387 fails to handle the `fucomp'
   opcode.  fucomp is only used when generating IEEE compliant code.
   So don't make TARGET_IEEE_FP default for ISC.  */

#undef TARGET_SUBTARGET_DEFAULT
#define TARGET_SUBTARGET_DEFAULT (MASK_80387 | MASK_FLOAT_RETURNS)

/* The ISC 2.0.2 software FPU emulator apparently can't handle
   80-bit XFmode insns, so don't generate them.  */
#undef LONG_DOUBLE_TYPE_SIZE
#define LONG_DOUBLE_TYPE_SIZE 64

/* The ISC assembler does not like a .file directive with a name
   longer than 14 characters.  Truncating it will not permit
   debugging to work properly, but at least we won't get an error
   message.  */

#undef ASM_FILE_START
#define ASM_FILE_START(FILE)				\
  do {							\
    const int len = strlen (main_input_filename);	\
    const char *na = main_input_filename + len;		\
    char shorter[15];					\
    /* NA gets MAIN_INPUT_FILENAME sans directory names.  */\
    while (na > main_input_filename)			\
      {							\
	if (na[-1] == '/')				\
	  break;					\
	na--;						\
      }							\
    strncpy (shorter, na, 14);				\
    shorter[14] = 0;					\
    fprintf (FILE, "\t.file\t");			\
    output_quoted_string (FILE, shorter);		\
    fprintf (FILE, "\n");				\
  } while (0)

/* Work around assembler forward label references generated in exception
   handling code.  */
#define DWARF2_UNWIND_INFO 0