rs6000.c

GCC编译器源代码

/* Subroutines used for code generation on IBM RS/6000.
   Copyright (C) 1991, 93, 94, 95, 96, 1997 Free Software Foundation, Inc.
   Contributed by Richard Kenner ([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 <stdio.h>
#include <ctype.h>
#include "config.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 "obstack.h"
#include "tree.h"
#include "except.h"
#include "function.h"

#ifndef TARGET_NO_PROTOTYPE
#define TARGET_NO_PROTOTYPE 0
#endif

extern char *language_string;
extern int profile_block_flag;

#define min(A,B)	((A) < (B) ? (A) : (B))
#define max(A,B)	((A) > (B) ? (A) : (B))

/* Target cpu type */

enum processor_type rs6000_cpu;
struct rs6000_cpu_select rs6000_select[3] =
{
  /* switch	name,			tune	arch */
  { (char *)0,	"--with-cpu=",		1,	1 },
  { (char *)0,	"-mcpu=",		1,	1 },
  { (char *)0,	"-mtune=",		1,	0 },
};

/* Set to non-zero by "fix" operation to indicate that itrunc and
   uitrunc must be defined.  */

int rs6000_trunc_used;

/* Set to non-zero once they have been defined.  */

static int trunc_defined;

/* Set to non-zero once AIX common-mode calls have been defined.  */
static int common_mode_defined;

/* Save information from a "cmpxx" operation until the branch or scc is
   emitted.  */
rtx rs6000_compare_op0, rs6000_compare_op1;
int rs6000_compare_fp_p;

#ifdef USING_SVR4_H
/* Label number of label created for -mrelocatable, to call to so we can
   get the address of the GOT section */
int rs6000_pic_labelno;
int rs6000_pic_func_labelno;

/* Which abi to adhere to */
char *rs6000_abi_name = RS6000_ABI_NAME;

/* Semantics of the small data area */
enum rs6000_sdata_type rs6000_sdata = SDATA_DATA;

/* Which small data model to use */
char *rs6000_sdata_name = (char *)0;
#endif

/* Whether a System V.4 varargs area was created.  */
int rs6000_sysv_varargs_p;

/* ABI enumeration available for subtarget to use.  */
enum rs6000_abi rs6000_current_abi;

/* Offset & size for fpmem stack locations used for converting between
   float and integral types.  */
int rs6000_fpmem_offset;
int rs6000_fpmem_size;

/* Debug flags */
char *rs6000_debug_name;
int rs6000_debug_stack;		/* debug stack applications */
int rs6000_debug_arg;		/* debug argument handling */

/* Flag to say the TOC is initialized */
int toc_initialized;


/* Default register names.  */
char rs6000_reg_names[][8] =
{
      "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",
      "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",
     "mq", "lr", "ctr","ap",
      "0",  "1",  "2",  "3",  "4",  "5",  "6",  "7",
  "fpmem"
};

#ifdef TARGET_REGNAMES
static char alt_reg_names[][8] =
{
   "%r0",   "%r1",  "%r2",  "%r3",  "%r4",  "%r5",  "%r6",  "%r7",
   "%r8",   "%r9", "%r10", "%r11", "%r12", "%r13", "%r14", "%r15",
  "%r16",  "%r17", "%r18", "%r19", "%r20", "%r21", "%r22", "%r23",
  "%r24",  "%r25", "%r26", "%r27", "%r28", "%r29", "%r30", "%r31",
   "%f0",   "%f1",  "%f2",  "%f3",  "%f4",  "%f5",  "%f6",  "%f7",
   "%f8",   "%f9", "%f10", "%f11", "%f12", "%f13", "%f14", "%f15",
  "%f16",  "%f17", "%f18", "%f19", "%f20", "%f21", "%f22", "%f23",
  "%f24",  "%f25", "%f26", "%f27", "%f28", "%f29", "%f30", "%f31",
    "mq",    "lr",  "ctr",   "ap",
  "%cr0",  "%cr1", "%cr2", "%cr3", "%cr4", "%cr5", "%cr6", "%cr7",
 "fpmem"
};
#endif

#ifndef MASK_STRICT_ALIGN
#define MASK_STRICT_ALIGN 0
#endif

/* Override command line options.  Mostly we process the processor
   type and sometimes adjust other TARGET_ options.  */

void
rs6000_override_options (default_cpu)
     char *default_cpu;
{
  int i, j;
  struct rs6000_cpu_select *ptr;

  /* Simplify the entries below by making a mask for any POWER
     variant and any PowerPC variant.  */

#define POWER_MASKS (MASK_POWER | MASK_POWER2 | MASK_MULTIPLE | MASK_STRING)
#define POWERPC_MASKS (MASK_POWERPC | MASK_PPC_GPOPT \
		       | MASK_PPC_GFXOPT | MASK_POWERPC64)
#define POWERPC_OPT_MASKS (MASK_PPC_GPOPT | MASK_PPC_GFXOPT)

  static struct ptt
    {
      char *name;		/* Canonical processor name.  */
      enum processor_type processor; /* Processor type enum value.  */
      int target_enable;	/* Target flags to enable.  */
      int target_disable;	/* Target flags to disable.  */
    } processor_target_table[]
      = {{"common", PROCESSOR_COMMON, MASK_NEW_MNEMONICS,
	    POWER_MASKS | POWERPC_MASKS},
	 {"power", PROCESSOR_POWER,
	    MASK_POWER | MASK_MULTIPLE | MASK_STRING,
	    MASK_POWER2 | POWERPC_MASKS | MASK_NEW_MNEMONICS},
	 {"power2", PROCESSOR_POWER,
	    MASK_POWER | MASK_POWER2 | MASK_MULTIPLE | MASK_STRING,
	    POWERPC_MASKS | MASK_NEW_MNEMONICS},
	 {"powerpc", PROCESSOR_POWERPC,
	    MASK_POWERPC | MASK_NEW_MNEMONICS,
	    POWER_MASKS | POWERPC_OPT_MASKS | MASK_POWERPC64},
	 {"rios", PROCESSOR_RIOS1,
	    MASK_POWER | MASK_MULTIPLE | MASK_STRING,
	    MASK_POWER2 | POWERPC_MASKS | MASK_NEW_MNEMONICS},
	 {"rios1", PROCESSOR_RIOS1,
	    MASK_POWER | MASK_MULTIPLE | MASK_STRING,
	    MASK_POWER2 | POWERPC_MASKS | MASK_NEW_MNEMONICS},
	 {"rsc", PROCESSOR_PPC601,
	    MASK_POWER | MASK_MULTIPLE | MASK_STRING,
	    MASK_POWER2 | POWERPC_MASKS | MASK_NEW_MNEMONICS},
	 {"rsc1", PROCESSOR_PPC601,
	    MASK_POWER | MASK_MULTIPLE | MASK_STRING,
	    MASK_POWER2 | POWERPC_MASKS | MASK_NEW_MNEMONICS},
	 {"rios2", PROCESSOR_RIOS2,
	    MASK_POWER | MASK_MULTIPLE | MASK_STRING | MASK_POWER2,
	    POWERPC_MASKS | MASK_NEW_MNEMONICS},
	 {"403", PROCESSOR_PPC403,
	    MASK_POWERPC | MASK_SOFT_FLOAT | MASK_NEW_MNEMONICS | MASK_STRICT_ALIGN,
	    POWER_MASKS | POWERPC_OPT_MASKS | MASK_POWERPC64},
	 {"505", PROCESSOR_MPCCORE,
	    MASK_POWERPC | MASK_NEW_MNEMONICS,
	    POWER_MASKS | POWERPC_OPT_MASKS | MASK_POWERPC64},
	 {"601", PROCESSOR_PPC601,
	    MASK_POWER | MASK_POWERPC | MASK_NEW_MNEMONICS | MASK_MULTIPLE | MASK_STRING,
	    MASK_POWER2 | POWERPC_OPT_MASKS | MASK_POWERPC64},
	 {"602", PROCESSOR_PPC603,
	    MASK_POWERPC | MASK_PPC_GFXOPT | MASK_NEW_MNEMONICS,
	    POWER_MASKS | MASK_PPC_GPOPT | MASK_POWERPC64},
	 {"603", PROCESSOR_PPC603,
	    MASK_POWERPC | MASK_PPC_GFXOPT | MASK_NEW_MNEMONICS,
	    POWER_MASKS | MASK_PPC_GPOPT | MASK_POWERPC64},
	 {"603e", PROCESSOR_PPC603,
	    MASK_POWERPC | MASK_PPC_GFXOPT | MASK_NEW_MNEMONICS,
	    POWER_MASKS | MASK_PPC_GPOPT | MASK_POWERPC64},
	 {"604", PROCESSOR_PPC604,
	    MASK_POWERPC | MASK_PPC_GFXOPT | MASK_NEW_MNEMONICS,
	    POWER_MASKS | MASK_PPC_GPOPT | MASK_POWERPC64},
	 {"604e", PROCESSOR_PPC604,
	    MASK_POWERPC | MASK_PPC_GFXOPT | MASK_NEW_MNEMONICS,
	    POWER_MASKS | MASK_PPC_GPOPT | MASK_POWERPC64},
	 {"620", PROCESSOR_PPC620,
	    MASK_POWERPC | MASK_PPC_GFXOPT | MASK_NEW_MNEMONICS,
	    POWER_MASKS | MASK_PPC_GPOPT | MASK_POWERPC64},
	 {"801", PROCESSOR_MPCCORE,
	    MASK_POWERPC | MASK_SOFT_FLOAT | MASK_NEW_MNEMONICS,
	    POWER_MASKS | POWERPC_OPT_MASKS | MASK_POWERPC64},
	 {"821", PROCESSOR_MPCCORE,
	    MASK_POWERPC | MASK_SOFT_FLOAT | MASK_NEW_MNEMONICS,
	    POWER_MASKS | POWERPC_OPT_MASKS | MASK_POWERPC64},
	 {"823", PROCESSOR_MPCCORE,
	    MASK_POWERPC | MASK_SOFT_FLOAT | MASK_NEW_MNEMONICS,
	    POWER_MASKS | POWERPC_OPT_MASKS | MASK_POWERPC64},
	 {"860", PROCESSOR_MPCCORE,
	    MASK_POWERPC | MASK_SOFT_FLOAT | MASK_NEW_MNEMONICS,
	    POWER_MASKS | POWERPC_OPT_MASKS | MASK_POWERPC64}};

  int ptt_size = sizeof (processor_target_table) / sizeof (struct ptt);

  int multiple = TARGET_MULTIPLE;	/* save current -mmultiple/-mno-multiple status */
  int string   = TARGET_STRING;		/* save current -mstring/-mno-string status */

  profile_block_flag = 0;

  /* Identify the processor type */
  rs6000_select[0].string = default_cpu;
  rs6000_cpu = PROCESSOR_DEFAULT;

  for (i = 0; i < sizeof (rs6000_select) / sizeof (rs6000_select[0]); i++)
    {
      ptr = &rs6000_select[i];
      if (ptr->string != (char *)0 && ptr->string[0] != '\0')
	{
	  for (j = 0; j < ptt_size; j++)
	    if (! strcmp (ptr->string, processor_target_table[j].name))
	      {
		if (ptr->set_tune_p)
		  rs6000_cpu = processor_target_table[j].processor;

		if (ptr->set_arch_p)
		  {
		    target_flags |= processor_target_table[j].target_enable;
		    target_flags &= ~processor_target_table[j].target_disable;
		  }
		break;
	      }

	  if (i == ptt_size)
	    error ("bad value (%s) for %s switch", ptr->string, ptr->name);
	}
    }

  /* If -mmultiple or -mno-multiple was explicitly used, don't
     override with the processor default */
  if (TARGET_MULTIPLE_SET)
    target_flags = (target_flags & ~MASK_MULTIPLE) | multiple;

  /* If -mstring or -mno-string was explicitly used, don't
     override with the processor default */
  if (TARGET_STRING_SET)
    target_flags = (target_flags & ~MASK_STRING) | string;

  /* Don't allow -mmultiple or -mstring on little endian systems, because the
     hardware doesn't support the instructions used in little endian mode */
  if (!BYTES_BIG_ENDIAN)
    {
      if (TARGET_MULTIPLE)
	{
	  target_flags &= ~MASK_MULTIPLE;
	  if (TARGET_MULTIPLE_SET)
	    warning ("-mmultiple is not supported on little endian systems");
	}

      if (TARGET_STRING)
	{
	  target_flags &= ~MASK_STRING;
	  if (TARGET_STRING_SET)
	    warning ("-mstring is not supported on little endian systems");
	}
    }

  /* Set debug flags */
  if (rs6000_debug_name)
    {
      if (!strcmp (rs6000_debug_name, "all"))
	rs6000_debug_stack = rs6000_debug_arg = 1;
      else if (!strcmp (rs6000_debug_name, "stack"))
	rs6000_debug_stack = 1;
      else if (!strcmp (rs6000_debug_name, "arg"))
	rs6000_debug_arg = 1;
      else
	error ("Unknown -mdebug-%s switch", rs6000_debug_name);
    }

#ifdef TARGET_REGNAMES
  /* If the user desires alternate register names, copy in the alternate names
     now.  */
  if (TARGET_REGNAMES)
    bcopy ((char *)alt_reg_names, (char *)rs6000_reg_names, sizeof (rs6000_reg_names));
#endif

#ifdef SUBTARGET_OVERRIDE_OPTIONS
  SUBTARGET_OVERRIDE_OPTIONS;
#endif
}

/* Do anything needed at the start of the asm file.  */

void
rs6000_file_start (file, default_cpu)
     FILE *file;
     char *default_cpu;
{
  int i;
  char buffer[80];
  char *start = buffer;
  struct rs6000_cpu_select *ptr;

  if (flag_verbose_asm)
    {
      sprintf (buffer, "\n%s rs6000/powerpc options:", ASM_COMMENT_START);
      rs6000_select[0].string = default_cpu;

      for (i = 0; i < sizeof (rs6000_select) / sizeof (rs6000_select[0]); i++)
	{
	  ptr = &rs6000_select[i];
	  if (ptr->string != (char *)0 && ptr->string[0] != '\0')
	    {
	      fprintf (file, "%s %s%s", start, ptr->name, ptr->string);
	      start = "";
	    }
	}

#ifdef USING_SVR4_H
      switch (rs6000_sdata)
	{
	case SDATA_NONE: fprintf (file, "%s -msdata=none", start); start = ""; break;
	case SDATA_DATA: fprintf (file, "%s -msdata=data", start); start = ""; break;
	case SDATA_SYSV: fprintf (file, "%s -msdata=sysv", start); start = ""; break;
	case SDATA_EABI: fprintf (file, "%s -msdata=eabi", start); start = ""; break;
	}

      if (rs6000_sdata && g_switch_value)
	{
	  fprintf (file, "%s -G %d", start, g_switch_value);
	  start = "";
	}
#endif

      if (*start == '\0')
	fputs ("\n", file);
    }
}


/* Create a CONST_DOUBLE from a string.  */

struct rtx_def *
rs6000_float_const (string, mode)
     char *string;
     enum machine_mode mode;
{
  REAL_VALUE_TYPE value = REAL_VALUE_ATOF (string, mode);
  return immed_real_const_1 (value, mode);
}


/* Create a CONST_DOUBLE like immed_double_const, except reverse the
   two parts of the constant if the target is little endian.  */

struct rtx_def *
rs6000_immed_double_const (i0, i1, mode)
     HOST_WIDE_INT i0, i1;
     enum machine_mode mode;
{
  if (! WORDS_BIG_ENDIAN)
    return immed_double_const (i1, i0, mode);

  return immed_double_const (i0, i1, mode);
}


/* Return non-zero if this function is known to have a null epilogue.  */

int
direct_return ()
{
  if (reload_completed)
    {
      rs6000_stack_t *info = rs6000_stack_info ();

      if (info->first_gp_reg_save == 32
	  && info->first_fp_reg_save == 64
	  && !info->lr_save_p
	  && !info->cr_save_p
	  && !info->push_p)
	return 1;
    }

  return 0;
}

/* Returns 1 always.  */

int
any_operand (op, mode)
     register rtx op;
     enum machine_mode mode;
{
  return 1;
}

/* Returns 1 if op is the count register */
int
count_register_operand(op, mode)
     register rtx op;
     enum machine_mode mode;
{
  if (GET_CODE (op) != REG)
    return 0;

  if (REGNO (op) == COUNT_REGISTER_REGNUM)
    return 1;

  if (REGNO (op) > FIRST_PSEUDO_REGISTER)
    return 1;

  return 0;
}

/* Returns 1 if op is memory location for float/int conversions that masquerades
   as a register.  */
int
fpmem_operand(op, mode)
     register rtx op;
     enum machine_mode mode;
{
  if (GET_CODE (op) != REG)
    return 0;

  if (FPMEM_REGNO_P (REGNO (op)))
    return 1;

#if 0
  if (REGNO (op) > FIRST_PSEUDO_REGISTER)
    return 1;