path: root/libgcc/libgcc2.c

/* More subroutines needed by GCC output code on some machines.  */
/* Compile this one with gcc.  */
/* Copyright (C) 1989, 92-97, 1998 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.  */

/* As a special exception, if you link this library with other files,
   some of which are compiled with GCC, to produce an executable,
   this library does not by itself cause the resulting executable
   to be covered by the GNU General Public License.
   This exception does not however invalidate any other reasons why
   the executable file might be covered by the GNU General Public License.  */

#include <stddef.h>

/* In the first part of this file, we are interfacing to calls generated
   by the compiler itself.  These calls pass values into these routines
   which have very specific modes (rather than very specific types), and
   these compiler-generated calls also expect any return values to have
   very specific modes (rather than very specific types).  Thus, we need
   to avoid using regular C language type names in this part of the file
   because the sizes for those types can be configured to be anything.
   Instead we use the following special type names.  */

typedef unsigned int UQItype	__attribute__ ((mode (QI)));
typedef 	 int SItype	__attribute__ ((mode (SI)));
typedef unsigned int USItype	__attribute__ ((mode (SI)));
typedef		 int DItype	__attribute__ ((mode (DI)));
typedef unsigned int UDItype	__attribute__ ((mode (DI)));

typedef 	float SFtype	__attribute__ ((mode (SF)));
typedef		float DFtype	__attribute__ ((mode (DF)));

typedef int word_type __attribute__ ((mode (__word__)));

/* Make sure that we don't accidentally use any normal C language built-in
   type names in the first part of this file.  Instead we want to use *only*
   the type names defined above.  The following macro definitions insure
   that if we *do* accidentally use some normal C language built-in type name,
   we will get a syntax error.  */

#define char bogus_type
#define short bogus_type
#define int bogus_type
#define long bogus_type
#define unsigned bogus_type
#define float bogus_type
#define double bogus_type

#define SI_TYPE_SIZE (sizeof (SItype) * 8)

struct DIstruct {SItype low, high;};

/* We need this union to unpack/pack DImode values, since we don't have
   any arithmetic yet.  Incoming DImode parameters are stored into the
   `ll' field, and the unpacked result is read from the struct `s'.  */

typedef union
{
  struct DIstruct s;
  DItype ll;
} DIunion;

#if (defined (L_udivmoddi4) || defined (L_muldi3) || defined (L_udiv_w_sdiv)\
     || defined (L_divdi3) || defined (L_udivdi3) \
     || defined (L_moddi3) || defined (L_umoddi3))

#include "longlong.h"

#endif /* udiv or mul */

extern DItype __fixunssfdi (SFtype a);
extern DItype __fixunsdfdi (DFtype a);

#if defined (L_negdi2) || defined (L_divdi3) || defined (L_moddi3)
#if defined (L_divdi3) || defined (L_moddi3)
static inline
#endif
DItype
__negdi2 (DItype u)
{
  DIunion w;
  DIunion uu;

  uu.ll = u;

  w.s.low = -uu.s.low;
  w.s.high = -uu.s.high - ((USItype) w.s.low > 0);

  return w.ll;
}
#endif

/* Unless shift functions are defined whith full ANSI prototypes,
   parameter b will be promoted to int if word_type is smaller than an int.  */
#ifdef L_lshrdi3
DItype
__lshrdi3 (DItype u, word_type b)
{
  DIunion w;
  word_type bm;
  DIunion uu;

  if (b == 0)
    return u;

  uu.ll = u;

  bm = (sizeof (SItype) * 8) - b;
  if (bm <= 0)
    {
      w.s.high = 0;
      w.s.low = (USItype)uu.s.high >> -bm;
    }
  else
    {
      USItype carries = (USItype)uu.s.high << bm;
      w.s.high = (USItype)uu.s.high >> b;
      w.s.low = ((USItype)uu.s.low >> b) | carries;
    }

  return w.ll;
}
#endif

#ifdef L_ashldi3
DItype
__ashldi3 (DItype u, word_type b)
{
  DIunion w;
  word_type bm;
  DIunion uu;

  if (b == 0)
    return u;

  uu.ll = u;

  bm = (sizeof (SItype) * 8) - b;
  if (bm <= 0)
    {
      w.s.low = 0;
      w.s.high = (USItype)uu.s.low << -bm;
    }
  else
    {
      USItype carries = (USItype)uu.s.low >> bm;
      w.s.low = (USItype)uu.s.low << b;
      w.s.high = ((USItype)uu.s.high << b) | carries;
    }

  return w.ll;
}
#endif

#ifdef L_ashrdi3
DItype
__ashrdi3 (DItype u, word_type b)
{
  DIunion w;
  word_type bm;
  DIunion uu;

  if (b == 0)
    return u;

  uu.ll = u;

  bm = (sizeof (SItype) * 8) - b;
  if (bm <= 0)
    {
      /* w.s.high = 1..1 or 0..0 */
      w.s.high = uu.s.high >> (sizeof (SItype) * 8 - 1);
      w.s.low = uu.s.high >> -bm;
    }
  else
    {
      USItype carries = (USItype)uu.s.high << bm;
      w.s.high = uu.s.high >> b;
      w.s.low = ((USItype)uu.s.low >> b) | carries;
    }

  return w.ll;
}
#endif

#ifdef L_ffsdi2
DItype
__ffsdi2 (DItype u)
{
  DIunion uu, w;
  uu.ll = u;
  w.s.high = 0;
  w.s.low = ffs (uu.s.low);
  if (w.s.low != 0)
    return w.ll;
  w.s.low = ffs (uu.s.high);
  if (w.s.low != 0)
    {
      w.s.low += 8 * sizeof (SItype);
      return w.ll;
    }
  return w.ll;
}
#endif

#ifdef L_muldi3
DItype
__muldi3 (DItype u, DItype v)
{
  DIunion w;
  DIunion uu, vv;

  uu.ll = u,
  vv.ll = v;

  w.ll = __umulsidi3 (uu.s.low, vv.s.low);
  w.s.high += ((USItype) uu.s.low * (USItype) vv.s.high
	       + (USItype) uu.s.high * (USItype) vv.s.low);

  return w.ll;
}
#endif

#ifdef L_udiv_w_sdiv
#if defined (sdiv_qrnnd)
USItype
__udiv_w_sdiv (USItype *rp, USItype a1, USItype a0, USItype d)
{
  USItype q, r;
  USItype c0, c1, b1;

  if ((SItype) d >= 0)
    {
      if (a1 < d - a1 - (a0 >> (SI_TYPE_SIZE - 1)))
	{
	  /* dividend, divisor, and quotient are nonnegative */
	  sdiv_qrnnd (q, r, a1, a0, d);
	}
      else
	{
	  /* Compute c1*2^32 + c0 = a1*2^32 + a0 - 2^31*d */
	  sub_ddmmss (c1, c0, a1, a0, d >> 1, d << (SI_TYPE_SIZE - 1));
	  /* Divide (c1*2^32 + c0) by d */
	  sdiv_qrnnd (q, r, c1, c0, d);
	  /* Add 2^31 to quotient */
	  q += (USItype) 1 << (SI_TYPE_SIZE - 1);
	}
    }
  else
    {
      b1 = d >> 1;			/* d/2, between 2^30 and 2^31 - 1 */
      c1 = a1 >> 1;			/* A/2 */
      c0 = (a1 << (SI_TYPE_SIZE - 1)) + (a0 >> 1);

      if (a1 < b1)			/* A < 2^32*b1, so A/2 < 2^31*b1 */
	{
	  sdiv_qrnnd (q, r, c1, c0, b1); /* (A/2) / (d/2) */

	  r = 2*r + (a0 & 1);		/* Remainder from A/(2*b1) */
	  if ((d & 1) != 0)
	    {
	      if (r >= q)
		r = r - q;
	      else if (q - r <= d)
		{
		  r = r - q + d;
		  q--;
		}
	      else
		{
		  r = r - q + 2*d;
		  q -= 2;
		}
	    }
	}
      else if (c1 < b1)			/* So 2^31 <= (A/2)/b1 < 2^32 */
	{
	  c1 = (b1 - 1) - c1;
	  c0 = ~c0;			/* logical NOT */

	  sdiv_qrnnd (q, r, c1, c0, b1); /* (A/2) / (d/2) */

	  q = ~q;			/* (A/2)/b1 */
	  r = (b1 - 1) - r;

	  r = 2*r + (a0 & 1);		/* A/(2*b1) */

	  if ((d & 1) != 0)
	    {
	      if (r >= q)
		r = r - q;
	      else if (q - r <= d)
		{
		  r = r - q + d;
		  q--;
		}
	      else
		{
		  r = r - q + 2*d;
		  q -= 2;
		}
	    }
	}
      else				/* Implies c1 = b1 */
	{				/* Hence a1 = d - 1 = 2*b1 - 1 */
	  if (a0 >= -d)
	    {
	      q = -1;
	      r = a0 + d;
	    }
	  else
	    {
	      q = -2;
	      r = a0 + 2*d;
	    }
	}
    }

  *rp = r;
  return q;
}
#else
/* If sdiv_qrnnd doesn't exist, define dummy __udiv_w_sdiv.  */
USItype
__udiv_w_sdiv (USItype *rp __attribute__ ((__unused__)),
	       USItype a1 __attribute__ ((__unused__)),
	       USItype a0 __attribute__ ((__unused__)),
	       USItype d __attribute__ ((__unused__)))
{
  return 0;
}
#endif
#endif

#if (defined (L_udivdi3) || defined (L_divdi3) || \
     defined (L_umoddi3) || defined (L_moddi3))
#define L_udivmoddi4
#endif

#ifdef L_udivmoddi4
static const UQItype __clz_tab[] =
{
  0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
  6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
  7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
  7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
  8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
  8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
  8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
  8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
};

#if (defined (L_udivdi3) || defined (L_divdi3) || \
     defined (L_umoddi3) || defined (L_moddi3))
static inline
#endif
UDItype
__udivmoddi4 (UDItype n, UDItype d, UDItype *rp)
{
  DIunion ww;
  DIunion nn, dd;
  DIunion rr;
  USItype d0, d1, n0, n1, n2;
  USItype q0, q1;
  USItype b, bm;

  nn.ll = n;
  dd.ll = d;

  d0 = dd.s.low;
  d1 = dd.s.high;
  n0 = nn.s.low;
  n1 = nn.s.high;

  if (d1 == 0)
    {
      if (d0 > n1)
	{
	  /* 0q = nn / 0D */

	  count_leading_zeros (bm, d0);

	  if (bm != 0)
	    {
	      /* Normalize, i.e. make the most significant bit of the
		 denominator set.  */

	      d0 = d0 << bm;
	      n1 = (n1 << bm) | (n0 >> (SI_TYPE_SIZE - bm));
	      n0 = n0 << bm;
	    }

	  udiv_qrnnd (q0, n0, n1, n0, d0);
	  q1 = 0;

	  /* Remainder in n0 >> bm.  */
	}
      else
	{
	  /* qq = NN / 0d */

	  if (d0 == 0)
	    d0 = 1 / d0;	/* Divide intentionally by zero.  */

	  count_leading_zeros (bm, d0);

	  if (bm == 0)
	    {
	      /* From (n1 >= d0) /\ (the most significant bit of d0 is set),
		 conclude (the most significant bit of n1 is set) /\ (the
		 leading quotient digit q1 = 1).

		 This special case is necessary, not an optimization.
		 (Shifts counts of SI_TYPE_SIZE are undefined.)  */

	      n1 -= d0;
	      q1 = 1;
	    }
	  else
	    {
	      /* Normalize.  */

	      b = SI_TYPE_SIZE - bm;

	      d0 = d0 << bm;
	      n2 = n1 >> b;
	      n1 = (n1 << bm) | (n0 >> b);
	      n0 = n0 << bm;

	      udiv_qrnnd (q1, n1, n2, n1, d0);
	    }

	  /* n1 != d0...  */

	  udiv_qrnnd (q0, n0, n1, n0, d0);

	  /* Remainder in n0 >> bm.  */
	}

      if (rp != 0)
	{
	  rr.s.low = n0 >> bm;
	  rr.s.high = 0;
	  *rp = rr.ll;
	}
    }

  else
    {
      if (d1 > n1)
	{
	  /* 00 = nn / DD */

	  q0 = 0;
	  q1 = 0;

	  /* Remainder in n1n0.  */
	  if (rp != 0)
	    {
	      rr.s.low = n0;
	      rr.s.high = n1;
	      *rp = rr.ll;
	    }
	}
      else
	{
	  /* 0q = NN / dd */

	  count_leading_zeros (bm, d1);
	  if (bm == 0)
	    {
	      /* From (n1 >= d1) /\ (the most significant bit of d1 is set),
		 conclude (the most significant bit of n1 is set) /\ (the
		 quotient digit q0 = 0 or 1).

		 This special case is necessary, not an optimization.  */

	      /* The condition on the next line takes advantage of that
		 n1 >= d1 (true due to program flow).  */
	      if (n1 > d1 || n0 >= d0)
		{
		  q0 = 1;
		  sub_ddmmss (n1, n0, n1, n0, d1, d0);
		}
	      else
		q0 = 0;

	      q1 = 0;

	      if (rp != 0)
		{
		  rr.s.low = n0;
		  rr.s.high = n1;
		  *rp = rr.ll;
		}
	    }
	  else
	    {
	      USItype m1, m0;
	      /* Normalize.  */

	      b = SI_TYPE_SIZE - bm;

	      d1 = (d1 << bm) | (d0 >> b);
	      d0 = d0 << bm;
	      n2 = n1 >> b;
	      n1 = (n1 << bm) | (n0 >> b);
	      n0 = n0 << bm;

	      udiv_qrnnd (q0, n1, n2, n1, d1);
	      umul_ppmm (m1, m0, q0, d0);

	      if (m1 > n1 || (m1 == n1 && m0 > n0))
		{
		  q0--;
		  sub_ddmmss (m1, m0, m1, m0, d1, d0);
		}

	      q1 = 0;

	      /* Remainder in (n1n0 - m1m0) >> bm.  */
	      if (rp != 0)
		{
		  sub_ddmmss (n1, n0, n1, n0, m1, m0);
		  rr.s.low = (n1 << b) | (n0 >> bm);
		  rr.s.high = n1 >> bm;
		  *rp = rr.ll;
		}
	    }
	}
    }

  ww.s.low = q0;
  ww.s.high = q1;
  return ww.ll;
}
#endif

#ifdef L_divdi3
UDItype __udivmoddi4 ();

DItype
__divdi3 (DItype u, DItype v)
{
  word_type c = 0;
  DIunion uu, vv;
  DItype w;

  uu.ll = u;
  vv.ll = v;

  if (uu.s.high < 0)
    c = ~c,
    uu.ll = __negdi2 (uu.ll);
  if (vv.s.high < 0)
    c = ~c,
    vv.ll = __negdi2 (vv.ll);

  w = __udivmoddi4 (uu.ll, vv.ll, (UDItype *) 0);
  if (c)
    w = __negdi2 (w);

  return w;
}
#endif

#ifdef L_moddi3
UDItype __udivmoddi4 ();
DItype
__moddi3 (DItype u, DItype v)
{
  word_type c = 0;
  DIunion uu, vv;
  DItype w;

  uu.ll = u;
  vv.ll = v;

  if (uu.s.high < 0)
    c = ~c,
    uu.ll = __negdi2 (uu.ll);
  if (vv.s.high < 0)
    vv.ll = __negdi2 (vv.ll);

  (void) __udivmoddi4 (uu.ll, vv.ll, &w);
  if (c)
    w = __negdi2 (w);

  return w;
}
#endif

#ifdef L_umoddi3
UDItype __udivmoddi4 ();
UDItype
__umoddi3 (UDItype u, UDItype v)
{
  UDItype w;

  (void) __udivmoddi4 (u, v, &w);

  return w;
}
#endif

#ifdef L_udivdi3
UDItype __udivmoddi4 ();
UDItype
__udivdi3 (UDItype n, UDItype d)
{
  return __udivmoddi4 (n, d, (UDItype *) 0);
}
#endif

#ifdef L_cmpdi2
word_type
__cmpdi2 (DItype a, DItype b)
{
  DIunion au, bu;

  au.ll = a, bu.ll = b;

  if (au.s.high < bu.s.high)
    return 0;
  else if (au.s.high > bu.s.high)
    return 2;
  if ((USItype) au.s.low < (USItype) bu.s.low)
    return 0;
  else if ((USItype) au.s.low > (USItype) bu.s.low)
    return 2;
  return 1;
}
#endif

#ifdef L_ucmpdi2
word_type
__ucmpdi2 (DItype a, DItype b)
{
  DIunion au, bu;

  au.ll = a, bu.ll = b;

  if ((USItype) au.s.high < (USItype) bu.s.high)
    return 0;
  else if ((USItype) au.s.high > (USItype) bu.s.high)
    return 2;
  if ((USItype) au.s.low < (USItype) bu.s.low)
    return 0;
  else if ((USItype) au.s.low > (USItype) bu.s.low)
    return 2;
  return 1;
}
#endif

#ifdef L_fixunsdfdi
#define WORD_SIZE (sizeof (SItype) * 8)
#define HIGH_WORD_COEFF (((UDItype) 1) << WORD_SIZE)

DItype
__fixunsdfdi (DFtype a)
{
  DFtype b;
  UDItype v;

  if (a < 0)
    return 0;

  /* Compute high word of result, as a flonum.  */
  b = (a / HIGH_WORD_COEFF);
  /* Convert that to fixed (but not to DItype!),
     and shift it into the high word.  */
  v = (USItype) b;
  v <<= WORD_SIZE;
  /* Remove high part from the DFtype, leaving the low part as flonum.  */
  a -= (DFtype)v;
  /* Convert that to fixed (but not to DItype!) and add it in.
     Sometimes A comes out negative.  This is significant, since
     A has more bits than a long int does.  */
  if (a < 0)
    v -= (USItype) (- a);
  else
    v += (USItype) a;
  return v;
}
#endif

#ifdef L_fixdfdi
DItype
__fixdfdi (DFtype a)
{
  if (a < 0)
    return - __fixunsdfdi (-a);
  return __fixunsdfdi (a);
}
#endif

#ifdef L_fixunssfdi
#define WORD_SIZE (sizeof (SItype) * 8)
#define HIGH_WORD_COEFF (((UDItype) 1) << WORD_SIZE)

DItype
__fixunssfdi (SFtype original_a)
{
  /* Convert the SFtype to a DFtype, because that is surely not going
     to lose any bits.  Some day someone else can write a faster version
     that avoids converting to DFtype, and verify it really works right.  */
  DFtype a = original_a;
  DFtype b;
  UDItype v;

  if (a < 0)
    return 0;

  /* Compute high word of result, as a flonum.  */
  b = (a / HIGH_WORD_COEFF);
  /* Convert that to fixed (but not to DItype!),
     and shift it into the high word.  */
  v = (USItype) b;
  v <<= WORD_SIZE;
  /* Remove high part from the DFtype, leaving the low part as flonum.  */
  a -= (DFtype)v;
  /* Convert that to fixed (but not to DItype!) and add it in.
     Sometimes A comes out negative.  This is significant, since
     A has more bits than a long int does.  */
  if (a < 0)
    v -= (USItype) (- a);
  else
    v += (USItype) a;
  return v;
}
#endif

#ifdef L_fixsfdi
DItype
__fixsfdi (SFtype a)
{
  if (a < 0)
    return - __fixunssfdi (-a);
  return __fixunssfdi (a);
}
#endif

#ifdef L_floatdidf
#define WORD_SIZE (sizeof (SItype) * 8)
#define HIGH_HALFWORD_COEFF (((UDItype) 1) << (WORD_SIZE / 2))
#define HIGH_WORD_COEFF (((UDItype) 1) << WORD_SIZE)

DFtype
__floatdidf (DItype u)
{
  DFtype d;

  d = (SItype) (u >> WORD_SIZE);
  d *= HIGH_HALFWORD_COEFF;
  d *= HIGH_HALFWORD_COEFF;
  d += (USItype) (u & (HIGH_WORD_COEFF - 1));

  return d;
}
#endif

#ifdef L_floatdisf
#define WORD_SIZE (sizeof (SItype) * 8)
#define HIGH_HALFWORD_COEFF (((UDItype) 1) << (WORD_SIZE / 2))
#define HIGH_WORD_COEFF (((UDItype) 1) << WORD_SIZE)
#define DI_SIZE (sizeof (DItype) * 8)

/* IEEE format */
#define DF_SIZE 53
#define SF_SIZE 24

SFtype
__floatdisf (DItype u)
{
  /* Do the calculation in DFmode
     so that we don't lose any of the precision of the high word
     while multiplying it.  */
  DFtype f;

  /* Protect against double-rounding error.
     Represent any low-order bits, that might be truncated in DFmode,
     by a bit that won't be lost.  The bit can go in anywhere below the
     rounding position of the SFmode.  A fixed mask and bit position
     handles all usual configurations.  It doesn't handle the case
     of 128-bit DImode, however.  */
  if (DF_SIZE < DI_SIZE
      && DF_SIZE > (DI_SIZE - DF_SIZE + SF_SIZE))
    {
#define REP_BIT ((USItype) 1 << (DI_SIZE - DF_SIZE))
      if (! (- ((DItype) 1 << DF_SIZE) < u
	     && u < ((DItype) 1 << DF_SIZE)))
	{
	  if ((USItype) u & (REP_BIT - 1))
	    u |= REP_BIT;
	}
    }
  f = (SItype) (u >> WORD_SIZE);
  f *= HIGH_HALFWORD_COEFF;
  f *= HIGH_HALFWORD_COEFF;
  f += (USItype) (u & (HIGH_WORD_COEFF - 1));

  return (SFtype) f;
}
#endif

#ifdef L_fixunsdfsi
/* Reenable the normal types, in case limits.h needs them.  */
#undef char
#undef short
#undef int
#undef long
#undef unsigned
#undef float
#undef double
#undef MIN
#undef MAX
#include <limits.h>

USItype
__fixunsdfsi (DFtype a)
{
  if (a >= - (DFtype) LONG_MIN)
    return (SItype) (a + LONG_MIN) - LONG_MIN;
  return (SItype) a;
}
#endif

#ifdef L_fixunssfsi
/* Reenable the normal types, in case limits.h needs them.  */
#undef char
#undef short
#undef int
#undef long
#undef unsigned
#undef float
#undef double
#undef MIN
#undef MAX
#include <limits.h>

USItype
__fixunssfsi (SFtype a)
{
  if (a >= - (SFtype) LONG_MIN)
    return (SItype) (a + LONG_MIN) - LONG_MIN;
  return (SItype) a;
}
#endif

/* From here on down, the routines use normal data types.  */

#define SItype bogus_type
#define USItype bogus_type
#define DItype bogus_type
#define UDItype bogus_type
#define SFtype bogus_type
#define DFtype bogus_type

#undef char
#undef short
#undef int
#undef long
#undef unsigned
#undef float
#undef double