vax.c

linux下的gcc编译器

/* Subroutines for insn-output.c for VAX.
   Copyright (C) 1987, 1994, 1995, 1997, 1998, 1999, 2000, 2001, 2002
   Free Software Foundation, Inc.

This file is part of GNU CC.

GNU CC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU CC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU CC; see the file COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

#include "config.h"
#include "system.h"
#include "rtl.h"
#include "tree.h"
#include "regs.h"
#include "hard-reg-set.h"
#include "real.h"
#include "insn-config.h"
#include "conditions.h"
#include "function.h"
#include "output.h"
#include "insn-attr.h"
#include "recog.h"
#include "expr.h"
#include "flags.h"
#include "debug.h"
#include "tm_p.h"
#include "target.h"
#include "target-def.h"

static int follows_p PARAMS ((rtx, rtx));
static void vax_output_function_prologue PARAMS ((FILE *, HOST_WIDE_INT));
#if VMS_TARGET
static void vms_asm_out_constructor PARAMS ((rtx, int));
static void vms_asm_out_destructor PARAMS ((rtx, int));
static void vms_select_section PARAMS ((tree, int, unsigned HOST_WIDE_INT));
static void vms_encode_section_info PARAMS ((tree, int));
static void vms_globalize_label PARAMS ((FILE *, const char *));
#endif
static void vax_output_mi_thunk PARAMS ((FILE *, tree, HOST_WIDE_INT,
					 HOST_WIDE_INT, tree));

/* Initialize the GCC target structure.  */
#undef TARGET_ASM_ALIGNED_HI_OP
#define TARGET_ASM_ALIGNED_HI_OP "\t.word\t"

#undef TARGET_ASM_FUNCTION_PROLOGUE
#define TARGET_ASM_FUNCTION_PROLOGUE vax_output_function_prologue

#if VMS_TARGET
#undef TARGET_ASM_SELECT_SECTION
#define TARGET_ASM_SELECT_SECTION vms_select_section
#undef TARGET_ENCODE_SECTION_INFO
#define TARGET_ENCODE_SECTION_INFO vms_encode_section_info
#undef TARGET_ASM_GLOBALIZE_LABEL
#define TARGET_ASM_GLOBALIZE_LABEL vms_globalize_label
#endif

#undef TARGET_ASM_OUTPUT_MI_THUNK
#define TARGET_ASM_OUTPUT_MI_THUNK vax_output_mi_thunk
#undef TARGET_ASM_CAN_OUTPUT_MI_THUNK
#define TARGET_ASM_CAN_OUTPUT_MI_THUNK default_can_output_mi_thunk_no_vcall

struct gcc_target targetm = TARGET_INITIALIZER;

/* Set global variables as needed for the options enabled.  */

void
override_options ()
{
  /* We're VAX floating point, not IEEE floating point.  */
  memset (real_format_for_mode, 0, sizeof real_format_for_mode);
  real_format_for_mode[SFmode - QFmode] = &vax_f_format;
  real_format_for_mode[DFmode - QFmode]
    = (TARGET_G_FLOAT ? &vax_g_format : &vax_d_format);
}

/* Generate the assembly code for function entry.  FILE is a stdio
   stream to output the code to.  SIZE is an int: how many units of
   temporary storage to allocate.

   Refer to the array `regs_ever_live' to determine which registers to
   save; `regs_ever_live[I]' is nonzero if register number I is ever
   used in the function.  This function is responsible for knowing
   which registers should not be saved even if used.  */

static void
vax_output_function_prologue (file, size)
     FILE * file;
     HOST_WIDE_INT size;
{
  register int regno;
  register int mask = 0;

  for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
    if (regs_ever_live[regno] && !call_used_regs[regno])
      mask |= 1 << regno;

  fprintf (file, "\t.word 0x%x\n", mask);

  if (dwarf2out_do_frame ())
    {
      const char *label = dwarf2out_cfi_label ();
      int offset = 0;

      for (regno = FIRST_PSEUDO_REGISTER-1; regno >= 0; --regno)
	if (regs_ever_live[regno] && !call_used_regs[regno])
	  dwarf2out_reg_save (label, regno, offset -= 4);

      dwarf2out_reg_save (label, PC_REGNUM, offset -= 4);
      dwarf2out_reg_save (label, FRAME_POINTER_REGNUM, offset -= 4);
      dwarf2out_reg_save (label, ARG_POINTER_REGNUM, offset -= 4);
      dwarf2out_def_cfa (label, FRAME_POINTER_REGNUM, -(offset - 4));
    }

  if (VMS_TARGET)
    {
      /* Adjusting the stack pointer by 4 before calling C$MAIN_ARGS
	 is required when linking with the VMS POSIX version of the C
	 run-time library; using `subl2 $4,r0' is adequate but we use
	 `clrl -(sp)' instead.  The extra 4 bytes could be removed
	 after the call because STARTING_FRAME_OFFSET's setting of -4
	 will end up adding them right back again, but don't bother.  */

      if (MAIN_NAME_P (DECL_NAME (current_function_decl)))
	asm_fprintf (file, "\tclrl -(%Rsp)\n\tjsb _C$MAIN_ARGS\n");
    }

  size -= STARTING_FRAME_OFFSET;
  if (size >= 64)
    asm_fprintf (file, "\tmovab %d(%Rsp),%Rsp\n", -size);
  else if (size)
    asm_fprintf (file, "\tsubl2 $%d,%Rsp\n", size);
}

/* This is like nonimmediate_operand with a restriction on the type of MEM.  */

void
split_quadword_operands (operands, low, n)
     rtx *operands, *low;
     int n ATTRIBUTE_UNUSED;
{
  int i;
  /* Split operands.  */

  low[0] = low[1] = low[2] = 0;
  for (i = 0; i < 3; i++)
    {
      if (low[i])
	/* it's already been figured out */;
      else if (GET_CODE (operands[i]) == MEM
	       && (GET_CODE (XEXP (operands[i], 0)) == POST_INC))
	{
	  rtx addr = XEXP (operands[i], 0);
	  operands[i] = low[i] = gen_rtx_MEM (SImode, addr);
	  if (which_alternative == 0 && i == 0)
	    {
	      addr = XEXP (operands[i], 0);
	      operands[i+1] = low[i+1] = gen_rtx_MEM (SImode, addr);
	    }
	}
      else
	{
	  low[i] = operand_subword (operands[i], 0, 0, DImode);
	  operands[i] = operand_subword (operands[i], 1, 0, DImode);
	}
    }
}

void
print_operand_address (file, addr)
     FILE *file;
     register rtx addr;
{
  register rtx reg1, breg, ireg;
  rtx offset;

 retry:
  switch (GET_CODE (addr))
    {
    case MEM:
      fprintf (file, "*");
      addr = XEXP (addr, 0);
      goto retry;

    case REG:
      fprintf (file, "(%s)", reg_names[REGNO (addr)]);
      break;

    case PRE_DEC:
      fprintf (file, "-(%s)", reg_names[REGNO (XEXP (addr, 0))]);
      break;

    case POST_INC:
      fprintf (file, "(%s)+", reg_names[REGNO (XEXP (addr, 0))]);
      break;

    case PLUS:
      /* There can be either two or three things added here.  One must be a
	 REG.  One can be either a REG or a MULT of a REG and an appropriate
	 constant, and the third can only be a constant or a MEM.

	 We get these two or three things and put the constant or MEM in
	 OFFSET, the MULT or REG in IREG, and the REG in BREG.  If we have
	 a register and can't tell yet if it is a base or index register,
	 put it into REG1.  */

      reg1 = 0; ireg = 0; breg = 0; offset = 0;

      if (CONSTANT_ADDRESS_P (XEXP (addr, 0))
	  || GET_CODE (XEXP (addr, 0)) == MEM)
	{
	  offset = XEXP (addr, 0);
	  addr = XEXP (addr, 1);
	}
      else if (CONSTANT_ADDRESS_P (XEXP (addr, 1))
	       || GET_CODE (XEXP (addr, 1)) == MEM)
	{
	  offset = XEXP (addr, 1);
	  addr = XEXP (addr, 0);
	}
      else if (GET_CODE (XEXP (addr, 1)) == MULT)
	{
	  ireg = XEXP (addr, 1);
	  addr = XEXP (addr, 0);
	}
      else if (GET_CODE (XEXP (addr, 0)) == MULT)
	{
	  ireg = XEXP (addr, 0);
	  addr = XEXP (addr, 1);
	}
      else if (GET_CODE (XEXP (addr, 1)) == REG)
	{
	  reg1 = XEXP (addr, 1);
	  addr = XEXP (addr, 0);
	}
      else if (GET_CODE (XEXP (addr, 0)) == REG)
	{
	  reg1 = XEXP (addr, 0);
	  addr = XEXP (addr, 1);
	}
      else
	abort ();

      if (GET_CODE (addr) == REG)
	{
	  if (reg1)
	    ireg = addr;
	  else
	    reg1 = addr;
	}
      else if (GET_CODE (addr) == MULT)
	ireg = addr;
      else if (GET_CODE (addr) == PLUS)
	{
	  if (CONSTANT_ADDRESS_P (XEXP (addr, 0))
	      || GET_CODE (XEXP (addr, 0)) == MEM)
	    {
	      if (offset)
		{
		  if (GET_CODE (offset) == CONST_INT)
		    offset = plus_constant (XEXP (addr, 0), INTVAL (offset));
		  else if (GET_CODE (XEXP (addr, 0)) == CONST_INT)
		    offset = plus_constant (offset, INTVAL (XEXP (addr, 0)));
		  else
		    abort ();
		}
	      offset = XEXP (addr, 0);
	    }
	  else if (GET_CODE (XEXP (addr, 0)) == REG)
	    {
	      if (reg1)
		ireg = reg1, breg = XEXP (addr, 0), reg1 = 0;
	      else
		reg1 = XEXP (addr, 0);
	    }
	  else if (GET_CODE (XEXP (addr, 0)) == MULT)
	    {
	      if (ireg)
		abort ();
	      ireg = XEXP (addr, 0);
	    }
	  else
	    abort ();

	  if (CONSTANT_ADDRESS_P (XEXP (addr, 1))
	      || GET_CODE (XEXP (addr, 1)) == MEM)
	    {
	      if (offset)
		{
		  if (GET_CODE (offset) == CONST_INT)
		    offset = plus_constant (XEXP (addr, 1), INTVAL (offset));
		  else if (GET_CODE (XEXP (addr, 1)) == CONST_INT)
		    offset = plus_constant (offset, INTVAL (XEXP (addr, 1)));
		  else
		    abort ();
		}
	      offset = XEXP (addr, 1);
	    }
	  else if (GET_CODE (XEXP (addr, 1)) == REG)
	    {
	      if (reg1)
		ireg = reg1, breg = XEXP (addr, 1), reg1 = 0;
	      else
		reg1 = XEXP (addr, 1);
	    }
	  else if (GET_CODE (XEXP (addr, 1)) == MULT)
	    {
	      if (ireg)
		abort ();
	      ireg = XEXP (addr, 1);
	    }
	  else
	    abort ();
	}
      else
	abort ();

      /* If REG1 is nonzero, figure out if it is a base or index register.  */
      if (reg1)
	{
	  if (breg != 0 || (offset && GET_CODE (offset) == MEM))
	    {
	      if (ireg)
		abort ();
	      ireg = reg1;
	    }
	  else
	    breg = reg1;
	}

      if (offset != 0)
	output_address (offset);

      if (breg != 0)
	fprintf (file, "(%s)", reg_names[REGNO (breg)]);

      if (ireg != 0)
	{
	  if (GET_CODE (ireg) == MULT)
	    ireg = XEXP (ireg, 0);
	  if (GET_CODE (ireg) != REG)
	    abort ();
	  fprintf (file, "[%s]", reg_names[REGNO (ireg)]);
	}
      break;

    default:
      output_addr_const (file, addr);
    }
}

const char *
rev_cond_name (op)
     rtx op;
{
  switch (GET_CODE (op))
    {
    case EQ:
      return "neq";
    case NE:
      return "eql";
    case LT:
      return "geq";
    case LE:
      return "gtr";
    case GT:
      return "leq";
    case GE:
      return "lss";
    case LTU:
      return "gequ";
    case LEU:
      return "gtru";
    case GTU:
      return "lequ";
    case GEU:
      return "lssu";

    default:
      abort ();
    }
}

int
vax_float_literal(c)
    register rtx c;
{
  register enum machine_mode mode;
  REAL_VALUE_TYPE r, s;
  int i;

  if (GET_CODE (c) != CONST_DOUBLE)
    return 0;

  mode = GET_MODE (c);

  if (c == const_tiny_rtx[(int) mode][0]
      || c == const_tiny_rtx[(int) mode][1]
      || c == const_tiny_rtx[(int) mode][2])
    return 1;

  REAL_VALUE_FROM_CONST_DOUBLE (r, c);

  for (i = 0; i < 7; i++)
    {
      int x = 1 << i;
      REAL_VALUE_FROM_INT (s, x, 0, mode);

      if (REAL_VALUES_EQUAL (r, s))
	return 1;
      if (!exact_real_inverse (mode, &s))
	abort ();
      if (REAL_VALUES_EQUAL (r, s))
	return 1;
    }
  return 0;
}


/* Return the cost in cycles of a memory address, relative to register
   indirect.

   Each of the following adds the indicated number of cycles:

   1 - symbolic address
   1 - pre-decrement
   1 - indexing and/or offset(register)
   2 - indirect */


int
vax_address_cost (addr)
    register rtx addr;
{
  int reg = 0, indexed = 0, indir = 0, offset = 0, predec = 0;
  rtx plus_op0 = 0, plus_op1 = 0;
 restart:
  switch (GET_CODE (addr))
    {
    case PRE_DEC:
      predec = 1;
    case REG:
    case SUBREG:
    case POST_INC:
      reg = 1;
      break;
    case MULT:
      indexed = 1;	/* 2 on VAX 2 */
      break;
    case CONST_INT:
      /* byte offsets cost nothing (on a VAX 2, they cost 1 cycle) */
      if (offset == 0)
	offset = (unsigned HOST_WIDE_INT)(INTVAL(addr)+128) > 256;
      break;
    case CONST:
    case SYMBOL_REF:
      offset = 1;	/* 2 on VAX 2 */
      break;
    case LABEL_REF:	/* this is probably a byte offset from the pc */
      if (offset == 0)
	offset = 1;
      break;
    case PLUS:
      if (plus_op0)
	plus_op1 = XEXP (addr, 0);
      else
	plus_op0 = XEXP (addr, 0);
      addr = XEXP (addr, 1);
      goto restart;
    case MEM:
      indir = 2;	/* 3 on VAX 2 */
      addr = XEXP (addr, 0);
      goto restart;
    default:
      break;
    }

  /* Up to 3 things can be added in an address.  They are stored in
     plus_op0, plus_op1, and addr.  */

  if (plus_op0)
    {
      addr = plus_op0;
      plus_op0 = 0;
      goto restart;
    }
  if (plus_op1)
    {
      addr = plus_op1;
      plus_op1 = 0;
      goto restart;
    }
  /* Indexing and register+offset can both be used (except on a VAX 2)
     without increasing execution time over either one alone.  */
  if (reg && indexed && offset)
    return reg + indir + offset + predec;
  return reg + indexed + indir + offset + predec;
}