dsp16xx.c

gcc-you can use this code to learn something about gcc, and inquire further into linux,

/* Subroutines for assembler code output on the DSP1610.
   Copyright (C) 1994, 1995, 1997, 1998, 2001 Free Software Foundation, Inc.
   Contributed by Michael Collison ([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.  */

/* Some output-actions in dsp1600.md need these.  */
#include "config.h"
#include "system.h"
#include "rtl.h"
#include "regs.h"
#include "hard-reg-set.h"
#include "real.h"
#include "insn-config.h"
#include "conditions.h"
#include "output.h"
#include "insn-attr.h"
#include "tree.h"
#include "expr.h"
#include "function.h"
#include "flags.h"
#include "ggc.h"
#include "toplev.h"
#include "recog.h"
#include "tm_p.h"
#include "target.h"
#include "target-def.h"

const char *text_seg_name;
const char *rsect_text;
const char *data_seg_name;
const char *rsect_data;
const char *bss_seg_name;
const char *rsect_bss;
const char *const_seg_name;
const char *rsect_const;

const char *chip_name;
const char *save_chip_name;

/* Save the operands of a compare. The 16xx has not lt or gt, so
   in these cases we swap the operands and reverse the condition.  */

rtx dsp16xx_compare_op0;
rtx dsp16xx_compare_op1;
rtx (*dsp16xx_compare_gen) PARAMS (());

static const char *fp;
static const char *sp;
static const char *rr;
static const char *a1h;

struct dsp16xx_frame_info current_frame_info;
struct dsp16xx_frame_info zero_frame_info;

rtx dsp16xx_addhf3_libcall = (rtx) 0;
rtx dsp16xx_subhf3_libcall = (rtx) 0;
rtx dsp16xx_mulhf3_libcall = (rtx) 0;
rtx dsp16xx_divhf3_libcall = (rtx) 0;
rtx dsp16xx_cmphf3_libcall = (rtx) 0;
rtx dsp16xx_fixhfhi2_libcall = (rtx) 0;
rtx dsp16xx_floathihf2_libcall = (rtx) 0;
rtx dsp16xx_neghf2_libcall = (rtx) 0;

rtx dsp16xx_mulhi3_libcall = (rtx) 0;
rtx dsp16xx_udivqi3_libcall = (rtx) 0;
rtx dsp16xx_udivhi3_libcall = (rtx) 0;
rtx dsp16xx_divqi3_libcall = (rtx) 0;
rtx dsp16xx_divhi3_libcall = (rtx) 0;
rtx dsp16xx_modqi3_libcall = (rtx) 0;
rtx dsp16xx_modhi3_libcall = (rtx) 0;
rtx dsp16xx_umodqi3_libcall = (rtx) 0;
rtx dsp16xx_umodhi3_libcall = (rtx) 0;
rtx dsp16xx_ashrhi3_libcall = (rtx) 0;
rtx dsp16xx_ashlhi3_libcall = (rtx) 0;
rtx dsp16xx_ucmphi2_libcall = (rtx) 0;
rtx dsp16xx_lshrhi3_libcall = (rtx) 0;

static const char *const himode_reg_name[] = HIMODE_REGISTER_NAMES;

#define SHIFT_INDEX_1   0
#define SHIFT_INDEX_4   1
#define SHIFT_INDEX_8   2
#define SHIFT_INDEX_16  3

static const char *const ashift_right_asm[] = 
{
  "%0=%0>>1",
  "%0=%0>>4",
  "%0=%0>>8",
  "%0=%0>>16"
};

static const char *const ashift_right_asm_first[] = 
{
  "%0=%1>>1",
  "%0=%1>>4",
  "%0=%1>>8",
  "%0=%1>>16"
};

static const char *const ashift_left_asm[] = 
{
  "%0=%0<<1",
  "%0=%0<<4",
  "%0=%0<<8",
  "%0=%0<<16"
};

static const char *const ashift_left_asm_first[] = 
{
  "%0=%1<<1",
  "%0=%1<<4",
  "%0=%1<<8",
  "%0=%1<<16"
};

static const char *const lshift_right_asm[] = 
{
  "%0=%0>>1\n\t%0=%b0&0x7fff",
  "%0=%0>>4\n\t%0=%b0&0x0fff",
  "%0=%0>>8\n\t%0=%b0&0x00ff",
  "%0=%0>>16\n\t%0=%b0&0x0000"
};

static const char *const lshift_right_asm_first[] = 
{
  "%0=%1>>1\n\t%0=%b0&0x7fff",
  "%0=%1>>4\n\t%0=%b0&0x0fff",
  "%0=%1>>8\n\t%0=%b0&0x00ff",
  "%0=%1>>16\n\t%0=%b0&0x0000"
};

static int reg_save_size PARAMS ((void));
static void dsp16xx_output_function_prologue PARAMS ((FILE *, HOST_WIDE_INT));
static void dsp16xx_output_function_epilogue PARAMS ((FILE *, HOST_WIDE_INT));

/* Initialize the GCC target structure.  */
#undef TARGET_ASM_BYTE_OP
#define TARGET_ASM_BYTE_OP "\tint\t"
#undef TARGET_ASM_ALIGNED_HI_OP
#define TARGET_ASM_ALIGNED_HI_OP NULL
#undef TARGET_ASM_ALIGNED_SI_OP
#define TARGET_ASM_ALIGNED_SI_OP NULL

#undef TARGET_ASM_FUNCTION_PROLOGUE
#define TARGET_ASM_FUNCTION_PROLOGUE dsp16xx_output_function_prologue
#undef TARGET_ASM_FUNCTION_EPILOGUE
#define TARGET_ASM_FUNCTION_EPILOGUE dsp16xx_output_function_epilogue

struct gcc_target targetm = TARGET_INITIALIZER;

int 
hard_regno_mode_ok (regno, mode)
     int regno;
     enum machine_mode mode;
{
  switch ((int) mode)
    {
    case VOIDmode:
      return 1;
      
      /* We can't use the c0-c2 for QImode, since they are only
	 8 bits in length.  */

    case QImode:
      if (regno != REG_C0 && regno != REG_C1 && regno != REG_C2)
	return 1;
      else
	return 0;
      
      /* We only allow a0, a1, y, and p to be allocated for 32-bit modes.
         Additionally we allow the virtual ybase registers to be used for 32-bit
	 modes.  */
      
    case HFmode:
    case SFmode:
    case DFmode:
    case XFmode:
    case HImode:
    case SImode:
    case DImode:
      if (regno == REG_A0 || regno == REG_A1 || regno == REG_Y || regno == REG_PROD
	  || (IS_YBASE_REGISTER_WINDOW(regno) && ((regno & 1) == 0)))
	return 1;
      else
	return 0;
      
    default:
      return 0;
    }
}

enum reg_class
dsp16xx_reg_class_from_letter (c)
     int c;
{
  switch (c)
    {
    case 'A':
      return ACCUM_REGS;

    case 'l':
      return A0_REG;

    case 'C':
      return A1_REG;
      
    case 'h':
      return ACCUM_HIGH_REGS;
      
    case 'j':
      return A0H_REG;
      
    case 'k':
      return A0L_REG;
      
    case 'q':
      return A1H_REG;
      
    case 'u':
      return A1L_REG;
      
    case 'x':
      return X_REG;

    case 'y':
      return YH_REG;

    case 'z':
      return YL_REG;

    case 't':
      return P_REG;

    case 'Z':
      return Y_OR_P_REGS;

    case 'd':
      return ACCUM_Y_OR_P_REGS;

    case 'a':
      return Y_ADDR_REGS;

    case 'B':
      return (TARGET_BMU ? BMU_REGS : NO_REGS);

    case 'Y':
      return YBASE_VIRT_REGS;

    case 'v':
      return PH_REG;

    case 'w':
      return PL_REG;

    case 'W':
      return J_REG;

    case 'e':
      return YBASE_ELIGIBLE_REGS;

    case 'b':
      return ACCUM_LOW_REGS;

    case 'c':
      return NON_YBASE_REGS;

    case 'f':
      return Y_REG;

    case 'D':
      return SLOW_MEM_LOAD_REGS;

    default:
      return NO_REGS;
    }
}

/* Return the class number of the smallest class containing
   reg number REGNO.  */

int 
regno_reg_class(regno)
     int regno;
{
  switch (regno)
    {
    case REG_A0L:
      return (int) A0L_REG;
    case REG_A1L:
      return (int) A1L_REG;
      
    case REG_A0:
      return (int) A0H_REG;
    case REG_A1:
      return (int) A1H_REG;
      
    case REG_X:
      return (int) X_REG;
      
    case REG_Y:
      return (int) YH_REG;
    case REG_YL:
      return (int) YL_REG;
      
    case REG_PROD:
      return (int) PH_REG;
    case REG_PRODL:
      return (int) PL_REG;
      
    case REG_R0: case REG_R1: case REG_R2: case REG_R3:
      return (int) Y_ADDR_REGS;
      
    case REG_J:
      return (int) J_REG;
    case REG_K:
      return (int) GENERAL_REGS;
      
    case REG_YBASE:
      return (int) GENERAL_REGS;
      
    case REG_PT:
      return (int) GENERAL_REGS;
      
    case REG_AR0: case REG_AR1: case REG_AR2: case REG_AR3:
      return (int) BMU_REGS;
      
    case REG_C0: case REG_C1: case REG_C2:
      return (int) GENERAL_REGS;
      
    case REG_PR:
      return (int) GENERAL_REGS;
      
    case REG_RB:
      return (int) GENERAL_REGS;
      
    case REG_YBASE0: case REG_YBASE1: case REG_YBASE2: case REG_YBASE3:
    case REG_YBASE4: case REG_YBASE5: case REG_YBASE6: case REG_YBASE7:
    case REG_YBASE8: case REG_YBASE9: case REG_YBASE10: case REG_YBASE11:
    case REG_YBASE12: case REG_YBASE13: case REG_YBASE14: case REG_YBASE15:
    case REG_YBASE16: case REG_YBASE17: case REG_YBASE18: case REG_YBASE19:
    case REG_YBASE20: case REG_YBASE21: case REG_YBASE22: case REG_YBASE23:
    case REG_YBASE24: case REG_YBASE25: case REG_YBASE26: case REG_YBASE27:
    case REG_YBASE28: case REG_YBASE29: case REG_YBASE30: case REG_YBASE31:
      return (int) YBASE_VIRT_REGS;
      
    default:
      return (int) NO_REGS;
    }
}

/* A C expression for the maximum number of consecutive registers of class CLASS
   needed to hold a value of mode MODE.  */

int
class_max_nregs(class, mode)
     enum reg_class class ATTRIBUTE_UNUSED;
     enum machine_mode mode;
{
    return (GET_MODE_SIZE(mode));
}

enum reg_class
limit_reload_class (mode, class)
     enum machine_mode mode ATTRIBUTE_UNUSED;
     enum reg_class class;
{
  return class;
}

int
dsp16xx_register_move_cost (from, to)
     enum reg_class from, to;
{
  if (from == A0H_REG || from == A0L_REG || from == A0_REG ||
      from == A1H_REG || from == ACCUM_HIGH_REGS || from == A1L_REG ||
      from == ACCUM_LOW_REGS || from == A1_REG || from == ACCUM_REGS)
    {
      if (to == Y_REG || to == P_REG)
	return 4;
      else
	return 2;
    }

  if (to == A0H_REG || to == A0L_REG || to == A0_REG ||
      to == A1H_REG || to == ACCUM_HIGH_REGS || to == A1L_REG ||
      to == ACCUM_LOW_REGS || to == A1_REG || to == ACCUM_REGS)
    {
      return 2;
    }

  if (from == YBASE_VIRT_REGS)
    {
      if (to == YBASE_VIRT_REGS)
	return 16;

      if (to == X_REG || to == YH_REG || to == YL_REG ||
	  to == Y_REG || to == PL_REG || to == PH_REG ||
	  to == P_REG || to == Y_ADDR_REGS || to == YBASE_ELIGIBLE_REGS ||
	  to == Y_OR_P_REGS)
	{
	  return 8;
	}
      else
	return 10;
    }

  if (to == YBASE_VIRT_REGS)
    {
      if (from == X_REG || from == YH_REG || from == YL_REG ||
	  from == Y_REG || from == PL_REG || from == PH_REG ||
	  from == P_REG || from == Y_ADDR_REGS || from == YBASE_ELIGIBLE_REGS ||
	  from == Y_OR_P_REGS)
	{
	  return 8;
	}
      else
	return 10;
    }

  return 8;
}

/* Given an rtx X being reloaded into a reg required to be
   in class CLASS, return the class of reg to actually use.
   In general this is just CLASS; but on some machines
   in some cases it is preferable to use a more restrictive class.
   Also, we must ensure that a PLUS is reloaded either
   into an accumulator or an address register.  */

enum reg_class
preferred_reload_class (x, class)
     rtx x;
     enum reg_class class;
{
  /* The ybase registers cannot have constants copied directly
     to them.  */

  if (CONSTANT_P (x))
    {
      switch ((int) class)
	{
	case YBASE_VIRT_REGS:
	  return (!reload_in_progress ? NO_REGS : class);

	case ACCUM_LOW_OR_YBASE_REGS:
	  return ACCUM_LOW_REGS;

	case ACCUM_OR_YBASE_REGS:
	  return ACCUM_REGS;

	case X_OR_YBASE_REGS:
	  return X_REG;

	case Y_OR_YBASE_REGS:
	  return Y_REG;

	case ACCUM_LOW_YL_PL_OR_YBASE_REGS:
	  return YL_OR_PL_OR_ACCUM_LOW_REGS;

	case P_OR_YBASE_REGS:
	  return P_REG;

	case ACCUM_Y_P_OR_YBASE_REGS:
	  return ACCUM_Y_OR_P_REGS;

	case Y_ADDR_OR_YBASE_REGS:
	  return Y_ADDR_REGS;

	case YBASE_OR_NOHIGH_YBASE_ELIGIBLE_REGS:
	  return NON_HIGH_YBASE_ELIGIBLE_REGS;;
	  
	case YBASE_OR_YBASE_ELIGIBLE_REGS:
	  return YBASE_ELIGIBLE_REGS;

	case NO_HIGH_ALL_REGS:
	  return NOHIGH_NON_YBASE_REGS;

	case ALL_REGS:
	  return NON_YBASE_REGS;

	default:
	  return class;
	}
    }

  /* If x is not an accumulator or a ybase register, restrict the class of registers
     we can copy the register into.  */

  if (REG_P (x) && !IS_ACCUM_REG (REGNO (x)) && !IS_YBASE_REGISTER_WINDOW (REGNO (x)))
    {
      switch ((int) class)
	{
	case NO_REGS:
	case A0H_REG: case A0L_REG: case A0_REG: case A1H_REG:
	case ACCUM_HIGH_REGS: case A1L_REG: case ACCUM_LOW_REGS: 
	case A1_REG: case ACCUM_REGS:
	  return class;

	case X_REG: 
	  return (!reload_in_progress ? NO_REGS : class);

	case X_OR_ACCUM_LOW_REGS: 
	  return ACCUM_LOW_REGS;

	case X_OR_ACCUM_REGS:
	  return ACCUM_REGS;

	case YH_REG:
	  return (!reload_in_progress ? NO_REGS : class);

	case YH_OR_ACCUM_HIGH_REGS:
	  return ACCUM_HIGH_REGS;

	case X_OR_YH_REGS: 
	case YL_REG:
	  return (!reload_in_progress ? NO_REGS : class);

	case YL_OR_ACCUM_LOW_REGS: 
	  return ACCUM_LOW_REGS;

	case X_OR_YL_REGS:
	case X_OR_Y_REGS: case Y_REG:
	  return (!reload_in_progress ? NO_REGS : class);

	case ACCUM_OR_Y_REGS: 
	  return ACCUM_REGS;

	case PH_REG:
	case X_OR_PH_REGS: case PL_REG: 
	  return (!reload_in_progress ? NO_REGS : class);

	case PL_OR_ACCUM_LOW_REGS:
 	  return ACCUM_LOW_REGS;

	case X_OR_PL_REGS:
	  return (!reload_in_progress ? NO_REGS : class);

	case YL_OR_PL_OR_ACCUM_LOW_REGS: 
 	  return ACCUM_LOW_REGS;

	case P_REG:
	  return (!reload_in_progress ? NO_REGS : class);

	case ACCUM_OR_P_REGS: 
	  return ACCUM_REGS;

	case YL_OR_P_REGS:
	  return (!reload_in_progress ? NO_REGS : class);

	case ACCUM_LOW_OR_YL_OR_P_REGS: 
 	  return ACCUM_LOW_REGS;

	case Y_OR_P_REGS:
	  return (!reload_in_progress ? NO_REGS : class);

	case ACCUM_Y_OR_P_REGS: 
	  return ACCUM_REGS;

	case NO_FRAME_Y_ADDR_REGS:
	case Y_ADDR_REGS:
	  return (!reload_in_progress ? NO_REGS : class);

	case ACCUM_LOW_OR_Y_ADDR_REGS:
 	  return ACCUM_LOW_REGS;

	case ACCUM_OR_Y_ADDR_REGS: 
	  return ACCUM_REGS;

	case X_OR_Y_ADDR_REGS:
	case Y_OR_Y_ADDR_REGS: 
	case P_OR_Y_ADDR_REGS:
	  return (!reload_in_progress ? NO_REGS : class);

	case NON_HIGH_YBASE_ELIGIBLE_REGS: 
 	  return ACCUM_LOW_REGS;

	case YBASE_ELIGIBLE_REGS:
	  return ACCUM_REGS;

	case J_REG:
	case J_OR_DAU_16_BIT_REGS:
	case BMU_REGS: 
	  return (!reload_in_progress ? NO_REGS : class);

	case YBASE_VIRT_REGS:
	  if (IS_YBASE_ELIGIBLE_REG (REGNO (x)))
	    return class;
	  else
	    return (!reload_in_progress ? NO_REGS : class);

	case ACCUM_LOW_OR_YBASE_REGS:
	  if (IS_YBASE_ELIGIBLE_REG (REGNO (x)))
	    return class;
	  else
	    return ACCUM_LOW_REGS;

	case ACCUM_OR_YBASE_REGS:
	  if (IS_YBASE_ELIGIBLE_REG (REGNO (x)))
	    return class;
	  else
	    return ACCUM_REGS;

	case X_OR_YBASE_REGS:
	case Y_OR_YBASE_REGS:
	  if (IS_YBASE_ELIGIBLE_REG (REGNO (x)))
	    return YBASE_VIRT_REGS;
	  else
	    return (!reload_in_progress ? NO_REGS : class);

	case ACCUM_LOW_YL_PL_OR_YBASE_REGS:
	  if (IS_YBASE_ELIGIBLE_REG (REGNO (x)))
	    return ACCUM_LOW_OR_YBASE_REGS;
	  else
	    return ACCUM_LOW_REGS;

	case P_OR_YBASE_REGS:
	  if (IS_YBASE_ELIGIBLE_REG (REGNO (x)))
	    return YBASE_VIRT_REGS;
	  else
	    return (!reload_in_progress ? NO_REGS : class);

	case ACCUM_Y_P_OR_YBASE_REGS:
	  if (IS_YBASE_ELIGIBLE_REG (REGNO (x)))
	    return ACCUM_OR_YBASE_REGS;
	  else
	    return ACCUM_REGS;