rtl.c

这是完整的gcc源代码

/* Allocate, read and print RTL for C-Compiler
   Copyright (C) 1987, 1988 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 1, 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, 675 Mass Ave, Cambridge, MA 02139, USA.  */


#include "config.h"
#include <ctype.h>
#include <stdio.h>
#include "rtl.h"

#include "obstack.h"
#define	obstack_chunk_alloc	xmalloc
#define	obstack_chunk_free	free
extern int xmalloc ();
extern void free ();

/* Obstack used for allocating RTL objects.
   Between functions, this is the permanent_obstack.
   While parsing and expanding a function, this is maybepermanent_obstack
   so we can save it if it is an inline function.
   During optimization and output, this is temporary_obstack.  */

extern struct obstack *rtl_obstack;

#define MIN(x,y) ((x < y) ? x : y)

extern long ftell();

/* Indexed by rtx code, gives number of operands for an rtx with that code.
   Does NOT include rtx header data (code and links).
   This array is initialized in init_rtl.  */

int rtx_length[NUM_RTX_CODE + 1];

/* Indexed by rtx code, gives the name of that kind of rtx, as a C string.  */

#define DEF_RTL_EXPR(ENUM, NAME, FORMAT)   NAME ,

char *rtx_name[] = {
#include "rtl.def"		/* rtl expressions are documented here */
};

#undef DEF_RTL_EXPR

/* Indexed by machine mode, gives the name of that machine mode.
   This name does not include the letters "mode".  */

#define DEF_MACHMODE(SYM, NAME, CLASS, SIZE, UNIT, WIDER)  NAME,

char *mode_name[] = {
#include "machmode.def"
};

#undef DEF_MACHMODE

/* Indexed by machine mode, gives the length of the mode, in bytes.
   GET_MODE_CLASS uses this.  */

#define DEF_MACHMODE(SYM, NAME, CLASS, SIZE, UNIT, WIDER)  CLASS,

enum mode_class mode_class[] = {
#include "machmode.def"
};

#undef DEF_MACHMODE

/* Indexed by machine mode, gives the length of the mode, in bytes.
   GET_MODE_SIZE uses this.  */

#define DEF_MACHMODE(SYM, NAME, CLASS, SIZE, UNIT, WIDER)  \
  (SIZE*UNITS_PER_WORD+3)/4,

int mode_size[] = {
#include "machmode.def"
};

#undef DEF_MACHMODE

/* Indexed by machine mode, gives the length of the mode's subunit.
   GET_MODE_UNIT_SIZE uses this.  */

#define DEF_MACHMODE(SYM, NAME, CLASS, SIZE, UNIT, WIDER)  \
  (UNIT*UNITS_PER_WORD+3)/4,

int mode_unit_size[] = {
#include "machmode.def"		/* machine modes are documented here */
};

#undef DEF_MACHMODE

/* Indexed by machine mode, gives next wider natural mode
   (QI -> HI -> SI -> DI, etc.)  Widening multiply instructions
   use this.  */

#define DEF_MACHMODE(SYM, NAME, CLASS, SIZE, UNIT, WIDER)  \
  (enum machine_mode) WIDER,

enum machine_mode mode_wider_mode[] = {
#include "machmode.def"		/* machine modes are documented here */
};

#undef DEF_MACHMODE

/* Indexed by rtx code, gives a sequence of operand-types for
   rtx's of that code.  The sequence is a C string in which
   each charcter describes one operand.  */

char *rtx_format[] = {
  /* "*" undefined.
         can cause a warning message
     "0" field is unused (or used in a phase-dependent manner)
         prints nothing
     "i" an integer
         prints the integer
     "s" a pointer to a string
         prints the string
     "S" like "s", but optional:
	 the containing rtx may end before this operand
     "e" a pointer to an rtl expression
         prints the expression
     "E" a pointer to a vector that points to a number of rtl expressions
         prints a list of the rtl expressions
     "u" a pointer to another insn
         prints the uid of the insn.  */

#define DEF_RTL_EXPR(ENUM, NAME, FORMAT)   FORMAT ,
#include "rtl.def"		/* rtl expressions are defined here */
#undef DEF_RTL_EXPR
};

/* Names for kinds of NOTEs and REG_NOTEs.  */

char *note_insn_name[] = { "NOTE_INSN_FUNCTION_BEG", "NOTE_INSN_DELETED",
			   "NOTE_INSN_BLOCK_BEG", "NOTE_INSN_BLOCK_END",
			   "NOTE_INSN_LOOP_BEG", "NOTE_INSN_LOOP_END",
			   "NOTE_INSN_FUNCTION_END", "NOTE_INSN_SETJMP",
			   "NOTE_INSN_LOOP_CONT" };

char *reg_note_name[] = { "", "REG_DEAD", "REG_INC", "REG_EQUIV", "REG_WAS_0",
			  "REG_EQUAL", "REG_RETVAL", "REG_LIBCALL",
			  "REG_NONNEG", "REG_UNSET" };

/* Allocate an rtx vector of N elements.
   Store the length, and initialize all elements to zero.  */

rtvec
rtvec_alloc (n)
     int n;
{
  rtvec rt;
  int i;

  rt = (rtvec) obstack_alloc (rtl_obstack,
			      sizeof (struct rtvec_def)
			      + (( n - 1) * sizeof (rtunion)));

  /* clear out the vector */
  PUT_NUM_ELEM(rt, n);
  for (i=0; i < n; i++)
    rt->elem[i].rtvec = NULL;	/* @@ not portable due to rtunion */

  return rt;
}

/* Allocate an rtx of code CODE.  The CODE is stored in the rtx;
   all the rest is initialized to zero.  */

rtx
rtx_alloc (code)
  RTX_CODE code;
{
  rtx rt;
  register int nelts = GET_RTX_LENGTH (code);
  register int length = sizeof (struct rtx_def)
    + (nelts - 1) * sizeof (rtunion);

  rt = (rtx) obstack_alloc (rtl_obstack, length);

  * (int *) rt = 0;
  PUT_CODE (rt, code);

  return rt;
}

/* Create a new copy of an rtx.
   Recursively copies the operands of the rtx,
   except for those few rtx codes that are sharable.  */

rtx
copy_rtx (orig)
     register rtx orig;
{
  register rtx copy;
  register int i, j;
  register RTX_CODE code;
  register char *format_ptr;

  code = GET_CODE (orig);

  switch (code)
    {
    case REG:
    case QUEUED:
    case CONST_INT:
    case CONST_DOUBLE:
    case SYMBOL_REF:
    case CODE_LABEL:
    case PC:
    case CC0:
      return orig;
    }

  copy = rtx_alloc (code);
  PUT_MODE (copy, GET_MODE (orig));
  copy->in_struct = orig->in_struct;
  copy->volatil = orig->volatil;
  copy->unchanging = orig->unchanging;
  copy->integrated = orig->integrated;
  
  format_ptr = GET_RTX_FORMAT (GET_CODE (copy));

  for (i = 0; i < GET_RTX_LENGTH (GET_CODE (copy)); i++)
    {
      switch (*format_ptr++)
	{
	case 'e':
	  XEXP (copy, i) = XEXP (orig, i);
	  if (XEXP (orig, i) != NULL)
	    XEXP (copy, i) = copy_rtx (XEXP (orig, i));
	  break;

	case 'E':
	  XVEC (copy, i) = XVEC (orig, i);
	  if (XVEC (orig, i) != NULL)
	    {
	      XVEC (copy, i) = rtvec_alloc (XVECLEN (orig, i));
	      for (j = 0; j < XVECLEN (copy, i); j++)
		XVECEXP (copy, i, j) = copy_rtx (XVECEXP (orig, i, j));
	    }
	  break;

	default:
	  XINT (copy, i) = XINT (orig, i);
	  break;
	}
    }
  return copy;
}

/* Printing rtl for debugging dumps.  */

static FILE *outfile;

char spaces[] = "                                                                                                                                                                ";

static int sawclose = 0;

/* Print IN_RTX onto OUTFILE.  This is the recursive part of printing.  */

static void
print_rtx (in_rtx)
     register rtx in_rtx;
{
  static int indent;
  register int i, j;
  register char *format_ptr;

  if (sawclose)
    {
      fprintf (outfile, "\n%s",
	       (spaces + (sizeof spaces - indent * 2)));
      sawclose = 0;
    }

  if (in_rtx == 0)
    {
      fprintf (outfile, "(nil)");
      sawclose = 1;
      return;
    }

  /* print name of expression code */
  fprintf (outfile, "(%s", GET_RTX_NAME (GET_CODE (in_rtx)));

  if (in_rtx->in_struct)
    fprintf (outfile, "/s");

  if (in_rtx->volatil)
    fprintf (outfile, "/v");

  if (in_rtx->unchanging)
    fprintf (outfile, "/u");

  if (in_rtx->integrated)
    fprintf (outfile, "/i");

  if (GET_MODE (in_rtx) != VOIDmode)
    {
      /* Print REG_NOTE names for EXPR_LIST and INSN_LIST.  */
      if (GET_CODE (in_rtx) == EXPR_LIST || GET_CODE (in_rtx) == INSN_LIST)
	fprintf (outfile, ":%s", GET_REG_NOTE_NAME (GET_MODE (in_rtx)));
      else
	fprintf (outfile, ":%s", GET_MODE_NAME (GET_MODE (in_rtx)));
    }

  format_ptr = GET_RTX_FORMAT (GET_CODE (in_rtx));

  for (i = 0; i < GET_RTX_LENGTH (GET_CODE (in_rtx)); i++)
    switch (*format_ptr++)
      {
      case 'S':
      case 's':
	if (XSTR (in_rtx, i) == 0)
	  fprintf (outfile, " \"\"");
	else
	  fprintf (outfile, " (\"%s\")", XSTR (in_rtx, i));
	sawclose = 1;
	break;

	/* 0 indicates a field for internal use that should not be printed.  */
      case '0':
	break;

      case 'e':
	indent += 2;
	if (!sawclose)
	  fprintf (outfile, " ");
	print_rtx (XEXP (in_rtx, i));
	indent -= 2;
	break;

      case 'E':
	indent += 2;
	if (sawclose)
	  {
	    fprintf (outfile, "\n%s",
		     (spaces + (sizeof spaces - indent * 2)));
	    sawclose = 0;
	  }
	fprintf (outfile, "[ ");
	if (NULL != XVEC (in_rtx, i))
	  {
	    indent += 2;
	    if (XVECLEN (in_rtx, i))
	      sawclose = 1;

	    for (j = 0; j < XVECLEN (in_rtx, i); j++)
	      print_rtx (XVECEXP (in_rtx, i, j));

	    indent -= 2;
	  }
	if (sawclose)
	  fprintf (outfile, "\n%s",
		   (spaces + (sizeof spaces - indent * 2)));

	fprintf (outfile, "] ");
	sawclose = 1;
	indent -= 2;
	break;

      case 'i':
	fprintf (outfile, " %d", XINT (in_rtx, i));
	sawclose = 0;
	break;

      /* Print NOTE_INSN names rather than integer codes.  */

      case 'n':
	if (XINT (in_rtx, i) <= 0)
	  fprintf (outfile, " %s", GET_NOTE_INSN_NAME (XINT (in_rtx, i)));
	else
	  fprintf (outfile, " %d", XINT (in_rtx, i));
	sawclose = 0;
	break;

      case 'u':
	if (XEXP (in_rtx, i) != NULL)
	  fprintf(outfile, " %d", INSN_UID (XEXP (in_rtx, i)));
	else
	  fprintf(outfile, " 0");
	sawclose = 0;
	break;

      default:
	fprintf (stderr,
		 "switch format wrong in rtl.print_rtx(). format was: %c.\n",
		 format_ptr[-1]);
	abort ();
      }

  fprintf (outfile, ")");