h8300.c

gcc-2.95.3 Linux下最常用的C编译器

/* Subroutines for insn-output.c for Hitachi H8/300.
   Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000
   Free Software Foundation, Inc. 
   Contributed by Steve Chamberlain ([e-mail]),
   Jim Wilson ([e-mail]), and Doug Evans ([e-mail]).

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 <stdio.h>
#include "rtl.h"
#include "regs.h"
#include "hard-reg-set.h"
#include "real.h"
#include "insn-config.h"
#include "conditions.h"
#include "insn-flags.h"
#include "output.h"
#include "insn-attr.h"
#include "flags.h"
#include "recog.h"
#include "expr.h"
#include "tree.h"
#include "obstack.h"

/* Forward declarations.  */
void print_operand_address ();
char *index ();

static int h8300_interrupt_function_p PROTO ((tree));
static int h8300_monitor_function_p PROTO ((tree));
static int h8300_os_task_function_p PROTO ((tree));

/* CPU_TYPE, says what cpu we're compiling for.  */
int cpu_type;

/* True if the current function is an interrupt handler
   (either via #pragma or an attribute specification).  */
int interrupt_handler;

/* True if the current function is an OS Task
   (via an attribute specification).  */
int os_task;

/* True if the current function is a monitor
   (via an attribute specification).  */
int monitor;

/* True if a #pragma saveall has been seen for the current function.  */
int pragma_saveall;

static char *names_big[] =
{"r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7"};

static char *names_extended[] =
{"er0", "er1", "er2", "er3", "er4", "er5", "er6", "er7"};

static char *names_upper_extended[] =
{"e0", "e1", "e2", "e3", "e4", "e5", "e6", "e7"};

/* Points to one of the above.  */
/* ??? The above could be put in an array indexed by CPU_TYPE.  */
char **h8_reg_names;

/* Various operations needed by the following, indexed by CPU_TYPE.  */

static char *h8_push_ops[2] =
{"push", "push.l"};
static char *h8_pop_ops[2] =
{"pop", "pop.l"};
static char *h8_mov_ops[2] =
{"mov.w", "mov.l"};

char *h8_push_op, *h8_pop_op, *h8_mov_op;

/* Initialize various cpu specific globals at start up.  */

void
h8300_init_once ()
{
  if (TARGET_H8300)
    {
      cpu_type = (int) CPU_H8300;
      h8_reg_names = names_big;
    }
  else
    {
      /* For this we treat the H8/300 and H8/S the same.  */
      cpu_type = (int) CPU_H8300H;
      h8_reg_names = names_extended;
    }
  h8_push_op = h8_push_ops[cpu_type];
  h8_pop_op = h8_pop_ops[cpu_type];
  h8_mov_op = h8_mov_ops[cpu_type];
}

char *
byte_reg (x, b)
     rtx x;
     int b;
{
  static char *names_small[] =
  {"r0l", "r0h", "r1l", "r1h", "r2l", "r2h", "r3l", "r3h",
   "r4l", "r4h", "r5l", "r5h", "r6l", "r6h", "r7l", "r7h"};

  return names_small[REGNO (x) * 2 + b];
}

/* REGNO must be saved/restored across calls if this macro is true.  */

#define WORD_REG_USED(regno)					\
  (regno < 7 &&							\
   (interrupt_handler						\
    || pragma_saveall						\
    || (regno == FRAME_POINTER_REGNUM && regs_ever_live[regno])	\
    || (regs_ever_live[regno] && !call_used_regs[regno])))

/* Output assembly language to FILE for the operation OP with operand size
   SIZE to adjust the stack pointer.  */

static void
dosize (file, op, size)
     FILE *file;
     char *op;
     unsigned int size;
{
  /* On the h8300h and h8300s, for sizes <= 8 bytes it is as good or
     better to use adds/subs insns rather than add.l/sub.l
     with an immediate value.   */
  if (size > 4 && size <= 8 && (TARGET_H8300H || TARGET_H8300S))
    {
      /* Crank the size down to <= 4 */
      fprintf (file, "\t%ss\t#%d,sp\n", op, 4);
      size -= 4;
    }

  switch (size)
    {
    case 4:
      if (TARGET_H8300H || TARGET_H8300S)
	{
	  fprintf (file, "\t%ss\t#%d,sp\n", op, 4);
	  size = 0;
	  break;
	}
    case 3:
      fprintf (file, "\t%ss\t#%d,sp\n", op, 2);
      size -= 2;
      /* Fall through...  */
    case 2:
    case 1:
      fprintf (file, "\t%ss\t#%d,sp\n", op, size);
      size = 0;
      break;
    case 0:
      break;
    default:
      if (TARGET_H8300)
	{
	  if (current_function_needs_context
	      && strcmp (op, "sub") == 0)
	    {
	      /* Egad.  We don't have a temporary to hold the
		 size of the frame in the prologue!  Just inline
		 the bastard since this shouldn't happen often.  */
	      while (size >= 2)
		{
		  fprintf (file, "\tsubs\t#2,sp\n");
		  size -= 2;
		}

	      if (size)
		fprintf (file, "\tsubs\t#1,sp\n");

	      size = 0;
	    }
	  else
	    fprintf (file, "\tmov.w\t#%d,r3\n\t%s.w\tr3,sp\n", size, op);
	}
      else
	fprintf (file, "\t%s\t#%d,sp\n", op, size);
      size = 0;
      break;
    }
}

/* Output assembly language code for the function prologue.  */
static int push_order[FIRST_PSEUDO_REGISTER] =
{0, 1, 2, 3, 4, 5, 6, -1, -1, -1};
static int pop_order[FIRST_PSEUDO_REGISTER] =
{6, 5, 4, 3, 2, 1, 0, -1, -1, -1};

/* This is what the stack looks like after the prolog of 
   a function with a frame has been set up:

   <args>
   PC
   FP			<- fp
   <locals>
   <saved registers> 	<- sp

   This is what the stack looks like after the prolog of
   a function which doesn't have a frame:

   <args>
   PC
   <locals>
   <saved registers>   	<- sp
*/

void
function_prologue (file, size)
     FILE *file;
     int size;
{
  register int mask = 0;
  int fsize = (size + STACK_BOUNDARY / 8 - 1) & -STACK_BOUNDARY / 8;
  int idx;

  /* Note a function with the interrupt attribute and set interrupt_handler
     accordingly.  */
  if (h8300_interrupt_function_p (current_function_decl))
    interrupt_handler = 1;

  /* If the current function has the OS_Task attribute set, then
     we have a naked prologue.  */
  if (h8300_os_task_function_p (current_function_decl))
    {
      fprintf (file, ";OS_Task prologue\n");
      os_task = 1;
      return;
    }

  if (h8300_monitor_function_p (current_function_decl))
    {
      /* My understanding of monitor functions is they act just
	 like interrupt functions, except the prologue must
	 mask interrupts.  */
      fprintf (file, ";monitor prologue\n");
      interrupt_handler = 1;
      monitor = 1;
      if (TARGET_H8300)
	{
	  fprintf (file, "\tsubs\t#2,sp\n");
	  fprintf (file, "\tpush\tr0\n");
	  fprintf (file, "\tstc\tccr,r0l\n");
	  fprintf (file, "\torc\t#128,ccr\n");
	  fprintf (file, "\tmov.b\tr0l,@(4,sp)\n");
	}
      else
	{
	  fprintf (file, "\tpush\ter0\n");
	  fprintf (file, "\tstc\tccr,r0l\n");
	  fprintf (file, "\torc\t#128,ccr\n");
	  fprintf (file, "\tmov.b\tr0l,@(4,sp)\n");
	}
    }

  if (frame_pointer_needed)
    {
      /* Push fp */
      fprintf (file, "\t%s\t%s\n", h8_push_op,
	       h8_reg_names[FRAME_POINTER_REGNUM]);
      fprintf (file, "\t%s\t%s,%s\n", h8_mov_op,
	       h8_reg_names[STACK_POINTER_REGNUM],
	       h8_reg_names[FRAME_POINTER_REGNUM]);
    }

  /* leave room for locals */
  dosize (file, "sub", fsize);

  /* Push the rest of the registers */
  for (idx = 0; idx < FIRST_PSEUDO_REGISTER; idx++)
    {
      int regno = push_order[idx];

      if (regno >= 0
	  && WORD_REG_USED (regno)
	  && (!frame_pointer_needed || regno != FRAME_POINTER_REGNUM))
	{
	  if (TARGET_H8300S)
	    {
	      /* Try to push multiple registers.  */
	      if (regno == 0 || regno == 4)
		{
		  int second_regno = push_order[idx + 1];
		  int third_regno = push_order[idx + 2];
		  int fourth_regno = push_order[idx + 3];

		  if (fourth_regno >= 0
		      && WORD_REG_USED (fourth_regno)
		      && (!frame_pointer_needed
			  || fourth_regno != FRAME_POINTER_REGNUM)
		      && third_regno >= 0
		      && WORD_REG_USED (third_regno)
		      && (!frame_pointer_needed
			  || third_regno != FRAME_POINTER_REGNUM)
		      && second_regno >= 0
		      && WORD_REG_USED (second_regno)
		      && (!frame_pointer_needed
			  || second_regno != FRAME_POINTER_REGNUM))
		    {
		      fprintf (file, "\tstm.l %s-%s,@-sp\n", 
			       h8_reg_names[regno],
			       h8_reg_names[fourth_regno]);
		      idx += 3;
		      continue;
		    }
		}
	      if (regno == 0 || regno == 4)
		{
		  int second_regno = push_order[idx + 1];
		  int third_regno = push_order[idx + 2];

		  if (third_regno >= 0
		      && WORD_REG_USED (third_regno)
		      && (!frame_pointer_needed
			  || third_regno != FRAME_POINTER_REGNUM)
		      && second_regno >= 0
		      && WORD_REG_USED (second_regno)
		      && (!frame_pointer_needed
			  || second_regno != FRAME_POINTER_REGNUM))
		    {
		      fprintf (file, "\tstm.l %s-%s,@-sp\n", 
			       h8_reg_names[regno],
			       h8_reg_names[third_regno]);
		      idx += 2;
		      continue;
		    }
		}
	      if (regno == 0 || regno == 2 || regno == 4 || regno == 6)
		{
		  int second_regno = push_order[idx + 1];

		  if (second_regno >= 0
		      && WORD_REG_USED (second_regno)
		      && (!frame_pointer_needed
			  || second_regno != FRAME_POINTER_REGNUM))
		    {
		      fprintf (file, "\tstm.l %s-%s,@-sp\n", 
			       h8_reg_names[regno],
			       h8_reg_names[second_regno]);
		      idx += 1;
		      continue;
		    }
		}
	    }
	  fprintf (file, "\t%s\t%s\n", h8_push_op, h8_reg_names[regno]);
	}
    }
}

/* Output assembly language code for the function epilogue.  */

void
function_epilogue (file, size)
     FILE *file;
     int size;
{
  register int regno;
  register int mask = 0;
  int fsize = (size + STACK_BOUNDARY / 8 - 1) & -STACK_BOUNDARY / 8;
  int idx;
  rtx insn = get_last_insn ();

  if (os_task)
    {
      /* OS_Task epilogues are nearly naked -- they just have an
	 rts instruction.  */
      fprintf (file, ";OS_task epilogue\n");
      fprintf (file, "\trts\n");
      goto out;
    }

  /* monitor epilogues are the same as interrupt function epilogues.
     Just make a note that we're in an monitor epilogue.  */
  if (monitor)
    fprintf(file, ";monitor epilogue\n");

  /* If the last insn was a BARRIER, we don't have to write any code.  */
  if (GET_CODE (insn) == NOTE)
    insn = prev_nonnote_insn (insn);
  if (insn && GET_CODE (insn) == BARRIER)
    goto out;

  /* Pop the saved registers. */
  for (idx = 0; idx < FIRST_PSEUDO_REGISTER; idx++)
    {
      int regno = pop_order[idx];

      if (regno >= 0
	  && WORD_REG_USED (regno)
	  && (!frame_pointer_needed || regno != FRAME_POINTER_REGNUM))
	{
	  if (TARGET_H8300S)
	    {
	      /* Try to pop multiple registers.  */
	      if (regno == 7 || regno == 3)
		{
		  int second_regno = pop_order[idx + 1];
		  int third_regno = pop_order[idx + 2];
		  int fourth_regno = pop_order[idx + 3];

		  if (fourth_regno >= 0
		      && WORD_REG_USED (fourth_regno)
		      && (!frame_pointer_needed
			  || fourth_regno != FRAME_POINTER_REGNUM)
		      && third_regno >= 0
		      && WORD_REG_USED (third_regno)
		      && (!frame_pointer_needed
			  || third_regno != FRAME_POINTER_REGNUM)
		      && second_regno >= 0
		      && WORD_REG_USED (second_regno)
		      && (!frame_pointer_needed
			  || second_regno != FRAME_POINTER_REGNUM))
		    {
		      fprintf (file, "\tldm.l @sp+,%s-%s\n", 
			       h8_reg_names[fourth_regno],
			       h8_reg_names[regno]);
		      idx += 3;
		      continue;
		    }
		}
	      if (regno == 6 || regno == 2)
		{
		  int second_regno = pop_order[idx + 1];
		  int third_regno = pop_order[idx + 2];

		  if (third_regno >= 0
		      && WORD_REG_USED (third_regno)
		      && (!frame_pointer_needed
			  || third_regno != FRAME_POINTER_REGNUM)
		      && second_regno >= 0
		      && WORD_REG_USED (second_regno)
		      && (!frame_pointer_needed
			  || second_regno != FRAME_POINTER_REGNUM))
		    {
		      fprintf (file, "\tldm.l @sp+,%s-%s\n", 
			       h8_reg_names[third_regno],
			       h8_reg_names[regno]);
		      idx += 2;
		      continue;
		    }
		}
	      if (regno == 7 || regno == 5 || regno == 3 || regno == 1)
		{
		  int second_regno = pop_order[idx + 1];

		  if (second_regno >= 0
		      && WORD_REG_USED (second_regno)
		      && (!frame_pointer_needed
			  || second_regno != FRAME_POINTER_REGNUM))
		    {
		      fprintf (file, "\tldm.l @sp+,%s-%s\n", 
			       h8_reg_names[second_regno],
			       h8_reg_names[regno]);
		      idx += 1;
		      continue;
		    }
		}
	    }
	  fprintf (file, "\t%s\t%s\n", h8_pop_op, h8_reg_names[regno]);
	}
    }

  /* deallocate locals */
  dosize (file, "add", fsize);

  /* pop frame pointer if we had one. */
  if (frame_pointer_needed)
    fprintf (file, "\t%s\t%s\n", h8_pop_op, h8_reg_names[FRAME_POINTER_REGNUM]);

  /* If this is a monitor function, there is one register still left on
     the stack.  */
  if (monitor)
    fprintf (file, "\t%s\t%s\n", h8_pop_op, h8_reg_names[0]);

  if (interrupt_handler)
    fprintf (file, "\trte\n");
  else
    fprintf (file, "\trts\n");

out:
  interrupt_handler = 0;
  os_task = 0;
  monitor = 0;