i386.h

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   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 zero if the register is not fixed on either 32 or
   64 bit targets, one if the register if fixed on both 32 and 64
   bit targets, two if it is only fixed on 32bit targets and three
   if its only fixed on 64bit targets.
   Proper values are 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, 1, 0,  0,  0,  0,  0,  0,  0,  0,	\
/*arg,flags,fpsr,dir,frame*/					\
    1,    1,   1,  1,    1,					\
/*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*/			\
     2,   2,   2,   2,   2,   2,   2,   2,			\
/*xmm8,xmm9,xmm10,xmm11,xmm12,xmm13,xmm14,xmm15*/		\
     2,   2,    2,    2,    2,    2,    2,    2}


/* 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 zero if the register is not call used on either 32 or
   64 bit targets, one if the register if call used on both 32 and 64
   bit targets, two if it is only call used on 32bit targets and three
   if its only call used on 64bit targets.
   Proper values are 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*/	\
{  1, 1, 1, 0, 3, 3, 0, 1, 1,  1,  1,  1,  1,  1,  1,  1,	\
/*arg,flags,fpsr,dir,frame*/					\
     1,   1,   1,  1,    1,					\
/*xmm0,xmm1,xmm2,xmm3,xmm4,xmm5,xmm6,xmm7*/			\
     1,   1,   1,   1,   1,  1,    1,   1,			\
/*mmx0,mmx1,mmx2,mmx3,mmx4,mmx5,mmx6,mmx7*/			\
     1,   1,   1,   1,   1,   1,   1,   1,			\
/*  r8,  r9, r10, r11, r12, r13, r14, r15*/			\
     1,   1,   1,   1,   2,   2,   2,   2,			\
/*xmm8,xmm9,xmm10,xmm11,xmm12,xmm13,xmm14,xmm15*/		\
     1,   1,    1,    1,    1,    1,    1,    1}		\

/* 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.  */

#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 allocate 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++)				\
      {									\
	if (fixed_regs[i] > 1)						\
	  fixed_regs[i] = (fixed_regs[i] == (TARGET_64BIT ? 3 : 2));	\
	if (call_used_regs[i] > 1)					\
	  call_used_regs[i] = (call_used_regs[i]			\
			       == (TARGET_64BIT ? 3 : 2));		\
      }									\
    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, reg_names[i] = "";	\
      }									\
    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, reg_names[i] = "";	\
      }									\
    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, reg_names[i] = "";	\
      }									\
    if (! TARGET_64BIT)							\
      {									\
	int i;								\
	for (i = FIRST_REX_INT_REG; i <= LAST_REX_INT_REG; i++)		\
	  reg_names[i] = "";						\
	for (i = FIRST_REX_SSE_REG; i <= LAST_REX_SSE_REG; i++)		\
	  reg_names[i] = "";						\
      }									\
  } 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) == XFmode							\
      ? (TARGET_64BIT ? 2 : 3)						\
      : (MODE) == XCmode						\
      ? (TARGET_64BIT ? 4 : 6)						\
      : ((GET_MODE_SIZE (MODE) + UNITS_PER_WORD - 1) / UNITS_PER_WORD)))

#define VALID_SSE2_REG_MODE(MODE) \
    ((MODE) == V16QImode || (MODE) == V8HImode || (MODE) == V2DFmode    \
     || (MODE) == V2DImode || (MODE) == DFmode)

#define VALID_SSE_REG_MODE(MODE)					\
    ((MODE) == TImode || (MODE) == V4SFmode || (MODE) == V4SImode	\
     || (MODE) == SFmode || (MODE) == TFmode)

#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)

/* ??? No autovectorization into MMX or 3DNOW until we can reliably
   place emms and femms instructions.  */
#define UNITS_PER_SIMD_WORD (TARGET_SSE ? 16 : UNITS_PER_WORD)

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

/* Return true for modes passed in SSE registers.  */
#define SSE_REG_MODE_P(MODE) \
 ((MODE) == TImode || (MODE) == V16QImode || (MODE) == TFmode		\
   || (MODE) == V8HImode || (MODE) == V2DFmode || (MODE) == V2DImode	\
   || (MODE) == V4SFmode || (MODE) == V4SImode)

/* 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)  ix86_modes_tieable_p (MODE1, MODE2)

/* It is possible to write patterns to move flags; but until someone
   does it,  */
#define AVOID_CCMODE_COPIES

/* 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), false)\
   : (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 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 lossage
   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.

   To avoid clobbering a call-saved register unnecessarily, we renumber
   the pic register when possible.  The change is visible after the
   prologue has been emitted.  */

#define REAL_PIC_OFFSET_TABLE_REGNUM  3

#define PIC_OFFSET_TABLE_REGNUM				\
  ((TARGET_64BIT && ix86_cmodel == CM_SMALL_PIC)	\
   || !flag_pic ? INVALID_REGNUM			\
   : reload_completed ? REGNO (pic_offset_table_rtx)	\
   : REAL_PIC_OFFSET_TABLE_REGNUM)

#define GOT_SYMBOL_NAME "_GLOBAL_OFFSET_TABLE_"

/* 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)

/* This is overridden by <cygwin.h>.  */
#define MS_AGGREGATE_RETURN 0

/* This is overridden by <netware.h>.  */
#define KEEP_AGGREGATE_RETURN_POINTER 0

/* Define the classes of registers for register constraints in the
   machine description.  Also define ranges of constants.