i386.h

这是一个开放源代码的与WINNT/WIN2K/WIN2003兼容的操作系统

#define REG_ALLOC_ORDER 					\
{  0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,\
   18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32,	\
   33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,  \
   48, 49, 50, 51, 52 }

/* ORDER_REGS_FOR_LOCAL_ALLOC is a macro which permits reg_alloc_order
   to be rearranged based on a particular function.  When using sse math,
   we want to allocase SSE before x87 registers and vice vera.  */

#define ORDER_REGS_FOR_LOCAL_ALLOC x86_order_regs_for_local_alloc ()


/* Macro to conditionally modify fixed_regs/call_used_regs.  */
#define CONDITIONAL_REGISTER_USAGE					\
do {									\
    int i;								\
    for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)				\
      {									\
        fixed_regs[i] = (fixed_regs[i] & (TARGET_64BIT ? 2 : 1)) != 0;	\
        call_used_regs[i] = (call_used_regs[i]				\
			     & (TARGET_64BIT ? 2 : 1)) != 0;		\
      }									\
    if (PIC_OFFSET_TABLE_REGNUM != INVALID_REGNUM)			\
      {									\
	fixed_regs[PIC_OFFSET_TABLE_REGNUM] = 1;			\
	call_used_regs[PIC_OFFSET_TABLE_REGNUM] = 1;			\
      }									\
    if (! TARGET_MMX)							\
      {									\
	int i;								\
        for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)			\
          if (TEST_HARD_REG_BIT (reg_class_contents[(int)MMX_REGS], i))	\
	    fixed_regs[i] = call_used_regs[i] = 1;		 	\
      }									\
    if (! TARGET_SSE)							\
      {									\
	int i;								\
        for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)			\
          if (TEST_HARD_REG_BIT (reg_class_contents[(int)SSE_REGS], i))	\
	    fixed_regs[i] = call_used_regs[i] = 1;		 	\
      }									\
    if (! TARGET_80387 && ! TARGET_FLOAT_RETURNS_IN_80387)		\
      {									\
	int i;								\
	HARD_REG_SET x;							\
        COPY_HARD_REG_SET (x, reg_class_contents[(int)FLOAT_REGS]);	\
        for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)			\
          if (TEST_HARD_REG_BIT (x, i)) 				\
	    fixed_regs[i] = call_used_regs[i] = 1;			\
      }									\
  } while (0)

/* Return number of consecutive hard regs needed starting at reg REGNO
   to hold something of mode MODE.
   This is ordinarily the length in words of a value of mode MODE
   but can be less for certain modes in special long registers.

   Actually there are no two word move instructions for consecutive
   registers.  And only registers 0-3 may have mov byte instructions
   applied to them.
   */

#define HARD_REGNO_NREGS(REGNO, MODE)   \
  (FP_REGNO_P (REGNO) || SSE_REGNO_P (REGNO) || MMX_REGNO_P (REGNO)	\
   ? (COMPLEX_MODE_P (MODE) ? 2 : 1)					\
   : ((MODE) == TFmode							\
      ? (TARGET_64BIT ? 2 : 3)						\
      : (MODE) == TCmode						\
      ? (TARGET_64BIT ? 4 : 6)						\
      : ((GET_MODE_SIZE (MODE) + UNITS_PER_WORD - 1) / UNITS_PER_WORD)))

#define VALID_SSE_REG_MODE(MODE)					\
    ((MODE) == TImode || (MODE) == V4SFmode || (MODE) == V4SImode	\
     || (MODE) == SFmode						\
     || (TARGET_SSE2 && ((MODE) == DFmode || VALID_MMX_REG_MODE (MODE))))

#define VALID_MMX_REG_MODE_3DNOW(MODE) \
    ((MODE) == V2SFmode || (MODE) == SFmode)

#define VALID_MMX_REG_MODE(MODE)					\
    ((MODE) == DImode || (MODE) == V8QImode || (MODE) == V4HImode	\
     || (MODE) == V2SImode || (MODE) == SImode)

#define VECTOR_MODE_SUPPORTED_P(MODE)					\
    (VALID_SSE_REG_MODE (MODE) && TARGET_SSE ? 1			\
     : VALID_MMX_REG_MODE (MODE) && TARGET_MMX ? 1			\
     : VALID_MMX_REG_MODE_3DNOW (MODE) && TARGET_3DNOW ? 1 : 0)

#define VALID_FP_MODE_P(MODE)						\
    ((MODE) == SFmode || (MODE) == DFmode || (MODE) == TFmode		\
     || (!TARGET_64BIT && (MODE) == XFmode)				\
     || (MODE) == SCmode || (MODE) == DCmode || (MODE) == TCmode	\
     || (!TARGET_64BIT && (MODE) == XCmode))

#define VALID_INT_MODE_P(MODE)						\
    ((MODE) == QImode || (MODE) == HImode || (MODE) == SImode		\
     || (MODE) == DImode						\
     || (MODE) == CQImode || (MODE) == CHImode || (MODE) == CSImode	\
     || (MODE) == CDImode						\
     || (TARGET_64BIT && ((MODE) == TImode || (MODE) == CTImode)))

/* Value is 1 if hard register REGNO can hold a value of machine-mode MODE.  */

#define HARD_REGNO_MODE_OK(REGNO, MODE)	\
   ix86_hard_regno_mode_ok ((REGNO), (MODE))

/* Value is 1 if it is a good idea to tie two pseudo registers
   when one has mode MODE1 and one has mode MODE2.
   If HARD_REGNO_MODE_OK could produce different values for MODE1 and MODE2,
   for any hard reg, then this must be 0 for correct output.  */

#define MODES_TIEABLE_P(MODE1, MODE2)				\
  ((MODE1) == (MODE2)						\
   || (((MODE1) == HImode || (MODE1) == SImode			\
	|| ((MODE1) == QImode					\
	    && (TARGET_64BIT || !TARGET_PARTIAL_REG_STALL))	\
        || ((MODE1) == DImode && TARGET_64BIT))			\
       && ((MODE2) == HImode || (MODE2) == SImode		\
	   || ((MODE1) == QImode				\
	       && (TARGET_64BIT || !TARGET_PARTIAL_REG_STALL))	\
	   || ((MODE2) == DImode && TARGET_64BIT))))


/* Specify the modes required to caller save a given hard regno.
   We do this on i386 to prevent flags from being saved at all.

   Kill any attempts to combine saving of modes.  */

#define HARD_REGNO_CALLER_SAVE_MODE(REGNO, NREGS, MODE)			\
  (CC_REGNO_P (REGNO) ? VOIDmode					\
   : (MODE) == VOIDmode && (NREGS) != 1 ? VOIDmode			\
   : (MODE) == VOIDmode ? choose_hard_reg_mode ((REGNO), (NREGS))	\
   : (MODE) == HImode && !TARGET_PARTIAL_REG_STALL ? SImode		\
   : (MODE) == QImode && (REGNO) >= 4 && !TARGET_64BIT ? SImode 	\
   : (MODE))
/* Specify the registers used for certain standard purposes.
   The values of these macros are register numbers.  */

/* on the 386 the pc register is %eip, and is not usable as a general
   register.  The ordinary mov instructions won't work */
/* #define PC_REGNUM  */

/* Register to use for pushing function arguments.  */
#define STACK_POINTER_REGNUM 7

/* Base register for access to local variables of the function.  */
#define HARD_FRAME_POINTER_REGNUM 6

/* Base register for access to local variables of the function.  */
#define FRAME_POINTER_REGNUM 20

/* First floating point reg */
#define FIRST_FLOAT_REG 8

/* First & last stack-like regs */
#define FIRST_STACK_REG FIRST_FLOAT_REG
#define LAST_STACK_REG (FIRST_FLOAT_REG + 7)

#define FLAGS_REG 17
#define FPSR_REG 18
#define DIRFLAG_REG 19

#define FIRST_SSE_REG (FRAME_POINTER_REGNUM + 1)
#define LAST_SSE_REG  (FIRST_SSE_REG + 7)

#define FIRST_MMX_REG  (LAST_SSE_REG + 1)
#define LAST_MMX_REG   (FIRST_MMX_REG + 7)

#define FIRST_REX_INT_REG  (LAST_MMX_REG + 1)
#define LAST_REX_INT_REG   (FIRST_REX_INT_REG + 7)

#define FIRST_REX_SSE_REG  (LAST_REX_INT_REG + 1)
#define LAST_REX_SSE_REG   (FIRST_REX_SSE_REG + 7)

/* Value should be nonzero if functions must have frame pointers.
   Zero means the frame pointer need not be set up (and parms
   may be accessed via the stack pointer) in functions that seem suitable.
   This is computed in `reload', in reload1.c.  */
#define FRAME_POINTER_REQUIRED  ix86_frame_pointer_required ()

/* Override this in other tm.h files to cope with various OS losage
   requiring a frame pointer.  */
#ifndef SUBTARGET_FRAME_POINTER_REQUIRED
#define SUBTARGET_FRAME_POINTER_REQUIRED 0
#endif

/* Make sure we can access arbitrary call frames.  */
#define SETUP_FRAME_ADDRESSES()  ix86_setup_frame_addresses ()

/* Base register for access to arguments of the function.  */
#define ARG_POINTER_REGNUM 16

/* Register in which static-chain is passed to a function.
   We do use ECX as static chain register for 32 bit ABI.  On the
   64bit ABI, ECX is an argument register, so we use R10 instead.  */
#define STATIC_CHAIN_REGNUM (TARGET_64BIT ? FIRST_REX_INT_REG + 10 - 8 : 2)

/* Register to hold the addressing base for position independent
   code access to data items.  We don't use PIC pointer for 64bit
   mode.  Define the regnum to dummy value to prevent gcc from
   pessimizing code dealing with EBX.  */
#define PIC_OFFSET_TABLE_REGNUM \
  (TARGET_64BIT || !flag_pic ? INVALID_REGNUM : 3)

/* Register in which address to store a structure value
   arrives in the function.  On the 386, the prologue
   copies this from the stack to register %eax.  */
#define STRUCT_VALUE_INCOMING 0

/* Place in which caller passes the structure value address.
   0 means push the value on the stack like an argument.  */
#define STRUCT_VALUE 0

/* A C expression which can inhibit the returning of certain function
   values in registers, based on the type of value.  A nonzero value
   says to return the function value in memory, just as large
   structures are always returned.  Here TYPE will be a C expression
   of type `tree', representing the data type of the value.

   Note that values of mode `BLKmode' must be explicitly handled by
   this macro.  Also, the option `-fpcc-struct-return' takes effect
   regardless of this macro.  On most systems, it is possible to
   leave the macro undefined; this causes a default definition to be
   used, whose value is the constant 1 for `BLKmode' values, and 0
   otherwise.

   Do not use this macro to indicate that structures and unions
   should always be returned in memory.  You should instead use
   `DEFAULT_PCC_STRUCT_RETURN' to indicate this.  */

#define RETURN_IN_MEMORY(TYPE) \
  ix86_return_in_memory (TYPE)


/* Define the classes of registers for register constraints in the
   machine description.  Also define ranges of constants.

   One of the classes must always be named ALL_REGS and include all hard regs.
   If there is more than one class, another class must be named NO_REGS
   and contain no registers.

   The name GENERAL_REGS must be the name of a class (or an alias for
   another name such as ALL_REGS).  This is the class of registers
   that is allowed by "g" or "r" in a register constraint.
   Also, registers outside this class are allocated only when
   instructions express preferences for them.

   The classes must be numbered in nondecreasing order; that is,
   a larger-numbered class must never be contained completely
   in a smaller-numbered class.

   For any two classes, it is very desirable that there be another
   class that represents their union.

   It might seem that class BREG is unnecessary, since no useful 386
   opcode needs reg %ebx.  But some systems pass args to the OS in ebx,
   and the "b" register constraint is useful in asms for syscalls.

   The flags and fpsr registers are in no class.  */

enum reg_class
{
  NO_REGS,
  AREG, DREG, CREG, BREG, SIREG, DIREG,
  AD_REGS,			/* %eax/%edx for DImode */
  Q_REGS,			/* %eax %ebx %ecx %edx */
  NON_Q_REGS,			/* %esi %edi %ebp %esp */
  INDEX_REGS,			/* %eax %ebx %ecx %edx %esi %edi %ebp */
  LEGACY_REGS,			/* %eax %ebx %ecx %edx %esi %edi %ebp %esp */
  GENERAL_REGS,			/* %eax %ebx %ecx %edx %esi %edi %ebp %esp %r8 - %r15*/
  FP_TOP_REG, FP_SECOND_REG,	/* %st(0) %st(1) */
  FLOAT_REGS,
  SSE_REGS,
  MMX_REGS,
  FP_TOP_SSE_REGS,
  FP_SECOND_SSE_REGS,
  FLOAT_SSE_REGS,
  FLOAT_INT_REGS,
  INT_SSE_REGS,
  FLOAT_INT_SSE_REGS,
  ALL_REGS, LIM_REG_CLASSES
};

#define N_REG_CLASSES ((int) LIM_REG_CLASSES)

#define INTEGER_CLASS_P(CLASS) \
  reg_class_subset_p ((CLASS), GENERAL_REGS)
#define FLOAT_CLASS_P(CLASS) \
  reg_class_subset_p ((CLASS), FLOAT_REGS)
#define SSE_CLASS_P(CLASS) \
  reg_class_subset_p ((CLASS), SSE_REGS)
#define MMX_CLASS_P(CLASS) \
  reg_class_subset_p ((CLASS), MMX_REGS)
#define MAYBE_INTEGER_CLASS_P(CLASS) \
  reg_classes_intersect_p ((CLASS), GENERAL_REGS)
#define MAYBE_FLOAT_CLASS_P(CLASS) \
  reg_classes_intersect_p ((CLASS), FLOAT_REGS)
#define MAYBE_SSE_CLASS_P(CLASS) \
  reg_classes_intersect_p (SSE_REGS, (CLASS))
#define MAYBE_MMX_CLASS_P(CLASS) \
  reg_classes_intersect_p (MMX_REGS, (CLASS))

#define Q_CLASS_P(CLASS) \
  reg_class_subset_p ((CLASS), Q_REGS)

/* Give names of register classes as strings for dump file.   */

#define REG_CLASS_NAMES \
{  "NO_REGS",				\
   "AREG", "DREG", "CREG", "BREG",	\