i386.h

这是一个开放源代码的与WINNT/WIN2K/WIN2003兼容的操作系统

#ifndef CPP_CPU_SPEC
#ifdef TARGET_BI_ARCH
#ifdef TARGET_64BIT_DEFAULT
#define CPP_CPU_SPEC "%{m32:%(cpp_cpu32)}%{!m32:%(cpp_cpu64)} %(cpp_cpucommon)"
#else
#define CPP_CPU_SPEC "%{m64:%(cpp_cpu64)}%{!m64:%(cpp_cpu32)} %(cpp_cpucommon)"
#endif
#else
#ifdef TARGET_64BIT_DEFAULT
#define CPP_CPU_SPEC "%(cpp_cpu64) %(cpp_cpucommon)"
#else
#define CPP_CPU_SPEC "%(cpp_cpu32) %(cpp_cpucommon)"
#endif
#endif
#endif

#ifndef CC1_SPEC
#define CC1_SPEC "%(cc1_cpu) "
#endif

/* This macro defines names of additional specifications to put in the
   specs that can be used in various specifications like CC1_SPEC.  Its
   definition is an initializer with a subgrouping for each command option.

   Each subgrouping contains a string constant, that defines the
   specification name, and a string constant that used by the GNU CC driver
   program.

   Do not define this macro if it does not need to do anything.  */

#ifndef SUBTARGET_EXTRA_SPECS
#define SUBTARGET_EXTRA_SPECS
#endif

#define EXTRA_SPECS							\
  { "cpp_cpu_default",	CPP_CPU_DEFAULT_SPEC },				\
  { "cpp_cpu",	CPP_CPU_SPEC },						\
  { "cpp_cpu32", CPP_CPU32_SPEC },					\
  { "cpp_cpu64", CPP_CPU64_SPEC },					\
  { "cpp_cpu32sizet", CPP_CPU32_SIZE_TYPE_SPEC },			\
  { "cpp_cpu64sizet", CPP_CPU64_SIZE_TYPE_SPEC },			\
  { "cpp_cpucommon", CPP_CPUCOMMON_SPEC },				\
  { "cc1_cpu",  CC1_CPU_SPEC },						\
  SUBTARGET_EXTRA_SPECS

/* target machine storage layout */

/* Define for XFmode or TFmode extended real floating point support.
   This will automatically cause REAL_ARITHMETIC to be defined.

   The XFmode is specified by i386 ABI, while TFmode may be faster
   due to alignment and simplifications in the address calculations.
 */
#define LONG_DOUBLE_TYPE_SIZE (TARGET_128BIT_LONG_DOUBLE ? 128 : 96)
#define MAX_LONG_DOUBLE_TYPE_SIZE 128
#ifdef __x86_64__
#define LIBGCC2_LONG_DOUBLE_TYPE_SIZE 128
#else
#define LIBGCC2_LONG_DOUBLE_TYPE_SIZE 96
#endif
/* Tell real.c that this is the 80-bit Intel extended float format
   packaged in a 128-bit or 96bit entity.  */
#define INTEL_EXTENDED_IEEE_FORMAT 1


#define SHORT_TYPE_SIZE 16
#define INT_TYPE_SIZE 32
#define FLOAT_TYPE_SIZE 32
#define LONG_TYPE_SIZE BITS_PER_WORD
#define MAX_WCHAR_TYPE_SIZE 32
#define DOUBLE_TYPE_SIZE 64
#define LONG_LONG_TYPE_SIZE 64

#if defined (TARGET_BI_ARCH) || defined (TARGET_64BIT_DEFAULT)
#define MAX_BITS_PER_WORD 64
#define MAX_LONG_TYPE_SIZE 64
#else
#define MAX_BITS_PER_WORD 32
#define MAX_LONG_TYPE_SIZE 32
#endif

/* Define if you don't want extended real, but do want to use the
   software floating point emulator for REAL_ARITHMETIC and
   decimal <-> binary conversion.  */
/* #define REAL_ARITHMETIC */

/* Define this if most significant byte of a word is the lowest numbered.  */
/* That is true on the 80386.  */

#define BITS_BIG_ENDIAN 0

/* Define this if most significant byte of a word is the lowest numbered.  */
/* That is not true on the 80386.  */
#define BYTES_BIG_ENDIAN 0

/* Define this if most significant word of a multiword number is the lowest
   numbered.  */
/* Not true for 80386 */
#define WORDS_BIG_ENDIAN 0

/* number of bits in an addressable storage unit */
#define BITS_PER_UNIT 8

/* Width in bits of a "word", which is the contents of a machine register.
   Note that this is not necessarily the width of data type `int';
   if using 16-bit ints on a 80386, this would still be 32.
   But on a machine with 16-bit registers, this would be 16.  */
#define BITS_PER_WORD (TARGET_64BIT ? 64 : 32)

/* Width of a word, in units (bytes).  */
#define UNITS_PER_WORD (TARGET_64BIT ? 8 : 4)
#define MIN_UNITS_PER_WORD 4

/* Width in bits of a pointer.
   See also the macro `Pmode' defined below.  */
#define POINTER_SIZE BITS_PER_WORD

/* Allocation boundary (in *bits*) for storing arguments in argument list.  */
#define PARM_BOUNDARY BITS_PER_WORD

/* Boundary (in *bits*) on which stack pointer should be aligned.  */
#define STACK_BOUNDARY BITS_PER_WORD

/* Boundary (in *bits*) on which the stack pointer preferrs to be
   aligned; the compiler cannot rely on having this alignment.  */
#define PREFERRED_STACK_BOUNDARY ix86_preferred_stack_boundary

/* As of July 2001, many runtimes to not align the stack properly when
   entering main.  This causes expand_main_function to forcably align
   the stack, which results in aligned frames for functions called from
   main, though it does nothing for the alignment of main itself.  */
#define FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN \
  (ix86_preferred_stack_boundary > STACK_BOUNDARY && !TARGET_64BIT)

/* Allocation boundary for the code of a function.  */
#define FUNCTION_BOUNDARY 16

/* Alignment of field after `int : 0' in a structure.  */

#define EMPTY_FIELD_BOUNDARY BITS_PER_WORD

/* Minimum size in bits of the largest boundary to which any
   and all fundamental data types supported by the hardware
   might need to be aligned. No data type wants to be aligned
   rounder than this.

   Pentium+ preferrs DFmode values to be aligned to 64 bit boundary
   and Pentium Pro XFmode values at 128 bit boundaries.  */

#define BIGGEST_ALIGNMENT 128

/* Decide whether a variable of mode MODE must be 128 bit aligned.  */
#define ALIGN_MODE_128(MODE) \
 ((MODE) == XFmode || (MODE) == TFmode || ((MODE) == TImode) \
  || (MODE) == V4SFmode	|| (MODE) == V4SImode)

/* The published ABIs say that doubles should be aligned on word
   boundaries, so lower the aligment for structure fields unless
   -malign-double is set.  */
/* BIGGEST_FIELD_ALIGNMENT is also used in libobjc, where it must be
   constant.  Use the smaller value in that context.  */
#ifndef IN_TARGET_LIBS
#define BIGGEST_FIELD_ALIGNMENT (TARGET_64BIT ? 128 : (TARGET_ALIGN_DOUBLE ? 64 : 32))
#else
#define BIGGEST_FIELD_ALIGNMENT 32
#endif

/* If defined, a C expression to compute the alignment given to a
   constant that is being placed in memory.  EXP is the constant
   and ALIGN is the alignment that the object would ordinarily have.
   The value of this macro is used instead of that alignment to align
   the object.

   If this macro is not defined, then ALIGN is used.

   The typical use of this macro is to increase alignment for string
   constants to be word aligned so that `strcpy' calls that copy
   constants can be done inline.  */

#define CONSTANT_ALIGNMENT(EXP, ALIGN) ix86_constant_alignment ((EXP), (ALIGN))

/* If defined, a C expression to compute the alignment for a static
   variable.  TYPE is the data type, and ALIGN is the alignment that
   the object would ordinarily have.  The value of this macro is used
   instead of that alignment to align the object.

   If this macro is not defined, then ALIGN is used.

   One use of this macro is to increase alignment of medium-size
   data to make it all fit in fewer cache lines.  Another is to
   cause character arrays to be word-aligned so that `strcpy' calls
   that copy constants to character arrays can be done inline.  */

#define DATA_ALIGNMENT(TYPE, ALIGN) ix86_data_alignment ((TYPE), (ALIGN))

/* If defined, a C expression to compute the alignment for a local
   variable.  TYPE is the data type, and ALIGN is the alignment that
   the object would ordinarily have.  The value of this macro is used
   instead of that alignment to align the object.

   If this macro is not defined, then ALIGN is used.

   One use of this macro is to increase alignment of medium-size
   data to make it all fit in fewer cache lines.  */

#define LOCAL_ALIGNMENT(TYPE, ALIGN) ix86_local_alignment ((TYPE), (ALIGN))

/* If defined, a C expression that gives the alignment boundary, in
   bits, of an argument with the specified mode and type.  If it is
   not defined, `PARM_BOUNDARY' is used for all arguments.  */

#define FUNCTION_ARG_BOUNDARY(MODE, TYPE) \
  ix86_function_arg_boundary ((MODE), (TYPE))

/* Set this non-zero if move instructions will actually fail to work
   when given unaligned data.  */
#define STRICT_ALIGNMENT 0

/* If bit field type is int, don't let it cross an int,
   and give entire struct the alignment of an int.  */
/* Required on the 386 since it doesn't have bitfield insns.  */
#define PCC_BITFIELD_TYPE_MATTERS 1

/* Standard register usage.  */

/* This processor has special stack-like registers.  See reg-stack.c
   for details.  */

#define STACK_REGS
#define IS_STACK_MODE(MODE)					\
  ((MODE) == DFmode || (MODE) == SFmode || (MODE) == XFmode	\
   || (MODE) == TFmode)

/* Number of actual hardware registers.
   The hardware registers are assigned numbers for the compiler
   from 0 to just below FIRST_PSEUDO_REGISTER.
   All registers that the compiler knows about must be given numbers,
   even those that are not normally considered general registers.

   In the 80386 we give the 8 general purpose registers the numbers 0-7.
   We number the floating point registers 8-15.
   Note that registers 0-7 can be accessed as a  short or int,
   while only 0-3 may be used with byte `mov' instructions.

   Reg 16 does not correspond to any hardware register, but instead
   appears in the RTL as an argument pointer prior to reload, and is
   eliminated during reloading in favor of either the stack or frame
   pointer.  */

#define FIRST_PSEUDO_REGISTER 53

/* Number of hardware registers that go into the DWARF-2 unwind info.
   If not defined, equals FIRST_PSEUDO_REGISTER.  */

#define DWARF_FRAME_REGISTERS 17

/* 1 for registers that have pervasive standard uses
   and are not available for the register allocator.
   On the 80386, the stack pointer is such, as is the arg pointer.

   The value is an mask - bit 1 is set for fixed registers
   for 32bit target, while 2 is set for fixed registers for 64bit.
   Proper value is computed in the CONDITIONAL_REGISTER_USAGE.
 */
#define FIXED_REGISTERS						\
/*ax,dx,cx,bx,si,di,bp,sp,st,st1,st2,st3,st4,st5,st6,st7*/	\
{  0, 0, 0, 0, 0, 0, 0, 3, 0,  0,  0,  0,  0,  0,  0,  0,	\
/*arg,flags,fpsr,dir,frame*/					\
    3,    3,   3,  3,    3,					\
/*xmm0,xmm1,xmm2,xmm3,xmm4,xmm5,xmm6,xmm7*/			\
     0,   0,   0,   0,   0,   0,   0,   0,			\
/*mmx0,mmx1,mmx2,mmx3,mmx4,mmx5,mmx6,mmx7*/			\
     0,   0,   0,   0,   0,   0,   0,   0,			\
/*  r8,  r9, r10, r11, r12, r13, r14, r15*/			\
     1,   1,   1,   1,   1,   1,   1,   1,			\
/*xmm8,xmm9,xmm10,xmm11,xmm12,xmm13,xmm14,xmm15*/		\
     1,   1,    1,    1,    1,    1,    1,    1}


/* 1 for registers not available across function calls.
   These must include the FIXED_REGISTERS and also any
   registers that can be used without being saved.
   The latter must include the registers where values are returned
   and the register where structure-value addresses are passed.
   Aside from that, you can include as many other registers as you like.

   The value is an mask - bit 1 is set for call used
   for 32bit target, while 2 is set for call used for 64bit.
   Proper value is computed in the CONDITIONAL_REGISTER_USAGE.
*/
#define CALL_USED_REGISTERS					\
/*ax,dx,cx,bx,si,di,bp,sp,st,st1,st2,st3,st4,st5,st6,st7*/	\
{  3, 3, 3, 0, 2, 2, 0, 3, 3,  3,  3,  3,  3,  3,  3,  3,	\
/*arg,flags,fpsr,dir,frame*/					\
     3,   3,   3,  3,    3,					\
/*xmm0,xmm1,xmm2,xmm3,xmm4,xmm5,xmm6,xmm7*/			\
     3,   3,   3,   3,   3,  3,    3,   3,			\
/*mmx0,mmx1,mmx2,mmx3,mmx4,mmx5,mmx6,mmx7*/			\
     3,   3,   3,   3,   3,   3,   3,   3,			\
/*  r8,  r9, r10, r11, r12, r13, r14, r15*/			\
     3,   3,   3,   3,   1,   1,   1,   1,			\
/*xmm8,xmm9,xmm10,xmm11,xmm12,xmm13,xmm14,xmm15*/		\
     3,   3,    3,    3,    3,    3,    3,    3}		\

/* Order in which to allocate registers.  Each register must be
   listed once, even those in FIXED_REGISTERS.  List frame pointer
   late and fixed registers last.  Note that, in general, we prefer
   registers listed in CALL_USED_REGISTERS, keeping the others
   available for storage of persistent values.

   The ORDER_REGS_FOR_LOCAL_ALLOC actually overwrite the order,
   so this is just empty initializer for array.  */