gcc/config/m68k/m68kemb.h

/* Definitions of target machine for GNU compiler.  "embedded" 68XXX.
   This is meant to be included after m68k.h.
   Copyright (C) 1994-2021 Free Software Foundation, Inc.  */

/* Override the SVR4 ABI for this target.  */

#define PTRDIFF_TYPE "long int"
#define SIZE_TYPE "long unsigned int"

/* In order for bitfields to work on a 68000, or with -mnobitfield, we must
   define either PCC_BITFIELD_TYPE_MATTERS or STRUCTURE_SIZE_BOUNDARY.
   Defining STRUCTURE_SIZE_BOUNDARY results in structure packing problems,
   so we define PCC_BITFIELD_TYPE_MATTERS.  */
#define PCC_BITFIELD_TYPE_MATTERS 1

/* Don't default to pcc-struct-return, so that we can return small structures
   and unions in registers, which is slightly more efficient.  */
#define DEFAULT_PCC_STRUCT_RETURN 0

#undef FUNCTION_VALUE
#define FUNCTION_VALUE(VALTYPE,FUNC) LIBCALL_VALUE (TYPE_MODE (VALTYPE))

#undef LIBCALL_VALUE
#define LIBCALL_VALUE(MODE)					\
  m68k_libcall_value (MODE)

#undef FUNCTION_VALUE_REGNO_P
#define FUNCTION_VALUE_REGNO_P(N)			\
  ((N) == D0_REG || (TARGET_68881 && (N) == FP0_REG))

#undef NEEDS_UNTYPED_CALL
#define NEEDS_UNTYPED_CALL 1

/* Target OS builtins.  */
#define TARGET_OS_CPP_BUILTINS()		\
  do						\
    {						\
      builtin_define ("__embedded__");		\
    }						\
  while (0)

/* Override the default LIB_SPEC from gcc.c.  We don't currently support
   profiling, or libg.a.  */

#undef  LIB_SPEC
#define LIB_SPEC "-lc"

/* Make this be null, since we want the crt0.o to come from the linker
   script */

#undef  STARTFILE_SPEC
#define STARTFILE_SPEC ""